Lee R. Mobley

Spatial analysis of elderly access to primary care services

BackgroundAdmissions for Ambulatory Care Sensitive Conditions (ACSCs) are considered preventable admissions, because they are unlikely to occur when good preventive health care is received. Thus, high rates of admissions for ACSCs among the elderly (persons aged 65 or above who qualify for Medicare health insurance) are signals of poor preventive care utilization. The relevant geographic market to use in studying these admission rates is the primary care physician market. Our conceptual model assumes that local market conditions serving as interventions along the pathways to preventive care services utilization can impact ACSC admission rates.ResultsWe examine the relationships between market-level supply and demand factors on market-level rates of ACSC admissions among the elderly residing in the U.S. in the late 1990s. Using 6,475 natural markets in the mainland U.S. defined by The Health Resources and Services Administrations Primary Care Service Area Project, spatial regression is used to estimate the model, controlling for disease severity using detailed information from Medicare claims files. Our evidence suggests that elderly living in impoverished rural areas or in sprawling suburban places are about equally more likely to be admitted for ACSCs. Greater availability of physicians does not seem to matter, but greater prevalence of non-physician clinicians and international medical graduates, relative to U.S. medical graduates, does seem to reduce ACSC admissions, especially in poor rural areas.ConclusionThe relative importance of non-physician clinicians and international medical graduates in providing primary care to the elderly in geographic areas of greatest need can inform the ongoing debate regarding whether there is an impending shortage of physicians in the United States. These findings support other authors who claim that the existing supply of physicians is perhaps adequate, however the distribution of them across the landscape may not be optimal. The finding that elderly who reside in sprawling urban areas have access impediments about equal to residents of poor rural communities is new, and demonstrates the value of conceptualizing and modelling impedance based on place and local context.

An international comparison of hospital efficiency: does institutional environment matter?

The consensus among many health economists is that no meaningful performance differences exist among for-profit and non-profit hospitals in the US, but this topic has continued to be a matter of academic, judicial, and public policy interest. A similar debate has ensued internationally, regarding the potential efficiency gains from privatization of public enterprises. In this paper, we examine empirical evidence from the public, highly regulated Norwegian hospital sector and the private, highly competitive and unregulated California hospital sector to ascertain whether institutional environment and level of market competition significantly affect the degree of productive efficiency in hospitals. We compare and discuss the productive efficiency of four similar sets of hospitals operating in different institutional and competitive environments. The four samples are carefully matched in the dimensions of sample size, hospital size, and average lengths of stay. Heterogeneity in output definition is used to control for other dimensions (casemix, age distribution of patients). We use Data Envelopment Analysis (DEA) to estimate and compare average long-run as well as short-run efficiency measures across groups. We find that scale and scope regulation of Norwegian hospitals improves long-run efficiency, primarily due to better utilization of capital.

Racial/Ethnic Disparities in Coronary Heart Disease Risk Factors among WISEWOMAN Enrollees

BACKGROUND We used the baseline data collected for the Well-integrated Screening and Evaluation for Women Across the Nation (WISEWOMAN) participants to provide a snapshot of cardiovascular disease (CVD) risk on enrollment and to address racial/ethnic disparities in the following CVD risk factors: body mass index (BMI), systolic and diastolic blood pressure, high-density lipoprotein (HDL) and total cholesterol, diabetes and smoking prevalence, 10-year coronary heart disease (CHD) risk, and treatment and awareness of high cholesterol, hypertension, and diabetes. METHODS We used linear regression analysis to (1) assess the presence of racial/ethnic disparities and test whether existing disparities can be explained by (2) differences in individual characteristics or by (3) differences in individual and community characteristics. RESULTS Our results reveal a high degree of CVD risk among the WISEWOMAN participants and statistically significant racial/ethnic disparities in risk factors. Black participants were at the greatest risk of CVD, and Hispanic and Alaska Native participants were healthier in terms of CVD risk than white participants. Some racial/ethnic disparities were explained by differences in individual and community characteristics, but other disparities persisted even after controlling for these factors. CONCLUSIONS Because differences in community characteristics explain many of the racial/ethnic disparities in CVD risk factors, eliminating disparities may require community-wide interventions. Successful WISEWOMAN projects are likely to not only reduce CVD risk factors overall but also to lessen racial/ethnic disparities in these risk factors.

