Associations Between Social Determinants and Hypertension, Stage 2 Hypertension, and Controlled Blood Pressure Among Men and Women in the United States

Abstract

Background

Social determinants influence the development and control of hypertension.

METHODS

National Health and Nutrition Examination Survey (2011–2018) data for adults aged ≥18 included education, income, employment, race/ethnicity, healthcare access, marital status, and nativity status. Outcomes were hypertension (blood pressure [BP] ≥130/80 mm Hg or self-reported hypertension medication use), stage 2 hypertension (BP ≥140/90 mm Hg), and controlled BP (BP <130/80 mm Hg among those with hypertension). Poisson regression with robust variance estimates was used to examine associations between social determinants and outcomes, by sex.

RESULTS

The analysis included 21,664 adults (mean age 47.1 years), of whom 51% were women. After adjustment, hypertension and stage 2 hypertension prevalence remained higher among Black and Asian than White adults, regardless of sex. Blacks had lower prevalence of controlled BP than Whites. Compared with college graduates, men and women with less education had a higher prevalence of hypertension and stage 2 hypertension. Men (prevalence ratio [PR]: 0.28, 95% confidence interval: 0.16–0.49) and women (PR: 0.44, 0.24–0.78) with no routine place for healthcare had lower prevalence of controlled BP than those who had a routine place for healthcare. Uninsured men (PR: 0.66, 0.44–0.99) and women (PR: 0.67, 0.51–0.88) had lower prevalence of controlled BP than those insured. Unemployed or unmarried women were more likely to have controlled BP than employed or married women.

Conclusions

Social determinants were independently associated with hypertension outcomes in US adults. Policy interventions are urgently needed to address healthcare access and education, and eliminate racial disparities.

Graphical Abstract

Graphical Abstract.

Hypertension is an established risk factor for cardiovascular disease (CVD) and contributes to 1 in 7 cardiovascular-related deaths.¹ Costs associated with hypertension in the United States for 2014–2015 were approximately $56 billion.¹ The age-adjusted prevalence of hypertension (≥130/80 mm Hg or taking medication to lower blood pressure [BP]) increased from 41.7% in 2013–2014 to 45.4% in 2017–2018 with substantial disparities by sex and race/ethnicity.^1,2 Despite the well-documented burden and costs associated with uncontrolled BP, BP control (<140/90 mm Hg) worsened from 53.8% in 2013–2014 to 43.7% in 2017–2018.³ As such, the National Hypertension Control Roundtable was convened to improve national hypertension control to at least 80% by 2025 and reduce disparities in hypertension.⁴

Disparities in hypertension and hypertension-related outcomes among racial and ethnic minority groups are well established.⁵ Factors such as social disadvantage, neighborhood conditions, low socioeconomic status, and disparities in healthcare resources are associated with excess CVD burden.^6,7 Collectively, these factors are considered social determinants of health, which is defined by the World Health Organization (WHO) as “the circumstances in which people are born, grow, live, work, and age, and the systems put in place to deal with illness.”  ⁸ The five key determinants identified by the WHO include economic stability, education, social and community context, health and healthcare, neighborhood, and built environment. An American Heart Association (AHA) scientific statement⁹ was published to increase awareness of social determinants as important predictors of CVD and associated risk factors. However, understanding of the influence of these social determinants on hypertension outcomes among US adults is inadequate.

The objective of this study is to examine the associations between social determinants (education, income, employment, race/ethnicity, healthcare access, marital status, and nativity status) and hypertension, stage 2 hypertension, and controlled BP among US adults after controlling for traditional CVD risk factors.

METHODS

The National Health and Nutrition Examination Survey (NHANES) conducted by the National Center for Health Statistics (NCHS) is a cross-sectional, nationally representative survey of the civilian noninstitutionalized population in the United States. NHANES uses a complex, stratified, multistage sampling design. Participants are initially interviewed in their homes, where information on their sociodemographic background, medical and family histories are obtained. Participants subsequently visit a mobile examination center (MEC), where standardized physical examinations are performed to collect anthropometric, laboratory, and physical measures. The full methodology of NHANES is published elsewhere.^10,11 Pooled data from the 2011–2018 continuous NHANES data releases were used to increase the precision of our estimates. All participants provided informed consent, and ethical approval was obtained through the Research Ethics Review Board of NCHS. For the analyses, 23,825 individuals aged >18 years were examined in the MEC for the years 2011–2018. Of those examined, 2,179 persons were excluded due to pregnancy (n = 247), missing systolic blood pressure (SBP) or diastolic blood pressure (DBP) (n = 1,914), or current treatment with antihypertensive medications (n = 560). The final analytic sample included 21,664 participants.

Covariates

Demographic characteristics

Age was categorized as: 18–39, 40–59, 60–79, or ≥80 years. Sex was categorized as man or woman.

