Milbank Q. 2005 Sep; 83(3): 457–502. Evidence of the health-promoting influence of primary care has been accumulating ever since researchers have been able to distinguish primary care from other aspects of the health services delivery system. This evidence shows that primary care helps prevent illness and death, regardless of whether the
care is characterized by supply of primary care physicians, a relationship with a source of primary care, or the receipt of important features of primary care. The evidence also shows that primary care (in contrast to specialty care) is associated with a more equitable distribution of health in populations, a finding that holds in both cross-national and within-national studies. The means by which primary care improves health have been identified, thus suggesting ways to improve overall health
and reduce differences in health across major population subgroups. Keywords: Primary care, health outcomes, population health The term primary care is thought to date back to about 1920, when the Dawson Report was released in the United Kingdom. That report, an official “white paper,” mentioned “primary health care centres,” intended to become the hub of regionalized services in that country. Although primary
care came to be the cornerstone of the health services system in the United Kingdom as well as in many other countries, no comparable focus developed in the United States. Indeed, the formation of one after another specialty board in the early decades of the 20th century signaled the increasing specialization of the U.S. physician workforce (Stevens 1971). The GI Bill of Rights, which supported
the further training of physicians returning from service in World War II, helped increase the specialization of many who had been general practitioners (generalists) before the war. At that time, general practitioners were physicians who lacked additional training after graduation from medical school, apart from a short clinical internship. Concerned that the survival of generalist physicians would be threatened by the disproportionate increase in the supply of specialists in the
United States—to the detriment of generalist practice—family physicians, working with international colleagues, established standards for credentialing the new “specialty” of family practice. Thus, in the 1960s and 1970s, longer postgraduate training became part of generalist physicians’ preparation for practice. This recognition of a “specialty” of primary care, which, in the United States, covered general internal medicine as well as general pediatrics, resulted in two reports from the
Institute of Medicine (IOM) (Donaldson et al. 1996; IOM 1978). These reports defined primary care as “the provision of integrated, accessible health care services by clinicians who are accountable for addressing a large majority of personal health care needs, developing a sustained partnership with
patients, and practicing in the context of family and community.” This definition is consistent with at least two international reports (WONCA 1991; World Health Organization 1978) and has been used to measure the four main features of primary care services: first-contact access for each need;
long-term person- (not disease) focused care; comprehensive care for most health needs; and coordinated care when it must be sought elsewhere. Primary care is assessed as “good” according to how well these four features are fulfilled. For some purposes, an orientation toward family and community is included as well (Starfield 1998). Despite the greater recognition of the importance
of primary care to health services systems (World Health Organization 1978, 2003), professionals have recently called for increasing even further the supply of specialist physicians in the United States
(Cooper et al. 2002). Compared with other industrialized nations, the United States already has a surplus of specialists, but not of primary care physicians. On the basis of the studies reviewed in this article, we believe that health of the U.S. population will improve if this maldistribution is corrected. Specifically, a greater emphasis on primary care can be expected to lower the costs of care,
improve health through access to more appropriate services, and reduce the inequities in the population's health. We first review the evidence concerning the relationship between primary care and health, using three different measures of primary care. The effect of health policy on primary care and health can also be determined by between-country comparisons, which we summarize next. We then consider the impact of primary care in reducing disparities in health across population
groups. After a section on cost considerations, we discuss why primary care would be expected to have a beneficial effect on health. We then look at the analyses’ limitations and discuss the likely nature of primary care in the future in accordance with the policy implications of this evidence. We used research on the effects of primary care on health from studies of the supply of primary care physicians, studies
of people who identified a primary care physician as their regular source of care, and studies linking the receipt of high-quality primary care services with health status. These three lines of evidence represent a progressively stronger demonstration that primary care improves health by showing, first, that health is better in areas with more primary care physicians; second, that people who receive care from primary care physicians are healthier; and, third, that the characteristics of primary
care are associated with better health. We used three systematic literature reviews of primary care (Atun 2004; Engstrom, Foldevi, and Borgquist 2001; Health Council of the Netherlands 2004), supplemented by
our own compilation of articles in major national and international general medical journals. We concentrated on publications written in English and mainly on studies from the United States (which accounted for most of them).We did, however, include studies from other countries if they addressed primary care, as measured by at least one of the three types of studies. A study's inclusion or exclusion did not depend on its findings. Rather, the only criterion for inclusion was a clear
