Abstract
Introduction
Patient portals are central to health care communication, yet disparities in adoption persist among underserved populations. Most implementation strategies draw on general population research, but adoption mechanisms may differ substantially in safety-net settings.
Methods
This mixed-methods cross-sectional study examined portal adoption barriers at a student-run free clinic serving predominantly uninsured, Spanish-speaking adults (n = 112 patients, N = 42 practitioners), with comparison to the Health Information National Trends Survey 6 (n = 5232). Exploratory cluster analysis identified patient engagement patterns. Semistructured interviews (n = 11) contextualized quantitative findings. Logistic regression models compared behavioral predictors across settings.
Results
Portal adoption was 22.3% locally vs 66.1% nationally. Cluster analysis identified 4 engagement patterns reflecting distinct barriers, including patients with high health confidence but low information access. Qualitative interviews revealed system usability and trust barriers rather than health literacy deficits. A logistic regression model using behavioral predictors performed well nationally (area under the curve = 0.78) but poorly locally (area under the curve = 0.37), suggesting different adoption mechanisms in safety-net settings. Only 44.3% of practitioners found the portal easy to use.
Conclusions
Equitable digital health implementation requires community-specific barrier assessment rather than reliance on generalized national models. System-level usability and trust barriers, rather than individual behavioral deficits, may drive low portal adoption in underserved populations.
Keywords: patient portal, safety-net clinic, health disparities, digital divide, underserved populations, student-run free clinic, mixed-methods
Introduction
Digital health technologies have become central to patient-clinician communication. Patient portals serve as a foundation for health care communication, providing patients with access to health information, secure messaging with care teams, and self-management tools. 1,2 National policies, including the 21st Century Cures Act mandating patient access to electronic health information, have accelerated portal adoption across health systems. 3,4
However, the promise of digital health is tempered by the chance of widening the “digital divide.” Despite growing portal adoption, substantial disparities persist, particularly among racially and ethnically minoritized groups, low-income individuals, and those with limited English proficiency. 5–12 These disparities are not merely about technology access; they are intertwined with social determinants of health, digital literacy, and institutional trust. 13–18 Identifying the drivers of patient engagement in underserved populations is therefore essential to achieving digital health equity. 19
Most patient portal implementation strategies draw on general population research, yet the mechanisms driving adoption may differ substantially in safety-net populations where patients face intersecting barriers including poverty, limited English proficiency, immigration-related concerns, and unfamiliarity with digital health systems. 20–24 To address this gap, the authors employed a mixed-methods approach with 3 aims 1 : characterize patterns of portal-related engagement and barriers through exploratory cluster analysis, 2 contextualize these patterns with qualitative patient and practitioner data, 3 and explore whether established behavioral predictors of portal use in a national sample apply in this safety-net context.
Methods
STUDY DESIGN AND SETTING
This mixed-methods cross-sectional study was conducted at a weekly student-run free clinic (hereafter “the clinic”) serving approximately between 120 and 150 uninsured, predominantly Spanish-speaking adults monthly. The clinic meets national safety-net clinic criteria, with more than 85% of its patients living at or below 200% of the federal poverty level, aligning its patient population with Health Resources and Services Administration–designated health centers. The clinic is staffed by medical student volunteers under faculty supervision, with services including primary care, chronic disease management, and social services referrals. Patients are predominantly undocumented immigrants who lack employer-sponsored insurance and are ineligible for most public coverage programs. Data were collected from October 29, 2022, to May 11, 2024.
ETHICAL APPROVAL AND CONSENT
Survey data were initially collected as part of ongoing clinic quality-improvement activities; the California Northstate University Institutional Review Board (IRB) subsequently determined the study to be exempt (IRB# 2403-02-149) under 45 CFR 46.104(d)(2)(ii), as the survey instrument posed no more than minimal risk. Participants were informed that participation was voluntary and anonymous; given the exempt, anonymous design, written documentation of consent was not required. Participants were also informed that there would be no compensation for participation nor any consequences for declining.
