Peripheral artery disease (PAD), a common circulatory problem in which narrowed arteries reduce blood flow to limbs, is a major public health problem. A robust epidemiologic literature shows that patients with PAD have up to three times the risk of all cause mortality. The risks of death from coronary artery disease are up to six times greater for PAD patients in comparison to those without the disease. PAD, however, is usually not recognized as a major public health threat and motivation to evaluate patients for PAD is much lower than it is for other cardiovascular conditions. Peripheral artery disease is a serious health condition that increases an individual's risk for heart attack, stroke, and leg amputation. While PAD is highly prevalent in primary care settings and is easily detected with the ABI during a routine office visit, the procedure is underutilized and without a pulse volume recording or Doppler waveform tracings, it is not reimbursable by healthcare payers. Demonstration that the ABI is a low cost and effective screening technique for identifying PAD in patients with cardiovascular risk factors would support its adoption into primary care and specialty care settings. Furthermore, newly identified PAD patients could be targeted for prevention measures such as treatment with antiplatelet drugs, ACE inhibitors, and statins, decreasing their overall risk of cardiovascular events while increasing functionality and quality of life. With the combined high risk that PAD represents and the availability of effective treatment, systematic use of screening using the ABI to identify patients with asymptomatic PAD is warranted in patients with cardiovascular risk, and is critical to reduce overall morbidity and mortality.

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This dissertation applies techniques in comparative effectiveness research (CER) to understand the determinants of hospice stay duration, the cost-effectiveness of Human Papillomavirus (HPV) vaccination, and the optimal method for evaluating non-experimental and experimental data. The research on hospice stay duration uses data from the Dartmouth Atlas. It finds that for the logarithm of hospice days, nurse staffing numbers are a significant determinant of length-of-stay. Total Medicare reimbursements go down by $117 for each day that a patient stays in hospice. The HPV paper aggregates results across 7 published papers. It finds that male-female HPV vaccination is cost-effective at a $100,000/QALY cost-effectiveness threshold. Finally, the statistics paper compares the accuracy of linear regression, propensity score matching, and simple subtraction for approximating the results of a RCT. It finds all methods excepting simple subtraction and nearest neighbor propensity score matching produce results that are not significantly different from the RCT result.

South Asians are people with origins in India, Pakistan, Bangladesh, Sri Lanka, Nepal, Bhutan, and the Maldives. In the United States (US), South Asians are among the fastest growing ethnic/immigrant groups with a growth rate of 70% from the 2000 to the 2010 Census, now consisting of 1-2% of the total population. California is the state with the largest population of South Asians in the US.

South Asians have a genetic tendency towards insulin resistance and central adiposity, increasing their risk for cardiovascular disease (CVD), coronary heart disease, and diabetes mellitus. Immigrants to Western countries may have an amplified risk of CVD due to the adoption of a Western diet and physical inactivity. Two potential social factors that may moderate CVD risk factors among South Asians in the US are acculturation and religiosity. Chapter 1 provides a literature review of acculturation and health, CVD risk factors among South Asians and how they may vary by duration of residence in the US, and religion and health. Conceptual models for the relationships between acculturation and CVD risk factors and between religiosity and obesity are also presented in Chapter 1.

Acculturation to American cultural practices has generally been associated with unfavorable changes in CVD risk factors among foreign-born populations. There are few validated measures of acculturation for Asian Americans or South Asians, and acculturation is often operationalized as duration of residence in the US despite problems with this proxy measure. Chapter 2, the first manuscript, examines the validity of acculturation proxy measures, such as duration of residence in the US, with self-reported acculturation measures in validated acculturation scales using the California Asian Indian Tobacco Survey. We found that greater duration of residence in the US, greater percentage of lifetime in the US, and younger age at immigration were associated with more American acculturated responses to the items for South Asian immigrants. We also developed an 11-item acculturation scale for South Asians using existing survey items with an internal consistency reliability of 0.73 and examined the psychometric properties of the scale.