conceptualization of primary care, systematic data collection and analysis, and comparison populations. Several studies in the systematic literature reviews, although uniformly favorable to primary care, did not meet these criteria and therefore were excluded. As a group, these studies covered a variety of health
outcomes: total and cause-specific mortality, low birth weight, and self-reported health. They examined the relationship between the supply of primary care physicians and health at different levels of geographic aggregation (state, county, metropolitan, and nonmetropolitan regions); controlled for various population characteristics (such as income, education, and racial distribution); and used several different analytic approaches (standard regressions, path analyses) in individual years
(cross-sectional) as well as over time (longitudinal). The number of primary care physicians per 10,000 population is the measure of “supply.” Primary care physicians include family and general practitioners, general internists, and general pediatricians. These three types of physicians constitute the primary care physician workforce and have been shown to provide the highest levels of primary care characteristics in their practices
(Weiner and Starfield 1983). Studies in the early 1990s (Shi 1992, 1994) showed that those U.S. states with higher ratios of primary care physicians to population had better health
outcomes, including lower rates of all causes of mortality: mortality from heart disease, cancer, or stroke; infant mortality; low birth weight; and poor self-reported health, even after controlling for sociodemographic measures (percentages of elderly, urban, and minority; education; income; unemployment; pollution) and lifestyle factors (seatbelt use, obesity, and smoking). Vogel and Ackerman
(1998) subsequently showed that the supply of primary care physicians was associated with an increase in life span and with reduced low birth-weight rates. Other studies added sophistication to these early studies by examining the relationship between primary care and health after considering other potentially confounding characteristics. One of these confounders was income inequality, or the extent to which income is concentrated in certain social groups rather than being
equitably distributed. In 1999, Shi and colleagues reported that both primary care and income inequality had a strong and significant influence on life expectancy, total mortality, stroke mortality, and postneonatal mortality at the state level. They also found smoking rates to be related to these outcomes, but the effect of the primary care physician supply persisted after they controlled for smoking
(Shi et al. 1999). A later study confirmed these findings, this time using self-assessed health as the health outcome (Shi and Starfield 2000). These relationships remained significant after controlling for age, sex, race/ethnicity, education, paid work (employment and type of employment), hourly
wage, family income, health insurance, physical health (SF-12), and smoking. Additional studies examined the influence of the supply of primary care physicians at the state level while also taking into account the supply of specialist physicians. These analyses found, in the same year as well as in time-lagged (between 1985 and 1995) analyses, that the supply of primary care physicians was significantly associated with lower all-cause mortality, whereas a greater supply of
specialty physicians was associated with higher mortality. When the supply of primary care physicians was disaggregated into family physicians, general internists, and pediatricians, only the supply of family physicians showed a significant relationship to lower mortality (Shi et al. 2003a). Mortality attributed to cerebrovascular stroke also was found to be influenced by the
supply of primary care physicians. Using 11 years of state-level data and adjusting for income inequality, educational level, unemployment, racial/ethnic composition, and percentage of urban residents, the supply of primary care physicians remained significantly associated with reduced mortality and even wiped out the adverse effect of income inequality (Shi et al. 2003b). Consistent
with these findings for total and cause-specific mortality, the reduction in low birth weight at the state level was significantly associated with the supply of primary care physicians in the concurrent year as well as after one-, three-, and five-year lag periods (Shi et al. 2004). A greater supply of primary care physicians was associated with lower infant mortality as well and persisted after
controlling for various socioeconomic characteristics and income inequality. County-level analyses confirmed the positive influence of an adequate supply of primary care physicians by showing that all-cause mortality, heart disease mortality, and cancer mortality were lower where the supply of primary care physicians was greater. When urban areas (counties including a city with at least 50,000 people) and nonurban areas were examined separately
(Shi et al. 2005b), nonurban counties with a greater number of primary care physicians experienced 2 percent lower all-cause mortality, 4 percent lower heart disease mortality, and 3 percent lower cancer mortality than did nonurban counties with a smaller number of primary care physicians. In urban areas, however, the relationship appeared more complex, possibly resulting from the lesser degree of
income inequality and the greater racial differences in urban areas. A study of premature mortality (mortality before age 75) in U.S. metropolitan, urban, and rural areas found inconsistent relationships to the supply of primary care physicians, possibly owing to a statistical instability in the way in which the supply of physicians was categorized, which was inappropriate for areas with great variability in both the supply and the population size
