Discrepancies between the medical record and patient medication list are common. The relationship of discrepancies to chronic disease control has not been established.

To determine the frequency and type of antihypertensive medication discrepancies between patient-named antihypertensive medications and the medical record, we performed a cross-sectional study of 315 adults with medically treated hypertension from 6 safety-net clinics in 3 states. We determined the association between medication discrepancies and uncontrolled blood pressure (≥140/90 mm Hg or ≥130/80 mm Hg if diabetes) using multivariate logistic regression models.

Discrepancies were present for 75.2% of patients; 25.7% of patients could not provide the name of any antihypertensive medication they took; 49.5% could name 1 or more antihypertensive medications but had discrepancies between patient-reported antihypertensive medications and those listed in the medical record. Both patients who were unable to name any of their antihypertensive medications and patients with discrepancies between patient-named medications and the medical record were significantly more likely to have uncontrolled blood pressure than patients who named the same medications as the medical record in adjusted analyses, adjusted risk ratios 1.66 (95% confidence interval, 1.31-2.10) and 1.51 (95% confidence interval, 1.11-2.07), respectively. Twelve percent of patients reporting medications took antihypertensive medication that altered potassium metabolism that was not in their medical record.

Among patients at safety-net clinics, inability to name one's antihypertensive medications and discrepancies between patient-reported medications and the medical record were very common. Both were strongly associated with inadequate hypertension control. Performing medication reconciliation at the point of care may be an important way to identify patients at high risk for inadequate disease control or safety problems.