Leiyu Shi

The contribution of primary care systems to health outcomes within Organization for Economic Cooperation and Development (OECD) countries, 1970-1998

OBJECTIVE To assess the contribution of primary care systems to a variety of health outcomes in 18 wealthy Organization for Economic Cooperation and Development (OECD) countries over three decades. DATA SOURCES/STUDY SETTING Data were primarily derived from OECD Health Data 2001 and from published literature. The unit of analysis is each of 18 wealthy OECD countries from 1970 to 1998 (total n = 504). STUDY DESIGN Pooled, cross-sectional, time-series analysis of secondary data using fixed effects regression. DATA COLLECTION/EXTRACTION METHODS Secondary analysis of public-use datasets. Primary care system characteristics were assessed using a common set of indicators derived from secondary datasets, published literature, technical documents, and consultation with in-country experts. PRINCIPAL FINDINGS The strength of a countrys primary care system was negatively associated with (a) all-cause mortality, (b) all-cause premature mortality, and (c) cause-specific premature mortality from asthma and bronchitis, emphysema and pneumonia, cardiovascular disease, and heart disease (p<0.05 in fixed effects, multivariate regression analyses). This relationship was significant, albeit reduced in magnitude, even while controlling for macro-level (GDP per capita, total physicians per one thousand population, percent of elderly) and micro-level (average number of ambulatory care visits, per capita income, alcohol and tobacco consumption) determinants of population health. CONCLUSIONS (1) Strong primary care system and practice characteristics such as geographic regulation, longitudinality, coordination, and community orientation were associated with improved population health. (2) Despite health reform efforts, few OECD countries have improved essential features of their primary care systems as assessed by the scale used here. (3) The proposed scale can also be used to monitor health reform efforts intended to improve primary care.

Policy relevant determinants of health: an international perspective

BACKGROUND International comparisons can provide clues to understanding some of the important policy-related determinants of health, including those related to the provision of health care services. An earlier study indicated that the strength of the primary care infrastructure of a health services system might be related to overall costs of health services. The purpose of the current research was to determine the robustness of the findings in the light of the passage of 5-10 years, the addition of two more countries, and the findings of other research on the possible importance of other determinants of country health levels. METHODS Thirteen industrialized countries, all with populations of at least 5 million, were characterized by the relative strength of their primary care infrastructure, the degree of national income inequality, and a major manifestation of a behavioral determinant of health that is amenable to policy intervention (smoking), using international data sets and national informants. Health system and primary care practice characteristics were judged according to pre-set criteria. Major indicators of health were used as dependent variables, as were health care costs. FINDINGS The stronger the primary care, the lower the costs. Countries with very weak primary care infrastructures have poorer performance on major aspects of health. Although countries that are intermediate in the strength of their primary care generally have levels of health at least as good as those with high levels of primary care, this is not the case in early life, when the impact of strong primary care is greatest. A subset of characteristics (equitable distribution of resources, publicly accountable universal financial coverage, low cost sharing, comprehensive services, and family-oriented services) distinguishes countries with overall good health from those with poor health at all ages. Neither income inequality nor smoking status accurately identified those countries with either consistently high or consistently poor performance on the health indicators. INTERPRETATION A certain level of health care expenditures may be required to achieve overall good health levels, even in the presence of strong primary care infrastructures. Very low costs may interfere with achievement of good health, particularly at older ages, although very high levels of costs may signal excessive and potentially health-compromising care. Five policy-relevant characteristics appear to be related to better population health levels. There is no consistent relationship between income inequality, smoking, and health levels as measured by various indicators of health in different age groups.

Quantifying the health benefits of primary care physician supply in the United States.

This analysis addresses the question, Would increasing the number of primary care physicians improve health outcomes in the United States? A search of the PubMed database for articles containing “primary care physician supply” or “primary care supply” in the title, published between 1985 and 2005, identified 17 studies, and 10 met all inclusion criteria. Results were reanalyzed to assess primary care effect size and the predicted effect on health outcomes of a one-unit increase in primary care physicians per 10,000 population. Primary care physician supply was associated with improved health outcomes, including all-cause, cancer, heart disease, stroke, and infant mortality; low birth weight; life expectancy; and self-rated health. This relationship held regardless of the year (1980–1995) or level of analysis (state, county, metropolitan statistical area (MSA), and non-MSA levels). Pooled results for all-cause mortality suggest that an increase of one primary care physician per 10,000 population was associated with an average mortality reduction of 5.3 percent, or 49 per 100,000 per year.

Vulnerability and Unmet Health Care Needs: The Influence of Multiple Risk Factors

AbstractCONTEXT: Previous studies have demonstrated a strong association between minority race, low socioeconomic status (SES), and lack of potential access to care (e.g., no insurance coverage and no regular source of care) and poor receipt of health care services. Most studies have examined the independent effects of these risk factors for poor access, but more practical models are needed to account for the clustering of multiple risks. OBJECTIVE: To present a profile of risk factors for poor access based on income, insurance coverage, and having a regular source of care, and examine the association of the profiles with unmet health care needs due to cost. Relationships are examined by race/ethnicity. DESIGN: Analysis of 32,374 adults from the 2000 National Health Interview Survey. MAIN OUTCOME MEASURES: Reported unmet needs due to cost: missing/delaying needed medical care, and delaying obtaining prescriptions, mental health care, or dental care. RESULTS: Controlling for personal demographic and community factors, individuals who were low income, uninsured, and had no regular source of care were more likely to miss or delay needed health care services due to cost. After controlling for these risk factors, whites were more likely than other racial/ethnic groups to report unmet needs. When presented as a risk profile, a clear gradient existed in the likelihood of having an unmet need according to the number of risk factors, regardless of racial/ethnic group. CONCLUSION: Unmet health care needs due to cost increased with higher risk profiles for each racial and ethnic group. Without attention to these co-occurring risk factors for poor access, it is unlikely that substantial reductions in disparities will be made in assuring access to needed health care services among vulnerable populations.