Social determinants of hypertension outcomes

Social determinants were selected from the AHA’s Scientific Statement on Social Determinants of Risk and Outcomes for Cardiovascular Disease which include socioeconomic position, race/ethnicity, social support, culture, and language, access to care and residential environment.⁹ Social determinants were assessed using the NHANES household questionnaires.¹² Race/ethnicity was categorized as Hispanic, non-Hispanic (NH) White, NH Black, and NH Asian. Education was categorized as ≤high school education, some college, and ≥college graduate. Employment status was categorized as employed or unemployed. Access to a routine place for healthcare was dichotomized as Yes or No and determined from the question “Is there a place that you usually go when you are sick or need advice about your health?” Health insurance status was determined from responses to the question “Are you covered by health insurance or some other kind of healthcare plan?” Family income-to-poverty ratio was calculated as the ratio of a family’s income to the appropriate poverty guidelines.¹³ Four categories of approximately equal numbers of participants were constructed: <1.00, 1.00–1.99, 2.00–3.99, and ≥4.00. Marital status was considered a proxy measure of social support^14,15 and categorized as married/cohabitating or not married/cohabitating. Nativity status was categorized as US-born vs. foreign-born.¹⁶ Neighborhood-level social determinants are not publicly available, and census tract is considered a restricted-use variable to ensure confidentiality of participants and therefore are not included in the analysis. The social determinants included in this study reflect individual-level factors.

Hypertension risk factors

Traditional risk factors for hypertension were included as covariates in the analyses and included smoking, body mass index, and leisure-time physical activity. Smoking status was categorized as never smoker, current smoker, and former smoker. Body mass index was categorized as normal (18.5 to 24.9 kg/m²), overweight (25 to 29.9 kg/m²), and Class 1 obesity (≥30 to <35 kg/m²), Class 2 obesity (≥35 to <40 kg/m²), and Class 3 obesity (≥40 kg/m²).¹⁷ Diagnosed diabetes was defined based on participant self-report of ever having been told by a doctor or healthcare provider that he/she has diabetes or a glycated hemoglobin ≥6.5%.¹² Chronic kidney disease was defined as estimated glomerular filtration rate <60 ml/min/1.73 m² using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation¹⁸ or albumin-to-creatinine ratio ≥30 mg/g.¹⁸

Outcomes

BP measurements were obtained during a single MEC examination visit using a standardized protocol¹¹ The mean of up to 3 brachial SBP and DBP readings was used as the participant’s SBP and DBP values. Hypertension was defined as SBP ≥130 or DBP ≥80 mm Hg per the 2017 Hypertension Clinical Guidelines⁵ or current use of antihypertensive medication.² Stage 2 hypertension was defined as SBP ≥140 or DBP ≥90 mm Hg (regardless of medication use). Controlled BP was defined as SBP <130 and DBP <80 mm Hg among adults with hypertension.

Statistical analysis

Sampling weights were applied to the data analysis to obtain nationally representative estimates of the US adult population and per NCHS guidelines to account for the complex sampling design.¹² Sample characteristics were examined and stratified by sex because of established sex differences in hypertension prevalence^2,19 and compared characteristics among men and women using chi-squared tests for categorical variables and t-tests for continuous variables. The prevalence of hypertension and stage 2 hypertension was age adjusted by the direct method using the age groups of 18–39, 40–59, 60–79, and ≥80 years with weights of 0.4203, 0.3572, 0.1776, and 0.0449, respectively, for the 2000 US standard population. Furthermore, the prevalence of controlled BP was calculated using Crim et al.’s²⁰ uniform surveillance definition of hypertension control where the prevalence of controlled BP is age adjusted to the subpopulation of adults who had hypertension in the 2007–2016 NHANES cycles, rather than the standard age adjustment to the US population. This approach accounts for the higher prevalence of hypertension among older adults.²¹ Thus, the age-adjusted prevalence of controlled BP was calculated using age groups of 18–39, 40–59, 60–79, and ≥80 years with weights of 0.1661, 0.4061, 0.3446, and 0.0832, respectively.²⁰ Next, unadjusted associations of social determinants with the outcomes of hypertension prevalence, stage 2 hypertension, and controlled BP were examined using Poisson regression with robust variance estimates to calculate prevalence ratios (PRs). Unadjusted and adjusted PRs with a 95% confidence interval (CI) which excluded 1 were considered statistically significant. Finally, multivariable associations of social determinants and hypertension, stage 2 hypertension, and controlled BP, adjusting for other social determinants, demographic characteristics, and clinical risk factors were examined. Interaction terms were created between sex and the social determinants on the respective outcomes. Since some of the interactions were statistically significant, stratified outcomes were presented for consistency. Results were considered statistically significant at P values <0.05. All analyses were conducted using Stata/S.E. version 16.1 (StataCorp, College Station, TX).

RESULTS

Sample characteristics

A total of 21,664 participants were included; mean age (±SE) was 47.1 (±0.3) years and 51% were female (Table 1). With respect to social determinants, 67%, 12%, 6%, and 16% were NH White, NH Black, NH Asian, and Hispanic, respectively; 48% were unmarried, 69% had less than a college education, 15% lived below the poverty level, 18% were foreign-born, 17% had no routine place for healthcare, and 16% had no health insurance. The prevalence of diabetes and chronic kidney disease was 12% and 15%, respectively. There were sex differences in all sample characteristics except nativity status. Although women had higher education levels, they were more likely to be unemployed and live below the poverty line than men. Women were also more likely to have healthcare access with higher insurance prevalence and more frequent visits to a healthcare provider in the previous year than men.

