Medication reconciliation problems were highly prevalent among patients receiving hypertension care at three federally qualified health centers. Patients frequently could not name their antihypertensive medications, and there was little agreement between antihypertensive medications in the medical record and those named by patients. These deficits were particularly striking for patients with inadequate health literacy. Of these patients, 60% could not name any antihypertensive medications and nearly two thirds named no antihypertensive medication that was recorded in their medical record. Inadequate health literacy may therefore pose a major obstacle to patients and their providers as they attempt to reconcile medications used for hypertension.
Being unable to state which medications they are using by name (and also by dose) could be especially important when patients interact with health care providers other than their usual source of outpatient care (e.g., emergency departments, inpatient settings).17
For patients routinely using safety-net providers, poor reconciliation may further complicate the challenge of coordination of care.
For chronic conditions, such as hypertension that frequently require multidrug regimens, the inability to name one’s medications could increase the chance of medication errors or nonadherence. This study did not assess adherence or medication errors directly, but supports a possible association between health literacy and medication-taking behaviors. Our finding that inadequate health literacy was associated with having two or more antihypertensive medications recorded in the medical record but not with the number of antihypertensive medications patients reported taking could indicate a relationship between inadequate health literacy and nonadherence in this population. Prior findings in HIV treatment found inconclusive results as to the relationship between health literacy and medication adherence.10,13,18–20
Yet HIV may differ from hypertension. Antiretroviral medications generally have a single manufacturer, and a prior study found that patients with limited literacy often rely on pill characteristics for identification.21
This would be difficult with antihypertensive drugs, which frequently come in multiple forms from different manufacturers. Patients may be dispensed different appearing versions of the same medication from 1 month to the next. Using medications correctly by depending on pill shape, size, or color seems particularly unreliable in this case. A recent study found inadequate health literacy to be related to lower refill adherence for cardiovascular-related diseases and diabetes.22
Further research is needed to explore plausible causal pathways linking health literacy to medication errors and adherence for hypertension.
Limitations of the study should be noted. Patients were from one city, all spoke English, and all had diagnosed hypertension. How these results generalize to other populations with different medical conditions is not known. The medical record was intentionally abstracted 2 weeks after the interview, yet it is possible that the record did not contain the most up to date documentation. One might expect errors or omissions to be more prevalent in paper chart documentation compared to an electronic record. It is also possible that medical information was incomplete as patients could have received care from other sites. However, patients at federally qualified health centers have fewer resources and, therefore, may be less likely to access multiple providers. Finally, our study population was small. We were able to detect significant differences in the ability to name antihypertensive medications by health literacy status but were limited by our sample size to detect clinically meaningful differences in blood pressure.
Greater attention should be directed to medication reconciliation in ambulatory care and potential strategies to overcome related health literacy barriers. Future research should examine in detail the relationship between health literacy, medication discrepancies, and chronic disease outcomes. The efficacy of interventions to improve communication and patient recall of medicines should also be tested. At present, clinicians might also encourage patients to bring their medications with them to office visits.