UCLA

ABSTRACT OF THE DISSERTATION

Trust in the Medical Profession

and Health-Related Quality of Life

in Patients with Hypertension

by

Lilia Susana Meltzer

Doctor of Philosophy in Nursing

University of California, Los Angeles, 2016

Professor Ronald D. Hays, Co-Chair

Professor Felicia S. Hodge, Co-Chair

Hypertension is a precursor to cardiovascular disease and a major contributor to disability from stroke and coronary heart disease. Prevalence of hypertension among US adults has remained unchanged (30%) from 1999 to 2016, and analyzed national data indicate that 90% of adults with uncontrolled hypertension have a usual source of health care and insurance. Under-resourced race/ethnic minorities are disproportionately affected by hypertension and its adverse cardiovascular outlook, particularly stroke. Hispanics have less awareness of hypertension, receive less management of the disease, are less likely to take prescribed medicines, and have lower blood pressure control than non-Hispanics (Whites, African Americans, and Asians). Hispanics comprise 16% of the US population and have a high poverty rate (26%), similar to African Americans.

This study examined associations of trust in the medical profession with health-related quality of life (HRQOL) in adults with hypertension and the extent to which the effect of trust was mediated by improving medication adherence and enhancing resilience. In addition, it evaluated whether the effects of trust vary by ethnicity (Hispanic vs. non-Hispanic). The hypothesized relationships were derived from the Vulnerable Populations Conceptual Model’s (VPCM) domains of resource availability, relative risk, and health status; the VPCM is a population-based model with focus on the social conditions that influence the differential vulnerability to adverse health outcomes of minority groups. It was posited that among adults under medical treatment for hypertension, having trust in the medical profession is related to greater medication adherence and resilience and, in turn, better HRQOL.

A cross-sectional survey was conducted with 201 adults (101 Hispanics and 100 non-Hispanics), recruited from a medical practice consisting of five cardiologists. The study included the Patient-Reported Outcomes Measurement Information System (PROMIS�) Global Health Items; Trust in Doctors Generally Scale; Connor-Davidson Resilience Scale-25; and Morisky Medication Adherence Scale-8. Structural equation modeling was used to evaluate the hypothesized associations (direct and indirect effects) among variables.

The proposed model fit the data well and most of the hypothesized associations were supported. The model explained 37% of the variance in global mental health and 15% of the variance in global physical health. A simultaneous group analysis indicated that ethnicity (i.e., non-Hispanic vs. Hispanic) did not moderate the associations between trust, resilience, medication adherence, and HRQOL. Two alternative theoretically plausible models proposing different directional relationships were tested and these also fit the data well indicating that causality cannot be inferred when cross-sectional designs are used. Findings suggest that trust in the medical profession serves as a protective mechanism for improving health outcomes in adults with hypertension by promoting medication adherence and enhancing resilience regardless of Hispanic ethnicity.