Proxy validation of patient self-reports of ADL and IADL function before and after electroconvulsive therapy.

OBJECTIVE: To determine whether electroconvulsive therapy (ECT) patients' self-reported functional status is similar to that reported by a proxy.
BACKGROUND: Increasing levels of depression are associated with deteriorating functional status as reflected in the Instrumental Activities of Daily Living (IADL) scale. Depressed patients referred for ECT have poorer IADL status compared with depressed patients receiving medications, suggesting that IADL status may shape physicians' decision to recommend ECT ( 1). Further, IADL status improves with treatment of depression, both in ECT-and medication-treated patients. Given the potential importance of IADL status for ECT patients, we examined whether IADL status as reported by patients prior to ECT was comparable to IADL status as described by a proxy. DESIGN/
METHODS: Forty depressed patients (23 men and 17 women, mean age 58.1 +/- 17.5) were each interviewed alone with the 21-item Hamilton Depression Rating Scale (HDRS), Mini-Mental State Exam (MMSE), an Activities of Daily Living (ADL) scale, and an IADL scale. We then privately interviewed a first-degree relative who lived with each patient and recorded their impression of the patient's ADL and IADL function before ECT, and at 2 and 4 weeks after ECT.
RESULTS: baseline scores for HDRS and MMSE were consistent with a severe level of depressive symptoms and intact global cognitive function. Patients' and proxies' IADL scores were highly correlated before ECT, 2 weeks after ECT, and 4 weeks after ECT. Significant, but slightly weaker correlations were seen for ADL scores.
CONCLUSIONS: Ideally, ADL and IADL function would be measured by direct observation rather than either patient or proxy report. At this time it is unknown whether the patient or the proxy report should be considered the "gold standard." In this study, the patients' self-reported functional scores were highly correlated with the proxies' scores. We conclude that patients' reports of their function are roughly comparable to proxies' impressions before and after ECT.