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The Government of India (GOI) has recommended the use of Indian Disability Evaluation and Assessment Scale (IDEAS) for the assessment and certification of disability in patients with mental illness. Although data are available in terms of internal consistency and construct validity of IDEAS, concurrent validity of IDEAS has rarely been evaluated.
The aim was to study the concurrent validity of IDEAS with Global Assessment of Functioning (GAF) and Social and Occupational Functioning Scale (SOFS) in patients with schizophrenia.
One hundred and seventy-eight consenting patients with schizophrenia in remission were assessed for disability, functioning, and psychopathology using the IDEAS, SOFS, GAF, and Positive and Negative symptom scale (PANSS) respectively.
This study shows that the GOI-modified IDEAS had good concurrent validity with global and sociooccupational functioning as assessed by GAF and SOFS respectively.
Keywords: Concurrent validity, disability, Indian Disability Evaluation and Assessment ScaleSchizophrenia is a chronic mental disorder which is often associated with marked disability. The decline in the level of functioning in individuals with schizophrenia starts since the onset of illness or even before the full syndromal diagnosis is made. Available research suggests that disability is one of the outcome indices for chronic illnesses such as schizophrenia. A “disability certificate” is necessary to access benefits under the Persons with Disabilities Act (1995) in India.[1] Accordingly, disability assessment and certification is of utmost importance for individuals suffering from schizophrenia. In 2001, the Government of India (GOI) recommended the use of Indian Disability Evaluation and Assessment Scale (IDEAS), developed by Indian Psychiatric Society for the assessment and certification of disability in patients with mental illness.[2] Since then, this scale has been widely used for disability certification in patients with schizophrenia across India. It has been found to have good internal consistency, face, content, and criterion validities.[3]
Several studies have employed IDEAS to evaluate the prevalence and pattern of psychiatric disabilities in hospital-based and community samples.[4,5,6] Other studies have evaluated the impact of pharmacological and psychological interventions on disability.[7,8,9] Studies have also reported the pattern of disability in patients seeking certification.[10,11] Recent studies have also established the reliability, construct, and convergent validity, and internal consistency of IDEAS.[12] The convergent validity of IDEAS was evaluated against the quality of life scale.[12] However, literature is still limited. Accordingly, the present study aimed to evaluate the concurrent validity of IDEAS with level of functioning assessed by standardized scales, i.e., sociooccupational functioning (SOF) scale and global assessment of functioning (GAF) scale. In addition, an attempt was also made to study the pattern of disability among patients with schizophrenia.
The study was conducted at the Department of Psychiatry, Postgraduate Institute of Medical Education and Research, Chandigarh, a tertiary care multispecialty hospital catering to a major part of North India. It was a cross-sectional study in which patients with schizophrenia in remission were recruited using convenience sampling. The study was approved by the Institute's Ethics Committee, and all the participants were recruited after obtaining written informed consent.
To be included in the study, participants were required to have a diagnosis of schizophrenia (as per the Diagnostic and Statistical Manual of Mental Disorders-IV edition [as assessed by Mini International Neuropsychiatric Interview],[13] in clinical remission [as per Andreasen et al., 2005[14] criteria], aged >18 years, with no other psychiatric comorbidity including substance dependence (except nicotine) and no associated chronic physical illness. Those with organic brain syndrome and mental retardation were excluded from the study. All the assessments in a patient were done by the same rater.
The IDEAS evaluates disability in four domains, namely, self-care, interpersonal activities, communication and understanding, and work. Each item is scored on a 5-point scale with a range of 0–4, i.e., from no (0) to profound disability (4). In addition, the duration of illness is also given weightage while calculating the disability score. The total disability score is obtained by summing up the ratings on the four domains. The global disability score is calculated by adding the “total disability score” and duration of illness score. Global disability score of more than 7 signifies disability of >40%.[2]
GAF[15] was used to assess the overall level of functioning of the participants.
