Agreement between maternal report and medical records on use of medications during early pregnancy in New York

Background: Studies evaluating associations between medication use in preg-nancy and birth outcomes rely on various sources of exposure information. We sought to assess agreement between self-reported use of medications during early pregnancy and medication information in prenatal medical records to understand the reliability of each of these information sources.Methods: We compared self-reported prescription medication use in early pregnancy to medical records from 184 New York women with deliveries in 2018 who participated in the Birth Defects Study To Evaluate Pregnancy expo-sureS. We assessed medications used chronically and episodically, and medica-tions within 12 therapeutic groups. We calculated agreement using kappa (x) coefficients, sensitivity, and specificity. We assessed differences by case/control status, maternal age, education, time to interview, and interview language.Results: Medications used chronically showed substantial agreement between self-report and medical records (x = 0.75, 0.61-0.88), with agreement for therapeu-tic groups used chronically ranging from x = 0.61 for antidiabetics to x = 1.00 for antihypertensives. Prescription medications used episodically showed worse agree-ment (x = 0.40, 0.25-0.54), with the lowest agreement for opioid analgesics (x = 0.20) and anti-infectives (x = 0.33). Agreement did not differ by the character-istics examined, although we observed potential differences by interview language.Conclusions: Among our sample, we observed good agreement between self-report and medical records for medications used chronically and substantially less agreement for medications used episodically. Differences by source may be due to poor recall in self-reports, non-adherence with prescribed medications and lack of complete prescription information within medical records. Limita-tions should be considered when assessing prescription medication exposures during early pregnancy in epidemiologic studies.