Difference in Effectiveness of Medication Adherence Intervention by Health Literacy Level

There is little research investigating whether health information technologies, such as interactive voice recognition, are effective ways to deliver information to individuals with lower health literacy. Determine the extent to which the impact of an interactive voice recognition-based intervention to improve medication adherence appeared to vary by participants' health literacy level. Promoting Adherence to Improve Effectiveness of Cardiovascular Disease Therapies (PATIENT) was a randomized clinical trial designed to test the impact, compared with usual care, of 2 technology-based interventions that leveraged interactive voice recognition to promote medication adherence. A 14% subset of participants was sent a survey that included questions on health literacy. This exploratory analysis was limited to the 833 individuals who responded to the survey and provided data on health literacy. Adherence to statins and/or angiotensin-converting enzyme inhibitors and/or angiotensin II receptor blockers. Although intervention effects did not differ significantly by level of health literacy, the data were suggestive of differential intervention effects by health literacy level. The differences in intervention effects for high vs low health literacy in this exploratory analysis are consistent with the hypothesis that individuals with lower health literacy may derive greater benefit from this type of intervention compared with individuals with higher health literacy. Additional studies are needed to further explore this finding.