Protocol for a Systematic Review: Interventions to Improve the Labour Market Situation of Adults with Physical and/or Sensory Disabilities in Low- and Middle-Income Countries

Abstract

BACKGROUND

The Problem

Disability is a key development issue. Recent estimates suggest that more than one billion people (or about 15% of the world's population) are living with some form of disability (World Health Organization [WHO], 2011). Of this total, 80% live in developing countries, according to the UN Development Programme (UNDP). Disability and poverty are complex, dynamic, and intricately linked phenomena, with the result that disabled people are over-represented among the world's poor, and many experience multiple deprivations at higher rates and in higher breadth, depth, and severity than people without disabilities (Mitra, Posarac, & Vick, 2013; Samman & Rodriguez-Takeuchi, 2013). Low rates of employment among disabled persons are one of the principal pathways through which disability may lead to poverty (Braitwaite & Mont, 2009; Haveman & Wolfe, 1990; Hoogeveen, 2005; Peiyun & Livermore, 2008; Zaidi & Burchardt, 2005). Employment is, therefore, considered a key factor in the process of empowerment and inclusion into society for people with disabilities (Department for International Development [DFID], 2000). The Millennium Development Goals (MDGs) on eliminating poverty, launched by the United Nations in 2000, are unlikely to be achieved unless action is taken to support disabled people's participation in the labour market.

Over the course of the last 30 years, the conceptualisation of disability has moved from an individual perspective in which disability was simply expressed as a medical condition, to a structural, social perspective in which individuals are viewed as being disabled by society rather than their bodies (Barnes & Mercer, 2010; Oliver, 1990). Although defining disability remains complex and controversial, the International Classification of Functioning, Disability and Health (ICF), which was developed through a long process involving academics, clinicians, and—importantly—disabled persons, has further advanced the understanding and measurement of disability (WHO, 2001). Representing a workable compromise between medical and social models, the ICF understands disability as arising from the interaction of health conditions with contextual factors (both environmental and personal). Disability is thus viewed not as a static feature of an individual, but rather as a complex, multi-dimensional, and changing experience for the individual (Schneider & Hartley, 2006). Widely used by researchers and policy makers when addressing disability issues in the global development literature, the ICF is adopted as the conceptual framework for this systematic review.

Despite the ICF, a lack of standardisation in disability statistics and definitions continues. While reliable data on the employment of people with disabilities worldwide is difficult to come by, a growing body of empirical evidence indicates that employment participation rates for disabled people are below that of the overall population; and when disabled people do work, they generally do so for longer hours and lower incomes, have fewer chances of promotion, are more likely to work in the informal labour market, and are at greater risk of becoming unemployed for longer periods (Coleridge, 2005; Contreras, Ruiz-Tagle, Garces, & Azocar, 2006; Houtenville, Stapleton, Weathers, & Burkhauser, 2009; Mete, 2008; Mitra, 2008; Mitra et al., 2013; Mitra & Sambamoorthi, 2006; Mizunoya & Mitra, 2012; Roulstone, 2012; Roulstone, Gradwell, Price, & Child, 2003).

The costs of disability are particularly acute in low- and middle-income countries (LMICs), where it is estimated that in some countries 80% of people with disabilities of working age are unemployed, around twice that for disabled people in industrialised countries (Contreras et al., 2006; Groce, Kembhavi, Wirz, Lang, Trani, & Kett, 2011; Houtenville et al., 2009; International Disability Rights Monitor, 2004; Mete, 2008; Mitra, 2008, 2009; Mitra et al., 2013; Organisation for Economic Cooperation and Development [OECD], 2010). It is less clear whether the wage gap between disabled and non-disabled persons is as marked in developing counties as it is in industrialised countries (Mitra & Sambamoorthi, 2006, 2008, 2009; OECD, 2003; WHO, 2011). However, the disability experience varies greatly. While disability correlates with disadvantage, not all people with disabilities are equally disadvantaged. In practice, the extent of the negative effect of disability on employment will vary depending on a variety of factors (Goertz, van Lierop, Houkes, & Nijhuis, 2010; Ingstad & Reynolds-Whyte, 1995; Kidd, Sloane, & Ferko, 2000; Mitra et al., 2013; OECD, 2010; Sena-Martins, 2010; World Bank, 2009). These include personal factors such as age, sex, level of education, motivation to work, and lack of financial resources. For instance, women with disabilities are recognised to be multiply disadvantaged, experiencing exclusion on account of their gender and their disability. There is evidence that disabled women tend to have poorer access to jobs, lower employment rates, and considerably lower earnings than male peers in similar jobs (Emmett, 2006; Mitra & Sambamoorthi, 2006; Mitra et al., 2013). People with more severe impairments often experience greater disadvantage in the labour market; the links between disability and employment have also been shown to vary across disability types and duration (WHO, 2011; World Blind Union, 2004). Secondly, the effects of disability on employment depend on various environmental factors, including the physical accessibility of local workplaces and transport facilities, available accommodations, and social attitudes (Baldwin & Johnson, 2006; Bound & Burkhauser, 1999; Mitra & Sambamoorthi 2008). There is also some evidence that disabled people seeking to access and sustain employment in competitive, tight labour markets are disadvantaged (Mitra, 2009). The policy context is relevant, too. The particular educational facilities, employment supports, health services, disability benefit systems, and other interventions, available in a given context can influence whether, and to what extent, disability has employment consequences.

The Intervention

The scope of this review is atypical in that it is not limited to one type of intervention. Rather, it extends to any intervention likely to help disabled persons in LMICs gain or maintain employment. Such interventions may take the form of a device, policy, programme, strategy, or other type of action. Broad groupings for these interventions are presented in Table 1. This preliminary typology is not intended as an exhaustive list of interventions, or even categories, and is likely to be refined as the review progresses.

The characteristics of eligible interventions are also broad. They include complex, specialised, multi-dimensional programmes that: implement multiple strategies as well as much simpler interventions based on a single strategy; may be implemented in any setting, including the workplace, health care facility, home, or community; include both routine and structured/tailored interventions; can vary not only by type but also by intensity; can be delivered at various stages of the employment process (pre-employment, transition to employment, and post-employment); and need not have the core objective of restoring capacity for work.