PARTICIPANTS AND RECRUITMENT
The authors analyzed data from the Health Information National Trends Survey 6 (HINTS6), a nationally representative 2022 survey of US adults (N = 6252). 25 The authors excluded participants who had not visited a health care practitioner in the past 12 months (n = 629, 10.1%), those with missing data on key variables (n = 326, 5.2%), and those with question response errors (n = 65, 1.0%). The final analytic sample included 5232 participants, representing 83.7% of the original sample. Of these, 3460 (66.1%) reported accessing an online patient portal. Clinic recruitment flow is shown in Figure 1.
Figure 1:

Patient recruitment and enrollment flow diagram. Consolidated Standards of Reporting Trials–style flow diagram showing the recruitment process at the clinic (October 2022 to May 2024). Of approximately 1400 unique patients served during the study period, 112 participants completed the patient survey on portal use and health information management confidence. Simultaneously, 42 clinic practitioners completed a separate survey on portal implementation. HINTS6 = Health Information National Trends Survey 6.
DATA COLLECTION AND VARIABLES
The authors administered an anonymous, cross-sectional survey (under 5 minutes) via Google Forms, with trained bilingual interviewers assisting patients as needed. The questionnaire measured self-management self-efficacy using 5 items. Three used 5-point Likert scales (1 = strongly disagree, 5 = strongly agree): "I understand my medical condition(s) and symptoms," "I understand my overall health and treatment goals," and "I understand my health information." Two used binary responses: "I can easily access my medical information" and "I can easily share my medical care information with my family/caregivers." Portal use was assessed with a single yes/no item and technology access by smartphone or computer ownership. Spanish versions were forward- and back-translated by 2 bilingual staff members, with adjudication by a third. Interviewers completed a 15-minute training on neutral phrasing, confidentiality, and anonymity. No identifying information was collected. Based on clinic census data over the 18.5-month period, the authors estimated approximately between 1300 and 1500 unique patients, yielding an estimated response rate of 7% to 9% for the 112-patient analytic sample.
Qualitative Methods
Eleven semistructured interviews (9 portal users, 2 nonusers) were conducted using a 10-item guide developed by the coauthors and reviewed by student-volunteer leadership for clarity and cultural appropriateness. Trained undergraduate volunteers administered questions verbatim in English or Spanish in a private clinic setting, transcribing responses onto structured forms.
Transcripts were uploaded to Taguette for thematic analysis using a dual-coder approach. Two researchers trained in qualitative methods independently read the initial 3 transcripts, performed open coding, and then compared codes and resolved discrepancies through consensus to develop a unified codebook with operational definitions. Both researchers independently coded all 11 transcripts. Intercoder agreement was evaluated through systematic consensus-building discussions, with all discrepancies resolved until 100% agreement. Final codes were grouped into higher-level themes, with audit trails maintained throughout. This study followed the Consolidated Criteria for Reporting on Qualitative Research checklist.
SAMPLE SIZE AND POWER
As an exploratory study, no a priori power calculation was performed; the authors enrolled all eligible consenting clinic attendees (n = 112). A posthoc 1-sample Z-test comparing the observed adoption rate (22.3%, 25/112) to the national benchmark (66.1%) yielded greater than 99% power. This applies only to the proportion test; predictive modeling and between-group comparisons should be interpreted as exploratory given the modest sample size (see Supplemental Table 1, which shows behavioral differences between clinic users and nonusers).
STATISTICAL ANALYSIS
Cluster Analysis
All 5 survey items on health understanding and information access were standardized (z scores). Cluster stability was assessed via 1000 bootstrap resamples. The authors applied k-means clustering 26,27 and selected the optimal cluster number (k = 4) by triangulating 3 metrics: the elbow method, average silhouette width (silhouette coefficient = 0.31), and gap statistic (see Supplemental Figure 1, which shows the elbow method validation). 27 Given the modest sample size, cluster results are interpreted as exploratory patient engagement patterns rather than definitive typologies.
