Good agreement between physician and self-reported hormone therapy data in a case-control study.
OBJECTIVE
In a population-based case-control study examining the effects of postmenopausal hormone therapy (HT) on breast cancer risk, the authors conducted a validation study comparing prescription data from gynecologists with self-reports.


METHODS
The study was conducted in the Rhein-Neckar and Hamburg regions of Germany from 2002 to 2005. A total of 224 cases and 225 controls, stratified by region, age, and hormone use were randomly selected for the validation study.


RESULTS
For ever/never use 88.2% agreement was seen, and agreement for ever/never use by type of HT was 80.6%, 80.3%, and 90.5% for mono-estrogen, cyclical combined, and continuous combined therapy, respectively. The intraclass correlation coefficient (ICC) for duration of use was high, 0.82 (95% confidence interval [CI]: 0.77, 0.85), as were the ICCs for age at first and last use, 0.88 (95% CI: 0.85, 0.91) and 0.98 (95% CI: 0.97, 0.98). Despite the exceptionally high number of different HT prescriptions available in Germany, comparison of exact brand name resulted in perfect agreement for 50.2% of participants, partial agreement for 29.3%, and no agreement for 20.7%. In general, agreement was not differential by disease status.


CONCLUSIONS
Overall, the self-reported HT of the study participants corresponded well with physicians' reports.
Kropp
S
S
Department of Cancer Epidemiology, German Cancer Research Center, Heidelberg, Germany. s.kropp@dkfz.de
Terboven
T
T
Hedicke
J
J
Mutschelknauss
E
E
Slanger
T
T
Braendle
W
W
Berger
J
J
Chang-Claude
J
J
Flesch-Janys
D
D
D000367:Age Factors; D000368:Aged; D001943:Breast Neoplasms / Q000209:etiology*; D016022:Case-Control Studies; D004334:Drug Administration Schedule; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D015914:Estrogen Replacement Therapy / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D011939:Mental Recall; D008875:Middle Aged; D017698:Postmenopause; D015203:Reproducibility of Results; D012650:Self Disclosure