Background and purpose: The Activities of Daily Living scale (ADL) and instrumental activities of daily living scale (IADL) are two instruments that screen elderly respondents for physical functioning. They also assess whether they are dependent or independent in performing their activities. This study was conducted to investigate the reliability and validity of Iranian version of ADL and IADL.

Materials and methods: ADL and IADL Persian versions were prepared by the forward-backward method. Content Validity Index (CVI) was also used. The questionnaire was given to 300 individuals. To determine the criterion validity, sensitivity and specificity of the ADL and IADL were calculated. To assess the construct validity convergent validity and known groups were used and ADL and IADL mean scores were compared using the Mini Mental State Examination (MMSE). Internal consistency and reliability was assessed by Cronbach's alpha and test-retest.

Results: The content validity index was more than 0.82 for both ADL and IADL. Convergent validity showed that the mean scores of ADL and IADL in elderly individuals with normal and adverse normal cognitive ability were significantly different. Also, the studied instruments were able to differentiate between different age groups. The sensitivity and specificity of ADL and IADL were 0.75 and 0.96, respectively. Cronbach'salpha and ICC were more than 0.75.

Conclusion: The Persian version of ADL and IADL were found to be consistent and valid measures for assessing daily activities and instrumental activities of Iranian elderly. They are also easy to use and are recommended for research projects.