Table 1

INTERVENTION CATEGORIES

Category	Description (and examples)
Treatment/therapy	Treatment, management, and/or care of a patient to alleviate or prevent a worsening of disease or disorder, or one or more of its symptoms or manifestations. Includes specific healthcare interventions (e.g., medication, surgery, and cognitive/behavioural therapies), broader healthcare management programmes, and psychosocial therapeutic approaches.
Assistive devices & accommodations	Devices and accommodations that target different types of accessibility issues: • assistive devices refer to any appliance or tool designed, made, or adapted to increase, maintain, or improve the functional capabilities of people with disabilities (e.g., prosthetic limbs, talking calculators). • assistive accommodation refers to environmental access accommodations (physical and non-physical), both in the workplace itself and the wider environment (e.g., modifications to workplace bathrooms, flexible work schedules, tailored transport schemes).
Education	Skills development and training strategies, projects, and initiatives aimed at addressing educational deficits and developing human resources. Includes capacity-building in the following areas: professional/job-related skills; basic skills (e.g., literacy); transferrable/social skills (e.g., communication skills); functional skills (e.g., how to operate a Braille typewriter or wheelchair).
Employment services	Multi-dimensional programmes encompassing multiple employment services designed to facilitate and support entry/re-entry to work, such as vocational assessment and evaluation, vocational training, general skills upgrading, refresher courses, career counselling, on-the-job training, job search, and consultation with employers for job accommodations and modifications.
Regulations, legislation & policies	Initiatives aimed at enforcing behaviour change, such as reforms of labour market regulations, anti-discrimination legislation, labour market quotas, legislation supporting institutional capacity building of the education system for disabled people, affirmative action policies, and organisational policies.
Financial	Different forms of financial incentive, such as those to promote: • financial inclusion (such as business training and micro-finance) • educational inclusion (such as financial vouchers to facilitate access to education and training) • employment inclusion (such as employer subsidies, tax breaks and sanctions) • participation in the intervention itself (such as stipends to cover costs of attending training workshops).
Community-based-rehabilitation (CBR)	Multi-dimensional programmes comprised of activities aimed at strengthening the social capacities of the target group, through attempts to combine (i) physical rehabilitation through medical care with empowerment and (ii) social inclusion through the participation of both the individual with a disability and the community in the process of rehabilitation.
Awareness campaigns	Different approaches for changing perceptions of disability within the community, such as advertising/advocacy campaigns, employers' forums.

How the Intervention Might Work

Conceptual understanding of the causal pathways through which available interventions may influence the employment prospects of disabled people in developing country contexts is under-developed. It was necessary, therefore, to develop a logic model specifically for this review. Originating from the field of programme evaluation, logic models (also known as theoretical, conceptual, or impact models) are typically diagrams or flow charts that illustrate pathways between inputs, strategies, outputs, and short-term, intermediate and longer-term outcomes (Anderson et al., 2011; Joly et al., 2007). Designed to read from left to right, they provide a valuable road map that spells out how, and for whom, a programme is meant to produce the desired outcomes. We hypothesised that the types of interventions detailed in Table 1 affect a range of different labour market outcomes for disabled people through various mechanisms. An initial version of this model is detailed in Figure 1 (see Appendix 2). It illustrates both intermediary factors through which the intervention may exert its impact, and additional personal and contextual factors that may modify or inhibit the desired effect. The intention is to revise this model as the review progresses.

Why it is Important to do the Review

Efforts to promote development and poverty reduction have not always adequately included disability; for example, disabled people are not included explicitly in any of the Millennium Development Goal (MDG) targets and indicators (WHO, 2011). Disability issues are, however, slowly being brought into the mainstream of development policy and practice, and over the past two decades there has been a noticeable change in the legal and policy responses of many governments and bilateral and multilateral donor agencies (DFID, 2000, 2007; Thomas, 2005). In 2002, for example, the World Bank embarked on mainstreaming disability into Bank operations and analysis (Mont, 2007). A major catalyst has been the Convention on the Rights of Persons with Disabilities (CRPD) adopted by the United Nations in 2006, which marked a significant advance in the recognition of the rights of disabled persons, including the right to work, on an equal basis with others (United Nations [UN], 2006). With increasing recognition of employment as a key factor in the process of empowerment and inclusion into society of people with disabilities, a shift to a broader framework for action has occurred, and the role of interventions to improve labour market outcomes of disabled people is receiving increased international attention (DFID, 2000; International Labour Organization [ILO], 2008; WHO, 2004). Nevertheless, translating policy commitments into better lives for disabled people remains a profound social challenge. Establishing a firm evidence base to support the implementation of the CRPD is therefore a priority. Building a clearer understanding of which measures are effective at increasing employment amongst disabled people, and under which circumstances, can provide such an evidence base for policy development and contribute to the development of practical suggestions for meeting this challenge.

The existence of a growing body of evidence on interventions to increase the labour market participation of disabled people is highlighted in a recent comprehensive review of the literature in this area (Waddell, Burton, & Kendall, 2008). Taking a broad definition of vocational rehabilitation, and focusing on the work conditions that account for two-thirds of long-term sickness absence—mild/moderate musculoskeletal, mental health, and cardio-respiratory conditions—this study reviews the data from a large number of scientific reports and literature reviews, mainly published between 2000 and 2007, covering a wide range of intervention strategies. While the authors conducted a systematic search, assessed the strength of the evidence, and included data in evidence tables, they did not report effect sizes or perform a meta-analysis, making it difficult to judge and compare the effectiveness of the interventions. Other systematic reviews—some of which do use meta-analytic synthesis methods—are more limited in scope, focusing on (a) specific countries (e.g., Bambra, Whithead, & Hamilton, 2004; Clayton et al., 2011); (b) single aspects of disability/illness, such as autism (e.g., Westbrook et al., 2012), mental illness (e.g., Crowther, Marshall, Bond, & Huxley, 2001; Underwood, Thomas, Williams, & Thieba, 2006), multiple sclerosis (e.g., Khan, Ng, & Turner-Stokes, 2009), traumatic brain injury (Graham & West, 2012), low back pain (e.g., Tveito, Hysing, & Eriksen, 2004) or spinal cord injury (Lidal, Huynh, & Biering-Sørensen, 2007); or (c) particular intervention types, such as interventions based on an empowerment perspective (e.g., Varekamp, Verbeek, & Dijk, 2006), workplace disability management programmes (e.g., Gensby et al., 2011) or workplace-based return-to-work interventions (e.g., Franche et al., 2005). Some of these reviews are, in addition, quite dated, and none are explicitly focused on literature conducted in LMICs. The literature on assistive technology in developing countries has recently been examined in two non-systematic literature reviews (Andrysek, 2010; Borg, Lindstrom, & Larsson, 2011). However, although some evaluative activities were identified, none measured employment outcomes. Another recent LMIC-focused non-systematic review (Velema, Ebenso, & Fuzikawa, 2008) examines evidence for the effectiveness of community-based rehabilitation (CBR) programmes for disabled people on a range of outcomes, including employment. A descriptive overview of the literature is presented, but there is no pooling of data. More recently, a protocol has been submitted for a joint Campbell/Cochrane systematic review of CBR for people with physical and mental disabilities in LMICs (Iemmi et al., 2012). Data will be collected on a number of different functional outcomes (including employment), and the authors aim to present mean effect sizes for different types of interventions, and examine the potential variation of effects for different subject populations.

