An interview strategy was critical for obtaining valid information on the use of hormone replacement therapy.
OBJECTIVE
We compared telephone reports of hormone replacement therapy (HRT) use to claims for drugs dispensed.


METHODS
The study subjects included 106 women who were dispensed HRT and 107 who were not dispensed HRT.


RESULTS
Recall of drug use overall was relatively good (65/79=82.3%, 95% confidence interval [CI] 73.9-90.7). Agreement between recall of drug name and the claims for dispensed drugs was lower (61/79=77.2%, 95% CI 68.0-86.5). Of 65 women reporting use of HRT in response to the indication prompt, nine (13.8%) could not identify the drug name using the drug list prompt, but all 65 women identified a drug using the photo prompt. Recall of start date of drug use was poor (29.2% agreement on month/year; 45.8% agreement within 1 month), and recall of end date of drug use was poorer yet (7.7% agreement on month/year; 21.5% agreement within 1 month).


CONCLUSIONS
Recall of drug use and drug names is far better than recall of dates of use. Recall can be enhanced with lists of drug names and color photos, but even with memory prompts, recall remains imperfect. If drug use is the primary exposure of interest in a study, considerable effort is needed to collect it correctly. If not, then perhaps drug histories should be omitted.
Strom
Brian L
BL
Department of Biostatistics and Epidemiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6021, USA. bstrom@cceb.med.upenn.edu
Schinnar
Rita
R
D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D004522:Educational Status; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008568:Memory; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012923:Social Class