The Health Information National Trends Survey (HINTS) is a probability-based, nationally representative survey of US noninstitutionalized adults aged ≥18 years [30], sponsored by the US Department of Health and Human Services. HINTS has been administered approximately every 1-3 years since 2003, with the goal of collecting nationally representative data that track changes in health communication and information technology. The sample design for the 2017 HINTS 5, Cycle 1, consisted of a single-mode mail survey using the next-birthday method for respondent selection and comprised two stages. In the first stage, a stratified sample of addresses was selected from a file of residential addresses. In the second stage, one adult was selected within each sampled household. The sampling frame consisted of a database of addresses used by Marketing Systems Group to provide random samples of addresses. HINTS is approved by the Office of Management and Budget (approval number, 0925-0538), the office that reviews all federally sponsored surveys. Since the present study involves a secondary analysis of a publicly available dataset, it was exempt from institutional review board approval at the authors’ home institution. Full details about the HINTS methodology are available on the HINTS website [31].

The present study used a cross-sectional design to evaluate participant data from HINTS 5, Cycle 1 (N=3285). Survey responses were collected between January 25, 2017, and May 5, 2017, with complete data from 3191 respondents. The self-reported hypertension status was assessed using the question, “Has a doctor or other health professional ever told you that you had high blood pressure or hypertension (yes/no)?” Of the complete sample, approximately 1460 participants self-reported a history of hypertension (37.6% weighted prevalence).

Survey weights provided in the HINTS data were utilized to calculate weighted percentages of subject characteristics. To test for differences in outcomes across relevant patient characteristics, unadjusted chi-square tests were conducted on the weighted percent in agreement with various measures. Due to the survey weights, a Rao-Scott F-adjusted chi-square statistic was used, which yields a more conservative interpretation than the traditional Wald chi-square test used for unweighted analyses [34]. We used SAS software, version 9.4 of the SAS System, to conduct all analyses (SAS Institute Inc, Cary, NC), employing procedures that can account for the sampling design of HINTS, such as PROC SURVEYFREQ and PROC SURVEYREG. These procedures utilize the survey weights available in the HINTS data to obtain population-level point estimates and bootstrap accurate estimates of standard errors. To account for multiple comparisons, we applied methods to limit the false-discovery rate to 0.05 [35,36]. P values<.05 were considered statistically significant.

Compared to participants without a self-reported history of hypertension, those with a history of hypertension were significantly more likely to be older, male, and black and have received less formal education (Table 1).

Of the full sample, approximately 62%, 79%, and 22% of HINTS participants reported owning a tablet, smartphone, and basic mobile phone only, respectively, and 84% reported that they had either a tablet or smartphone. When evaluating device ownership by hypertension status, fewer participants with a history of hypertension reported owning a tablet (55% vs 66%) or smartphone (68% vs 86%) than those without a history hypertension. Additionally, those with a self-reported history of hypertension were almost twice as likely to own a basic mobile phone only as compared to those without a history of hypertension (16.3% vs 8.5%).

There were significant differences in device ownership by age and education, but not race or gender (Tables 2 and 3). For example, participants aged 18-24 years were more likely to own a tablet or smartphone than those aged 65-74 years (90% vs 51% and 90% vs 61%, respectively; P<.001). Of the people aged ≥75 years, the majority owned a basic mobile phone only (47%) compared to a tablet (29%) or smartphone (30%). As the level of education of participants increased, so did the likelihood of owning a smartphone or tablet. Compared to participants with less than a high school education, those with a college degree or higher education were more likely to own a tablet and smartphone (41% vs 71% and 47% vs. 87%, respectively, P<.001).

Significant differences were observed between participants with and those without a self-reported history of hypertension with regard to having health-related apps on their tablet or smartphone. For example, only 36.5% of participants with a history of hypertension reported having health-related apps compared to 49.2% of those without a history of hypertension (Figure 1; P<.001). Participants with a self-reported history of hypertension were also more likely to report that they did not know if they had a health-related app compared to those without a history of hypertension (ie, 6.2% vs 2.9%).

Among participants who owned a tablet or smartphone (Figure 2), those with a self-reported history of hypertension were less likely to report that their tablet or smartphone helped them reached a health-related goal like quitting smoking, losing weight, or increasing physical activity (62.6% vs 71.7%, P=.02). With regard to whether tablets or smartphones helped people make a decision about an illness or talk to health care providers, no differences were observed between participants with and those without a history of hypertension.

General trends were observed with regard to age when examining HINTS participants with a self-reported history of hypertension exclusively (Figure 3). Participants with health-related apps on their tablets or smartphones were mostly in age categories of 18-34 years (53%) and 35-49 years (51%), whereas percentages for age groups of 50-64, 65-74, and ≥75 years were lower (32%, 35%, and 21%, respectively). Participants who were ≥50 years of age were more likely to report that they did not know if they had any health-related apps on their tablets and smartphones.

