UCSF

Background & Significance: Mobile medical clinics have been an underrecognized source of care delivery for vulnerable and marginalized populations for decades; however, little is known about their post-Affordable Care Act impact. The overall goal of this dissertation was to describe predisposing, enabling, and need factors associated with mobile medical clinic use and to examine the effect of frequency of clinic use on chronic illness control.Methods: Guided by the Andersen Behavioral Model of Healthcare Service Use, this dissertation comprises three separate studies. The first study is an integrative review that synthesizes the current state of the science of mobile clinic research since 2010, identifies the gaps in knowledge, and discusses how those gaps might be addressed. The second is a retrospective cohort study of adults seeking care aboard medical clinics in Southern California between January 1, 2018 to December 31, 2019 (N = 411) and examines their predisposing, enabling and need factors associated with mobile medical clinic use and the relationship between mobile clinic utilization and presence and control of diabetes and hypertension. The third study leverages a subsample of regular mobile clinic users (N = 218) from the parent cohort to examine the association between frequency of mobile clinic visits and control of diabetes and hypertension. Result: Findings from the integrative review revealed mobile medical clinic use and services vary across the United States. Mobile clinics are used to address chronic illness in both children and adults, and services are particularly targeted towards underserved and uninsured populations. Evidence suggests that adults of all ethnicities benefit from their use, and regular and high utilizers of these clinics experience improved chronic illness outcomes. Findings from the retrospective cohort study of Southern California mobile clinic users (N = 411) revealed the majority of the patients are female (68%), married (47%), Hispanic (78%), with a mean age of 50 (range 42–57, SD = 11). Uninsured individuals account for 38% of mobile clinic users. Nearly all mobile clinic patients report a home address (98%) while only 2% indicate homeless housing status. In the adjusted zero-truncated negative binomial regression model, race/ethnicity was associated with the frequency of mobile clinic utilization, with Hispanics having almost twice as many visits than Whites (IRR = 1.68, 95% CI 1.14–2.48). Chronic illness and comorbidities were also significant factors in mobile clinic utilization. Patients with hypertension and diabetes had 1.61 and 1.22 times the rate of mobile medical clinic visits than those without those chronic conditions, respectively (Hypertension: IRR = 1.61, 95% CI 1.36–1.92; diabetes: IRR = 1.22, 95% CI 1.02–1.45). Findings from the retrospective cohort study of regular mobile clinic users suggest that patients with hypertension who were regular users of mobile clinics experienced an increase in hypertension control over time. As number of visits increased, hypertension control increased. However, the trajectory of hemoglobin A1c control over time among regular mobile clinic users did not differ by the frequency of clinic visits. Discussion and Conclusion: Mobile clinics serve as an important system of health care delivery, especially to vulnerable populations, those who are both insured and uninsured, and those with uncontrolled chronic illness. Evidence in the literature highlights the quality of care, cost effectiveness, and health outcome benefits of mobile medical clinics in the United States. The study findings showed that patients with chronic illness had higher rates of visits than those without chronic illness. Further, among those who were regular users of mobile clinics, patients with hypertension experience better hypertension control over time with more frequent clinic visits. However, for individuals with diabetes who used mobile medical clinics regularly, their number of visits had no significant effect on hemoglobin A1c control over time.