Estimating hospital market pricing: an equilibrium approach using spatial econometrics

Abstract This paper models hospital market pricing using price response curves estimated from California data, using spatial econometrics. This approach has not been exploited previously in the health economics literature. In our theoretical model, we show how the slope of the reaction function reflects hospital specialization, and how equilibrium prices are impacted by shifts in the reaction function. We posit that managed care penetration, hospital market structure, and/or efficiency effects—including the presence of excess capacity in the industry—determine the position and slope of the reaction function. We then examine empirically how these things impacted equilibrium prices.

Cost-effectiveness of osteoporosis screening and treatment with hormone replacement therapy, raloxifene, or alendronate:

Recent information about osteoporosis treatments and their nonfracture side effects suggests the need for a new costeffectiveness analysis. The authors estimate the cost effectiveness of screening women for osteoporosis at age 65 and treating those who screen positive with hormone replacement therapy (HRT), raloxifene, or alendronate. A Markov model of osteoporosis disease progression simulates costs and outcomes of women aged 65 years. Incremental cost effectiveness ratios of screen-and-treat strategies are calculated relative to a no-screen, no-treat (NST) strategy. Disease progression parameters are derived from clinical trials; cost and quality-of-life parameters are based on review of cost databases and cost-effectiveness studies. Women are screened using dual-energy x-ray absorptiometry, and women screening positive are treated with HRT, raloxifene, or alendronate. Screening and treatment with HRT increase costs and lower quality-adjusted life years (QALYs; relative to the NST strategy). The only scenario (of several) in the sensitivity analysis in which HRT increases QALYs is when it is assumed that there are no drug-related (nonfracture) health effects. Raloxifene increases costs and QALYs; its cost-effectiveness ratio is

Spatial Interaction, Spatial Multipliers and Hospital Competition

447,559 per QALY. When prescribed for the shortest duration modeled, raloxifene’s cost-effectiveness ratio approached

Mammography facilities are accessible, so why is utilization so low?

133,000 per QALY. Alendronate is the most cost-effective strategy; its cost-effectiveness ratio is

Spatial analysis of body mass index and smoking behavior among WISEWOMAN participants

72,877 per QALY. Alendronate’s cost-effectiveness ratio approaches

Geographic disparities in late-stage breast cancer diagnosis in California

55,000 per QALY when treatment effects last for 5 years or the discount rate is set to zero. The authors conclude that screening and treating with alendronate are more costeffective than screening and treating with raloxifene or HRT. Relative to an NST strategy, alendronate has a fairly good cost-effectiveness ratio

The Effects of Safety Net Hospital Closures and Conversions on Patient Travel Distance to Hospital Services

Abstract The hospital competition literature shows that estimates of the effect of local market structure (concentration) on pricing (competition) are sensitive to geographic market definition. Our spatial lag model approach effects smoothing of the explanatory variables across the discrete market boundaries, resulting in robust estimates of the impact of market structure on hospital pricing, which can be used to estimate the full effect of changes in prices inclusive of spillovers that cascade through the neighboring hospital markets. The full amount, generated by the spatial multiplier effect, is a robust estimate of the impacts of market factors on hospital competition. We contrast ordinary least squares and spatial lag estimates to demonstrate the importance of robust estimation in analysis of hospital market competition. In markets where concentration is relatively high before a proposed merger, we demonstrate that Ordinary Least Squares (OLS) can lead to the wrong policy conclusion while the more conservative lag estimates do not.