Table 1.

Characteristics of adults in 2011–2018 National Health and Nutrition Examination Surveys by sex, N = 21,664

	N	Male (N = 10,658)	Female (N = 11,006)	P valuea
		% (95% CI)
Age categories
18–39 years	7,792	51.7 (50.6–52.8)	48.3 (47.2–49.4)`	<0.001
40–59 years	6,837	49.0 (47.5–50.5)	51.0 (49.5–52.6)
60–79 years	5,732	46.7 (45.2–48.2)	53.3 (51.8–54.8)
≥80 years	1,303	39.4 (36.9–42.0)	60.6 (58.0–63.1)
Race/ethnicity
Non-Hispanic White	7,901	49.2 (48.1–50.3)	50.8 (49.7–51.9)	<0.001
Hispanic	5,245	50.6 (49.2–52.0)	49.4 (48.0–50.8)
Non-Hispanic Black	4,968	45.7 (44.5–46.9)	54.3 (53.1–55.5)
Non-Hispanic Asian	2,736	47.2 (45.7–48.7)	52.8 (51.3–54.3)
Marital status
Married	11,356	51.5 (50.8–52.2)	48.5 (47.8–49.2)	<0.001
Not married	10,308	46.3 (45.1–47.6)	53.7 (52.4–54.9)
Education
College graduate and above	5,117	48.9 (47.5–50.3)	51.1 (49.7–52.6)	<0.001
Some college	6,312	45.7 (44.1–47.2)	54.4 (52.8–55.9)
High school	9,104	51.8 (50.4–53.2)	48.2 (46.8–49.6)
Family income-to-poverty ratio (FIPR)
FIPR ≥4	4,085	51.8 (50.5–53.0)	48.3 (47.0–49.5)	<0.001
FIPR 2–3.99	5,054	49.4 (48.1–50.7)	50.6 (49.4–51.9)
FIPR 1–1.99	5,231	47.0 (45.34–48.6)	53.0 (51.4–54.7)
FIPR <1	4,472	45.2 (43.6–46.8)	54.8 (53.2–56.4)
Health insurance status
Has health insurance	17,426	47.7 (46.9–48.5)	52.3 (51.5–53.1)	<0.001
No health insurance	4,194	46.1 (54.2–57.9)	43.9 (42.1–45.8)
Routine place for healthcare
Yes	17,879	45.8 (44.9–46.6)	54.2 (53.4–55.1)	<0.001
No	3,784	65.3 (63.4–67.1)	34.7 (32.9–36.6)
Nativity status
US-born	15,128	48.9 (48.1–49.8)	51.1 (50.2–51.9)	0.40
Foreign-born	6,526	49..6 (48.2–51.0)	50.4 (49.0–51.8)
Diagnosed diabetes
No	18,234	48.6 (47.9–49.4)	51.4 (50.6–52.1)	0.0146
Yes	3,430	52.1 (49.4–54.8)	47.9 (45.2–50.6)
Smoking status
Never smoker	12,429	42.7 (41.6–43.8)	57.3 (56.2–58.4)	<0.001
Former smoker	4,221	57.9 (55.8–59.9)	42.1 (40.1–44.2)
Current smoker	4,089	55.4 (53.4–57.5)	44.6 (42.5–46.6)
BMI categories
Normal	6,080	44.5 (42.9–46.1)	55.5 (53.9–57.1)	<0.001
Overweight	6,760	55.7 (54.2–57.2)	44.3 (42.8–45.8)
Class 1 obesity	4,443	53.3 (51.1–55.4)	46.7 (44.6–48.9)
Class 2 obesity	2,077	43.6 (40.5–46.8)	56.4 (53.2–59.5)
Class 3 obesity	1,642	35.6 (32.1–39.3)	64.4 (60.7–67.9)
Chronic kidney disease
No	16,554	50.1 (49.2–51.0)	49.9 (49.0–50.8)	<0.001
Yes	3,536	43.9 (41.3–46.5)	56.12 (53.5–58.7)
Survey cycle
2011–2012	5,304	49.4 (47.8–51.0)	50.6 (49.0–52.2)	0.95
2013–2014	5,657	48.9 (47.6–50.1)	51.1 (49.9–52.4)
2015–2016	5,504	48.9 (47.7–50.1)	51.1 (49.9–52.3)
2017–2018	5,199	49.1 (47.2–51.0)	50.9 (49.0–52.8)

Abbreviations: ACR, albumin-to-creatinine ratio; BMI, body mass index; CI, confidence interval; CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration; eGFR, estimated glomerular filtration rate.