Taking into account what we already know, specific gaps in the evidence base, and policymaker priorities, there is evidently a need to comprehensively assess the full evidence base relating to low- and middle-income countries, using appropriate methods to evaluate the impact of a range of different intervention types supporting the employment of adults with physical and/or sensory disabilities.

OBJECTIVE

The first objective of the systematic review is to describe the range and diversity of interventions available for addressing the low labour market participation of adults with physical and sensory disabilities in developing country contexts.

Our second, and main, objective is to systematically identify, appraise, and synthesise the available evidence on the effects of such interventions.

A third objective is to identify the characteristics of the interventions and participants that are associated with variability in effects. The effect size moderators of interest are: intervention modality/type, intervention duration, intervention setting, participants' age and gender, and type and severity of disability.

A fourth objective is to extend the review of effectiveness and provide an explanation for the intervention effects by examining what participants in the included studies reported about why the interventions did, or did not, work for them.

A final objective is to construct a logic model of the wider evidence underpinning potential causal pathways between interventions to support disabled adults and improvements in labour market outcomes, and then document the level/strength of evidence on potential pathways of impact using this framework.

METHODOLOGY

The review will be conducted in accordance with Campbell Collaboration guidelines on systematic review methods, available at www.campbellcollaboration.org.

Study Selection Criteria

Studies will be included in the systematic review if they meet the following eligibility criteria.

Types of Participants

Study participants will have the following characteristics: •

Geographical location: Low- or middle-income country (as classified by the World Bank, see Appendix 3)

•

Age: Working age adults, defined for this review as individuals aged 16-65 years

•

Gender: Male or female

•

Disability: Physical and/or sensory impairments (i.e., health conditions) associated with disability

•

Employment status: Study participants may be in paid work or out of work at time of service receipt. Those out of work may be employees on sick leave or unemployed individuals who are seeking (or otherwise eligible for) paid employment. Study samples made up solely of employed or non-employed individuals are eligible, as are those that contain a mix of both.

•

Employment-related experience: Any prior work experiences, vocational skills or achievements, or level of education.

Following the ICF, disability is understood in this review as an umbrella term embracing impairments, activity limitations, and participation restrictions. The term impairment implies specific problems in body functions and structures, often identified as symptoms or signs of health conditions (i.e., diseases, injuries, and disorders).¹ For the purposes of conducting this systematic review, the following additional definitions/restrictions apply:

Physical impairment is defined as problems with the structure, development, or function of the bones, muscles, joints, and/or central nervous system. Physical characteristics may include paralysis; altered muscle tone (ranging from loss of muscle mass to uncontrolled muscle contraction); an unsteady gait; loss of, or inability to use, one or more limbs; difficulty with gross-motor skills (such as walking); and/or difficulty with fine-motor skills (such as writing). Reference to sensory impairment implies full or partial loss of one or more senses (e.g., sight, hearing, smell, touch, taste, and/or spatial awareness), causing difficulty with communication, gross-motor skills, fine-motor skills, and/or access to information.

The focus of this review is on impairments that meet customary/statutory definitions of disability. These are usually long-standing, for example, lasting at least one year, and have a substantial impact on a person's ability to do normal daily activities, such as getting dressed. The impairment/health condition may be acquired or congenital. It may be acute, chronic, progressive, or intermittent, and may or may not need ongoing medical intervention. Studies focused on work-related and non-work related health conditions are both eligible for inclusion in the review.

For the purposes of this review, physical impairments will include the following types of health condition: •

communicable diseases (e.g., leprosy, HIV/AIDS)

•

metabolism disorders (e.g., diabetes)

•

respiratory conditions (e.g., asthma)

•

neurological impairments (e.g., multiple sclerosis, epilepsy, those associated with brain injury)

•

musculoskeletal conditions (e.g., arthritis, amputations)

•

cardiovascular diseases

•

body disfigurements (e.g., facial burn injuries)

For sensory impairments, eligibility for the review is restricted to studies of the two most common types: •

visual impairment, including blindness

•

hearing loss

Studies focused solely on people with mental health conditions and/or intellectual impairments, or those with chronic illnesses that predominate in later life (e.g., chronic obstructive pulmonary disease (COPD), cancer, stroke, and renal disease) are not eligible for this review, on the grounds that these groups have different rehabilitation needs. Where study participants are described as multiply disabled, the study will be included if either physical or sensory impairment is the primary diagnosis. Where study samples are comprised of people with different disabilities, we will include the study if: (a) the majority (minimum 51%) of the sample is physically and/or sensory disabled; or (b) the authors report disaggregated results according to type of disability. As the review is focused on long-term disability, studies examining employment support for people with minor health problems, such as fractured bones or allergic rhinitis, are not eligible. Evaluations of return-to-work (RTW) interventions for employees on short-term sick leave are therefore outside the scope of this review. Finally, eligibility for the review is extended to both primary studies that incorporated the ICF diagnostic framework in identifying and selecting its subjects and studies that did not use this framework.