(Mansfield et al. 1999). Analyses conducted in counties in the state of Florida used cervical cancer mortality as the health outcome. Controlling for a variety of county-level characteristics (percentage of whites, low educational level, median household income, percentage of married females, and urban/nonurban), each one per 10,000 population increase in the supply of family
physicians was associated with a decrease in mortality of 0.65 per 100,000 population. That is, a one-third increase in the supply of family physicians was associated with a 20 percent lower mortality rate from cervical cancer. The positive effect of primary care was also found in the significant relationship between reduced mortality and the supply of general internists, but not the supply of obstetrician-gynecologists
(Campbell et al. 2003). The relationship between primary care physician supply and better health is not limited to studies in the United States. In England, the standardized mortality ratio for all-cause mortality at 15 to 64 years of age is lower in areas with a greater supply of general practitioners. (In England, pediatricians and internists are not considered, and do not function
as, primary care physicians.) Each additional general practitioner per 10,000 population (a 15 to 20 percent increase) is associated with about a 6 percent decrease in mortality (Gulliford 2002). A later study (Gulliford et al. 2004) found that the ratio of general practitioners to population was
significantly associated with lower all-cause mortality, acute myocardial infarction mortality, avoidable mortality, acute hospital admissions (both chronic and acute), and teenage pregnancies, but the statistical significance disappeared after controlling for socioeconomic deprivation and for partnership size, which the authors interpreted as suggesting that the structural characteristics of primary care practices may have had a greater impact on health outcomes than did the mere presence of
primary care physicians. The supply of general practitioners also has high salience for in-hospital mortality; that is, it is more closely associated with lower in-hospital standardized mortality than is the total number of physicians per 100 hospital beds (Jarman et al. 1999). In summary, the studies consistently show a relationship between more or better primary care and most of the health outcomes studied. Primary care was associated with improved health outcomes, regardless of the year (1980–1995), after variable lag periods between the assessment of primary care and of health outcomes, level of analysis (state, county, or local area), or type of outcome as measured by all-cause mortality, heart disease mortality, stroke mortality, infant mortality, low birth weight, life expectancy, and self-rated health. All but a few studies found this effect for cancer mortality. The magnitude of improvement associated with an increase of one primary care physician per 10,000 population (a 12.6 percent increase over the current average supply) averaged 5.3 percent. The results of these studies suggest that as many as 127,617 deaths per year in the United States could be averted through such an increase in the number of primary care physicians (Macinko, Starfield, and Shi 2005). Patients’ Relationship to Primary Care Facilities and ProvidersBecause a greater number of primary care physicians does not necessarily mean that all people in the area have greater access to or receipt of primary care services, analyses considering people's relationships to or experiences with a primary care practitioner are helpful to determining the association between primary care and health outcome. Thus the second line of evidence for the positive impact of primary care on health comes from comparing the health of people who do or do not have a primary care physician as their regular source of care. A nationally representative survey showed that adult U.S. respondents who reported having a primary care physician rather than a specialist as their regular source of care had lower subsequent five-year mortality rates after controlling for initial differences in health status, demographic characteristics, health insurance status, health perceptions, reported diagnoses, and smoking status (Franks and Fiscella 1998). That is, people who identify a primary care physician as their usual source of care are healthier, regardless of their initial health or various demographic characteristics. U.S. populations served by community health centers, which are required to emphasize primary care as a condition for federal funding, are healthier than populations with comparable levels of social deprivation receiving care in other types of physicians’ offices or clinics (O'Malley et al. 2005). People receiving care in community health centers receive more of the indicated preventive services than does the general population (Agency for Healthcare Research and Quality 2004). A comparison of rural patients receiving care in these community health centers with patients receiving care in other types of facilities showed that despite being sicker, they are significantly more likely to have received a Pap smear in the previous three years and to have been vaccinated against pneumococcal infection and less likely to have low-birth-weight babies (Regan et al. 2003). In some health systems, both in the United States and abroad, people normally go to their primary care physician before seeking care elsewhere (such as from another type of physician). Spain passed a law in the mid-1980s that strengthened primary care by reorganizing services to better achieve the main features of primary care, which led to the establishment of a national program of primary health care centers. The impact of this reform on health was evaluated after ten years by examining mortality rates for some major causes of death (Villalbi et al. 1999). Death rates associated with hypertension and stroke fell most in those areas in which the reform was first implemented. There even were fewer deaths from lung cancer in those areas with primary care reform