Predictive Modeling
To explore whether standard behavioral predictors apply in this setting, the authors developed a logistic regression model for portal use, selected for its interpretability, appropriateness for binary outcomes, and fit to modest sample sizes. The model was evaluated using 5-fold crossvalidation. Posthoc explainability analyses were not conducted on the local model given its poor discriminative performance.
National Comparison
The authors analyzed the publicly available HINTS6 dataset (n = 5232; see Supplemental Table 3, which shows the demographic breakdown of the HINTS6 sample), aligning key constructs (online medical record access, self-efficacy items) and comparing distributions using Mann-Whitney U tests and Spearman correlations. Dataset factorability was confirmed (Kaiser-Meyer-Olkin = 0.747; Bartlett χ² = 13,740.3; P < .001). 21 Classification models were trained using 7 behavioral features with 5-fold crossvalidation using the same framework as the local analysis (see Supplemental Table 4, which shows classification model performance metrics). This comparison is intended to contextualize the local findings rather than serve as formal external validation, given differences in sampling, population, and measurement between the 2 datasets.
Variables were operationalized by analytic method: binary indicators for predictive modeling (clinically meaningful thresholds) and original response scales for clustering (preserving engagement variation).
All analyses used Python version 3.12 (pandas, numpy, scikit-learn, scipy, statsmodels). Statistical significance was 2-sided at P < .05. This study followed Strengthening the Reporting of Observational Studies in Epidemiology guidelines.
Results
LOW ADOPTION AND HIGH ENGAGEMENT
Of 112 patient respondents, only 25 (22.3%) reported active portal use, compared with the 66.1% national benchmark in HINTS6. Despite low adoption, patients reported high confidence in understanding their health conditions and treatment goals. However, confidence in accessing health care information had the lowest agreement among nonusers (74.7%). Mann-Whitney U tests revealed no statistically significant differences between portal users and nonusers across any health information management items (all P > .05), with small effect sizes (Cohen’s d < 0.2). This contrasts with the significant differences observed in HINTS6 (Table 1).
Table 1:
Digital health equity gap: key differences between underserved safety-net population and national survey data
| Measure | Clinic (n = 112) | HINTS6 (n = 5232) | Key takeaway |
|---|---|---|---|
| Portal / online record access | 22.3% | 66.1% | Substantial adoption gap between settings |
| Confidence in health information | No significant difference between users and nonusers | Statistically significant difference (P < .001). Users are more confident | High confidence locally (M > 4.5) did not predict portal use, suggesting barriers beyond health literacy |
| Predictive model performance (AUC) | 0.37 (No better than chance) | 0.78 (strong discrimination) | Behavioral predictors may operate differently in safety-net settings |
AUC, area under the curve; HINTS6, Health Information National Trends Survey 6.
PATIENT ENGAGEMENT PATTERNS
Exploratory k-means clustering of patient survey responses suggested 4 engagement patterns, offering a more nuanced view than a simple user/nonuser dichotomy. The clustering solution showed reasonable stability (bootstrap stability = 0.80) and cohesion (average silhouette score = 0.31), although these results should be interpreted cautiously given the sample size. Patterns are detailed in Table 2 (see also Supplemental Table 2, which shows patient engagement pattern characteristics by cluster).
