Abstract
Background:
Schizophrenia has been described as the most disabling mental disorder, and patients with schizophrenia have been said to be disabled mostly in self-care, occupation, sexual relation and social relationship domains. Previous authors have studied disability among this study population. However, the limitations of these previous works include non-report of the prevalence rates of disability, report on disability limited to only a particular domain of life and the utilization of disability instruments fraught with significant weaknesses.
Aim:
To determine the prevalence, severity, domains and correlates of disability among outpatients with schizophrenia at the Neuropsychiatric Hospital, Aro, Abeokuta in Ogun State, Nigeria.
Methods:
It was a cross-sectional study conducted among three hundred consenting adult outpatients with schizophrenia attending the Neuropsychiatric Hospital, Aro, Abeokuta, Ogun State. Each participant was interviewed with the sociodemographic questionnaire, Mini International Neuropsychiatric Interview, Positive and Negative Syndrome Scale (PANSS) and the 36-item World Health Organization Disability Assessment Schedule.
Results:
The prevalence of disability was 78% (with 22% having no disability in any of the domains). Most were disabled in the mild to moderate range. Seventy-seven percent (77%) had mild to moderate disability while only 1% had severe disability. Excluding those free of disability, 98.7% of those with disability had mild to moderate form while only 1.3% had severe form. Highest prevalence rates for disability were reported in the ‘participation in society’ and ‘getting along’ domains while the lowest rates were reported in the ‘activities’ (household, work, school) and ‘self-care’ domains. Of all the sociodemographic and clinical variables explored, only the PANSS positive, negative and total scores demonstrated significant relationships with disability.
Conclusion:
Consistent with existing literature, disability is very prevalent among patients with schizophrenia and it is associated with higher levels of illness severity. Clinicians have a role in limiting disability by focusing on early and comprehensive treatment approaches.
Keywords
Introduction
Disability has been described as any condition of the body or mind (impairment) that makes it more difficult for the person with the condition to do certain activities (activity limitation) and interact with the world around them—participation restrictions (Centers for Disease Control and Prevention, 2017). The World Health Organization (WHO, 2018) also defined disability as an umbrella term, covering impairments, activity limitations, and participation restrictions. An impairment is a problem in body function or structure, an activity limitation is a difficulty encountered by an individual in executing a task or action, while a participation restriction is a problem experienced by an individual in involvement in life situations (WHO, 2018). In other words, disability encompasses more than physical limitations or handicap. Measures of disability are necessary for understanding the impact of disease conditions in the life of the sufferers (WHO, 2011). Various assessment tools for measuring disability exist (Cocchiarella, 2017), and this includes Groningen Social Disabilities Schedule (Wiersma et al., 1988), Schedule for Assessment of Psychiatric Disability (Valecha et al., 1988), Indian Disa-bility Evaluation and Assessment Scale (Thara, 2005), Brief Disability Questionnaire (Naismith et al., 2007) and World Health Organization Disability Assessment Schedule (WHO, 2014) among others. Usually, the identification of the weaknesses of an instrument necessitates development of a subsequent one (Chandrashekar et al., 2010). The prevalence of disability accompanying illnesses varies with higher rates reported in chronic illnesses (Bhattacharya et al., 2008).
Studies have shown that patients with schizophrenia have disabilities compared with their healthy counterparts (Akinsulore et al., 2015). In fact, schizophrenia has been described as the most maximally disabling of all mental disorders (Thaker & Carpenter, 2001). It is one of the top 10 medical disorders causing disability (Chaudhury et al., 2006), the sixth leading cause of years lived with disability (Murray & Lopez, 1997) and accounts for about 12.3% of the global disease burden (Narayan & Kumar, 2012). The prevalence of disability in Schizophrenia differs depending on the aspect of disability that is being assessed and the nature of the instrument used. Among this study population, rates such as 50% (Bland & Orn, 1978), 83% (Wiersma et al., 2000) and 100% (Solanki et al., 2010) have been reported by various authors.
Among patients with schizophrenia, most authors have noted a consistent pattern of disability in self-care, occupation, sexual relations and social relationships domains (Alptekin et al., 2005). Disability in these areas has been attributed to neurocognitive deficits (Harvey & Strassing, 2012), the latter being largely responsible for the burden experienced by the caregivers of these patients (Carpenter & Andrykowski, 1998). Factors associated with disability in schizophrenia include insidious onset of symptoms (Picchioni & Murray, 2007), negative symptomatology (Villalta-Gil et al., 2006), neurocognitive dysfunction (Green, 2006), side effects of medications (Harvey & Strassing, 2012), male gender (Liu et al., 2015) and poor premorbid functioning (Brill et al., 2009).