^a P values are from chi-squared tests; CKD: eGFR <60 ml/min/1.73 m² or ACR ratio >30 mg/g using CKD-EPI equation; BMI: normal: 18.5–24.9 kg/m², overweight: 25–29.9 kg/m², and Class 1 obesity: ≥30 to <35 kg/m², Class 2 obesity: ≥35 to <40 kg/m², and Class 3 obesity: ≥40 kg/m².

Prevalence of hypertension, stage 2 hypertension, and controlled BP

The age-adjusted prevalence of hypertension, stage 2 hypertension, and controlled BP is described in Figure 1. The overall age-adjusted prevalence of hypertension was 44% with a higher prevalence among men (48%) than women (39%) (P < 0.001). The prevalence of stage 2 hypertension was 15%, with a higher prevalence among men (16%) than women (13%) (P < 0.001). Among all those with hypertension, the prevalence of controlled BP was 22%, and higher among women (24%) than men (21%) (P < 0.001).

Figure 1.

Prevalence of hypertension, stage 2 hypertension, and controlled blood pressure. Hypertension defined as systolic blood pressure greater than or equal to 130 mm Hg or diastolic blood pressure greater than or equal to 80 mm Hg, or currently taking medication to lower blood pressure. Stage 2 hypertension defined as systolic blood pressure ≥140 or diastolic blood pressure ≥90 among all adults. Age-adjusted prevalence of hypertension and stage 2 hypertension was calculated using age groups of 18–39, 40–59, 60–79, and 80+ years with weights of 0.4203, 0.3572, 0.1776, and 0.0449, respectively, for the 2000 US standard population. Controlled blood pressure defined as systolic blood pressure <130 and diastolic blood pressure <80 among adults with hypertension, age adjusted using age groups 18–39, 40–59, 60–79, and 80+ years with weights of 0.1661, 0.4061, 0.3446, and 0.0832, respectively.

Social determinants of hypertension, stage 2 hypertension, and controlled BP, stratified by sex

Unadjusted associations

The unadjusted sex-specific associations are described in Table 2. Among men, NH Blacks had higher prevalence of hypertension (PR: 1.11, 95% CI 1.05–1.18) and stage 2 hypertension (PR: 1.41, 95% CI 1.24–1.61) than NH Whites, while Hispanic and NH Asians had lower prevalence of hypertension than NH Whites. All 3 racial and ethnic minority groups had lower prevalence of controlled BP than NH Whites, regardless of sex. Men and women who had no routine place for healthcare or no health insurance had a lower prevalence of controlled BP than those who had a routine place for healthcare or were insured. Men and women who were not college graduates had a higher prevalence of hypertension and stage 2 hypertension than those who were college graduates. Men and women who were unemployed had a higher prevalence of hypertension and stage 2 hypertension, but among those with hypertension, a higher prevalence of control than those who were employed. Men who were not married had a lower prevalence of hypertension, stage 2 hypertension, and controlled BP than those who were married. There was no association between marital status and hypertension outcomes among women. Foreign-born men and women had lower prevalence of hypertension, stage 2 hypertension, and controlled BP than US-born men and women.

Table 2.

Unadjusted associations between social determinants and hypertension, stage 2 hypertension, and controlled blood pressure among US adults, stratified by sex in the 2011–2018 National Health and Nutrition Examination Surveys