Types of Interventions

The scope of this review extends to any intervention with the means to help disabled persons in LMICs gain or maintain employment. Such interventions may take the form of a device, policy, programme, strategy, or other type of action. Examples of relevant interventions were detailed above in Section 1.2.

Types of Outcome Measures

To be eligible for this review, studies must measure/report at least one quantitative job-related outcome. Eligible job-related outcomes include primary outcomes and intermediate outcomes (see below).

Primary outcomes: Disabled people in LMICs are often prevented from work, constrained in the type and amount of work that they do, and have difficulty sustaining work; as a consequence, they are predominantly employed in the informal sector, which is characterised by low pay. In consideration of this, the primary outcomes of interest are those relating to the general constructs (a) employment status and (b) income.

For employment status, relevant indicators include: •

Gaining initial employment*

•

Return-to-work (e.g., from non-employment, or from long-term sick leave)

•

Gaining formal employment (i.e., a ‘better’ job in that it has written contract, etc.)

•

Change in working hours (e.g., from part-time to full-time)

•

Job retention

•

Promotion (i.e., vertical job mobility)

•

Change in job role/function (i.e., horizontal job mobility)

For income, relevant indicators include: •

Monthly earnings

•

Weekly wages

•

Hourly rate of pay

•

Profits/income from self-employment

*Unless otherwise stated, employment refers to paid employment and self-employment. The following definitions of paid employment and self-employment apply to this review.

Paid employment: defined as jobs involving some form of contractual relationship between the individual worker and an employer over time for remuneration. Employment contracts may be explicit (written or oral) or implicit. Remuneration will typically be in the form of wages and salaries, but people may also be paid by commission from sales, from piece-rates, bonuses, or in-kind payments such as food (ILO, 1993, para. 6). Those workers employed in the informal economy, over which there is little or no official control, are likely to be paid in cash. Within the definition of ‘paid employment’, the review includes both (a) competitive paid employment, broadly defined as jobs that are available on the open market and open to anyone who applies, and that offer payments and benefits that are comparable to industry/sector standards, and (b) jobs in an integrated work setting for individuals with disabilities who are working toward competitive employment with ongoing support services.

Self-employment: defined as jobs where ‘the remuneration is directly dependent upon the profits (or the potential for profits) derived from the goods or services produced … The incumbents make the operational decisions affecting the enterprise, or delegate such decisions while retaining responsibility for the welfare of the enterprise. In this context “enterprise” includes one-person operations’ (ILO, 1993, para. 7). Self-employment may take place anywhere: in the worker's home, fields, or any public place. Within the definition of ‘self-employment’, the review includes hawking, vending, and other street entrepreneurial activities (such as rickshaw pulling), but excludes other forms of ‘making out’, such as bartering, begging, foraging, and scavenging.

Intermediate outcomes: Intermediate outcomes reflect the pathways through which the primary outcomes may be influenced. Studies that only measure an intermediate job-related outcome (i.e., where individuals are still in the process of preparing for, and gradually moving closer to, work) are eligible for inclusion. Although we intend to collect data on all intermediate outcomes (both work-related and non-work related), studies that only report non-work related intermediate outcomes will not be included in the review.

Work-related intermediate outcomes may include, but are not limited to: attitudes to work, job search skills, job-related self-efficacy/confidence, career management skills, work readiness, job applications, and job interviews.

Other (non-work related) outcomes may include, but are not limited to: educational outcomes (e.g., attainment and attendance), health outcomes (e.g., intensity/severity of pain), functional limitations (e.g., range of movement), health care resource utilisation, and quality of life.

If any of the included studies measure outcomes for employers or other relevant stakeholders (e.g., co-workers, supervisors), in addition to outcomes for disabled people, we will also collect this outcome data.

Notes: The focus of this review is on economically productive ‘work’; therefore, it is not concerned with unpaid productivity, such as voluntary work, internships, household work, and family responsibilities/caring. It is also important to note that participation in education and training (including job training) is not defined as an employment outcome in this review. This takes into consideration growing evidence that many disabled people, particularly the young, are trapped in a ‘revolving door’ of training and vocational preparation abstracted from any real job opportunities (Corrigan & McCraken, 2005).

Types of Study Designs

As we expect the relevant literature to be scarce, both randomised experiments and quasiexperiments are eligible for inclusion in this review. Eligibility is extended to quasi-experimental designs that provide high levels of rigour and those using less rigorous methods for constructing the counterfactual.²

Eligible designs include those in which one of the following is true:

Experimental designs

•

participants are randomly assigned to the treatment and control groups by the investigator, using a process of random allocation, such as a random number generation (randomised controlled trial);

•

a non-random (including quasi-random) method of assignment to treatment and control groups has been used by the investigators, for example, allocation by date of birth or day of the week (non-randomised controlled trial);

Quasi-experimental designs

•

decisions about which individuals receive the intervention and which serve as the controls are not in the hands of the investigator; instead, this is decided by the individuals themselves or by other circumstances (includes, for example, designs commonly referred to as controlled before-and-after studies and natural experiments)

•

observations are made at multiple time points before and after an intervention in an attempt to detect whether the intervention has had an effect significantly greater than any underlying trend over time (time-series designs);

•

participants receiving an intervention are compared with a similar group from the past who did not (historically controlled study);

•

observations are made on a group of individuals before and after an intervention, with participants essentially acting as their own controls (single-group pre-post-test design; also known as uncontrolled before-and-after studies).

Studies collecting data at baseline and endline, and those collecting only endline data, are both eligible for inclusion in the review (conditional on the study meeting the above criteria).

Individually-allocated and cluster-allocated studies are both eligible. Additionally, the review will include studies that adjust for confounders at either the design or analysis stage (e.g., studies using propensity score matching or regression analysis) and studies that have made no attempt to account for differences between the groups. Finally, the control or comparison conditions in eligible studies may include disabled people receiving no treatment, treatment as usual, or an alternative treatment. No restriction will be placed on duration of follow up.

Date, Language, and Form of Publication

For this review, the date of publication or reporting of the study must be 1990 or later. This date marked the shift in thinking from the ‘medical model’ to the ‘social model’ of disability, both within academia and by a broad range of organisations dealing with disability and related issues in both the statutory and voluntary sectors (Oliver, 1990). Studies published in any language will be included, provided they meet all other eligibility criteria. Studies will be included regardless of their publication type (i.e., we will not exclude specific forms of publication, such as unpublished working papers, theses or dissertations).