than in other areas. Health outcomes that would not be expected to be influenced by primary care, for example, perinatal mortality, did not differ across the areas. Outcomes of care after surgery in Canada also were shown to be better when care was sought from a primary care physician who then referred children to specialists for recurrent tonsillitis or otitis media, compared with self-referral to a specialist (Roos 1979). The referred children had fewer postoperative complications, fewer respiratory episodes following surgery, and fewer episodes of otitis media after surgery, thus implying that specialist interventions were more appropriate when patients were referred from primary care. Finally, we note that Cuba and Costa Rica, which reformed their health systems to provide people with a source of primary care, now have much lower infant mortality rates than do other countries in Latin America. In Cuba, infant mortality rates now are on a par with those in the United States (PAHO 2005; Riveron Corteguera 2000; Waitzkin et al. 1997). The findings from studies of the impact of actually receiving care from a primary care source consistently show benefits for a variety of health and health-related outcomes. How Well the Characteristics of Primary Care Are AchievedAs we noted earlier, until recently primary care could be assessed only by determining the type of physician who provided it: family physicians, general internists, and general pediatricians in the United States; and family physicians or general practitioners in most other industrialized countries. The intensive examination of criteria for the designation of “primary care” in the most recent half century encouraged the development of tools to assess the adequacy of those health delivery characteristics that together define the practice of primary care. This development then enabled us to examine the extent to which the receipt of better primary care is associated with better health. Using these new methods, several studies have demonstrated a positive association between the adequacy of the features of primary care and the provision of preventive services. A cross-sectional study using a representative sample of 2,889 patients in Ohio evaluated the aforementioned four attributes of primary care for their relationship to the delivery of preventive services. After controlling for the patients’ age, race, health, and insurance in the hierarchical linear regression model (HLM), each of the measured primary care attributes was significantly associated with patients’ being up to date on screening, immunization, and health habit–counseling services (Flocke, Stange, and Zyzanski 1998). According to another study, adolescents with the same regular source of care for preventive and illness care (one indication that the source is focused on providing primary care) were much more likely to receive the indicated preventive care and less likely to seek care in emergency rooms (Ryan et al. 2001). The positive impact of primary care also was shown by comparing the self-assessed health of those who received better primary care (as assessed by the health delivery characteristics of primary care) with those who reported less adequate primary care. Among those who reported better primary care, more than 5 percent fewer people reported poor health and 6 percent fewer reported depression than did people experiencing less adequate primary care. Considering only those who reported the best primary care experiences, 8 percent fewer reported poor health, and more than 10 percent fewer reported feeling depressed, compared with those who received less adequate primary care (Shi et al. 2002). Studies in two different areas of Brazil confirmed the relationship between the adequacy of primary care delivery characteristics and self-reported health. In a study in Petropolis, Macinko, Almeida, and Sa (2005) showed that patients who had better primary care experiences were more likely to report better health, even after adjusting for other salient characteristics such as their age, whether or not they had a chronic illness or a recent illness, household wealth, educational level, and the type of facility in which they received their care. Using parents’ reports of their children's primary care, Erno Harzheim and colleagues confirmed these findings in a study conducted in Porto Alegre (Harzheim 2005, personal communication). International ComparisonsInternational comparisons extended our examination of the impact of primary care according to the achievement of its characteristics. Studies of the characteristics of different health systems were particularly useful because they enabled us to assess the impact of various policy characteristics on the practice and outcomes of primary care. Three studies, one using data from the mid-1980s and two from a decade later, demonstrated not only that countries with stronger primary care generally had a healthier population but also that certain aspects of policy were important to establishing strong primary care practice. The first study examined the association of primary care with health outcomes through an international comparison conducted in 11 industrialized countries (Starfield 1991, 1994). Each country's primary care was rated according to the four main characteristics of primary care practice: first-contact care, person-focused care over time, comprehensive care, and coordinated care, as well as family orientation and community orientation. Policy characteristics were the attempts to distribute health services resources equitably (according to the extent of health needs in different areas of the country); universal or near-universal financial coverage guaranteed by a publicly accountable body (government or government-regulated insurance carriers); low or no copayments for health services; percentage of physicians who were not primary care physicians; and professional earnings of primary care physicians relative to those of other specialists. (Operational definitions of these indicators and the method of scoring them are described in Starfield 