Agreement of medical record abstraction and self‐report of breast cancer treatment with an extended recall window.

Background Methods Results Conclusions Medical record abstraction (MRA) and self‐report questionnaires are two methods frequently used to ascertain cancer treatment information. Prior studies have shown excellent agreement between MRA and self‐report, but it is unknown how a recall window longer than 3 years may affect this agreement.The Women’s Environmental Cancer and Radiation Epidemiology (WECARE) Study is a multicenter, population‐based case‐control study of controls with unilateral breast cancer individually matched to cases with contralateral breast cancer. Participants who were diagnosed with a first primary breast cancer from 1985 to 2008 before the age of 55 years completed a questionnaire that included questions on treatment. First primary breast cancer treatment information was abstracted from the medical record from radiation oncology clinic notes for radiation treatment and from systemic adjuvant treatment reports for hormone therapy and chemotherapy. Agreement between MRA and self‐reported treatment was assessed with the kappa statistic and corresponding 95% confidence intervals (CIs).A total of 2808 participants with MRA and self‐reported chemotherapy treatment information, 2733 participants with MRA and self‐reported hormone therapy information, and 2905 participants with MRA and self‐reported radiation treatment information were identified. The median recall window was 12.5 years (range, 2.8–22.2 years). MRA and self‐reported treatment agreement was excellent across treatment modalities (kappachemo, 98.5; 95% CI, 97.9–99.2; kappahorm, 87.7; 95% CI, 85.9–89.5; kapparad, 97.9; 95% CI, 97.0–98.7). There was no heterogeneity across recall windows (<italic>p</italic>chemo = .46; <italic>p</italic>horm = .40; <italic>p</italic>rad = .61).Agreement between self‐reported and MRA primary breast cancer treatment modality information was excellent for young women diagnosed with breast cancer and was maintained even among women whose recall window was more than 20 years after diagnosis. [ABSTRACT FROM AUTHOR]