	Men			Women
	Hypertension	Stage 2 hypertension	Controlled blood pressure	Hypertension	Stage 2 hypertension	Controlled blood pressure
	Prevalence ratio (95% CI)			Prevalence ratio (95% CI)
Race and Hispanic status
Non-Hispanic White	1.0	1.0	1.0	1.0	1.0	1.0
Hispanic	0.81 (0.75–0.87)	0.78 (0.67–0.93)	0.54 (0.43–0.68)	0.73 (0.68–0.79)	0.80 (0.70–0.91)	0.80 (0.67–0.96)
Non-Hispanic Black	1.11 (1.05–1.18)	1.41 (1.24–1.61)	0.72 (0.61–0.84)	1.22 (1.15–1.28)	1.43 (1.27–1.62)	0.85 (0.74–0.98)
Non-Hispanic Asian	0.89 (0.82–0.96)	1.01 (0.87–1.18)	0.57 (0.44–0.75)	0.85 (0.77–0.94)	0.88 (0.73–1.05)	0.63 (0.51–0.78)
Routine place for healthcare
Yes	1.0	1.0	1.0	1.0	1.0	1.0
No	0.67 (0.62–0.71)	0.70 (0.60–0.81)	0.12 (0.07–0.20)	0.55 (0.49–0.63)	0.57 (0.46–0.70)	0.40 (0.25–0.66)
Family income–poverty ratio
FIPR ≥4	1.0	1.0	1.0	1.0	1.0	1.0
FIPR 2–3.99	1.00 (0.92–1.09)	0.99 (0.83–1.19)	0.87 (0.72–1.06)	1.08 (0.98–1.19)	1.22 (1.01–1.47)	0.92 (0.74–1.14)
FIPR 1–1.99	0.97 (0.89–1.06)	1.11 (0.92–1.33)	0.73 (0.61–0.88)	1.13 (1.02–1.25)	1.36 (1.12–1.65)	0.97 (0.77–1.23)
FIPR <1	0.89 (0.81–0.97)	1.02 (0.82–1.27)	0.64 (0.50–0.81)	0.94 (0.85–1.05)	1.78 (0.97–1.43)	0.92 (0.73–1.15)
Education
College graduate and above	1.0	1.0	1.0	1.0	1.0	1.0
Some college	1.10 (1.01–1.20)	1.14 (0.99–1.32)	0.94 (0.75–1.18)	1.31 (1.19–1.43)	1.36 (1.13–1.64)	1.16 (0.96–1.41)
High school	1.10 (1.02–1.18)	1.26 (1.08–1.46)	0.93 (0.76–1.13)	1.47 (1.34–1.62)	1.90 (1.58–2.29)	1.00 (0.82–1.21)
Employment status
Employed	1.0	1.0	1.0	1.0	1.0	1.0
Unemployed	1.32 (1.28–1.41)	1.56 (1.39–1.75)	1.63 (1.41–1.89)	1.60 (1.50–1.70)	2.41 (2.11–2.76)	1.24 (1.08–1.44)
Insurance status
Insured	1.0	1.0	1.0	1.0	1.0	1.0
Uninsured	0.75 (0.68–0.83)	0.79 (0.65–0.95)	0.32 (0.23–0.44)	0.67 (0.61–0.73)	0.68 (0.57–0.82)	0.57 (0.43–0.76)
Married
Yes	1.0	1.0	1.0	1.0	1.0	1.0
No	0.76 (0.72–0.81)	0.85 (0.75–0.96)	0.67 (0.54–0.82)	0.78 (0.93–1.03)	1.03 (0.91–1.16)	1.10 (0.95–1.28)
Nativity status
US-born	1.0	1.0	1.0	1.0	1.0	1.0
Foreign-born	0.87 (0.82–0.92)	0.88 (0.78–1.00)	0.60 (0.50–0.73)	0.81 (0.76–0.87)	0.87 (0.77–0.99)	0.75 (0.62–0.91)

Hypertension defined as systolic blood pressure ≥130 mm Hg, diastolic blood pressure ≥80 mm Hg or current use of antihypertensive medication. Stage 2 hypertension defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg among all adults, which excludes adults with systolic blood pressure between 130 and 139 mm Hg or diastolic blood pressure between 80 and 89 mm Hg. Controlled blood pressure defined as systolic blood pressure <130 mm Hg and diastolic blood pressure <80 mm Hg among adults with hypertension. Bold values P < 0.05. Abbreviations: CI, confidence interval; FIPR, family income-to-poverty ratio.

Adjusted associations

We observed sex differences in the associations between social determinants and hypertension outcomes in the multivariable analyses. After adjusting for other social determinants, demographic characteristics, and clinical risk factors, NH Asian and NH Black men and women had a higher prevalence of hypertension and stage 2 hypertension and a lower prevalence of controlled BP than NH White men and women (Table 3). Hispanic women had higher prevalence of stage 2 hypertension (PR: 1.24, 95% CI 1.04–1.48) only after adjustment for risk factors and covariates. Among men (PR: 0.28, 95% CI 0.16–0.49) and women (PR: 0.44, 95% CI 0.24–0.78), those with no routine place for healthcare had lower prevalence of controlled BP than those with a routine place for healthcare. Men and women with less than college education had higher prevalence of hypertension and stage 2 hypertension and those with at least college education. Among women, those who were unemployed were more likely to have stage 2 hypertension (PR: 1.18, 95% CI 1.01–1.38) and controlled BP (PR: 1.22, 95% CI 1.04–1.44) than those who were employed; there was no association among men. Unmarried women were more likely to have controlled BP (PR: 1.23, 95% CI 1.05–1.43) than married women; there was no association among men. After adjustment, there were no differences in hypertension prevalence and BP control by nativity status.

Table 3.

Adjusted associations between social determinants and hypertension, stage 2 hypertension, and blood pressure control among US adults, stratified by sex, in the 2011–2018 National Health and Nutrition Examination Surveys