1998.) The first important finding is that the score for the practice characteristics was highly correlated with the score for the policy characteristics. That is, the adequate delivery of primary care services was associated with supportive governmental policies. The second finding is that those countries with low primary care scores as a group had poorer health outcomes, most notably for indicators in early childhood, particularly low birth weight and postneonatal mortality. A more recent comparison, with 13 countries and an expanded set of indicators of both primary care policy characteristics and health outcomes, also showed better health outcomes for the primary care–oriented countries even after controlling for income inequality and smoking rates, most significantly for postneonatal mortality (r = .74, p < .001) and rates of low birth weight (r = .38, p < .001). Countries with weak primary care also performed less well on most major aspects of health, including mental health, such as years of potential life lost because of suicide (Starfield and Shi 2002). The positive impact of primary care orientation on low birth-weight rates may reflect a beneficial effect of primary care on mothers’ health before pregnancy (Davey Smith and Lynch 2004; Starfield and Shi 2002). The characteristics of primary care practice present in countries with high primary care scores and absent in countries with low primary care scores were the degree of comprehensiveness of primary care (i.e., the extent to which primary care practitioners provided a broader range of services rather than making referrals to specialists for those services) and a family orientation (the degree to which services were provided to all family members by the same practitioner). The most consistent policy characteristics were the government's attempts to distribute resources equitably, universal financial coverage that was either under the aegis of the government or regulated by the government, and low or no patient cost sharing for primary care services (Starfield and Shi 2002). The latter two were studied and confirmed by Or (2001). The positive contributions of primary care to health also were found in a much more extensive time-series analysis of 18 industrialized countries, including the United States (Macinko, Starfield, and Shi 2003). The stronger the country's primary care orientation (as measured by the same scoring system as in the earlier international comparison) was, the lower the rates were of all-cause mortality, all-cause premature mortality, and cause-specific premature mortality from asthma and bronchitis, emphysema and pneumonia, cardiovascular disease, and heart disease. This relationship held even after controlling for various system characteristics (GDP per capita, total physicians per 1,000 population, percentage of elderly people) and population characteristics, including the average number of ambulatory care visits, per capita income, alcohol consumption, and tobacco consumption. The analyses estimated that increasing a country's primary care score by five points (on a 20-point scale) would be expected to reduce premature deaths from asthma and bronchitis by as much as 6.5 percent and that the reduction in premature mortality for heart disease could be as high as 15 percent. Data from this study were analyzed as well to ascertain the robustness of primary care scores over time. The average primary care score increased by nearly one point from the 1970s to the 1990s. Countries that performed well in the 1970s remained high performers in each succeeding decade. When countries were divided into high and low performers (above or below the mean for each decade), no country crossed the threshold from low to high or from high to low, but the score of some countries changed. One country's score fell over time; Germany lowered access to ambulatory care services by imposing higher copayments, thus lowering its overall primary care score (OECD 2001). In general, policy changes over time paralleled improvements in primary care practice. For example, in the late 1980s and early 1990s, Spain strengthened its primary care by moving to a tax-based financing system, improving its geographic allocation of funds, and increasing the supply of family physicians as well as developing primary health care centers that improved integration, family orientation, coordination of care, and health promotion services (Larizgoitia and Starfield 1997). The United States’ score rose slightly over time, almost entirely resulting from the greater participation of Americans in health maintenance organizations (HMOs), which tend, on average, to use a higher percentage of primary care practitioners (Weiner 2004) and have (at least among the not-for-profit HMOs) a tradition of community involvement (Stevens and Shi 2003). Primary Care and Disparities in Health OutcomesBoth the World Health Organization and many countries (including the United States) have recognized the existence of marked disparities (inequities) in health across population subgroups and have identified reductions (and, for the United States, even elimination) of these as a priority (Sachs and McArthur 2005; U.S. Department of Health and Human Services 2000). In reviewing the impact of primary care on reductions in disparities in health, we looked at studies of physician supply, studies of the association with a primary care physician, and studies of the receipt of services that fulfilled the criteria for primary care delivery. Higher ratios of primary care physicians to population are associated with relatively greater effects on various aspects of health in more socially deprived areas (as measured by high levels of income inequality). Areas with abundant primary care resources and high income inequality have a 17 percent lower postneonatal mortality rate (compared with the population mean), whereas the postneonatal mortality rate in areas of high income inequality and few primary care resources was 7 percent higher. For stroke mortality, the comparable figures were 2 percent lower mortality where the