Abstract
Occupational therapy intervention can be effective in improving or maintaining physical activity levels, medication management, handwriting, and IADLs for people with PD.
Parkinson’s disease (PD) is a neurodegenerative disorder that affects almost 1 million people in the United States (Marras et al., 2018). PD is associated with motor and nonmotor manifestations that can lead to progressive disability and restricted participation in meaningful occupations (Duncan & Earhart, 2011; Shulman et al., 2008). Occupational therapy practitioners are well suited to address the occupational performance problems that result from PD.
One occupational domain negatively affected by PD is instrumental activities of daily living (IADLs; Choi et al., 2019; Foster, 2014). According to the Occupational Therapy Practice Framework: Domain and Process (3rd ed.; OTPF–3; American Occupational Therapy Association [AOTA], 2014), IADLs are complex activities that support daily life in the home and community and include caring for others, communication management, driving and community mobility, financial management, health management and maintenance, home establishment and management, meal preparation and cleanup, religious and spiritual activities, safety and emergency maintenance, and shopping. Studies have found PD-related limitations in a variety of IADLs, including driving, financial management, medication management, shopping, and household management, even very early in the disease course (Crizzle et al., 2012; Foster, 2014; Hariz & Forsgren, 2011; Kudlicka et al., 2018; Pirogovsky et al., 2014). IADL limitations in people with PD are associated with withdrawal from everyday activities and reduced quality of life (Klepac et al., 2008; Kudlicka et al., 2018). These findings highlight the necessity and importance of interventions to address IADL function among people with PD.
Occupational therapy practitioners should be prepared to address IADLs as part of an overall plan of care for clients with PD. The purpose of this review is to assist practitioners in making evidence-based decisions regarding such interventions. A prior systematic review of occupational therapy–related interventions for adults with PD found that physical activity, external cues, and self-management and cognitive–behavioral approaches can benefit motor skills, basic activities of daily living, and health-related quality of life in this population (Foster et al., 2014). When that review was published, IADL function had rarely, if ever, been reported as an intervention target or outcome, but the authors of the review noted that such work was emerging. Therefore, our objective was to systematically search for, assess, and synthesize the new evidence on occupational therapy interventions for people with PD with a specific focus on IADLs (see Boone et al., 2021, and Doucet et al., 2021, for the updated systematic reviews addressing other occupational outcomes). We used the following focused question: What is the evidence for the effectiveness of interventions within the scope of occupational therapy to improve or maintain performance and participation in IADLs for adults with PD?
Method
This systematic review was supported and funded by the AOTA Evidence-Based Practice Program. It was conducted following an a priori review protocol and Cochrane Collaboration methodology (Higgins et al., 2019) and is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (Moher et al., 2010). AOTA staff, a research methodologist (Elizabeth G. Hunter), a medical librarian, and external experts developed the research question and search terms.
Inclusion and Exclusion Criteria
Peer-reviewed journal articles published in English between January 2011 and December 2018 were eligible (the prior systematic review included articles published between January 2003 and May 2011; Foster et al., 2014). We included studies providing Level 1b, 2b, and 3b evidence (Oxford Centre for Evidence-Based Medicine, 2011; Table 1). We excluded systematic reviews and meta-analyses, Level 4 or 5 studies, protocols, dissertations and theses, presentations, abstracts, and commentaries and editorials. Systematic reviews were evaluated, and pertinent articles from them were included in the review. Included studies involved adults (age 18+) with PD; studies that did not report results specifically for participants with PD were excluded.
Levels of Evidence
Note. RCT = randomized controlled trial. Adapted from The Oxford 2009 Levels of Evidence, by Oxford Centre for Evidence-Based Medicine, 2009. https://www.cebm.ox.ac.uk/resources/levels-of-evidence/oxfordcentre-for-evidence-based-medicine-levels-of-evidence-march-2009
Interpreted as any single-subject design (e.g., single-case experimental design, case study).
We included studies of interventions within the scope of occupational therapy practice with outcomes of interest related to IADL performance and participation, with IADLs defined according to the OTPF–3. Measures could include performance-based assessments, questionnaires, questions, or objective measures (e.g., activity monitor). Health-related quality of life and other functional outcome measures were not included unless IADL-specific data from them were reported.