	Men			Women
	Hypertension	Stage 2 hypertension	Controlled blood pressure	Hypertension	Stage 2 hypertension	Controlled blood pressure
	Prevalence ratio (95% CI)			Prevalence ratio (95% CI)
Social determinants
Race and Hispanic status
Non-Hispanic White	1.0	1.0	1.0	1.0	1.0	1.0
Hispanic	0.93 (0.85–1.01)	0.92 (0.71–1.18)	0.83 (0.62–1.10)	0.97 (0.90–1.05)	1.24 (1.04–1.48)	0.92 (0.75–1.14)
Non-Hispanic Black	1.19 (1.11–1.27)	1.50 (1.29–1.75)	0.78 (0.66–0.93)	1.28 (1.22–1.34)	1.79 (1.56–2.05)	0.80 (0.67–0.94)
Non-Hispanic Asian	1.17 (1.05–1.30)	1.48 (1.15–1.92)	0.79 (0.54–1.13)	1.33 (1.16–1.54)	1.40 (1.08–1.82)	0.91 (0.64–1.28)
Routine place for healthcare
Yes	1.0	1.0	1.0	1.0	1.0	1.0
No	0.91 (0.84–0.99)	0.99 (0.79–1.23)	0.28 (0.16–0.49)	0.93 (0.82–1.06)	1.03 (0.78–1.36)	0.44 (0.24–0.78)
Family income–poverty ratio
FIPR ≥4	1.0	1.0	1.0	1.0	1.0	1.0
FIPR 2–3.99	1.02 (0.94–1.11)	0.95 (0.78–1.15)	0.92 (0.72–1.18)	1.02 (0.94–1.11)	1.00 (0.85–1.19)	0.92 (0.72–1.16)
FIPR 1–1.99	1.01 (0.93–1.10)	1.07 (0.85–1.36)	0.80 (0.62–1.04)	1.01 (0.92–1.10)	1.02 (0.84–1.24)	0.93 (0.72–1.18)
FIPR <1	1.04 (0.95–1.14)	1.10 (0.85–1.41)	0.79 (0.59–1.07)	0.99 (0.90–1.08)	1.08 (0.88–1.34)	0.90 (0.70–1.18)
Education
College graduate and above	1.0	1.0	1.0	1.0	1.0	1.0
Some college	1.09 (1.00–1.20)	1.04 (0.87–1.24)	1.08 (0.86–1.37)	1.15 (1.06–1.25)	1.24 (1.03–1.49)	1.01 (0.80–1.28)
High school	1.09 (1.00–1.19)	1.14 (0.96–1.36)	1.14 (0.90–1.44)	1.17 (1.09–1.26)	1.32 (1.09–1.61)	0.91 (0.71–1.17)
Employment status
Employed	1.0	1.0	1.0	1.0	1.0	1.0
Unemployed	1.02 (0.95–1.09)	0.98 (0.81–1.18)	1.16 (0.95–1.41)	1.05 (0.99–1.11)	1.18 (1.01–1.38)	1.22 (1.04–1.44)
Insurance status
Insured	1.0	1.0	1.0	1.0	1.0	1.0
Uninsured	0.92 (0.84–1.00)	0.97 (0.76–1.23)	0.66 (0.44–0.99)	0.91 (0.83–0.99)	1.13 (0.93–1.38)	0.67 (0.51–0.88)
Married
Yes	1.0	1.0	1.0	1.0	1.0	1.0
No	0.99 (0.93–1.06)	1.10 (0.94–1.28)	0.94 (0.75–1.17)	1.02 (0.96–1.08)	0.95 (0.82–1.09)	1.23 (1.05–1.43)
Nativity status
US-born	1.0	1.0	1.0	1.0	1.0	1.0
Foreign-born	0.99 (0.89–1.08)	1.01 (0.80–1.26)	0.86 (0.64–1.15)	0.91 (0.81–1.01)	0.89 (0.74–1.07)	0.86 (0.64–1.15)
Covariates
Age categories
18–39 years	1.0	1.0	1.0	1.0	1.0	1.0
40–59 years	1.71 (1.56–1.88)	2.40 (2.00–2.87)	4.10 (2.64–6.38)	3.19 (2.79–3.64)	4.34 (3.36–5.60)	1.57 (1.17–2.12)
60–79 years	2.03 (1.84–2.23)	3.32 (2.73–4.03)	5.15 (3.26–8.14)	4.55 (3.94–5.26)	8.56 (6.27–11.68)	1.71 (1.26–2.32)
≥80 years	2.33 (2.09–2.61)	4.95 (3.68–6.67)	4.52 (2.64–7.74)	5.63 (4.82–6.57)	14.83 (10.65–20.65)	0.99 (0.63–1.54)
BMI categories
Normal	1.0	1.0	1.0	1.0	1.0	1.0
Overweight	1.36 (1.21–1.53)	1.37 (1.13–1.66)	1.40 (1.02–1.92)	1.30 (1.19–1.43)	0.98 (0.83–1.16)	1.32 (1.03–1.68)
Class 1 obesity	1.57 (1.40–1.75)	1.62 (1.31–2.02)	1.42 (1.04–1.94)	1.48 (1.35–1.62)	0.93 (0.77–1.13)	1.64 (1.30–2.07)
Class 2 obesity	1.83 (1.59–2.11)	2.07 (1.58–2.72)	1.54 (1.09–2.17)	1.65 (1.50–1.82)	1.21 (0.99–1.48)	1.76 (1.35–2.29)
Class 3 obesity	2.09 (1.82–2.40)	2.88 (2.22–3.73)	1.29 (0.84–1.99)	2.00 (1.81–2.22)	1.46 (1.17–1.82)	1.54 (1.17–2.03)
Diabetes
No	1.0	1.0	1.0	1.0	1.0	1.0
Yes	1.14 (1.07–1.22)	1.01 (0.83–1.23)	1.31 (1.05–1.63)	1.13 (1.06–1.20)	0.94 (0.81–1.08)	1.40 (1.15–1.71)
Smoking status
Never smoker	1.0	1.0	1.0	1.0	1.0	1.0
Former smoker	1.06 (0.99–1.14)	0.99 (0.85–1.16)	1.07 (0.89–1.29)	1.05 (0.97–1.13)	1.13 (0.98–1.29)	1.00 (0.85–1.16)
Current smoker	1.03 (0.94–1.12)	1.05 (0.91–1.22)	1.20 (0.90–1.61)	1.11 (1.02–1.22)	1.06 (0.85–1.33)	1.19 (1.10–1.41)
Chronic kidney disease
No	1.0	1.0	1.0	1.0	1.0	1.0
Yes	1.20 (1.14–1.27)	1.42 (1.20–1.68)	1.11 (0.92–1.33)	1.21 (1.14–1.29)	1.57 (1.37–1.81)	0.97 (0.82–1.16)
Survey cycle
2011–2012	1.0	1.0	1.0	1.0	1.0	1.0
2013–2014	0.92 (0.84–1.01)	1.01 (0.81–1.27)	0.96 (0.81–1.15)	0.97 (0.90–1.03)	0.96 (0.77–1.19)	1.16 (0.89–1.51)
2015–2016	0.97 (0.88–1.07)	1.10 (0.89–1.35)	0.92 (0.72–1.17)	0.99 (0.92–1.07)	1.01 (0.83–1.22)	1.01 (0.74–1.36)
2017–2018	1.01 (0.91–1.12)	1.21 (0.99–1.49)	0.75 (0.60–0.94)	0.99 (0.91–1.08)	1.28 (1.05–1.56)	0.83 (0.63–1.10)