Search Strategy

A comprehensive search strategy will be used to search the international research literature for qualifying studies. To reduce the omission of relevant studies and ensure our search is as unbiased as possible, a wide range of sources will be used to capture both academic and ‘grey’ literature. Manual searching techniques will be used to supplement the electronic searching of databases and library catalogues. The search strategy includes many sources with a specific focus on low- and middle-income countries. The end date for the searches is 31 August 2013.

Search Sources

Bibliographic databases and library catalogues: The following major commercial electronic bibliographic databases will be searched. •

ASSIA (Applied Social Sciences Index and Abstracts) (ProQuest)

•

ERIC (Education Resources Information Centre) (ProQuest)

•

IBSS (International Bibliography of the Social Sciences) (ProQuest)

•

Medline (ProQuest)

•

Social Services Abstracts (ProQuest)

•

Sociological Abstracts (ProQuest)

•

Business Source Premier (EBSCO)

•

Econlit (EBSCO)

•

PsycINFO (EBSCO)

•

Web of Science (Web of Knowledge)³

Specialist bibliographic databases and library catalogues will also be searched. These are detailed in Appendix 4. These include databases of existing and ongoing impact evaluations, regional databases (some of which provide multilingual coverage⁴), grey literature databases, and databases/libraries specialising in information on employment, disability, and/or international development.

A tailored search query will be developed for each bibliographic database using controlled vocabulary and/or free-text terms. Four concepts will be used in the search, as shown in Table 2. A comprehensive list of search terms related to each of these concepts will be produced. Database thesauri will be consulted to ensure that all appropriate synonyms have been included, and wildcards will be applied as appropriate.

Table 2

SEARCH OVERVIEW

Concept A	Concept B	Concept C	Concept D
Disability terms	Intervention terms	Outcome terms	LMIC terms
• Physical disabilit*	• Cash transfer*	• Employment	• Developing nations
• Sensory disabilit*	• TVET	• Earnings	• Low-income countr*
• Etc	• Etc	• Etc	• Etc

The search will be constructed as follows: #1:

(concept A) AND (concept C)

#2:

(concept A) AND (concept B) AND (concept D)

#3:

(#1 OR #2)

There will be no language restrictions to the search.⁵ A publication year filter to identify studies published since 1990 will be used. A draft search query for the ERIC database is presented in Appendix 5.

It is anticipated that different terminology will have been used to describe disabled people in the primary studies. It seems likely that some authors, particularly those who have selected their sample based on a medical model, will refer to specific health conditions when describing the study subjects, while those who have selected their sample based on difficulties in functioning, such as restricted mobility, may not refer to any specific health condition in the study report. This presents a challenge for study identification. To try to capture both sets of literature, the search query for each database will contain both general terms (e.g., disabled people, neurological conditions) and specific terms (e.g., cerebral palsy). There is no recognised list of physical impairments associated with disability; therefore, the identification of relevant search terms to identify studies about physical disability drew on the expertise of the review team (AR, MM).

We will not explicitly search for studies that include only qualitative evidence. To address the fourth objective of the review, which seeks to provide an explanation for why the interventions did or did not work, we will identify relevant qualitative evidence in the studies that meet the eligibility criteria for the review.

Websites: Websites will be searched, including those for relevant research institutions, government-related aid agencies, non-governmental organisations (NGOs), and development banks (see Appendix 6). Websites incorporating a search facility that allows the user to enter terms will be searched using a limited range of keywords (such as physical disability; sensory disability; employment). Where no such facility exists, relevant sections of the website (for example, those headed ‘publications‘) will be searched.

Backward citation tracking: The bibliographic information contained within the reference lists of included studies and relevant reviews will be scanned for studies that meet the eligibility criteria. The following reviews will be searched (Franche et al., 2005; Khan et al., 2009; Varekamp et al., 2006; Velema et al., 2008; Waddell et al., 2008; Westbrook et al., 2012). Any others identified during the course of the review will also be searched.

Forward citation tracking: Studies that have cited the included studies since their publication will be checked for relevance. Citation tracking will be performed through Web of Knowledge and Google Scholar. All the hits from each citation search will be screened.

Personal contacts: Specialists in the field, including authors of included studies and relevant ongoing research, will be contacted with a request for information about any potentially relevant studies. Should any of the included studies be published in languages other than English, authors and funding agencies will be contacted regarding the availability of translated versions.

Networks: Requests for relevant literature will be made by posting a bulletin board/listserv message to members of the following networks. •

GLADNET (Global Applied Disability Research and Information Network on Employment and Training) http://www.gladnet.org/mail.cfm?pageID=7

•

ILO Global Business and Disability Network http://www.businessanddisability.org/

•

Latin American Network of Non-Governmental Organizations of Persons with Disabilities and their Families (RIADIS) http://www.riadis.org/en

•

National Network for the Rights of Persons with Disabilities (Red por los derechos de las personas con discapacidad - REDI) http://www.redi.org.ar/

A specific request for assistance with the location of studies published in languages other than English will be made.

Search engines: Google will be used to follow up on potentially relevant named programmes that come to light during the course of the review. As noted above, Google Scholar will be used to track citations of included studies.

Conference proceedings, dissertations and theses: One specialist source for dissertations and theses will be searched (ProQuest Dissertations & Theses: UK & Ireland). Most of the major bibliographic databases also index this type of publication (ERIC, for example, includes over 14,000 dissertations/theses published since 1990). As part of the Web of Science search (see above) a specific search for conference proceedings will be undertaken.

Journals: The Table of Contents (online version) of the following journals will be manually examined: •

International Journal of Disability Management (2006-2013)

•

ALTER - European Journal of Disability Research (2007-2013)

•

International Journal of Disability, Community & Rehabilitation (2002-2013)

•

International Journal of Disability, Development and Education (1990-2013)

•

Review of Disability Studies: An International Journal (2004-2013)

•

Work: A Journal of Prevention, Assessment and Rehabilitation (1999-2013)

Information provided by publishers about journal focus and content suggest these are the most relevant to search. Many of the articles published in ALTER are in French.