The purpose of this study was to describe the prevalence of mobile device ownership and presence of health-related apps according to the self-reported hypertension status and sociodemographic factors in a nationally representative sample of US adults. We also examined whether smartphones and tablets helped people improve health goal achievement, medical decision making, and patient-provider communication. In summary, we found that people with a self-reported history of hypertension were less likely to own a smartphone or tablet, have health apps on their mobile devices, and report that smartphone and tablets helped them achieve a health-related goal compared to those without a self-reported history of hypertension. We also found that among people with a history of hypertension exclusively, smartphone ownership was associated with age and education, but not race or sex. Specifically, younger people and people with a college education are more likely to have smartphones, whereas older adults and people with a less formal education are more likely to have basic mobile phones.

A key finding from our study was that participants with a self-reported history of hypertension were significantly less likely to have health-related apps on their smartphones or tablets than those without a self-reported history of hypertension. This finding differs from other research that has shown no difference in health app downloads between people with and those without a chronic illness [18]. It is possible that people without a self-reported history of hypertension had other medical conditions for which they were using health-related apps (eg, type 2 diabetes) or they used general health-promotion apps more often (eg, apps to help track diet and physical activity). Researchers should be cautious about solely relying on health apps to support hypertension self-management by patients, as such reliance may cause them to overlook patients who do not use health apps. It is also possible that some patients were not using health-related apps due to limited eHealth literacy [37], attitudes about technology [38], or challenges with self-regulation and self-control [39,40]. Nevertheless, health-related apps may still be promising tools for a subset of the population that likes to engage with mHealth tools and prefers technology-based strategies for managing health.

Regarding the various ways that smartphones or tablets may help people, participants with a self-reported history of hypertension were less likely to report that their smartphones and tablets helped them reach a health-related goal like quitting smoking, losing weight, or increasing physical activity. This finding is notable, given that lifestyle behaviors can help people manage hypertension [41] and that tracking behaviors is a common feature of many health apps [42].

A strength of this study was our use of the HINTS data set. HINTS collects nationally representative data every few years from a large sample of US adults. This routine data collection allows researchers to monitor health communication trends over time. Given that many survey items are unique to HINTS and not available in other publicly available data sets, HINTS is a rich resource for evaluating various aspects of health behavior, information seeking, and trends in health communication. Despite its strengths, some limitations of this study must be noted. The hypertension status was self-reported in HINTS and not confirmed through a clinical diagnosis. Over- or underreporting of hypertension may have affected the results in either direction; however, we are unable to quantify the degree of over- or underreporting in the HINTS data set. We have no information about whether people who took the survey were currently receiving antihypertensive medication; the level of blood pressure control among medication users, which may have implications for health app use generally; and how people may use mobile devices for health and wellness. We are unable to distinguish between the various types of hypertension that a person may have experienced (eg, pregnancy related, primary hypertension, or secondary hypertension caused by another medical problem). We do not have information about when participants were ever informed that they had hypertension. It is possible that people who were recently informed (eg, within the last 12 months) would be more motivated to use health-related apps than people who have been living with hypertension for many years, or vice versa.

Given the small but growing amount of data on mHealth interventions for hypertension, our findings raise several questions for future investigation. For example, because there are many ways to support hypertension prevention and management (eg, pharmacological, nonpharmacological, mHealth, eHealth, print, and in person), more research is needed to determine patients’ preferences for various interventions and whether these preferences are associated with long-term engagement. For example, it is possible that some people may prefer telephone-based counseling or text messaging interventions over health-related apps when given the choice. Further evaluation of which behavioral theory (or combination of theories) best predicts hypertension-related mHealth intervention uptake is also needed. A recent systematic review noted that few mHealth interventions are based on behavioral theories [43]. Of the limited studies that highlight such theories, the Health Belief Model is commonly selected [43]. Moreover, as more health apps are developed, further examination of the features that matter most to patients and the quality of these components warrant more attention [44,45]. For example, Khalid et al found that privacy and ethics concerns, hidden costs, interface design, and app crashes were commonly reported complaints among mobile app users [46]. Finally, further research on the correlations between an individual’s eHealth literacy and mHealth use may inform how patients will respond to mHealth interventions for hypertension in the future [47].

Smartphone and tablet ownership and the presence of health apps on mobile devices are less common in people with a self-reported history of hypertension compared to those without a history of hypertension. Future studies should examine how to disseminate and implement mHealth interventions in the populations most affected by hypertension. Moving forward, a combination of novel mHealth interventions and traditional health communication strategies (eg, print, web based, in person, and telephone based) may be needed to reach a wide cross-section of patients with a self-reported history of hypertension.