Table 2:
Patient patterns from clustering analysis: characteristics and targeted intervention strategies
| Pattern name | Pattern # | Key characteristics | Potential implication |
|---|---|---|---|
| Health care engaged | 1 | High confidence across all health-info management domains; frequent portal users | Leverage as peer mentors or beta-testers |
| Digitally disengaged | 2 | Primarily nonportal users; low ratings on portal features (secure messaging, labs, summaries) | Target for basic digital literacy and adoption |
| Information access challenged | 3 | Specifically low confidence/access in retrieving medical information; mixed portal use | Focus on simplifying info-retrieval workflows |
| System navigators | 4 | Similar to pattern 1 in most respects, comfortable with systems but not distinguished from health care engaged | Engage as codesigners for portal refinements |
Pattern 1 (health care engaged): high confidence across all domains and frequent portal use
Pattern 2 (digitally disengaged): predominantly nonusers with low confidence in managing health information; qualitative interviews with patients in this pattern revealed discomfort with technology; a nonuser described the portal as “too hard” to navigate
Pattern 3 (information access challenged): high confidence in understanding health but low confidence in accessing medical information, suggesting patients who are motivated but encountering usability barriers; qualitative data supported this interpretation; active portal users described difficulty “finding where things are” and called menus “cluttered”
Pattern 4 (system navigators): moderate engagement and comfort with health care systems, resembling the health care engaged pattern
PRACTITIONER PERSPECTIVES
Surveys of 42 practitioners revealed a disconnect between perceived portal importance and practical usability. Although 88.4% of practitioners found portal content important and relevant for patients, only 44.3% found the portal easy to use from the practitioner side (see Supplemental Table 5, which shows health care practitioner perceptions of patient portal implementation).
EXPLORATORY COMPARISON OF PREDICTIVE MODELS
To explore whether standard behavioral predictors of portal use apply in this setting, the authors built a logistic regression model using patient survey data. The model did not meaningfully distinguish users from nonusers (area under the curve [AUC] = 0.37). Although the small sample likely contributed to this poor performance, the contrast with national data is notable; when the identical modeling approach was applied to the HINTS6 sample, the same behavioral variables were strongly predictive (AUC = 0.78). This divergence is visualized in Figure 2, and different correlation patterns across populations (Figure 3) further illustrate these findings. This pattern is consistent with the interpretation that different mechanisms may drive portal adoption in safety-net vs general populations, although confirmation in larger samples is needed.
Figure 2:

Area under the curve comparison of predictive model performance: local vs national data. Bar chart comparing the predictive performance of identical behavioral models for patient portal adoption. The local safety-net clinic model (n = 112, dark bar) achieved area under the curve = 0.37 (95% confidence interval, 0.28–0.46), performing below random chance (area under the curve = 0.5, dashed line). The national HINTS6 model (n = 5232, light bar) achieved area under the curve = 0.78 (95% confidence interval, 0.76–0.80), suggesting that behavioral factors predictive of portal use nationally may not generalize to safety-net settings. Error bars represent 95% confidence intervals. AUC = area under the curve; HINTS6 = Health Information National Trends Survey 6.
Figure 3:

(A) Health care information management correlation patterns in clinic survey population: heatmap analysis revealing relationship strengths between patient portal adoption factors (n = 112). (B) Health care information management correlation patterns in HINTS6 population (n = 5232). HINTS6 = Health Information National Trends Survey 6.
QUALITATIVE FINDINGS
Interviews with 11 patients revealed 4 themes. Navigation and usability challenges affected both users and nonusers, with patients reporting difficulty "finding where things are" and describing menus as "cluttered." Among users, perceptions of utility were mixed: laboratory results were consistently the most valuable feature, although some users reported "nothing" as particularly useful. Technology comfort appeared linked to adoption decisions, with nonusers consistently reporting greater difficulty ("too hard," "confusing") compared to users who ranged from "easy" to "confusing." Both groups demonstrated awareness of needed improvements, requesting better log in systems and "more organized" interfaces.
Discussion
This mixed-methods study of patient portal adoption at a student-run free clinic serving predominantly uninsured, Spanish-speaking adults found a substantial gap compared with national benchmarks (22.3% vs 66.1%). Qualitative and quantitative findings converged to suggest that system-level usability and trust barriers, rather than individual behavioral deficits, may drive low adoption in this population. A behavioral predictive model that performed well nationally (AUC = 0.78) showed poor discrimination locally (AUC = 0.37), a pattern consistent with different adoption mechanisms operating in safety-net settings, although the small sample warrants cautious interpretation.
