Disability is related to the difficulty of maintaining premorbid or normal functionality for people suffering from a disease.[
] The World Health Organization (WHO) describes disability as difficulty in functioning at the body, person, or societal levels, in one or more life domains, as experienced by an individual with a health condition in interaction with contextual factors.[ 1 ] One of the research studies indicated that 2.21% of the population has some type of disability, with only 2.7% of them having a mental illness and 5.6% having mental retardation.[ 2 ] This may be because the information gathered could not detect mild or moderate degrees of mental disability that remained undiagnosed due to restricted understanding and the absence of appropriately qualified staff to evaluate.[ 3 ] It was seen that the International Classification of Functioning, Disability, and Health (ICF) was impractical for assessing and measuring disability in daily practice.[ 4 ] 5
Therefore, the WHO developed the WHO Disability Assessment Schedule (WHODAS 2.0) intending to overcome the limitations of other disability assessment instruments; in addition, it has a direct link to ICF.[
] It was developed based on extensive cross-cultural field studies across various countries including India. It applies to all adult groups and is applicable in all cultures. All illnesses, including addiction, neurological, and mental problems, can be treated with it.[ 6 ] It has been used to assess disability caused not only due to schizophrenia,[ 7 ] bipolar disorders, and depression[ 8 ] but also due to medical conditions such as osteoarthritis, osteoporosis,[ 9 ] arthritis,[ 10 ] Parkinson’s disease, multiple sclerosis, stroke,[ 11 ] hearing loss,[ 12 ] and persons in rehabilitation.[ 13 ] There are multiple versions of WHODAS 2.0 which are available as interviewer, self or proxy administered forms. Currently, each nation has a different system for assessing, measuring, and establishing the level of disability required to qualify for disability payments. Some nations lack a scale for certifying impairment and instead rely on the clinical judgment of the doctors. India is among the countries which have adopted ICF as a health-care information technology standard for reporting data about functioning, disability, and health.[ 14 ] Among the other commonly available disability assessment instruments, the Indian Disability Evaluation and Assessment Scale (IDEAS) is the one that is used in the Indian context for the assessment of disability and has been notified by the Government of India too. 15
IDEAS has been the most widely used instrument for determining the presence or absence of disability and is also the most commonly used tool for determining the degree of disability for various mental disorders.[
] Although it has been in widespread use since 2001, certain problems have been encountered with its usage. The most common difficulty encountered with IDEAS is that it gives the range of disabilities and not an exact percentage. Various researchers and clinicians alike are familiar and comfortable with IDEAS for determining and measuring disability, in the near future it may be expected that researchers and clinicians will be expected to assess and measure disability using WHODAS 2.0.[ 16 ] Hence, it becomes important and relevant not only to gather data on WHODAS 2.0 for psychiatric disorders but also to see its degree of concordance with IDEAS. If one can find concordance between the two scales, then the usage of WHODAS 2.0 should not pose significant difficulties in conducting research in the field of disability in India. 17 Objective of the study
The present study examine the agreement in the measurement of disability between WHODAS 2.0 (36 Item Version) and IDEAS among Persons with Severe Mental Illness.
ATERIALS AND M ETHODS
The present study was longitudinal in nature. A total of 60 samples were selected using a consecutive sampling procedure. A person diagnosed with severe mental illness as per the ICD-10 diagnosis criteria, aged above 18–60 years with a total duration of illness of at least 2 years was considered for inclusion in the study. The study was conducted at the outpatient department of psychiatry GMCH. Patients and their legal representatives willing to participate and fulfilling the following inclusion and exclusion criteria were included in the study. Those who refused to consent to the study and patients not staying with primary caregivers were excluded from the study. All the patients were administered WHODAS 2.0 36-item interviewer version. After a gap of at least 1 month, the IDEAS scale was administered to each patient in the presence of the same primary legal representatives. The study was approved by the institutional ethical committee.
Tools used for the study
Sociodemographic pro forma and clinical data sheet
This is a semi-structured pro forma that includes the name, age, gender, domicile, education level, marital status, type of family, occupation, religion, age of onset, duration of illness, and duration of treatment.