Although quite a number of studies had been done to assess disability among patients with schizophrenia in both developing and developed countries, African studies on this subject are few. Also, some of the previous studies on this subject have been fraught with some limitations. For instance, some of these works (Akinsulore et al., 2015; Ali, 2009; Gureje & Bamidele, 1999; Kumar et al., 2015; Olagunju et al., 2016; Thirthalli & Kumar, 2012) did not report the actual prevalence of disability among the study participants. Also, some authors assessed only a specific aspect or form of disability while some other authors utilized disability instruments which have been found to have significant limitations. Gureje and Bamidele (1999) assessed social disability only while Alptekin et al (2005) assessed more of physical disability. The culture-bias limitation of the Disability Assessment Schedule has been documented in literature (Valecha et al., 1988) while the Brief Disability Questionnaire used by Alptekin et al. (2005) has been shown to reflect more of physical disability or handicap. Another rationale for this current work is the ambiguity in which the results were derived in some studies in spite of the use of reliable and comprehensive instruments. An example of this can be seen in the work of Akinsulore et al. (2015) where ‘corrected’ summary scores (as advocated by the authors of the 36-item World Health Organization Disability Assessment Schedule version 2.0) were not used in the computation of disability.
Therefore, the aims of this study were to determine the prevalence, severity, domains and correlates of disability among outpatients with schizophrenia.
Materials and methods
It is a cross-sectional study which was conducted among outpatients with schizophrenia attending the Neuropsy-chiatric Hospital, Aro, Abeokuta, Ogun State. The inclusion criteria for participants were subjects aged between 18 and 64 years, having an ICD-10 (International Statistical Classification of Diseases and Related Health Problems, 10th revision) diagnosis of schizophrenia and having been a patient of the hospital for at least one-year period. Exclusion criteria include inability to understand neither Yoruba nor English language, having an obvious physical handicap or having a case note diagnosis of learning disability. Consecutive patients who met the study criteria were recruited for the study till the desired sample size of 300 was obtained.
Ethical approval to conduct the study was obtained from the Neuropsychiatric Hospital Aro Health Research Ethics Committee prior to the commencement of the study. Only individuals who gave their consent were recruited for the study. The participants were guaranteed of confidentiality of their responses and the freewill to withdraw from the study at any point in time.
Each participant was interviewed with
Sociodemographic questionnaire: This was used to obtain the sociodemographic characteristics (age, gender, educational status) as well as the clinical information (illness duration, family history of mental illness) of the patient.
Mini International Neuropsychiatric Interview: This is a short, structured clinical interview which is used to make psychiatric diagnosis according to the International Classification of Diseases. It has been widely used among Nigerians and was used to confirm the diagnosis of schizophrenia in the study participants.
Positive and Negative Syndrome Scale (PANSS): This is a 30-item, 7-point rating instrument which rates the positive (seven items) and negative (seven items) symptoms of schizophrenia as well as general psychopathology (16 items). It has been used extensively in Nigeria and was utilized in this work to assess the severity of psychosis. The overall score ranges from 30 to 210.
World Health Organization Disability Assessment Schedule version 2.0: This 36-item instrument assesses the level of functioning in six domains: cognition, mobility, self-care, getting along with others, household/work activities and participation in society. It was used in this study to assess the presence as well as severity of disability among the respondents.
All the instruments were translated into the Yoruba version for the benefit of the non-English speaking respondents. This was done by bilingual experts through iterative back translation.
Statistical analysis was done using the Statistical Package for the Social Sciences, version 16. Nominal data from qualitative variables were expressed as percentages of the total while continuous data of numerical variables were expressed in means (and standard deviations). Bivariate analysis (chi-square) was done to determine the relationship between presence/absence of disability with sociodemographic (gender, age, educational status and employment status) and clinical (age at illness onset, illness duration, history of previous hospitalization, class of antipsychotic currently in use, current experience of medication side-effects and severity of psychosis) variables. The tests were significant at a p-value of .05. The variables which demonstrated significance in the tests of association (PANSS positive, PANSS negative) were entered as predictor variables into a multivariate binary logistic regression model with ‘disability’ treated as the outcome. PANSS total scores were excluded from the model to avoid multicollinearity among scores. The derived logistic regression odd ratios were interpreted appropriately. All tests were considered significant at p < .05.