Study Inclusion Decision-Making

Review management software, EPPI-Reviewer 4, will be used to manage the entire review process (Thomas, Brunton, & Graziosi, 2010). Potentially relevant items identified through the electronic search of databases will be imported into EPPI-Reviewer (and will later be screened against the eligibility criteria). Details of relevant studies identified through hand searching will be entered manually.

Selection of primary studies will be based on the pre-developed selection criteria described above. The criteria will be piloted by two researchers who will screen (on titles and abstracts) a 10% sample of reports independently and compare their results. Discrepancies will be resolved by further review of the respective titles and abstracts and agreement reached by discussion. This process will be repeated until consistency in application of the selection criteria is achieved. Consistency is defined as: 100% agreement on whether an item meets the criteria (on the basis of the title and abstract) or does not meet the criteria (clear exclude), and 95% agreement on which of the exclusion criteria used in the selection of studies should be used to exclude it. The study selection process will then proceed as follows.

Phase one: title and abstract screening

The review team will manually examine the titles and abstracts of records identified through the searches of electronic databases to assess eligibility. The relevance of each item will be assessed by an individual reviewer (i.e., single screening) and decisions recorded in the reviewing software, EPPI-Reviewer. Items will be included at this stage if they appeared to meet the criteria on the basis of the information in the title and abstract, and excluded if they are clearly ineligible. Where there is any doubt as their eligibility, items will be marked as ‘unsure’. Where the title and/or abstract are not in English, the translation service offered by Google, http://translate.google.com/, will be used to translate the information into English; screening against the selection criteria will then proceed as normal. In cases where only the title of the study is available, reference within the wording of the title to (people of working age with a disability) AND (a relevant employment-related outcome OR a term suggesting the study was an evaluation) will automatically warrant a full length review of the article.

Following the manual screening of all items from the electronic searches, the hand searches referred to above will be conducted. Here, the searching and screening processes will run concurrently. Study eligibility will be assessed by an individual reviewer, who keeps a manual record of all items that appear to meet the inclusion criteria and those over which there is any doubt. Where only the title is available, and/or the information is not in the English language, the same procedures as for items identified through the electronic searches will be followed.

Phase two: full-text screening

The full length reports of all studies promoted from the first level of screening that (a) appear to meet the inclusion criteria, or (b) are marked as ‘unsure’, will be obtained.

Detailed manual examination of the full-length reports will be undertaken independently by pairs of reviewers, who will then meet to compare and discuss their assessments. Any disagreements between the reviewers' decisions will be resolved by identification of the source of the disagreement, re-reading of the text, and discussion. If a final decision cannot be reached, a third reviewer will be asked to reconcile differences.

All study selection and information retrieval activities in the review will be documented and described in sufficient detail in the final report so that the processes can be replicated by other researchers. Summary flowcharts will be used to convey relevant information.

Description of Methods Used in Primary Research

The following two studies exemplify the methods likely to meet the eligibility criteria for the proposed review.

Eniola and Adebiyi (2007) report on a small-scale evaluation of the impact of two therapeutic techniques (emotional intelligence and goal setting) upon the motivation to work among visually impaired students. The total sample size used for this study was 32. Participants were randomly selected from a school for visually impaired students in Nigeria and were assigned to one of the two treatment groups. Outcome measurements were taken before and immediately after training ended.

The study by Biggeri et al. (2012) examined the impact of community-based-rehabilitation (CBR) in improving the quality of life of persons with different types of impairments in India. Propensity score matching was used to take into account the possible differences between the two groups before the intervention impacted on their lives. The covariates used for the estimation of the propensity score in the models were age, gender, household size, type of disability, level of disability, caste, and level of wealth. The outcome variables analysed are health, livelihood (including employment status), social, and empowerment. The results are calculated over two periods of time – after two and after four years have elapsed since the programme started in the selected village. The authors also investigated the factors that constitute barriers to access CBR activities and support, and tried to capture spillover effects of CBR.

Details of Study Coding Categories

Two reviewers will independently evaluate each study using a coding/data extraction tool developed specifically for this review. The tool draws on previous tools developed by the authors. A draft version of the tool is included in Appendix 7. A coding manual (not reported) will be provided to reviewers to guide them through the process.

Eligible studies will be coded to capture both substantive and methodological characteristics. The coding will focus on the following features of the studies: general study characteristics, such as source of study funding (section B), variables related to the characteristics of the study samples (section C), the nature of the intervention and its implementation (section D), study methods (section E), and outcome measurements (section F). Sections C and D of the tool are designed to collect information about potential effect size moderators. Information about the quality of the reporting will be extracted (section G) and a risk of bias assessment undertaken (section H). The risk of bias framework will consist of seven dimensions: selection bias; confounding; performance bias; detection bias; attrition bias; reporting bias; other sources of bias. Reviewers' judgements regarding risk of bias will be graded for each criterion as low, high, or unclear risk of bias, and a summary assessment made. Finally, the study results and conclusions will be extracted, and effect sizes calculated where the data allows (section I).

Reviewers will enter data directly into the EPPI-Reviewer 4 database. Piloting of the coding tool will be undertaken by members of the review team who will work independently on a purposive sample of eligible studies (selected to test the tool on the full range of included study designs) before meeting to compare their decisions. Reviewers will be retrained on any coding items that show discrepancies during this process and the coding manual adapted accordingly. This process will be repeated until a very high level of consistency in reviewers' application of the codes is achieved (at which point the tool will be finalised). The remaining studies will be double-coded. Different combinations of two reviewers will independently extract information from each study report and then come together to compare their decisions. Any uncertainties and discrepancies will be resolved by discussion, further review of the respective study reports and, where necessary, consultations with a third reviewer.

The reviewers will attempt to contact the authors of studies that are missing data that are essential for the review. Where relevant studies have been published in languages other than English, authors and funding sources will be contacted regarding the availability of translated versions. Where these are unavailable, we will seek to identify additional reviewers to undertake the necessary data extraction and critical appraisal of studies in these languages. In the event that no additional reviewers can be identified, the study will be excluded from the review.

Data Analysis

Approach

The first objective of the review will be addressed by providing detailed descriptions that identify the range of interventions that are potentially available for tackling the labour market situation of disabled people in developing country contexts.

