Of the 1473 articles, 36 met the inclusion criteria (Figure 1). Studies are summarized in Multimedia Appendix 2. Twenty-five studies were from the United States, 4 studies from Australia [16-19], 4 from Canada [20-23], 1 from the United Kingdom [24], and 1 cross-cultural study that included people from Australia and India [25]. Studies included 34 cross-sectional survey designs, 1 mixed methods study [26], and 1 randomized controlled trial [27]. Sample sizes ranged from 22 [28] to 3258 [29] participants. The majority of studies (32/36, 88.9%) assessed digital health literacy using the eHealth Literacy Scale [30]. Across studies, variations on how digital health literacy scores were reported; some used a mean score (with higher scores indicating higher digital health literacy) and other studies used cutoff scores to determine those in high compared with low digital health literacy categories.

Five distinct population groups were identified across the studies. These included the general population, including older adults, patient groups, minority populations, and caregivers. Patient groups included people with HIV, cancer, chronic obstructive pulmonary disease (COPD), spinal injury, kidney disease, bipolar disorder, otolaryngological disease, orthopedic trauma, cardiovascular risk, diabetes, and transplant recipients. Minority groups included African Americans, Southeast Asians, adults in rural or remote regions, low-income groups, transgender and gender diverse, and young men who have sex with men. Caregivers included those of children with special health care needs, men with prostate cancer, and pediatric inpatients with subacute health conditions.

Twenty-seven (75%) studies were identified as examining associations between digital health literacy and sociodemographic characteristics, with varied findings. These are shown in Table 2 and Figure 2 and discussed in the following sections.

Twenty studies (20/36, 55.6%) examined associations between digital health literacy and health resource navigation distributed across all participant categories. Categories of health information engagement included eHealth information seeking; eHealth behaviors; access to and use of e-resources; use of health information sources; and eHealth satisfaction, and are shown in Table 3, Figure 3, and in the following sections.

Seventeen studies (17/36, 47.2%) examined associations between digital health literacy and health outcomes. The outcomes are grouped into 3 main categories: psychosocial health outcomes, chronic disease and health management behavioral outcomes, and perceived health status. These are shown in Table 4 and Figure 4 and described in the following sections.

This review advances our understanding of consumer digital health literacy through identifying and synthesizing recent literature that explored digital health literacy and its relationship with sociodemographic characteristics and health outcomes. The findings present mixed results regarding the relationship between digital health literacy and sociodemographic characteristics. However, studies broadly suggested that increased digital health literacy was positively associated with improved health outcomes. Based on the findings, we derive implications for practice in closing the digital health divide.

Education was the most common characteristic associated with digital health literacy. People with higher education levels were more likely to have increased literacy skills to better read and interpret web-based health information. Moreover, education has been shown to be a predictor of use of eHealth resources [16]. Education is considered a major determinant of health literacy, since educational levels often influence literacy skills, employment status and income, and, as such, enable access to better living circumstances and access to health care [53]. However, some individuals with higher education levels may still have inadequate health literacy [54]. Examining specific skills and knowledge, rather than sociodemographic characteristics alone, may offer a more comprehensive understanding of this relationship in future [53].

Some studies showed that older individuals were more likely to have lower digital health literacy than their younger counterparts, although other studies found no associations. Research has shown that digital health literacy decreases with age, and this is explained by age-related cognitive changes, decreased vision and hearing, reduced motor functioning, and decreased health status [55]. Notably, in our current review, studies with patient populations found no associations between age and digital health literacy levels, and 1 recent study [36] with older people had higher digital health literacy scores than their younger counterparts. Furthermore, in this study [36] the sample was younger and highly educated, and the findings could be related to increased use of digital products. People with chronic health conditions are likely required to engage with digital health resources to manage their health condition, which may account for their higher digital health literacy levels. Thus, while some findings suggest that older people require additional supports to improve digital health literacy capacities, given the varied outcomes, more in-depth analysis of these relationships between digital health literacy and age is recommended for future research including a full systematic review and meta-analysis. Findings showed predominantly no differences in digital health literacy across gender. While several studies reported that women had higher digital health literacy levels than men, the majority found no associations, suggesting that gender is not a likely predictor of digital health literacy. These findings may be attributed to increased use of electronic devices across populations and the closing gap in education levels between men and women [16].

Of the few included studies that examined ethnicity and digital health literacy, findings were also mixed. While some studies reported higher digital health literacy in White populations than in minority groups [25,35], other studies found no differences across ethnic groups [26,38], or conversely that people from minority groups had higher digital health literacy levels [24,32]. Findings from the current review suggest that ethnicity is not a reliable predictor of digital heath literacy; however, further evidence is needed. In addition, studies on digital health literacy among culturally and linguistically diverse communities were limited to a qualitive study, which was excluded from the current review [56]. Quantitative studies in culturally and linguistically diverse populations that met the study criteria were lacking. Thus, further studies are needed to explore these associations and to identify facilitators and barriers to digital health literacy for people in culturally and linguistically diverse communities.