Results
Sociodemographic profile of participants
There was an almost equal representation of both genders in the sample. Most (95%) of the respondents were below 60 years of age and of Yoruba tribe (92.7%). About one-third (30.7%) were currently living with their spouses, and a similar proportion (32.7%) had at least tertiary level of education. About a third of the sample population (33.3%) was unemployed and among those employed, none was occupying a managerial role at his or her workplace (Table 1). The averages of the various clinical parameters such as the age at illness onset, duration of untreated psychosis and PANSS scores are presented in Table 2.
Sociodemographic and some clinical characteristics (categorical data) of the patients.
Some clinical characteristics of participants (continuous data only).
Prevalence, severity and domains of disability
Table 3 shows the overall prevalence of disability in this sample was 78.0%. Most (77.0%) had disability in the mild to moderate range. Percentages of those with various domains of disability were calculated with reference to those with disability (i.e. 234 was used as the denominator). Few people (1.3%) reported disability in the ‘work/school activities’ domain while most people (69.7%) experienced disability in the ‘societal participation’ domain.
Prevalence, severity and domains of disability.
Correlates of disability
Only the PANSS positive, negative and total scores demonstrated significant relationship with disability (Table 4).
Correlates of disability.
PANSS: Positive and Negative Syndrome Scale.
Indicates chi-square test.
Indicates t-test.
Note: Bolded values signify p < 0.05.
Further analysis however revealed that the scores on the positive subscale of PANSS predicted disability—for every unit rise in the score, the odds of having disability increases by a factor of 1.2 (Table 5).
Independent correlates of disability.
OR: odds ratio; CI: confidence interval; PANSS: Positive and Negative Syndrome Scale.
Note: Bolded values signify p < 0.5
Discussion
The aim of this study was to examine the prevalence of disability and its correlates among patients with schizophrenia. This study adds to the existing literature by focusing on distinct domains of disability (Akinsulore et al., 2015) rather than non-delineated disability constructs as observed in previous studies (Rosan et al., 2015) which may not indicate specific areas for rehabilitative intervention. In adopting a cross-culturally validated disability measure, it has attempted to more reliably explore the nature and extent of disability in the population under study. This study extends the current understanding of the relationship between disability in schizophrenia and its correlates in a number of ways.
The prevalence of disability in this sample population is very high. Both African (Gureje & Bamidele, 1999) and non-African studies (Ali, 2009; McKibbin et al., 2008; Wiersma et al., 2000) on the subject matter have reported similar prevalence rates among patients with schizophrenia. Gureje and Bamidele (1999) reported a rate of 78% despite the fact that the instrument used was different from that utilized in this study. While Ali (2009) reported a rate of 96.7%, Wiersma et al. (2000) reported 83%. In other words, this buttresses the fact that generally the diagnosis of the illness confers some form of restriction in fulfilling maximal functions as expected of the patients, considering their age and gender. In terms of severity of disability, other authors (Ali, 2009; Parker & Hadzi-Pavlovic, 1995; Solanki et al., 2010) have reported that the disability in schizophrenia is mostly in the mild to moderate range. Perhaps, the advent of antipsychotics has contributed to this latter finding as their lack or absence could have resulted in greater illness severity and consequently higher levels of disability.
However, majority experiencing ‘disability in the participation in society’ domain is not a new finding (Ali, 2009; Krishnadas et al., 2007; McKibbin et al., 2008; Raj, 2014). It may be a reflection of the patient’s difficulty in initiating and maintaining social relationships. Possible reasons for this may be emotional blunting and apathy being experienced in schizophrenia which may make sufferers not appreciate the relationship needs and expectations of others (Raj, 2014; van Reekum et al., 2005). In addition, patients with schizophrenia also suffer self and public stigma (Herrman et al., 2002; Mosanya et al., 2014). This may make them feel inferior to others and explain why they interact poorly.
It was observed that very few patients reported being disabled in the cognition, mobility, self-care and activities domains. Cognitive processes of most of the respondents may have been slightly affected by the illness (Waddington et al., 1995, 1997) or even spared (Ertuǧrul & Uluǧ, 2002) as noted by some authors. This may explain why such patients may not report disability in cognition. Prior to the advent of anti-psychotics, patients with schizophrenia who had prolonged duration of untreated psychosis (DUP) usually manifested involuntary motor symptoms of the illness such as mutism, ambitendency, catatonia and negativism (McCreadie et al., 1996). These motor symptoms would have resulted in disability in mobility domains and also possibly limited their activities. This would also have impaired their functioning in ‘activities’ domain because of the difficulty in performing household activities or attend school/work. However, these are no longer common presentations today due to early introduction of anti-psychotics (Lieberman, 1999). Hence, a possible reason why only few reported restriction in this domain. Poor attention to self-care is an indicator of the negative symptoms of schizophrenia (WHO, 1993). Why we have very few people reporting disability in this area may also be attributed to the advent of anti-psychotics which has been shown to drastically reduce positive and negative symptoms of the illness (Alptekin et al., 2005).