The 4 engagement patterns identified through cluster analysis, although exploratory, offer a framework for understanding heterogeneity in portal adoption barriers. The information access challenged pattern is particularly notable; these patients reported high confidence in understanding their health yet low confidence in accessing health information, suggesting that portal design rather than patient capacity may be the limiting factor. The digitally disengaged pattern similarly pointed to the absence of culturally appropriate onboarding support rather than individual deficits. 28
Comparison with national data reinforces this interpretation. In HINTS6, confidence in understanding health information strongly predicted portal use (P < .001). In the authors’ clinic, this same confidence was uniformly high (M > 4.5) across users and nonusers, yet predicted nothing (all P > .05). This suggests that among patients in this setting, health comprehension is not the barrier; rather, system usability and access may be the primary constraints. 29
Qualitative findings converged with the clustering results, with navigation difficulties reported by interviewees directly mapping onto the information access challenged pattern and technology discomfort mapping onto the digitally disengaged pattern.
These findings have implications for both system design and implementation support. The predominance of usability barriers suggests that health care organizations should consider redesigning portals before deploying digital literacy interventions. User experience research 30,31 identifies cognitive load, navigation complexity, and unclear labeling as strong predictors of technology abandonment. These patterns were mirrored in the qualitative data, with users describing cluttered menus and difficulty locating information. Evidence-based redesign 32 should prioritize simplified navigation with plain-language labels tested in target populations, action-oriented dashboards centered on high-priority tasks, streamlined failure recovery, and iterative usability testing informed by patient engagement patterns like those identified in this study. The information access challenged patients, who were motivated but encountering design barriers, would benefit from such changes.
Practitioner-side usability barriers further compound this challenge. Only 44.3% of practitioners in the study found the portal easy to use, indicating that system redesign must address both patient- and practitioner-facing interfaces.
Beyond system redesign, human-centered support remains essential. Even optimally designed systems require human support for successful adoption in underserved populations. 33 Systematic reviews indicate that individually focused interventions are among the most effective strategies for increasing portal use in underserved communities. Two complementary models emerge from the patient engagement patterns.
Digital navigators programs may be well-suited for the digitally disengaged pattern. Community health workers or promotoras 34 providing one-on-one, culturally congruent training may help build technological confidence and address the language and trust barriers that limit portal use in this population. For undocumented and underserved Latino and Latina populations, 35 these navigators must do more than teach button-clicking; they must build trust, address privacy concerns, and bridge cultural gaps between patients and institutional systems. The Los Angeles County Department of Health Services' Health Technology Navigator program 22 offers a promising implementation model. Peer mentorship could leverage the health care engaged pattern. Patients who have successfully adopted the portal offer credible, relatable support that institutional staff cannot replicate. Peer support programs are effective across health care domains for building confidence and promoting technology adoption. A peer mentor sharing language, culture, and socioeconomic background with struggling patients can overcome intimidation and mistrust in ways technical training alone cannot.
STUDY LIMITATIONS
Several limitations warrant consideration. The modest quantitative sample (n = 112, 25 portal users) limited statistical power for subgroup comparisons and constrained predictive model stability. The AUC of 0.37 should be interpreted as a general indicator of poor discrimination rather than a precise estimate, and both the cluster analysis and predictive modeling results are exploratory.
The estimated response rate was low (7%–9%), reflecting recruitment challenges in walk-in safety-net settings where patients face competing demands and varying comfort with research participation. This raised selection bias concerns; nonrespondents may have been the most digitally marginalized, potentially causing the findings to underestimate the true extent of portal barriers. These recruitment challenges are themselves informative, reflecting the institutional trust and access barriers that characterize research in safety-net settings.
This study also lacked individual-level demographic data, preventing adjustment for key confounders (age, education, income). This decision was guided by IRB considerations to prioritize participant trust and reduce participation barriers in this underserved community. Future studies with sufficient trust-building infrastructure may be able to collect demographic data while maintaining participation rates.