Hypertension defined as systolic blood pressure ≥130 mm Hg, diastolic blood pressure ≥80 mm Hg, or current use of antihypertensive medication. Stage 2 hypertension defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg among all adults, which excludes adults with systolic blood pressure between 130 and 139 mm Hg or diastolic blood pressure between 80 and 89 mm Hg. Controlled blood pressure defined as systolic blood pressure <130 mm Hg and diastolic blood pressure <80 mm Hg among adults with hypertension. Bold values P < 0.05. Abbreviations: BMI, body mass index; CI, confidence interval; FIPR, family income-to-poverty ratio.

Discussion

In this cross-sectional analysis of nationally representative survey data, social determinants of health were independently associated with the prevalence of hypertension, stage 2 hypertension, and controlled BP. After adjusting for other social determinants, demographic factors, and clinical characteristics, NH Black race was associated with a higher prevalence of hypertension and stage 2 hypertension, and a lower prevalence of controlled BP compared with NH White race. Adults who were not college graduates had a higher prevalence of hypertension. Hypertension and stage 2 hypertension prevalence were higher in NH Asian men and women compared with NH White men and women. Stage 2 hypertension prevalence was higher in Hispanic than NH White women. The prevalence of controlled BP was lower in uninsured men and women. Women who were unemployed or unmarried were more likely to have controlled BP than their counterparts who were employed or married; similar associations were not observed among men.

The finding that NH Black adults have higher hypertension prevalence and lower prevalence of controlled BP than NH Whites, even after controlling for other factors is striking, but unfortunately not surprising. These differences do not likely reflect biological or genetic differences; rather, the effects of systemic and structural racism.^22,23 The AHA has recently acknowledged structural racism as “a fundamental cause of health and disparities in cardiovascular disease.”  ²⁴ Racism, not race, is the social determinant that must be intervened on at the individual, interpersonal, and institutional levels.²² Structural racism in the United States has contributed to persistent racial inequalities, particularly between Black and White people. For instance, Blacks are more likely to reside in socioeconomically deprived and racially segregated neighborhoods that are characterized by poor housing quality, environmental exposures, and food deserts contribute to CVD risk and management.^9,25 These neighborhood-level factors likely interact with individual-level socioeconomic status²⁶ and contribute to worse hypertension outcomes among Blacks. The prevalence of hypertension was lower among Hispanic adults and among NH Asian adults in unadjusted analyses. However, after controlling for other factors, the prevalence of hypertension was higher among NH Asian adults as compared with NH Whites. Thus, it is essential that healthcare and public health professionals implement targeted and culturally tailored strategies to reduce the burden of hypertension among these populations. To deepen our understanding of hypertension prevalence and control by race/ethnicity, it is also necessary to consider the subgroups within these categories and the substantial heterogeneity which may exist.^27–29

This study showed a strong, inverse association between level of education and hypertension and stage 2 hypertension. Other studies have also documented a higher prevalence of hypertension and other CVD risk factors among those with lower educational attainment.³⁰ Education may be associated with hypertension through health literacy or health behaviors, as well as through other mechanisms such as employment opportunities or income. Associations with income level were not found after adjustment. Among women, unemployment was associated with a higher prevalence of stage 2 hypertension, but also a higher prevalence of controlled BP. While it is unclear whether the association with education reflects a more stable measure of socioeconomic status than employment or income or a mechanistic factor in the development of hypertension, it is notable given widening educational disparities in CVD mortality.³¹ Previous reports have recommended the investigation of novel markers of socioeconomic position to better understand its relationship with cardiovascular health than single measures.⁹

