Urban Areas in US are Associated with Lower Rates of Hypertension Medication Adherence, New Study Finds

Americans with hypertension (HTN) living in large urban areas have lower rates of medication adherence and are less likely to have a primary care provider than those living in smaller rural areas, according to new research presented at the American Heart Association’s (AHA) Hypertension Scientific Sessions 2022, held September 7-10 in San Diego.

Results from the cross-sectional study also show that the Western US is correlated with a lower adherence rate compared to other regions.

"You might think people living in very rural areas, because they have less access to care and a lack of public transportation, would have lower adherence rates," said lead author Samantha Schoenl, a fourth-year medical student at the Medical College of Georgia in Augusta, in an AHA press release. "And in urban environments, you'd think having more transportation options would help, but that's not what the data showed."

Medication adherence can be difficult for the 47% of US adults with hypertension due to its benign course so Schoenl and colleagues aimed to characterize the difference in HTN medication adherence between major US regions and the incongruity between urban and rural communities.

Investigators analyzed data from 11 494 persons—representing over 71 million US adults—with a diagnosis of HTN. As variables they included HTN medication adherence, access to regular care, household region, and urban-rural classification as defined by the National Center for Health Statistics.Data was obtained from the 2020 National Health Interview Survey conducted by the Centers for Disease Control and Prevention.

The team found that HTN medication adherence was 75.6% in large urban, 81.5% in large fringe urban, 81.1% in medium urban, and 83.3% in nonmetro areas (p<.001).

Medication adherence across US regions (ie, Northeast, South, Midwest, and West) was statistically significant (p<.01), according to the study abstract. On logistic regression, the West had a significantly lower adherence rate at 76.6% when compared to other regions (odds ratio [OR], 0.69; 95% CI, 0.56–0.85; p<.05]. The odds increased further when researchers adjusted for covariates of body mass index, marital status, insurance status, race, and age [adjusted OR [aOR], 0.74; 95% CI 0.58–0.95; p<.05].

In addition, findings showed a correlation between medication adherence and access to primary care providers. Patients living in large urban areas were least likely to have a regular health care provider at 94.7%, followed by 95.9% in large fringe urban areas and 97% in medium urban and nonmetro areas (p<.01).

In the AHA release, Schoenl noted that access to health care can be affected by income, which she and her colleagues did not factor in. Also, persons living in cities tend to move more than those who live in rural communities and might have less continuity of care, explained Schoenl.

"The cause of non-adherence is very complex," said Khurram Nasir, MD, chief of cardiovascular prevention and wellness at Houston Methodist Hospital in Texas, in the release. Nasir, who was not involved in the current study, stated that the study should be replicated with the findings adjusted for income and education, another variable not considered in the analysis. Schoenl noted in the press release that her team plans to update their findings with such data in the final manuscript.

It should be noted that the current study is considered preliminary until the full results are published in a peer-reviewed journal.