The key features of the study participants and interventions, study design/methods, and methodological quality and relevance of each study will be described in summary tables in the final report. For each of the included studies, we will also report reasons given for any missing data and attrition rates, and report the number of participants who were included in the final analysis as a proportion of all participants in the study.

Where data allow, meta-analysis will be used to combine the results from multiple studies. This analysis will be performed using the specialised built-in meta-analysis functions within EPPI-Reviewer. Where there are insufficient data available for a meta-analysis, we will write a narrative synthesis for the results. Textual narrative synthesis is an approach that arranges studies into relatively homogenous groups according to a standard format, with similarities and differences compared across studies (Barnett-Page & Thomas, 2009). Whichever approach is taken for data synthesis, we will review the available evidence using the logic model framework and report the findings of the review along the causal chain.

Criteria for determination of independent findings

Efforts will be made to identify all affiliations between studies/reports before coding commences. Information on study sample sizes, intervention details, grant numbers, and so on will be used to identify multiple reports from single studies and multiple studies in single reports. The authors of the reports will be contacted if it is unclear whether reports and studies provide independent findings.

In cases where several different reports relating to a single study exist, reviewers will classify one (for example, the publication containing the most complete data set) as the main report. When extracting data, the full set of relevant reports will be used. In cases where a single report describes more than one study, each study will be coded separately (i.e., as if they had been published separately).

Where possible, effects sizes will be computed for all relevant outcomes within each study. In the event that a study provides more than one effect size for a particular outcome, our approach will be to drop outcomes. This will involve selecting the outcome that is most similar to those used by other studies in that category and retaining only that particular effect size in the analysis.

Where a study presents results for several periods of follow-up for the same outcome, we will undertake separate meta-analyses for each of the various time-points (e.g., outcomes at six months, two years, etc.). In the event that synthesising effect sizes separately at different points of duration is not feasible (e.g., not all studies may use common follow-up durations), we will form reasonable ranges of follow-up duration (e.g., short term 1-6 months, medium term 7-12 months, etc.) rather than discrete follow-up duration time points. Where a study presents data from a different time point to the other studies, we will present these data separately. If a sufficient number of such studies are available, we will also analyse outcomes by investigating the change in effect size over time.

Statistical Procedures and Conventions

Calculating Effect Sizes: The EPPI-Reviewer software has built-in functionality for calculating effect sizes from a range of statistics that are presented in study reports.⁶ Other web-based resources (for example, the Campbell Collaboration's effect sizecalculator) and expert consultation will be used for the less common statistical representations.

Several types of research design are eligible for inclusion in the review. Many of these designs use complex statistical analyses, and there is a lack of standard methods for computing effect sizes from these designs. In the event of included studies using propensity score matching and so forth, we will follow the methods used in a recent review by the lead author (Tripney et al., 2013).

For studies reporting dichotomous outcomes (for example, employment rates), both the risk ratios (RRs) and standard mean difference (SMD) effect sizes (Cohen's d) will be calculated. For outcomes measured on a continuous scale (for example, group differences in levels of income), we will calculate both SMDs and response ratios (RRs). By computing different effect sizes, we will be able to explore the sensitivity of the results to the selection of the effect size measure and cope with any possible loss of information arising from impossibility to compute all effect size measures from every included study. The review will correct for sample bias in the effect sizes by using the correction for sample bias procedure developed by Hedges and Olkin (1985). Reviewers will document the computations used for the effect size estimates derived from each study. All effect sizes will be coded such that positive effect sizes represent positive outcomes (e.g., less unemployment, higher wages).

The unit of assignment to treatment and comparison groups will be coded for all studies, and if cluster designs arise, we will correct for variation associated with cluster-level assignment by making appropriate adjustments to the effect sizes (Hedges, 2007).

For each outcome category, we will determine the number of effect sizes in each of the different metrics. Where more than one type occurs in a given outcome category, we will transform the effect size metric with the smaller proportion into the metric with the larger proportion using the Cox transform as shown by Sánchez-Meca, Marin-Martinez, & Chácon-Moscoso (2003). This will allow all the effect sizes for that outcome to be analysed together.

In the event that we do not have consistency across our data (i.e., effect sizes based on either all raw data or all log-transformed data), Higgins, White, and Anzures-Cabrera (2008) will be consulted for guidance on data transformation.

Synthesis of effect sizes: Effect sizes will be synthesised when participants, interventions, and outcomes are conceptually similar, regardless of the effect size heterogeneity. Given the diversity of disabilities and intervention strategies that we have included within the scope of this review, careful attention will be given to appropriate aggregation.

Meta-analysis will be carried out using random effects statistical models. To account for differences in sample sizes for individual studies, effect sizes will be averaged across studies by using an inverse variance weighting of the individual effect size. This weighting will result in the individual effect sizes of larger n studies being given more weight in the combined effect size. In the event that there is insufficient similarity to statistically combine the study results, forest plots will be presented to show each study's point estimate and error measurements.

Where studies using randomised and non-randomised designs are both included in the review, the synthesis will separate estimates of intervention effects for randomised versus non-randomised studies in the analyses. If relevant, the synthesis will separate studies with different kinds of counterfactuals. Single group studies will be analysed separately from studies with control groups.

To visibly examine variability in the effect-size estimates, forest plots will be used to display the estimated effect sizes from each study along with their 95% confidence intervals. Heterogeneity tests (Q and I²) will be used to examine whether variation in effect-size estimates were attributable to true systematic variation rather than sampling error (Deeks, Altman, & Bradburn, 2001). Where possible, included studies will be plotted onto a funnel plot and examined for possible publication bias; the ‘trim and fill’ method (Duval & Tweedie, 2000) and/or regression test (Egger, Davey Smith, Schneider, & Minder, 1997) will be used to assess the impact of missing studies on the results of the meta-analysis; and a post-hoc power analysis will be conducted for the main effect (Borenstein, Hedges, Higgins, & Rothstein, 2009).