Study Selection
A medical librarian conducted the search of MEDLINE, PsycINFO, CINAHL, OTseeker, and Cochrane databases for articles published from January 2011 to December 2018 (see the supplemental material, available online with this article at https://ajot.aota.org). The research methodologist conducted an initial review of the search results and eliminated duplicates and other articles not meeting the inclusion criteria (e.g., wrong year, non-PD participants). Three reviewers (Erin R. Foster, Lisa G. Carson, and Jamie Archer) then reviewed the output to identify studies for inclusion. At least two reviewers independently screened each citation and abstract to identify studies for full-text review. The team met to rectify discrepancies and determine which full-text articles to retrieve.
At least two reviewers then independently reviewed each full-text article, and again the team met to rectify discrepancies before making the final determination for inclusion. Systematic review articles were searched to identify individual studies that met eligibility criteria, which then went through the above-described review method (n = 263 additional records). Forward and backward citation searches of included articles were completed to identify additional studies. One study that had not been returned in the initial search results was identified during full-text review (Nackaerts et al., 2016). Decisions were reviewed by AOTA staff and the research methodologist for quality control. Reviewers independently extracted data related to level of evidence, study design, participants, inclusion criteria, intervention setting, intervention and control descriptions, and IADL outcome measures and results from the included studies.
Risk-of-Bias Assessment
Two reviewers (Foster and Carson) initially assessed study risk of bias; their results were then reviewed by the research methodologist (Hunter). The Cochrane risk-of-bias tool was used for randomized controlled trials (RCTs) and nonrandomized trials (Higgins et al., 2016), and the National Heart, Lung, and Blood Institute (n.d.) risk-of-bias tool was used for noncontrolled research studies.
Strength of Evidence Grading
The strength of evidence within a theme was determined by number of studies, level of evidence, risk-of-bias evaluation, and significance of outcomes (U.S. Preventive Services Task Force, 2018). Strong strength of evidence includes two or more Level 1b studies with low risk of bias and consistent results. Moderate strength of evidence includes at least one Level 1b study with low risk of bias or multiple Level 2b or 3b studies with low to moderate risk of bias providing evidence sufficient to determine effects on outcomes but with confidence constrained by number and size of studies, level of evidence, risk of bias, or inconsistent results. Low strength of evidence indicates insufficient evidence to assess effects on outcomes because of a variety of factors (e.g., small samples, inconsistent results, design or methodological flaws).
Results
We identified 22 articles describing 9 Level 1b, 9 Level 2b, and 4 Level 3b studies for inclusion in the final synthesis. Figure 1 depicts the flowchart for study selection. We organized the studies into four themes on the basis of primary type or focus of intervention: physical activity, specific IADL-focused, cognitive rehabilitation, and individualized occupational therapy interventions. The physical activity and specific IADL-focused themes were subdivided on the basis of study outcome. Table A.1 in the Appendix summarizes each study within the themes, and Tables A.2 and A.3 provide the risk-of-bias evaluations of included studies.
Flow diagram for studies included in the systematic review.
Physical Activity Interventions
Thirteen studies provide evidence related to the effect of physical activity interventions on IADL function in people with PD. Two studies (Pretzer-Aboff et al., 2011; van Nimwegen et al., 2013) used general or lifestyle “physical activity,” defined by the World Health Organization (WHO; 2018) as “any bodily movement produced by skeletal muscles that requires energy expenditure” (p. 14), including activities undertaken while working, engaging in recreational pursuits, and carrying out household chores. The remaining 11 studies used “exercise,” defined as physical activity that is “planned, structured, repetitive, and purposive” and that aims to improve or maintain physical fitness (WHO, 2018, p. 98). All studies used community- or home-based interventions. Three classes of IADL-related outcomes were assessed in these studies: physical activity level (11 studies), reported IADL function (3 studies), and reported IADL participation (1 study).