It is a 14-item scale which was used to assess social functioning. It has three main domains which include adaptive life skills, social appropriateness and communication, and interpersonal relationships. The items are rated by clinician on a 5-point scale ranging from 1 to 5, i.e., no impairment to extreme impairment. It is suitable for use in multiple treatment settings and has adequate psychometric properties. The alpha coefficient of the scale is 0.91.[16]
This 30-item scale is one of the most commonly used scales to assess the severity of symptoms among patients suffering from schizophrenia. The items are divided into three subscales, i.e., positive symptoms (7 items), negative symptoms (7 items), and general psychopathology subscale (16 items). Each item is rated on a 7-point severity scale. The concurrent and predictive validity and sensitivity to change for the scale has been well established. Total positive, negative, and general psychopathology scores were calculated.[17] Clinical remission was determined using Positive and Negative symptom scale (PANSS), based on the remission criteria proposed by Andreasen et al.[14]
Statistical Package for the Social Sciences, Windows, version 14 (SPSS version 14, SPSS Inc., Chicago, IL, USA) was used to analyze the data. Analysis included calculating frequency/percentage for categorical variables and mean and standard deviation (SD) for continuous variables. The relationship of disability with level of functioning, including sociooccupational functioning, demographic and clinical variables, was analyzed using Pearson's correlation coefficient.
The study included 178 participants. The mean age of the study sample was 34.73 (SD −10.84) years. There was slight preponderance of male (56.2%) participants in the study sample. About three-fifth (59.6%; n = 106) of the study participants were currently single and three-fourth (72.5%; n = 129) were unemployed and belonged to Hindu religion (79.8%; n = 142). Two-third of the patients were from urban background (66.3%; n = 118). The most common subtype of schizophrenia in the study sample was paranoid schizophrenia (73.6%). Mean duration of illness was 11.04 (SD −7.93) years, and the mean age of onset was 23.68 (SD −7.95) years. Mean total PANSS score was 51.30 (SD −11.19). The mean PANSS positive subscale score was 9.66 (SD −2.64), negative subscale score was 14.94 (4.65), and the mean general psychopathology subscale score was 26.7 (6.41).
The mean scores on different items of IDEAS are shown in Table 1 . Maximum disability was observed in the area of work, followed by the areas of communication and understanding, and interpersonal activities. The least disability was seen in the area of self-care. Disability (i.e., mean total disability score of >7) was present in 84.8% of the participants. All patients had at least mild disability in all the domains. In terms of severity of disability in different domains, majority of the patients had mild disability in the domain of self-care (80.3%), moderate disability in the domain of interpersonal activities (53.4%) and communication (57.9%). In terms of work domain, although moderate disability formed the largest group (43.3%), compared to disability in other domains, higher proportion of patients had severe (21.3%) and profound (15.2%) disability.
Level of disability in the study sample
The mean GAF score was 74.58 (SD −13.17). Maximum impairment in sociooccupational functioning as assessed by the SOFS was seen in the domain of adaptive life skills (mean: 10.35 [SD −3.24]; range: 6–20), followed by the domains of communication and interpersonal relationships (mean: 7.88 [SD −2.74]; range: 4–17) and the least level of dysfunction was seen in the domain of social appropriateness (mean: 6.06 [SD −1.90]; range: 4–12). The mean total SOFS score was 24.30 (SD −7.41) (range: 14–48).
As is evident from Table 2 , higher positive, negative, and general psychopathology scores correlated positively with higher disability in all the domains, i.e., self-care, interpersonal activities, communication and understanding, and work. Higher residual psychopathology (i.e., all domains of PANSS and PANSS total score) was also associated with overall higher disability as assessed by total IDEAS score and Global IDEAS score.
Relationship of the Indian Disability Evaluation and Assessment Scale with Social and Occupational Functioning Assessment Scale and Global Assessment of Functioning and Positive and Negative Symptom Scale (psychopathology) in patients with schizophrenia (n=178)
Higher disability in various domains was also associated with higher level of dysfunction in all the domains of sociooccupational dysfunction and overall functioning as assessed by SOFS and GAF scores, respectively.