World Health Organization Disability Assessment Schedule 2.0
The WHODAS 2.0 36-item version is an assessment tool developed by the WHO to measure disability and functional impairment in accordance with the ICF. The WHODAS 2.0 measures average functioning in everyday situations for the past 30 days, and surveys six domains of functioning: (1) Cognition, (2) mobility, (3) self-care, (4) getting along with others, (5) life activities, and (6) participation in society.[
] 18 Indian disability evaluation and assessment scale
It is a scale for measuring and quantifying disability in mental disorders developed by the Rehabilitation Committee of the Indian Psychiatric Society, in December 2000. It evaluates disability in four areas, 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 to profound disability.[
] 19 Statistical analysis
The collected data were entered in Excel 2007 and analyzed using the SPSS program (version 23.0; IBM Corporation, Armonk, NY, USA). Mean, SD for ordinal variables, and frequency tabulation for nominal variables was done. Comparative statistics across the group were applied in the form of Chi-square, Fisher’s exact probability test for nominal variables, and Student’s (unpaired)
t-test for ordinal variables. As per the normative assessment of the data, as both the variables were skewed for all the comparisons made, thus Spearman’s rho coefficient was used for finding the correlation between the two variables. Ethical consideration
The purpose and the design of the study were explained to the patient and accompanying primary caregiver in language that they understood, namely Hindi and Punjabi. The patients remained under the treating consultant. No interference was done in the treatment. The patient and the consenting family members were informed that they could withdraw at any time from the study without having to give reasons for the same. In any case, they continued to receive appropriate treatment for their condition. The confidentiality of the information obtained was maintained and was not revealed to doctors/auditors of the study. The defined guidelines of the Central Ethics Committee for Biomedical Research on human subjects by ICMR were adhered to, in addition to the principles enunciated in the “Declaration of Helsinki.”
ESULTS Table 1 shows the sociodemographic characteristics of the patients. The sample comprised predominantly of males (78.3%). Nearly 50% of the samples (48.3%) was in the age range of 18–39 years. The majority of the sample were followers of Hinduism (71.7%). Regarding marital status, most of the patients were unmarried (56.7%). The majority of the patients were belonging to the nuclear family (71.7%). Most of the patients (66.7%) were from rural communities. Table 1:
Sociodemographic profile of patients (
n=60) Table 2 shows the clinical characteristics of the participants. Majority (75%) had a long-standing illness of more than 5 years and also taken treatment for an illness of >5 years (73.3%). Most of the participant’s age of onset of illness was in the age group of 18–30 years (63.3%). The majority of the patients neither had any family history of psychiatric illness (91.7%) nor had any medico-legal issue (98.33%). Table 2:
Clinical profile of the patients (
n=60) Table 3 shows the domain wise and total score of the WHODAS 2.0 (36-item scale). The average scores obtained for domains: cognition, mobility, self care, and getting along with people were marginally higher than the average possible score in the available range, whereas it was marginally less than the average possible score in the available range for domains household activities and participation in society. The average score obtained for the total domain score was also marginally higher than the average possible score in the available range. Table 3: World Health Organization Disability Assessment Schedule 2.0 (36 item version) mean scores according to domains Table 4 shows the domain wise and total score of the IDEAS scale. The average scores obtained for all four domains were lower than the average possible score in the available range. The average score obtained for the total and global domain score was also lower than the average possible score in the available range. Table 4:
Domain and total scores of Indian Disability Evaluation and Assessment Scale
Table 5 shows the correlation between all the similar domains of WHODAS 2.0 and IDEAS. A significant positive correlation was found between all the domains of WHODAS 2.0 can be recommended either by itself instead of IDEAS for the assessment of disability in an Indian setting as there is a highly significant concordance of WHODAS 2.0 with IDEAS. Table 5:
World Health Organization Disability Assessment Schedule 2.0 (36 item version) and Indian Disability Evaluation and Assessment Scale ( n=60) D
The present study checks the agreement in disability between WHODAS 2.0 (36 Item Version) and IDEAS among Persons with Severe Mental Illness. In India, disability is certified at a score of 40% or greater of the total score being obtained on IDEAS. It is important to mention that WHODAS 2.0 has no cutoff like that. In the current study, average scores obtained for all the four Domains of IDEAS were much lower than the average possible score in the available range. The average score obtained for the total score and global domain score was also lower than the average possible score in the available range. This is in accordance with another study where patients with schizophrenia were evaluated in a tertiary care hospital setting.[