Inequality in America: The Contribution of Health Centers in Reducing and Eliminating Disparities in Access to Care

Reducing and eliminating health status disparities by providing access to appropriate health care is a goal of the nation’s health care delivery system. This article reviews the literature that demonstrates a relationship between access to appropriate health care and reductions in health status disparities. Using comprehensive site-level data, patient surveys, and medical record reviews, the authors present an evaluation of the ability of health centers to provide such access. Access to a regular and usual source of care alone can mitigate health status disparities. The safety net health center network has reduced racial/ethnic, income, and insurance status disparities in access to primary care and important preventive screening procedures. In addition, the network has reduced low birth weight disparities for African American infants. Evidence suggests that health centers are successful in reducing and eliminating health access disparities by establishing themselves as their patients’ usual and regular source of care. This relationship portends well for reducing and eliminating health status disparities.

Experience of primary care by racial and ethnic groups in the United States.

Objectives. The purpose of this study was to examine the experience of primary care by racial and ethnic groups and identify aspects of primary care where significant disparities in experience exist across racial and ethnic groups. Methods. Data for this study came from the Household Component of the 1997-1998 Medical Expenditure Panel Survey (MEPS), a nationally representative survey of the civilian noninstitutionalized population of the United States. Measures were identified within MEPS that denote race, ethnicity, experience of primary care, and socioeconomic covariates associated with access to care. Results. Racial and ethnic minorities experienced worse primary care, particularly in the first-contact aspect, than did white Americans. Their usual sources of care were more likely to be hospital settings than private clinics. They faced greater barriers accessing their usual source of care (USC), finding it more difficult to get an appointment and waiting longer during an appointment. Many of the significant differences persist after adjustment for sociodemographic and health-status characteristics. Conclusions. Racial and ethnic disparity in primary care experience is not simply a reflection of sociodemographic and health-status differences across racial/ethnic groups. Efforts must be made to reduce nonfinancial as well as financial barriers to care and ensure that quality primary care is provided in all settings, public as well as private, and to individuals of all colors.

Primary Care, Specialty Care, and Life Chances

The relationship between the availability of primary care and specialty care and certain life chance indicators such as mortality rates and life expectancy is analyzed using the multiple regression procedure. Dependent variables are life chance indicators; independent variables were selected based on Starfields and Blums health determinant models and include socioeconomic environment, lifestyles, demographics, and medical care. The author also examines the rankings of states in terms of these indicators, using Spearmans rho coefficient. Among the medical care variables, primary care is by far the most significant variable related to better health status, correlating with lower overall mortality, lower death rates due to diseases of the heart and cancer, longer life expectancy, lower neonatal death rate, and lower low birth weight. In contrast, the number of specialty physicians is positively and significantly related to total mortality, deaths due to heart diseases and cancer, shorter life expectancy, higher neonatal mortality, and higher low birth weight. From a policy perspective, a likely implication is to reorient the medical profession from its current expensive, clinically based, treatment-focused practice to a more cost-effective, prevention-oriented primary care system.

The Effect of Primary Care Physician Supply and Income Inequality on Mortality Among Blacks and Whites in US Metropolitan Areas

OBJECTIVES This study assessed whether income inequality and primary care physician supply have a different effect on mortality among Blacks compared with Whites. METHODS We conducted a multivariate ecologic analysis of 1990 data from 273 US metropolitan areas. RESULTS Both income inequality and primary care physician supply were significantly associated with White mortality (P < .01). After the inclusion of the socioeconomic status covariates, the effect of income inequality on Black mortality remained significant (P < .01), but the effect of primary care physician supply was no longer significant (P > .10), particularly in areas with high income inequality. CONCLUSIONS Improvement in population health requires addressing socioeconomic determinants of health, including income inequality and primary care availability and access.

Income inequality and health: a critical review of the literature.

This article critically reviews published literature on the relationship between income inequality and health outcomes. Studies are systematically assessed in terms of design, data quality, measures, health outcomes, and covariates analyzed. At least 33 studies indicate a significant association between income inequality and health outcomes, while at least 12 studies do not find such an association. Inconsistencies include the following: (1) the model of health determinants is different in nearly every study, (2) income inequality measures and data are inconsistent, (3) studies are performed on different combinations of countries and/or states, (4) the time period in which studies are conducted is not consistent, and (5) health outcome measures differ. The relationship between income inequality and health is unclear. Future studies will require a more comprehensive model of health production that includes health system covariates, sufficient sample size, and adjustment for inconsistencies in income inequality data.

Primary care, infant mortality, and low birth weight in the states of the USA

Study objective: The study tests the extent to which primary care physician supply (office based primary care physicians per 10 000 population) moderates the association between social inequalities and infant mortality and low birth weight throughout the 50 states of the USA. Design: Pooled cross sectional, time series analysis of secondary data. Analyses controlled for state level education, unemployment, racial/ethnic composition, income inequality, and urban/rural differences. Contemporaneous and time lagged covariates were modelled. Setting: Eleven years (1985–95) of data from 50 US states (final n = 549 because of one missing data point). Main results: Primary care was negatively associated with infant mortality and low birth weight in all multivariate models (p<0.0001). The association was consistent in contemporaneous and time lagged models. Although income inequality was positively associated with low birth weight and infant mortality (p<0.0001), the association with infant mortality disappeared with the addition of sociodemographic covariates. Conclusions: In US states, an increased supply of primary care practitioners—especially in areas with high levels of social disparities—is negatively associated with infant mortality and low birth weight.