World Health Organisation Disability Assessment Schedule II: Contribution to the Italian validation

INTRODUCTION: The World Health Organisation Disability Assessment Schedule II (WHODAS II) is an instrument developed by the World Health Organisation in order to assess behavioural limitations and restrictions to participation experienced by an individual, independently from a medical diagnosis. The conceptual frame of reference of this instrument is the International Classification of Functioning, Disability and Health: ICF. Specifically, the instrument is designed to evaluate the functioning of the individual in six activity domains: Understanding and communicating, Getting around, Self-care, Getting along with people, Life activities, Participation in society. PURPOSES: Considering the widespread consent about the usefulness of the WHODAS II, the general aim of the present study is to provide a contribution to the validation of the Italian version. METHOD: The WHODAS II Italian version has been administered to a sample of 500 participants subdivided in two groups: 271 normal adults and 229 disabled adults. The disabled participants group has been subdivided in three sub-groups, according to their disability: 111 motor disabled, 45 mental disabled, 73 sensory disabled. RESULTS: The mean Total score of the WHODAS II is 12.95 for the normal adults and 22.93 for the disabled group. Either group obtains the least impairment in the Self-care domain. This could be probably due to the presence of social-health workers in everyday life for all Italian disabled people. For the three disabled participant groups separately computed the mean Total score is: 28.66 for the motor disabled, 24.60 for the mental disabled, and 14.97 for the sensory disabled, confirming that sensory disabled do not perceive their disability as a personal functioning problem but a socially constructed one. Some subscales of WHODAS II show relatively strong floor effects. The Cronbach's Alpha calculated for each of the subscales is found to be high. The correlations of the subscales show strong correlations in all subscales. CONCLUSIONS: The WHODAS II is a useful instrument for measuring disability and functioning in normal and disabled people. It shows high reliability and a stable factor structure; although an additional psychometric evaluation of a representative sample of Italian disabled should be carried out in order to reach standard scores for each macro-category of disability.