Objectives: The Parkinson's disease is a progressive phenomenon that effort for maintain of independence in functional and self-care skills is considered as one of the most important aspects of their life. PASS (Performance Assessment of Self Care Skills) evaluates the activities of daily living (ADL), instrumental activities of daily living (IADL), and functional mobility (MOB) of the patients. Validity and reliability of this test has been evaluated in few disabilities and it has never been performed on patients with Parkinson's disease. The purpose of the present study was to assess the validity and reliability of PASS in evaluating the self-care skills of patients with Parkinson's disease.

Methods & Materials: PASS was first translated into Persian and' after minor modifications, was given to 5 specialists (all were occupational therapists) along with a questionnaire especially designed for this purpose. For the purpose of testing the reliability 50 patients with Parkinson's disease aging 45-85 years were no randomly selected from 5 geographic regions of Tehran. The test and retest was performed on 2 consecutive days using the PASS manual for evaluating the self-care skills of the patients for 3 aspects of independence, safety, and outcome. Pearson correlation coefficient was measured between the results using SPSS 11package.

Results: There was a significant agreement (P=95%) between the scores of 5 specialists in all 3 aspects of independence (X²=5.83, DF=4), safety (X²=5.44, DF=4), and outcome (X²=2.45, DF=4). Pearson correlation coefficient for test-retest results was 93%, 91%, and 91% for independence, safety, and outcome respectively (P=0.01) which is indicative of very high reliability of PASS for evaluating self-care skills of patients with Parkinson's disease.

Conclusion: The results of the present study indicate that PASS is highly valid and reliable in evaluating the self-care skills of patients with Parkinson's disease. These results were not unexpected in the sense that' as long as the standards of test performance are observed, there should be no difference between the test-retest results of the same patient performed in 2 sessions. One other important aspect is patient education and familiarization with the test procedure. This aspect was tried to be effectively observed during the tests. It can be concluded from the results of this study that PASS is an appropriate tool for assessment of the self-care skills of patients with Parkinson's disease by rehabilitation specialists including occupational therapists.