Chapter 3, the second manuscript, uses national and state-level cross-sectional data to examine the association of duration of residence in the US with self-reported CVD risk factors among South Asian adults using regression analysis. We found that South Asians immigrants who have resided in the US for greater than 15 years were more likely to be overweight or obese, drink alcohol, eat five or more servings of fruits and vegetables per day, and engage in physical activity compared with more recent immigrants in models adjusting for confounding socio-demographic characteristics, health status, health access, and health behaviors. Age at immigration modified the relationship between duration of residence in the US and body mass index, binge drinking, and alcohol use. Duration of residence was not associated with increased risk for hypertension, high cholesterol, diabetes mellitus, cigarette smoking, fast food intake, or soda intake in adjusted models.

Religious involvement has been associated with improved health practices and outcomes. Longitudinal and cross-sectional studies have found lower morality rates, lower prevalence of smoking, and better self-reported health status among individuals who report high levels of religiosity or attend religious services frequently. However, religiosity has also been associated with greater risk of obesity. For South Asians, religiosity and religious participation may be an especially important concept to understand in health promotion because of the dietary restrictions associated with traditional Indian religions and community fellowship for immigrant populations. Chapter 4, the third manuscript, examines the association of religiosity with obesity among a multi-religious group of South Asians in California using regression analysis. We found that high self-identified religiosity was significantly associated with higher BMI after adjusting for socio-demographic and acculturation measures, including the acculturation scale developed in Chapter 2. Highly religious South Asians had 1.53 greater odds (95% CI: 1.18, 2.00) of being overweight or obese than low religiosity immigrants, though this varied by religious affiliation. Religiosity was associated with greater odds of being overweight/obese for Hindus (OR 1.54; 95% CI: 1.08, 2.22) and Sikhs (OR 1.88; 95% CI: 1.07, 3.30), but not for Muslims (OR 0.69; 95% CI: 0.28, 1.70).

The findings from this dissertation may provide information on relevant social and cultural norms that may be incorporated in the conceptual model and design of a cardiovascular disease prevention lifestyle change intervention culturally tailored for South Asians in the US.

ABSTRACT

This dissertation consists of three studies, each applying a different method, to evaluate the use of pharmacists on the primary care team for people with chronic health conditions, such as high blood pressure and diabetes. Pharmacist interventions, also called Medication Therapy Management (MTM) services, are the subject of considerable current debate in health reform policy. Major associations representing pharmacists are advocating for legislation that will establish reimbursement for MTM services for a wide range of chronic conditions. The studies included in this report address unanswered research questions regarding 1) whether enough evidence exists to conclude that MTM services interventions will result in cost savings and significant return on investment, 2) which patient populations might benefit most from MTM services interventions, and 3) what are the challenges associated with the implementation of these types of MTM services in collaborative partnerships with public and private community health entities.

The first paper in the trilogy examined the existent literature on the cost-benefits of MTM programs. The findings suggest that existing economic studies of MTM services are lacking in quality and additional high-quality cost-effectiveness research work needs to be completed before there is enough evidence to support reimbursement and policy changes.

The second study considered whether different populations of people who have commercial health insurance, Medicare insurance, or Medicaid insurance who take long-term medications were more or less likely to receive medication monitoring. Presumably, those who take long-term medications but may not be receiving proper monitoring could benefit from interventions such as MTM services. Through quantitative regression analysis, it was determined that for populations on widely prescribed medications, such as angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and diuretics - those with commercial insurance were almost three times less likely to be monitored than those with Medicare insurance. Also, significant effects on medication monitoring were found for important patient characteristic covariates including gender - females less likely to be monitored, age - older age associated with lower likelihood of monitoring, and income - higher income associated with higher likelihood of monitoring.

The final study examined the efforts of a multi-sector collaborative partnership implementing an MTM services intervention using community pharmacists to assist with treatment of a population of school district employees and their dependents who have diabetes in San Diego, California. Contextual, resource, leadership, and internal conflict factors were evaluated with qualitative analysis to determine their effect on the abilities of the partnership to complete its initiatives. New contributions as a result of this research include developing a cost model to provide MTM services, quantifying relationships between health insurance status and medication monitoring, and revealing practical lessons on implementation of MTM models. This work provides an objective view on these subjects while adding to the growing number of studies on incorporating pharmacists on the primary care team.

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