Conducting this study in a student-run, free clinic also prevented fully disentangling the patient population from the clinic operational model. Future multisite research comparing student-run and professional-run clinics could address this. The cross-sectional design limited causal inferences, and high baseline ratings on many items may have introduced ceiling effects.
FUTURE RESEARCH DIRECTIONS
The authors’ findings suggest several research priorities: evaluating digital navigator programs for the digitally disengaged, testing simplified interfaces for the information access challenged, assessing peer mentorship leveraging the health care engaged, and developing culturally attuned assessment tools for Spanish-speaking populations.
At the policy level, federal digital health equity assessments should extend beyond adoption metrics to incorporate community-specific barrier assessment. At the health system level, implementation strategies could benefit from phased approaches informed by local engagement patterns. At the practice level, trained digital health navigators and partnerships with community-based organizations may be important components of equitable implementation in safety-net settings.
Conclusion
Patient portal implementation in underserved communities requires understanding of community-specific barriers. These findings suggested that uniform digital health approaches may primarily reach already-engaged patients while leaving the most marginalized behind. The divergence between local and national findings (AUC 0.37 vs 0.78) suggested that digital health equity may not be achievable through standardized top-down interventions alone. Health care organizations should invest in understanding community-specific barriers and developing tailored strategies from basic digital literacy support for the digitally disengaged to simplified workflows for the information access challenged. Only through such context-aware approaches can digital health tools become a bridge rather than a barrier for underserved patients.
Supplementary Material
online supplementary file 1:
Acknowledgments
The authors gratefully acknowledge the patients and practitioners of the clinic, whose willingness to share their experiences made this work possible.
Footnotes
Author Contributions: Solomon Kim, MPH, participated in study design, data collection, data analysis, interpretation of results, and drafting and critical revision of the final manuscript. Leah Bourgan, MD, participated in study design, data collection, qualitative analysis, and critical revision of the manuscript. Lawrence Chen, MD, participated in study design, data collection, and critical revision of the manuscript. Gizele Bracamontes, BS, participated in data collection and critical revision of the manuscript. Gary Chu, MD, participated in study design, supervision, and critical revision of the manuscript. All authors have given final approval to the manuscript.
Conflicts of Interest: None declared
Funding: None declared
Data-Sharing Statement: Data are available upon request. Readers may contact the corresponding author to request underlying data, which may be shared upon reasonable request and with appropriate institutional approval. Study instruments, the codebook, and protocols will be available on the Open Science Framework upon publication.
Artificial Intelligence Disclosure: An artificial intelligence–assisted tool (ChatGPT, GPT-5, OpenAI) was used for manuscript preparation, including language editing and formatting. It was not used for data collection, analysis, or interpretation of results.