An important observation was that all the socio-demographic variables as well as some clinical variables did not demonstrate any relationship with disability. It may be because a relatively stable population was utilized in this study and as a result, their clinical parameters were generally good and thus gave little room for variability among respondents. An exception was, however, the severity of psychosis (as measured by PANSS) of which the positive, negative and total scores demonstrated significant positive associations with disability. The significant relationship demonstrated by the total scores can be seen as an effect of multicollinearity (since it represents the additive sum of all the subscale scores). Discussing the relationship between the PANSS positive and negative subscale with disability, similar findings have been noted by previous authors (Górecka & Czernikiewicz, 2004; Gupta & Chadda, 2009). Possible reasons may be because the experiences of positive and negative symptoms by patients with schizophrenia constitute alterations of their hitherto normal state and serves as distraction to their real-world experiences and expectations (Aleman, 2014; Snyder, 2012). The inability to respond to these real-life situations and expectations is seen by others as restriction of activities (disability) in the specific areas of expected functioning. That the general subscale scores did not correlate with disability may essentially be because the items in this subscale are not specific to schizophrenia and so might not, on their own, result in altered experiences. As regard the predictive pattern observed, positive symptoms predicted disability while negative symptomatology did not. This finding is at variance with some of existing literature which found that both are predictors (Akinsulore et al., 2015; Harvey & Strassing, 2012) with negative symptomatology predicting more (Akinsulore et al., 2015). The relatively lower mean scores of negative symptomatology may contribute to this deviance.
In addition to the foregoing discussion on disability specifically, a few sociodemographic findings in the study are also worthy of mention. The observation that most of the respondents were of Yoruba tribe may be explained by the fact that the study was carried out in the south-western part of Nigeria which is largely dominated by the Yoruba tribe (Olabisi et al., 2008), and the study center serves as the first place of presentation for orthodox treatment. Also, a significant proportion of the respondents had poor socio-sexual functioning, and factors such as poor premorbid socio-sexual functioning (Joseph et al., 2013) and stigmatization from spouses (and in-laws) leading to separation/divorce (Aakansha et al., 2016) may have contributed to this. Although this sample had a good proportion being literate, most of them were unemployed. This may be a reflection of the high rate of unemployment in Nigeria (Kayoda et al., 2014). However, why none of the patients is functioning at a managerial level may be explained by a number of factors. Inability to attain the required level of qualifications for the office due to illness-related cognitive impairment (Schneider et al., 2009), poor people skills (Dickinson et al., 2007) which may be necessary to climb up a career ladder, and frequent illness-related work absenteeism (Sado et al., 2014) may all have been contributory.
An important clinical correlate worthy of mention is the DUP in this sample which is 46.8 months that is 3.5 years. In comparison to what was usually obtained in the past (McGlashan, 1999), this figure seems to indicate an improvement and this can be attributed to the advent of anti-psychotics (Perkins et al., 2005). However, considering civilization, one would have expected that the average DUP should be much lower than this. Reason for the dissonance may be explained by the high religious attribution to the illness (Ikwuka et al., 2016). Nigerians still attribute mental illness to be of spiritual origin, and the media is also not helping matters in this regard (Aina, 2004). Relatives usually first take their patients to spiritual homes and may spend days, months, or even years there before presentation for orthodox treatment (Adeosun et al., 2013). Overall, this may account for the prolonged DUP in this sample as also seen in other similar studies conducted in this environment (Adeosun et al., 2013; Effiong & Albert, 2016).
Limitations and strengths
A major limitation of this study is that it was conducted in only a single hospital. A multi-centered study, preferably cutting across the Nigerian geo-political zones, may be more representative of the actual findings across the country. In addition, being a cross-sectional survey, inference as regard causality of interested outcome cannot be made.
However, this work utilized a large sample size with the resultant advantage of robust statistical derivations. Also, an internationally recognized standard measure for disability across relevant domains was utilized, and a wide variety of possible correlates of disability was investigated. All these serve as significant improvements over existing studies in this field.
Conclusion
Disability is quite common among patients with schizophrenia albeit in the mild to moderate variety. Most patients have greatest difficulty in forming social relationships and least difficulty with self-care and physical activities. Pattern of symptomatology may, however, play a role in the manifestation of disability in this study population.