Our analysis has shown that healthcare access is a prerequisite to improve hypertension outcomes for all Americans. Among those with hypertension, those with no routine place for healthcare were less likely to have controlled BP than those with a routine place for healthcare. Also, both men and women without health insurance were less likely to have controlled BP. Together, these findings indicate that efforts to improve hypertension control that do not systematically address increasing access to a routine place for healthcare and affordable health insurance will likely fall short. Our results are consistent with Muntner et al.’s³ recent analysis of trends in controlled BP which demonstrated that BP control was less likely among those without health insurance and those without a usual healthcare facility. With disruptions in face-to-face visits as a result of the COVID-19 pandemic, telemedicine has emerged as a solution to improve access to care, including those with hypertension.³² However, it remains to be seen whether telehealth may narrow disparities in hypertension care or further exacerbate them. Self-measured BP monitoring has recently been offered as a safe and cost-effective solution to improve BP control by bringing hypertension care to the patients’ homes³³ and has the potential to narrow disparities in access to hypertension care.³⁴

Marital status was considered a proxy measure of social support, in line with previous studies.^14,15 Among women, being unmarried was independently associated with a higher prevalence of controlled BP. Prior studies have shown that although being married is associated with a lower incidence of CVD outcomes and mortality; there is effect modification according to sex where the beneficial effect is primarily observed among men.^35,36

As healthcare systems and healthcare professionals work to assess and address social determinants of health, our findings highlight several factors which may be particularly salient for improving prevention and management of hypertension. The COVID-19 pandemic and recent highly publicized racist acts have highlighted stark inequalities and galvanized the healthcare community.^37,38 The conversation has moved from what is the role of the healthcare system in addressing the social determinants, including systemic racism, to an understanding that the healthcare system can and should engage in advocating for a more just society.³⁹

Prior papers have offered targeted strategies to address social determinants including policy interventions, community-engaged research, and implementation research.^40,41 However, implementation of these strategies into clinical and public health practice remains elusive. To address the nonstandardized assessment of social determinants in clinical care, the Centers for Medicare and Medicaid Services has developed a brief tool to assess 5 domains of health-related social needs. The 2019 ACC/AHA Performance Measures for Adults with High Blood Pressure⁴² provided specific recommendations to assess and address social determinants, including utilization of standardized screening tools such as the Accountable Health Communities Screening Tool,⁴³ integration of social determinants in electronic health records, creation of partnerships with community-based organizations and pharmacies, training of the care delivery unit to address social determinants, and integration of community health workers into care delivery units.

This paper has some limitations. While the aim was to identify independent associations with social determinants, these factors do not occur in isolation but may interact to produce health inequalities. Intersectionality^44–46 provides a framework for understanding how multiple dimensions of social inequality such as gender, race, and socioeconomic status interact and increase the risk of hypertension or poor control of hypertension.⁴⁷ Because variables on the social determinants are self-reported in NHANES, there may be recall or social desirability bias. Neighborhood-level social determinants of health such as neighborhood deprivation, which is associated with incident hypertension²⁵ and racial disparities in hypertension outcomes,⁴⁸ was not included in this analysis. Furthermore, this study used multiple BP measurements are obtained on a single day by NHANES, which is not consistent with guidelines for diagnosing hypertension.⁴⁹ Thus, the results may be overestimated or underestimated due to masked or white-coat hypertension. The denominator for controlled BP was defined based on prescribed medications. However, nonpharmacologic treatment, including dietary modification and physical activity as considered treatment but was not included in the definition.

This study also has several strengths. The survey data are nationally representative of US adults. BP measurements are obtained using standardized procedures that were consistent across all survey cycles. Additionally, clinical risk factors for hypertension were assessed using standardized physical and laboratory measurements. Additional research is needed to examine the intersections of individual- and neighborhood-level social determinants and hypertension outcomes.

In a nationally representative sample, social determinants of health were independently associated with hypertension, stage 2 hypertension, and controlled BP. NH Black or Asian race was associated with a higher prevalence of hypertension and stage 2 hypertension, and NH Black race was associated with a lower prevalence of controlled BP. Additionally, poor healthcare access (no routine place for healthcare or health insurance) was associated a lower likelihood of controlled BP. Having less than a college education was associated with a higher prevalence of hypertension and stage 2 hypertension. To meaningfully reduce the burden of hypertension in the United States, policy interventions are urgently needed to address healthcare access, address education, and eliminate racial disparities.

FUNDING

Ruth-Alma Turkson-Ocran was supported by American Heart Association (17SFRN33590069). Kathryn Foti is supported by National Institutes of Health (NIH)/National Heart, Lung, and Blood Institute (NHLBI) grant T32 HL007024. Yvonne Commodore-Mensah is supported by National Institute of Health (NIH)/National Institute of Nursing Research(NINR) grant P30 NR018093. The funding sources had no role in the development of this manuscript.

DISCLOSURE

The authors declared no conflict of interest.