It was also found that most of the sociodemographic variables did not have any association with IDEAS component scores except for education in years (negatively correlated with self-care), occupation (those unemployed had high scores on IDEAS self-care, interpersonal activities, work domains, and higher global IDEAS score), and locality (patients in urban locality had less scores on IDEAS self-care and interpersonal activity domains). Among the clinical variables, age of onset negatively correlated with total IDEAS score and Global IDEAS score, and total duration of illness in years positively correlated with total Global IDEAS score. Duration of treatment also correlated positively with IDEAS domains of self-care, work, total, and Global IDEAS scores.
In the present study, an attempt was made to evaluate the concurrent validity of IDEAS with functioning and residual psychopathology. In addition, an attempt was made to evaluate the association of disability with demographic and clinical variables.
In the present study, the maximum level of disability was seen in the domain of work, with four-fifth of patients having at least moderate disability. Disability in the domain of work was followed by disability in the domains of communication and understanding, interpersonal activities, and self-care. Previous studies which have used IDEAS among patients with schizophrenia also echo similar findings.[5,12] However, it is important to note that assessment of disability does not take into account the reasons for the same. The high level of disability in the domain of work during the remission phase can be understood from various perspectives. This possibly suggests that, although the patients have symptomatic improvement, they are not sufficiently equipped to take up the work-related assigned duties. Second, this could also possibly reflect the lack of rehabilitation services in a country like India. Although patients are treated adequately with antipsychotic to achieve clinical remission, they are not provided with adequate vocational skills, cognitive remediation and rehabilitation. Hence, these patients are not able to take up the job responsibilities. Third, the high work-related disability could also be a reflection of lack of opportunities. In India, there is no special job reservation for mentally ill people and they have to compete with people with other disabilities to get job. Possibly, disclosure of their mental illness in the job applications leads to discrimination and lack of selection. Further, higher disability in work domain could also be due to self-stigma perceived by patients with mental illness. They may feel alienated, withdraw from the society, feel discriminated, and actually do not take up the available opportunities. Some of the earlier studies have also reported stigma as a barrier for rehabilitation in patients with schizophrenia.[18,19] In addition, studies also suggest that many patients prefer to hide their mental illness in their job applications.[20,21,22]
Findings of the present study also show that all the domains of disability, the total and global disability score, strongly correlate with residual positive, negative, general psychopathology scores, and total score of PANSS. Previous studies which had evaluated the relationship of disability and psychopathology have also reported similar findings.[12,23,24] These findings suggest that all efforts must be made to minimize the residual psychopathology among patients with schizophrenia and this would minimize the consequential disability.
Concurrent validity is demonstrated when a test correlates well with a measure that has previously been validated. In the present study, all the domains of disability as assessed using IDEAS along with the total IDEAS and global IDEAS score had a significant correlation with functioning as assessed using SOFS and GAF scores. Accordingly, it can be said that assessment of disability by IDEAS can give a fair impression regarding the sociooccupational and overall functioning of an individual with schizophrenia.
The present study had few limitations. It was conducted with a hospital-based sample and hence could not be generalized to community. The study involved cross-sectional evaluation of the relationship between disability, psychopathology, and functioning, and rating was nonblinded. All the ratings in a patient were done by the same rater; this could have led to bias. Future studies should attempt to overcome these limitations.
This study shows that the GOI-modified IDEAS had good concurrent validity as tested in patients with residual schizophrenia with global and sociooccupational functioning as assessed by GAF and SOFS scores. Hence, it can be said that the assessment of disability by IDEAS can be helpful in the assessment of overall functioning too in patients with schizophrenia. This study adds on to the validity of IDEAS for the assessment of psychiatric disability in individuals with schizophrenia. This study also shows that patients with schizophrenia have higher level of disability in the work domain. This calls for understanding the reasons for the same and addressing the work-related disability by improving the rehabilitation facilities and creating patient-friendly job opportunities.
There are no conflicts of interest.
