Comparison of self reported and physician reported antidepressant medication use

PURPOSE: Self-reported medication histories obtained in pharmacoepidemiolog ic case control studies are subject to non-differential misclassification a nd to recall bias. The accuracy of self-reported antidepressant medication use has never been evaluated, but it is important in light of the hypothesi s that antidepressant medications may be associated with cancer risk. METHODS: Within a case-control study of several cancer sites, we compared s elf-reported antidepressant medication use with antidepressant use recorded in physicians' records. All female cases (n = 147) and controls (n = 119) who reported antidepressant medication use, and a 10% random sample (n = 11 4) of those who reported no antidepressant use, were asked to provide conse nt to contact, and the name(s) of their physician(s). These physicians comp leted a data abstraction form including information on antidepressant presc riptions recorded in patients' medical records. RESULTS: Substantial agreement was found between subject- and physician-rep orted antidepressant medication use (kappa = 0.60 [95% confidence interval (CI), 0.47-0.74]; agreement. = 80%), and use of specific antidepressant med ications (agreement ranged from 82 to 100%), while moderate agreement was o bserved for duration of use (weighted kappa = 0.56 (95% CI, 0.32-0.79)), an d date of first use [weighted kappa = 0.48 (950/6 CI, 0.23-0.72)]. The leve l of agreement did not differ markedly between cases and controls, except f or duration of use, where agreement was somewhat greater for cases. CONCLUSIONS: The similar level of agreement among cases and controls sugges ts that differential misclassification (e.g., recall bias) is unlikely in t he reporting of most aspects of antidepressant medication use by women. Fur thermore, the overall accurate self-reporting of antidepressant use suggest s that there should be minimal non-differential antidepressant exposure mis classification. (C) 1999 Elsevier Science Inc. All rights reserved.