References
- 1. Carini E, Villani L, Pezzullo AM, et al. The impact of digital patient portals on health outcomes, system efficiency, and patient attitudes: Updated systematic literature review. J Med Internet Res. 2021;23(9):e26189. 10.2196/26189 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2. Ammenwerth E, Schnell-Inderst P, Hoerbst A. The impact of electronic patient portals on patient care: A systematic review of controlled trials. J Med Internet Res. 2012;14(6):e162. 10.2196/jmir.2238 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3. Richwine C. Progress and persistent disparities in patient access to electronic health information. JAMA Health Forum. 2023;4(11):e233883. 10.1001/jamahealthforum.2023.3883 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Strawley C, Richwine C. Individuals’ access and use of patient portals and smartphone health apps, 2022. Office of the National Coordinator for Health Information Technology; October 2023. ONC Data Brief No. 69. Accessed 24 June 2026. https://healthit.gov/data/data-briefs/individuals-access-and-use-patient-portals-and-smartphone-health-apps-2022
- 5. Bao C, Bardhan IR, Singh H, Meyer BA, Kirksey K. Patient–provider engagement and its impact on health outcomes: A longitudinal study of patient portal use. MIS Q. 2020;44(2):699–724. 10.25300/MISQ/2020/14180 [DOI] [Google Scholar]
- 6. Brands MR, Gouw SC, Beestrum M, Cronin RM, Fijnvandraat K, Badawy SM. Patient-centered digital health records and their effects on health outcomes: Systematic review. J Med Internet Res. 2022;24(12):e43086. 10.2196/43086 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7. Estrela M, Semedo G, Roque F, Ferreira PL, Herdeiro MT. Sociodemographic determinants of digital health literacy: A systematic review and meta-analysis. Int J Med Inform. 2023;177:105124. 10.1016/j.ijmedinf.2023.105124 [DOI] [PubMed] [Google Scholar]
- 8. Anthony DL, Campos-Castillo C, Lim PS. Who isn’t using patient portals and why? Evidence and implications from a national sample of US adults. Health Affairs. 2018;37(12):1948–1954. 10.1377/hlthaff.2018.05117 [DOI] [PubMed] [Google Scholar]
- 9. Reed ME, Huang J, Graetz I, et al. Patient characteristics associated with choosing a telemedicine visit vs office visit with the same primary care clinicians. JAMA Netw Open. 2020;3(6):e205873. 10.1001/jamanetworkopen.2020.5873 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10. Richwine C, Johnson C, Patel V. Disparities in patient portal access and the role of providers in encouraging access and use. J Am Med Inform Assoc. 2023;30(2):308–317. 10.1093/jamia/ocac227 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11. Yoon E, Hur S, Opsasnick L, et al. Disparities in patient portal use among adults with chronic conditions. JAMA Netw Open. 2024;7(2):e240680. 10.1001/jamanetworkopen.2024.0680 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12. Goel MS, Brown TL, Williams A, Hasnain-Wynia R, Thompson JA, Baker DW. Disparities in enrollment and use of an electronic patient portal. J Gen Intern Med. 2011;26(10):1112–1116. 10.1007/s11606-011-1728-3 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13. Irizarry T, DeVito Dabbs A, Curran CR. Patient portals and patient engagement: A state of the science review. J Med Internet Res. 2015;17(6):e148. 10.2196/jmir.4255 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14. Highfield L, Ottenweller C, Pfanz A, Hanks J. Interactive web-based portals to improve patient navigation and connect patients with primary care and specialty services in underserved communities. Perspect Health Inf Manag. 2014;11(Spring):1e. [PMC free article] [PubMed] [Google Scholar]
- 15. Goldberg N, Herrmann C, Di Gion P, et al. Sociodemographic and socioeconomic determinants for the usage of digital patient portals in hospitals: Systematic review and meta-analysis on the digital divide. J Med Internet Res. 2025;27:e68091. 10.2196/68091 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16. Kruse CS, Argueta DA, Lopez L, Nair A. Patient and provider attitudes toward the use of patient portals for the management of chronic disease: A systematic review. J Med Internet Res. 2015;17(2):e40. 10.2196/jmir.3703 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17. Higashi RT, Repasky EC, Gupta A, et al. Factors associated with portal and telehealth uptake and use in a minoritized, low-income community: Mixed methods study. JMIR Form Res. 2025;9:e70146. 10.2196/70146 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18. Deshpande N, Arora VM, Vollbrecht H, Meltzer DO, Press V. eHealth literacy and patient portal use and attitudes: Cross-sectional observational study. JMIR Hum Factors. 