Physical Activity Level
Physical activity level was the primary outcome for 5 studies (Colón-Semenza et al., 2018; Nakae & Tsushima, 2014; Pretzer-Aboff et al., 2011; Ridgel et al., 2016), including 1 Level 1b RCT with low risk of bias (van Nimwegen et al., 2013). The interventions in these studies ranged from 8 wk to 2 yr in duration and, in addition to prescribing physical activity or exercise, incorporated health behavior change components to promote increased engagement in physical activity. Physical activity level was a secondary outcome in 6 studies (Cheung et al., 2018; Demonceau et al., 2017), including 4 Level 1b RCTs with low to moderate risk of bias (Canning et al., 2015; Goodwin et al., 2011; Li et al., 2014; Reuter et al., 2011). These studies used exercise interventions ranging from 10 wk to 6 mo in duration such as resistance, aerobic and flexibility exercise, balance training, walking, Nordic walking, yoga, and tai chi. Regardless of primary intervention target and intervention characteristics (e.g., type, dose), almost all studies found significant treatment-related improvements in physical activity levels during the interventions, immediately postintervention, or at follow-up using a variety of standardized and unstandardized questionnaires or activity trackers or monitors as outcome measures. Thus, strong strength of evidence supports physical activity interventions to increase physical activity levels (measured by, e.g., steps per day, actigraphy, reported physical activity).
Reported IADL Function
Three studies assessed the effect of exercise interventions on reported IADL function (Colón-Semenza et al., 2018; Nakae & Tsushima, 2014; Nascimento et al., 2014). Only 1 of these studies, which used a more comprehensive exercise program with a higher dose than the others, found significant treatment-related improvements (Nascimento et al., 2014). Because of the small number of lower level studies with moderate risk of bias and inconsistent results, low strength of evidence is available that physical activity interventions can improve reported IADL function.
Reported IADL Participation
One Level 1b RCT with low risk of bias found significant treatment-related improvements in reported IADL participation during a 12-mo community-based tango dance intervention (Foster et al., 2013). This study provides moderate strength of evidence that participation in tango dance classes can increase IADL participation.
Specific IADL-Focused Interventions
Four studies provide evidence for interventions targeting a specific IADL in people with PD. Two IADLs were the target of intervention in these studies: handwriting (3 studies) and medication adherence (1 study).
Handwriting
Three studies, including 1 Level 1b RCT with low risk of bias (Collett et al., 2017), tested the effect of handwriting training on handwriting function (Nackaerts et al., 2016; Ziliotto et al., 2015). The interventions had different treatment components (e.g., hand exercises, writing with external cues); ranged in intensity, frequency, and duration (e.g., 30–90 min sessions, 1–5×/wk, over 6 wk to 6 mo); and had different delivery methods (e.g., workbook, in person). However, they all resulted in significant improvements in handwriting as assessed by self-report (Unified Parkinson’s Disease Rating Scale Item 2.7) or objective measures (e.g., writing amplitude, surface area, superior margin). Therefore, strong strength of evidence supports handwriting training.
Medication Adherence
One Level 1b RCT with moderate risk of bias found significant improvements in medication adherence after 7 weekly 1:1 home-based sessions using a cognitive–behavioral approach with care partner participation (Daley et al., 2014). Thus, moderate strength of evidence supports medication adherence therapy.
Cognitive Rehabilitation Interventions
Three studies provide evidence related to cognitive rehabilitation interventions to address IADL function in people with PD. Two studies used a cognitive process training approach in people with PD who did not have dementia; the approach involved structured practice on tasks designed to target and improve specific cognitive functions (e.g., working memory, processing speed; Disbrow et al., 2012; París et al., 2011). Neither found significant treatment-related improvements in objective or reported IADL function. One study used a functional goal–oriented strategy training approach with people with PD-related dementia; this approach involved the use of strategies to compensate for or reduce the impact of cognitive impairment and improve everyday activity function (Hindle et al., 2018). This study found no significant treatment-related improvements in informant-reported IADL function. Thus, low strength of evidence is available that cognitive rehabilitation may benefit IADL function in people with PD.
Individualized Occupational Therapy Interventions
Two Level 1b RCTs provide evidence related to guidelines-based, comprehensive, individualized occupational therapy interventions to address IADL function in people with PD. A large, multicenter, pragmatic RCT tested occupational therapy based on the U.K. National Health Service guidelines that was provided in an average of four 1-hr sessions over 8 wk in community and outpatient settings (Clarke et al., 2016). The intervention focused on transfers, dressing, grooming, sleep, fatigue, indoor mobility, household tasks, and other environmental issues and had no significant effect on clinician-rated IADL performance. A multicenter assessor-blind RCT tested occupational therapy following the Dutch national practice guidelines that was provided for an average of eight 1-hr sessions over 10 wk in the home (Sturkenboom et al., 2014). The intervention included self-management, coaching, and skills training for compensatory strategies, task and routine simplification, adaptive equipment, and environmental modification and had significant effects on reported IADL participation but not on IADL performance. Together, these studies provide moderate strength of evidence that comprehensive individualized occupational therapy interventions can improve IADL participation but low strength of evidence that it can improve IADL performance.
Discussion
This systematic review is part of an update of a prior systematic review of occupational therapy–related interventions for people with PD (Foster et al., 2014), but it focuses specifically on IADL function as an outcome. It revealed four general categories of interventions used to address IADL function in PD: physical activity, specific IADL-focused, cognitive rehabilitation, and individualized occupational therapy interventions. Strong strength of evidence indicates that physical activity interventions can increase physical activity levels and that handwriting interventions can improve handwriting. Moderate strength of evidence indicates that tango dance classes and individualized home-based occupational therapy can increase IADL participation and that medication adherence therapy can improve medication adherence. Low strength of evidence is available for physical activity interventions and cognitive rehabilitation to improve general IADL function. Our results are consistent with those of the prior review, which also found that interventions focused on physical activity or that incorporate external cues (e.g., Nackaerts et al., 2016) and self-management or cognitive–behavioral approaches (e.g., Daley et al., 2014; Sturkenboom et al., 2014; van Nimwegen et al., 2013) can benefit people with PD, and the current review extends these findings specifically to IADL function.
Physical activity, specifically exercise, can improve motor and nonmotor function and quality of life in people with PD; however, these benefits are likely derived only if the person engages in adequate levels of physical activity in daily life. Thus, occupational therapy practitioners have a role in helping people with PD incorporate and maintain physical activity in their daily routine as an aspect of health management and maintenance. This systematic review shows that education, peer mentoring, social support and interaction, goal setting, action and coping planning, and activity tracking may aid this process. In addition, social forms of exercise such as dance may stimulate increased participation in IADLs and other daily activities.
Interventions that focus on a specific problematic IADL, namely handwriting and medication adherence, appear to improve performance. Occupational therapy practitioners can provide hand exercises, writing activities, and external cues for increased writing amplitude (e.g., colored visual target zones) to improve subjective and objective handwriting ability. In addition to addressing actual performance of medication management activities in the context of the client’s life (AOTA, 2017), findings suggest that to improve medication management in people with PD, occupational therapy practitioners should involve the care partner, assess the client’s medication regimen, understand their perceptions of medication use, and help them problem solve practical and attitudinal barriers to adherence (Daley et al., 2014). Improvements in specific IADLs from a focused intervention may translate to improved overall occupational performance and participation in people with PD, but this possibility remains to be tested.
Because of the limited number of studies and lack of significant findings, low strength of evidence is available for the effect of cognitive rehabilitation interventions. Although cognitive process training can improve cognitive test performance among people with PD who do not have dementia, evidence supporting the translation of these improvements to IADL function is lacking (Disbrow et al., 2012; Leung et al., 2015; París et al., 2011). Notably, the functional goal–oriented cognitive strategy training approach resulted in improved goal attainment in participants with PD-related dementia (Hindle et al., 2018), but the goals may not have been IADL related. More research is needed in this area because cognitive impairment is related to reduced IADL function in people with PD (e.g., Cahn et al., 1998; Pirogovsky et al., 2014) and functional cognition is a critical domain of concern for occupational therapy practitioners (Giles et al., 2020).
The evidence is mixed for the effect of individualized occupational therapy interventions. Tailored home-based occupational therapy improved IADL participation (Sturkenboom et al., 2014), but no significant improvements were found in IADL performance (reported and observed) in either of the large RCTs included in this review (Clarke et al., 2016; Sturkenboom et al., 2014). In addition to increased IADL participation, Sturkenboom et al. (2014) reported improvement on the Canadian Occupational Performance Measure (COPM), but they did not specify whether or how many COPM goals were IADL related. The small number of studies and differences between them, such as intervention approach, dose, usual care versus best practice, and setting, limit firm conclusions. The findings within this theme do suggest that occupational therapy assessment should include measures of IADL performance and IADL participation, which are important and dissociable constructs, and that clients with PD need moderate to high doses of treatment (e.g., ≥8 sessions, ≥10 wk) to experience benefit.
Although the evidence base has increased greatly since the prior systematic review (Foster et al., 2014), the number of intervention studies explicitly addressing IADL outcomes aside from physical activity levels is still small. More research is needed on the effects of physical activity interventions on general IADL function, interventions targeting other problematic IADLs (e.g., financial management), comprehensive individualized occupational therapy, and cognitive rehabilitation. In addition, reporting of IADL-specific outcomes is limited. For example, many studies used outcome measures that include IADL items (e.g., Parkinson’s Disease Questionnaire–39), but the IADL items represent a small proportion of the entire scale or were not reported separately. Similarly, several studies used standardized measures of change in individualized treatment-related goals (e.g., Goal Attainment Scaling, COPM, Bangor Goal-Setting Interview), which is consistent with best practice principles of client-centeredness and tailoring. However, these outcomes were not included in this review because it was unclear whether the goals were IADL related. Because the use of these clinically meaningful measures is increasing in PD research (e.g., Foster et al., 2018; Hindle et al., 2018; Reuter et al., 2012; Sturkenboom et al., 2014; Vlagsma et al., 2018), a future systematic review on the effect of occupational therapy–related interventions on individualized goals in people with PD may be warranted.
Although we present four intervention themes, we note that these categories are not mutually exclusive. Many of the studies tested complex interventions that involved simultaneous application of different and interacting treatment components; multiple ingredients, targets, and outcomes; and flexibility and tailoring (Craig et al., 2008; Hart et al., 2019; Whyte, 2014; Whyte & Hart, 2003) and thus overlapped with one another in different ways. For example, studies in the physical activity (e.g., Pretzer-Aboff et al., 2011; van Nimwegen et al., 2013), specific IADL-focused (Daley et al., 2014), and individualized occupational therapy (Sturkenboom et al., 2014) themes used self-management or cognitive–behavioral strategies; a handwriting study used exercise (Collett et al., 2017); and both of the individualized occupational therapy studies (Clarke et al., 2016; Sturkenboom et al., 2014) incorporated task-specific training. As the field moves toward better specification of rehabilitative interventions, researchers’ ability to evaluate, synthesize, and compare treatments and treatment components and their effectiveness in addressing IADL function in people with PD will be enhanced (Fasoli et al., 2019; Zanca et al., 2019).
Limitations
The precision of our findings was limited by the small number and heterogeneity of studies targeting IADLs. Although a thorough search of research databases was conducted and standardized methodology was followed, it is possible that pertinent articles were missed. Additionally, this review was limited to English-language articles and ended in December 2018, which may have resulted in the exclusion of important articles. Finally, there is a chance that publication bias existed and that studies without positive findings were less often published and thus missed by this review.
Implications for Occupational Therapy Practice
The findings of this systematic review have the following implications for occupational therapy practice with people with PD:
Assessments should include measures of IADL performance and IADL participation.
Occupational therapy practitioners can promote engagement in physical activity by using health behavior change techniques.
Social physical activity may stimulate increased participation in IADLs.
Occupational therapy practitioners should consider task-specific training for problematic IADLs. Handwriting can be addressed through upper extremity strengthening, writing activities, and external cues. Medication management interventions should incorporate a cognitive–behavioral approach and care partner participation.
Conclusion
Occupational therapy interventions can improve health management and maintenance (i.e., physical activity levels, medication management), handwriting, and IADL participation for people with PD. Further research is needed on cognitive rehabilitation. This review is limited by the small number of studies that specifically addressed IADL function in treatment and as an outcome.
Footnotes
Acknowledgments
We thank Deborah Lieberman, Hillary Richardson, and Kim Lipsey for their guidance and support during the process of this review. Preliminary results from this review were presented at the 2020 American Occupational Therapy Association (AOTA) Virtual Conference.
Elizabeth G. Hunter works as a research methodologist for the AOTA Evidence-Based Practice Project. This did not influence the outcomes of this review. The other authors report no conflicts of interest.
AOTA provided support for this work. Erin R. Foster is funded by the National Institutes of Health (National Institute on Aging [NIA] Grant R21AG063974, NIA Grant R01AG065214, and National Institute of Diabetes and Digestive and Kidney Diseases Grant R01DK064832) and the Advanced Research Center of the Greater St. Louis chapter of the American Parkinson Disease Association.
Appendix
*
Indicates studies included in the systematic review.