Does Age Matter? Association Between Usual Source of Care and Hypertension Control in the US Population: Data From NHANES 2007-2012

The positive role of having a usual source of care (USOC) on the receipt of preventative services is known. However, associations between USOC and hypertension control and the differential association across age groups is unknown in the US population. We used data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2012. Multivariable logistic regression was used to evaluate the association between having a USOC and hypertension control. The differential effect of USOC on hypertension control by age was assessed using predicted marginal effects across age groups in the multivariable logistic model. In adjusted analyses, those with a USOC had higher odds of hypertension control (odds ratio = 3.89, 95% confidence interval (CI): 2.15-6.98). The marginal effect of having a USOC is associated with a 30 percentage point higher probability of controlled blood pressure compared to those without a USOC (marginal probability = 0.30, 95% CI: 0.19-0.41). The marginal effect of USOC on hypertension control varied by age groups, with a statistically significantly lower marginal effect of USOC on hypertension seen among those older than 74 years of age (marginal probability = 0.27, 95% CI: 0.18-0.36) and younger than 35 years of age (marginal probability = 0.23, 95% CI: 0.14-0.33). Having a USOC is significantly associated with improved hypertension control in the US population. The variation in the association across age groups has important implications in targeting age-specific antihypertensive strategies to reduce the burden of hypertension in the US population.