A Systematic Review of the Measurement of Function in Late-Life Depression

Recovery of everyday premorbid function is a primary goal in the treatment of depression. Measurement of function is an important part of achieving this goal. A multitude of scales have been used to measure function in depression, reflecting the complex, multifaceted nature of functioning. Currently, however, there are no evidence-based guidelines to assist the researcher or clinician in deciding which instruments are best suited to measure function in late-life depression (LLD). Thus, the aims of this study are to 1) systematically review and identify the instrumental activities of daily living and social functioning assessment instruments used in the LLD literature; 2) identify and appraise the measurement properties of these instruments; and 3) suggest factors for LLD researchers and clinicians to consider when selecting functional assessment instruments and make pertinent recommendations. We performed a systematic review of MEDLINE and CINAHL to identify studies that i) incorporated subjects aged 60 years and older with a depressive disorder, and ii) measured instrumental activities of daily living and/or social functioning. Our search yielded 21 functional assessment instruments. Only two of these instruments, the 36-Item Short Form Survey and the Performance Assessment of Self-Care Skills, have formal validation data in LLD. Four additional instruments, although not formally validated, have relevant data regarding their measurement properties. The primary finding of this study is that very few functional assessment instruments have been validated in LLD, and the available measurement property data are mixed; there is a need for further instrument validation in late-life depression. With this caveat in mind, we provide evidence-based suggestions for researchers and clinicians assessing functioning in LLD patients.