The included studies are likely to vary methodologically. If there are sufficient data, we will conduct sensitivity analyses to examine the influence of these variations on the pooled estimate of effect, in order to offer possible explanations for the differences between studies when interpreting the results. Where possible, we will examine whether the results are sensitive to the methodological quality of studies; the specific statistical procedures and methods for computing each effect size; our method of analysis (e.g., decisions relating to transformation between effect size metrics); the degree of missing/incomplete data; and the way outcomes were measured in the primary studies.

If there are sufficient data, we will conduct moderator analyses to try to explain variation in effect sizes (see the review ‘Objectives’ for a list of variables to be tested). It is highly likely that we will not have the minimum requirement of ten studies of sufficient quality for each moderator variable that would allow the use of meta-regression models (Borenstein et al., 2009). In this event, we will use an analogue to the ANOVA analysis (univariate) approach, as described in Lipsey and Wilson (2001). Power calculations will be conducted for these analyses (Hedges & Pigott, 2004).

If we have studies that are missing data that are considered essential for the review, we will make thorough attempts to contact the original investigators and funding sources and, if relevant, will discuss the potential impact of missing data on the findings of the review. Our approach may also involve imputing the missing data with replacement values. In this event, we will make explicit the methods used to impute missing data (Higgins & Green, 2011).

Treatment of Qualitative Research

We anticipate that some of the included studies may report relevant qualitative data that will allow us to address the fourth objective of the review. We intend to use thematic synthesis to combine the results from these studies. This will involve identifying prominent or recurring themes in the literature and summarising the findings of the different studies under thematic headings (Harden et al., 2004; Thomas & Harden, 2008).

Footnotes

REVIEW AUTHORS

Name:	Janice Tripney
Title:	Research Officer
Affiliation:	EPPI-Centre, Social Science Research Unit, Institute of Education, University of London
Address:	18 Woburn Square
City, State, Province or County:	London
Postal Code:	WC1H ONR
Country:	United Kingdom
Phone:	020 79115334
Email:	j.tripney@ioe.ac.uk

Name:	Ruth Stewart
Title:	Research Officer
Affiliation:	EPPI-Centre, Social Science Research Unit, Institute of Education, University of London
Address:	18 Woburn Square
City, State, Province or County:	London
Postal Code:	WC1H ONR
Country:	United Kingdom
Phone:	020 7612 6606
Email:	r.stewart@ioe.ac.uk

ROLES AND RESPONSIBLIITIES

Team member(s) with overall responsibility for the following areas are as follows. •

Content: Janice Tripney will lead on the overall content of the review and take responsibility for the integrity of the work as a whole. Alan Roulstone, Michele Moore and Elena Schmidt will provide content area expertise and will lead on the conceptualisation of the review question and the inclusion/exclusion criteria for the review

•

Systematic review methods: Janice Tripney, Ruth Stewart

•

Statistical analysis: Janice Tripney

•

Information retrieval: Janice Tripney, Carol Vigurs

SOURCES OF SUPPORT

Internal funding:

Institute of Education, University of London

External funding:

Sightsavers

International Initiative for Impact Evaluation (3ie)

REQUEST SUPPORT

No support is requested at this time.

DECLARATIONS OF INTEREST

None

PRELIMINARY TIMEFRAME

Approximate date for submission of Final Report: December 2013.

PLANS FOR UPDATING THE REVIEW

Janice Tripney is responsible for maintaining the review in light of new evidence, comments and criticisms, and ensuring that the review is updated (at three-yearly intervals).

AUTHOR DECLARATION

Authors' responsibilities

By completing this form, you accept responsibility for preparing, maintaining and updating the review in accordance with Campbell Collaboration policy. The Campbell Collaboration will provide as much support as possible to assist with the preparation of the review.

A draft review must be submitted to the relevant Coordinating Group within two years of protocol publication. If drafts are not submitted before the agreed deadlines, or if we are unable to contact you for an extended period, the relevant Coordinating Group has the right to de-register the title or transfer the title to alternative authors. The Coordinating Group also has the right to de-register or transfer the title if it does not meet the standards of the Coordinating Group and/or the Campbell Collaboration.

You accept responsibility for maintaining the review in light of new evidence, comments and criticisms, and other developments, and updating the review at least once every three years, or, if requested, transferring responsibility for maintaining the review to others as agreed with the Coordinating Group.

Publication in the Campbell Library

The support of the Campbell Collaboration and the relevant Coordinating Group in preparing your review is conditional upon your agreement to publish the protocol, finished review and subsequent updates in the Campbell Library. Concurrent publication in other journals is encouraged. However, a Campbell systematic review should be published either before, or at the same time as, its publication in other journals. Authors should not publish Campbell reviews in journals before they are ready for publication in the Campbell Library. Authors should remember to include the statement: “This is a version of a Campbell review, which is available in The Campbell Library” when publishing in journals or other venues. I understand the commitment required to undertake a Campbell review, and agree to publish in the Campbell Library. Signed on behalf of the authors:

Form completed by: Janice Tripney

Date: 25 October 2013

APPENDIX 1: ABBREVIATIONS

APPENDIX 2: LOGIC MODEL

APPENDIX 3: WORLD BANK CLASSIFICATION OF WORLD ECONOMIES

APPENDIX 4: SPECIALIST BIBLIOGRAPHIC DATABASES AND LIBRARY CATALOGUES

APPENDIX 5: ERIC DATABASE DRAFT SEARCH TERMS

APPENDIX 6: WEBSITES

APPENDIX 7: CODING TOOL

1

As such, the terms ‘impairment’ and ‘health condition’ are often used interchangeably (a practice adopted in this review).

2

As there is no consistent terminology used for different types of designs used for evaluating the effects of interventions, and the labels in common use are interpreted in different ways, the main focus here is on describing the key differences between designs. It is recognised that some do not classify the less rigorous designs described here as quasi-experimental.

3

The Web of Science search will include Science Citation Index Expanded, Social Sciences Citation Index, Arts and Humanities Citation Index, Conference Proceedings Citation Index - Science, Conference Proceedings Citation Index - Social Science and Humanities.

4

For example, our search includes the LILACS database, an underused source of trials that indexes journals mainly from Latin American and Caribbean.

5

Restricting part of the search ‘by country’ (i.e., the use of concept D) will be necessary due to the very high number of potentially relevant hits identified.

6

It supports the meta-analysis of both d and r families of continuous effect size, as well as binary outcomes.

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