The majority of studies reported positive associations between digital health literacy and health resource navigation, including higher levels of e-information seeking, e-resource engagement, access and use of technology, engagement with health information sources, eHealth satisfaction and trust, and comfort and use of digital resources. The findings suggest a bidirectional relationship between digital health literacy and eHealth resource use: those with greater access to digital devices and greater use of the internet had higher digital health literacy. It is likely that those with more confidence engaging with digital products will be more inclined to seek out health information in digital formats. The findings suggest that ensuring access to technology, as well as fostering skills to engage with eHealth resources is essential to promoting digital health literacy. Furthermore, for people with limited access to the internet or devices, we recommend providing information in nondigital formats.

Our review found that studies examined associations between digital health literacy and health outcomes including psychosocial outcomes, behaviors for managing health or chronic disease, and perceived health status. Studies showed that higher digital health literacy was associated with greater satisfaction with medical encounters, less perceived strain in medical encounters, increased empowerment, greater social networks for health information, and reduced affective distress and cancer fatalism. In these studies, higher digital health literacy enabled individuals to seek and understand information, which enabled them to feel more empowered to manage their health. However, findings were less consistent for associations between digital health literacy and chronic disease and health management outcomes.

Studies of chronic disease populations showed that digital health literacy was associated with greater disease knowledge and increased disease management efficacy, consistent with a prior systematic review [57]. However, while some studies suggested that digital health literacy was associated with increased health decision-making behaviors and health service use, other studies found no associations with health promotion behaviors or health service use.

Our findings support conclusions drawn from existing reviews [8], which identified that more studies are needed in the digital health field to examine whether digital advances are facilitating better outcomes for those with greater skills in using e-resources for health purposes. Furthermore, our findings from the review also highlight gaps in recent evidence on the impacts of digital health literacy on prevalent chronic health conditions (eg, cancer, heart disease, diabetes, stroke, and COPD). Given the increased use of telehealth during the COVID-19 pandemic, and importance of chronic disease self-management, research to understand how digital health literacy influences a person’s capacity to engage with digital health resources to manage their health is needed. Furthermore, research on understanding the impacts of digital health literacy on health outcomes in chronic disease populations is recommended. In addition, only 2 included studies examined digital health literacy in caregiver populations. Caregivers, particularly those of adult care recipients, may have unique health information needs given their role in providing support. Given the evidence gap, we recommend further research on caregivers to identify their digital health literacy needs and how these can be addressed across health settings.

Across all studies, digital health literacy was assessed using self-reported measures (eg, eHealth Literacy Scale) rather than assessments of specific digital knowledge and skills. Thus, these perceived digital health literacy skills may not translate to everyday digital health behaviors. Studies also varied in their reports of digital health literacy scores (eg, means vs cutoff criteria), thus limiting comparability across studies. Furthermore, included studies captured digital health literacy levels across a range of participant groups, which limit in-depth understanding of digital health literacy within specific populations. Thus, findings should be interpreted with caution for specific groups. Only bivariate associations were reported in the current review. Thus, nuanced understanding of relationships between digital health literacy and health outcomes and sociodemographic characteristics may be excluded. In addition, the aim of the rapid review was to inform the development and implementation of emerging digital health strategies across community settings in real time. In contrast to a full systematic review, the rapid review approach trades some methodological rigor for efficiency in addressing a critical topic and may therefore be vulnerable to bias. While MeSH terms were not used in the database search to limit outputs to articles that focused on measuring digital health literacy, ~1500 publications were still identified. Finally, the findings were limited to studies conducted from English-speaking countries. Thus, articles that capture key findings of the review may have been excluded. Notwithstanding, we note that the current findings highlight substantial gaps in research pertaining to digital health literacy within English-speaking countries and identify areas for future investigation.

Findings from this review suggest that sociodemographic characteristics may predict digital health literacy levels in some but not all contexts, but evidence suggests that these are not deterministic. Although in its infancy and with limited evidence, studies show some associations between increased digital health literacy and various improved health behaviors and outcomes. Further investigations of digital health literacy on positive chronic disease outcomes are needed, particularly across underrepresented but key populations, including diverse cultural and chronic disease groups. Empowering individuals with the skills to critically access and appraise reliable health information on digital platforms and devices is vital, given emerging evidence that suggests that those with low digital health literacy seek health information from unreliable sources. Identifying cost-effective strategies to rapidly assess and enhance digital health literacy capacities across community settings thus warrants continued further investigation. Our findings also confirm a warning that those with greatest digital skills may obtain greatest benefit from access to digital health resources and vice versa, with the implication that digital divides (gaps between knowledge of digital skills and access to health information) may become entrenched without specific efforts to overcome such divides. Our review contributes to the global digital health movement by identifying areas that require further investigation. It emphasizes the pivotal role of digital health literature in improving health care outcomes and promoting a more inclusive health care system. Digitalization and digital technologies transform and enhance the delivery of health care services; therefore, digital health literature becomes essential to engage health consumers and empower them to actively participate in their own health care and address health inequalities.