Measuring limitations in activities of daily living: a population-based validation of a short questionnaire.

ABSTRACT

PURPOSE: A newly developed questionnaire assessing limitations in activity of daily living (LADL-Q) that should improve assessment of LADL is tested in a large population-based validation study. METHODS: This survey was paper-based. Overall, 16,634 individuals who were representative of the working population in the German-speaking part of Switzerland participated in the study. Item analysis was used the final version of the LADL-Q to four items per subscale that correspond to potential problems in three body regions (back and neck, upper extremities, lower extremities). Analysis included tests for reliability, internal consistency, dimensionality and convergent validity. RESULTS: Test-retest reliability coefficients after 2 weeks ranged from 0.82 to 0.99 (Mdn = 0.87), with no item having a coefficient below 0.60. The median item-total coefficients ranged between moderate and good. Correlation coefficients between LADL-Q subscales and three validated clinical instruments (Western Ontario and McMaster Universities osteoarthritis index, shoulder pain disability index, Oswestry) ranged from 0.63 to 0.81. In structural equation modeling the three subscales were significantly related with two important outcomes in occupational rehabilitation self-reported general health and daily task performance. CONCLUSION: The new LADL-Q is a brief, reliable and valid tool for assessment of LADL in studies on musculoskeletal health.