2023;10:e40105. 10.2196/40105 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19. Lyles CR, Nguyen OK, Khoong EC, Aguilera A, Sarkar U. Multilevel determinants of digital health equity: A literature synthesis to advance the field. Annu Rev Public Health. 2023;44:383–405. 10.1146/annurev-publhealth-071521-023913 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20. Casillas A, Abhat A, Mahajan A, et al. Portals of change: How patient portals will ultimately work for safety net populations. J Med Internet Res. 2020;22(10):e16835. 10.2196/16835 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21. Grossman LV, Masterson Creber RM, Benda NC, Wright D, Vawdrey DK, Ancker JS. Interventions to increase patient portal use in vulnerable populations: A systematic review. J Am Med Inform Assoc. 2019;26(8–9):855–870. 10.1093/jamia/ocz023 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22. Casillas A, Abhat A. The Los Angeles County Department of Health Services Health Technology Navigators: A novel health workforce to digitally empower patient communities in safety net systems. J Med Access. 2024;8:27550834231223024. 10.1177/27550834231223024 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23. Casillas A, Cemballi AG, Abhat A, et al. An untapped potential in primary care: Semi-structured interviews with clinicians on how patient portals will work for caregivers in the safety net. J Med Internet Res. 2020;22(7):e18466. 10.2196/18466 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24. Nouri SS, Adler-Milstein J, Thao C. Patient characteristics associated with objective measures of digital health tool use in the United States: A literature review. J Am Med Inform Assoc. 2020;27(5):834–841. 10.1093/jamia/ocaa024 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25. HINTS 6 (2022). National Cancer Institute; 2023. Accessed 2 July 2026. https://hints.cancer.gov/data/download-data.aspx#H6 [Google Scholar]
- 26. Hair JF, Black WC, Babin BJ, et al. Multivariate Data Analysis. 7th ed. Pearson Education Limited: Pearson; 2014. [Google Scholar]
- 27. Tibshirani R, Walther G, Hastie T. Estimating the number of clusters in a data set via the gap statistic. J R Stat Soc Series B Stat Methodol. 2001;63(2):411–423. 10.1111/1467-9868.00293 [DOI] [Google Scholar]
- 28. Sadasivaiah S, Lyles CR, Kiyoi S, Wong P, Ratanawongsa N. Disparities in patient-reported interest in web-based patient portals: Survey at an urban academic safety-net hospital. J Med Internet Res. 2019;21(3):e11421. 10.2196/11421 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29. Andreadis K, Buderer N, Langford AT. Patients’ understanding of health information in online medical records and patient portals: Analysis of the 2022 Health Information National Trends Survey. J Med Internet Res. 2025;27:e62696. 10.2196/62696 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30. Portz JD, Bayliss EA, Bull S, et al. Using the technology acceptance model to explore user experience, intent to use, and use behavior of a patient portal among older adults with multiple chronic conditions: Descriptive qualitative study. J Med Internet Res. 2019;21(4):e11604. 10.2196/11604 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31. Simola S, Hörhammer I, Xu Y, et al. Patients’ experiences of a national patient portal and its usability: Cross-sectional survey study. J Med Internet Res. 2023;25:e45974. 10.2196/45974 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32. Lyles CR, Nelson EC, Frampton S, Dykes PC, Cemballi AG, Sarkar U. Using electronic health record portals to improve patient engagement: Research priorities and best practices. Ann Intern Med. 2020;172(11 Suppl):S123–S129. 10.7326/M19-0876 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33. Cheng C, Beauchamp A, Elsworth GR, Osborne RH. Applying the electronic health literacy lens: Systematic review of electronic health interventions targeted at socially disadvantaged groups. J Med Internet Res. 2020;22(8):e18476. 10.2196/18476 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 34. Brener S, Jiang S, Hazenberg E, Herrera D. A cyclical model of barriers to healthcare for the Hispanic/Latinx population. J Racial Ethn Health Disparities. 2024;11(2):1077–1088. 10.1007/s40615-023-01587-5 [DOI] [PubMed] [Google Scholar]
- 35. Rodríguez MA, Vargas Bustamante A, Ang A. Perceived quality of care, receipt of preventive care, and usual source of health care among undocumented and other Latinos. J Gen Intern Med. 2009;24(S3):508–513. 10.1007/s11606-009-1098-2 [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
online supplementary file 1:
