Validation study of the Participation Scale Short version (14-items) in people affected by leprosy and other disabilities in Tamil Nadu, India.
Aim The aim of this research is to validate the Participation Scale Short version (PSS) in Tamil Nadu, India, in order to assess the participation of people living with a disability. A related goal was to understand the concept of „participation‟ in this area.
Background A large number of people in the world with a given health condition are confronted by social problems, such as stigmatization and participation restrictions. Assessing the level of participation is relevant to specifically select individuals for rehabilitation programmes, monitor the population over time and develop a personal rehabilitation programme. The Participation Scale, also known as the P-scale, is based on the classification domains of „participation‟ according to the International Classification of Functioning, Health and Disability. Experiences from the field suggest that the P-scale is useful, but a number of participants from studies in Indonesia and Thailand noted that some items appeared similar. Therefore, five items were removed from the scale and resulted in the P-scale Short (PSS). A shorter P-scale is more useful for rapid assessment, which is relevant in certain emergency situations, e.g. surveys or as part of a toolkit of instruments. It would also result in less burden for the participant.
Methods This study took place in the Schieffelin Institute of Health-Research & Leprosy Centre in Karigiri. Semi-structured interviews were undertaken with people who have a disability and health workers to develop an understanding about the concept of „participation‟. The PSS was refined with the data from the semi-structured interviews before starting with the quantitative data collection. People living with leprosy, tuberculosis, HIV/AIDS and diabetes were interviewed with the PSS and, seven days later, with the gold standard, the P-scale. The conceptual and operational equivalence were measured by Herdman framework and the measurement equivalence was assessed with the use of the quality criteria of Terwee. The measurement equivalence included reliability to distinguish between groups, criterion validity, content validity, internal consistency, floor & ceiling effects and interpretability. To estimate a new cut-off point for the PSS (participation restrictions/no participation restrictions) a normative sample of people without a disability was interviewed.
Results All 13 questions were relevant to PWD living in Tamil Nadu. The concept „participation‟ had changed slightly over the years. Thus, a 14th question was added, as well as refinements to the other questions to upgrade the conceptual equivalence. The interviews with both the P-scale and the PSS involved 86 participants with an average of 7 days between the first and second measurement. The normative group included 50 participants. The results show that the PSS can distinguish well between different groups, for example in age, literacy and income. The PSS and the P-scale score were significantly correlated (r=0.762). The sensitivity and specificity of the PSS versus the P-scale are respectively 0.85 and 0.88. Furthermore, the PSS demonstrated good internal consistency with a Cronbach‟s alpha (total score) of 0.85. Lastly, it showed a reduction in interviewing time of 3 minutes and no floor or ceiling effects.
Conclusion The Tamil version of the Participation Scale Short version has adequate operational and (psychometric properties) measurement equality. The item and semantic equality were already assessed. To improve the conceptual equality of the scale, it is recommended to add a question about the „public utility services‟. This completes the concept of „participation‟ in Tamil Nadu.