In IDEAS maximum disability was seen in the domain of “Communication and Understanding,” followed by domains of “Work,” “Interpersonal Activities,” and “Self Care.” This is as opposed to other studies from the literature that have used IDEAS to measure disability in patients with Schizophrenia, where maximum disability has been found in the “Work” domain.[
] A total score of 4.79 on IDEAS indicates a disability score of <40% (i.e. mild disability) the reasons for such a finding could be the same as discussed earlier for WHODAS 2.0, i.e., patients with severe mental illness having long duration and also currently having a period of minimum 3 months of clinical stability.[ 16 ] For this, we compared the total score of the WHODAS 2.0 with the Global Score of IDEAS. As per the normative assessment of the data, both the variables were found to be skewed, thus Spearman’s rho coefficient for finding the correlation between the two variables was applied ( 21 r = 0.703, P < 0.01) indicating a significant correlation between the two scales. A significant positive correlation was found between all the domains of WHODAS 2.0 can be recommended either by itself instead of IDEAS for the assessment of disability in an Indian setting as there is a highly significant concordance of WHODAS 2.0 with IDEAS. The total scores of both the scales (IDEAS and WHODAS 2.0) showed a significant correlation with each other P < 0.01). Hence, both scales were seen to be concordant. This is an important finding as though both scales measure disability, yet they are from different constructs and have been developed in different settings and by different work groups, which can lead to different conceptual aspects influencing their practical application and interpretation.[ ] 22
There are various instruments that are used to assess health status and disability across the world.[
] Developed countries collect data regarding disability by surveys and have a higher prevalence of disability as compared to developing countries which collect data through census and have lower prevalence rates.[ 23 ] Many countries are in the process of implementing ICF to assess the disability status of individuals for availing of disability benefits.[ 24 ] The Diagnostic and Statistical Manual of Mental Disorders (DSM) has started using WHODAS 2.0 in place of the Global Assessment of Functioning which was used in the earlier versions of DSM. WHODAS 2.0 is expected to become the world standard for disability data and social policy modeling. As a disability measurement tool, IDEAS shares some advantages with WHODAS 2.0 in terms of ease of use and measuring disability in terms of the impact of mental illness on life domains.[ 25 ] Like IDEAS, WHODAS 2.0 is also easy to administer. Adoption of WHODAS 2.0 in India will be helpful to mental health professionals and administrators to measure health and disability according to ICF irrespective of the nature of health conditions.[ 26 ] Large-scale studies in community samples can generate normative data for the country which can help in determining the threshold for availing of concessions/welfare benefits.[ 27 ] 28
In addition, it has already been discussed earlier that the Government of India has notified the use of IDEAS for the assessment and certification of disability in patients with mental illness, and is being widely used for disability certification not only for patients with schizophrenia but also for all mental illnesses, across India.[
] Hence, concordance of WHODAS 2.0 with IDEAS provides the option of being able to apply and use WHODAS 2.0 instead of IDEAS; this shall help in being able to generate disability-related data which can be collated with uniformity across the world with its constructive research, clinical, and policy-related implications. It is important to mention here that no similar kind of study with the same aim of studying agreement between the two scales has been conducted before; hence, it was not possible to compare and contrast our findings. 29 Limitations and strengths of the study
The major limitation of the current study is its small sample size. Potential bias cannot be excluded as the rater was not blinded to the diagnosis of the assessment. Patients in this study were restricted to a specific diagnosis of severe mental illness who visited a clinical facility which could limit the generalization of the result. The data were skewed with large variation in some variables (like duration of illness), which may have had an impact on the findings. A single version of WHODAS 2.0 was used; not all versions were tested out again limiting generalizability. The strengths of the study were clinically stable patients were assessed, WHODAS 2.0 was compared with a standardized scale (IDEAS), and variability in assessment was kept to the minimum possible.
WHODAS 2.0 can be recommended either by itself instead of IDEAS for the assessment of disability in an Indian setting as there is a highly significant concordance of WHODAS 2.0 with IDEAS. This will help the disability boards to give an exact percentage of disability; an aspect that was lacking in IDEAS where a range is available. WHODAS 2.0 having excellent psychometric properties will probably be more appropriate for the assessment of disability in the Indian setting and also as it covers all the ICF domains, it will be a better measure of a person’s disability. Hence, a certain degree of caution needs to be exercised in interpreting the results so obtained, and additionally replication across the different patient populations, across different centers, cultures, and varying methodologies need to be conducted.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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