primary care resources were abundant and 1 percent higher where the primary care resources were scarce (calculated from data in Shi et al. 1999). These findings are even more striking in the case of self-reported health. Income inequality and primary care were significantly associated with self-rated health, but the supply of primary care physicians significantly reduced the effects of income inequality on self-reported health status (Shi and Starfield 2000). People in high-income-inequality areas were 33 percent more likely to report fair or poor health if the primary care resources were few (calculated from data in Shi and Starfield 2000). As in state-level analyses, the adverse impact of income inequality on all-cause mortality, heart disease mortality, and cancer mortality was considerably diminished where the number of primary care physicians in county-level analyses was high (Shi et al. 2005a). The supply of primary care physicians in the U.S. states has a larger positive impact on low birth weight and infant mortality in areas with high social inequality than it does in areas with less social inequality (Shi et al. 2004). Eleven years of state-level data found the supply of primary care physicians to be significantly related to lower all-cause mortality rates in both African American and white populations, after controlling for income inequality and socioeconomic characteristics (metropolitan area, percentage of unemployed, and educational levels). In these state-level analyses, the supply of primary care physicians had a greater positive impact on mortality among African Americans than among whites. The inclusions of both the supply of primary care physicians and sociodemographic characteristics eliminated the negative impact of income inequality. The association between a greater supply of primary care physicians and lower total mortality was found to be four times greater in the African American population than in the white majority population, indicating a reduction in racial disparities in mortality in the U.S. states (Shi et al. 2005c). But when exploring further the relationship between the supply of primary care physicians and health outcomes in African American and white populations in metropolitan areas of the United States, both the supply of primary care and income inequality were significantly associated with total mortality rates in the white population, whereas only income inequality maintained its significant relationships in African American populations (Shi and Starfield 2001). The authors interpreted this finding as suggesting that in many urban areas, a great supply of primary care physicians does not ensure certain population subgroups’ access to primary care; they may receive their care in places such as hospital clinics and emergency rooms, which do not emphasize primary care. The equity-related effect of having a good primary care source also was found in the study that examined the degree of primary care–oriented services that people received. Good primary care experiences were associated with reductions in the adverse effects of income inequality on health, with fewer differences in self-rated health between higher and lower income-inequality areas where primary care experiences were stronger (Shi et al. 2002). Although similar in the direction of effect, the relationship to “feeling depressed” was not statistically significant. In county-level analyses that stratified urban areas by race, the supply of primary care physicians had a strong and significant influence on white mortality in both low- and high-income-inequality areas, but only a weak association with African American mortality in low-income-inequality areas and no significant association in high-income-inequality areas (Shi et al. 2005b). Thus, the U.S. studies showed that an adequate supply of primary care physicians reduced disparities in health across racial and socioeconomic groups. Multivariate analyses controlling for individual, community, and state-level characteristics provided strong evidence for the association of primary care with fewer disparities in several aspects of health. These conclusions are buttressed by a study comparing the type of place where care is received. Disparities in low-birth-weight percentages between the majority white and African American infants are fewer in infants of mothers receiving care in primary care–oriented community health centers, compared with the population as a whole. In both white and African American populations in both urban and rural areas in the United States, the rates of low birth weight were lower, in both absolute numbers and ratios of rates, where the source of care was a community health center (Politzer et al. 2001). A study of civil servants in the United Kingdom, where access to primary care physicians is universal, found that socioeconomic differences in coronary heart disease mortality were not a result of differences in cardiac care (Britton et al. 2004). Another exploration of the effect of primary care found that blacks in London did not have greater rates of diabetes-related lower-extremity amputation than whites did (Leggetter et al. 2002), whereas blacks in the United States had rates two to three times higher than that in the white population. In the United Kingdom, the rates were lower in black men than in the white population, a difference wholly accounted for by lower rates of smoking, neuropathy, and peripheral vascular disease. The findings persisted even after controlling for socioeconomic differences, thus confirming other findings (van Doorslaer, Koolman, and Jones 2004) that a health system oriented toward primary care services (such as in the United Kingdom) reduced the disparities in health care so prominent in the United States (Agency for Healthcare Research and Quality 2004). Primary care programs aimed at improving health in deprived populations in less developed countries succeeded in narrowing the gaps in health between socially deprived and more socially advantaged populations. A matched case-control study in Mexico (Reyes et al. 1997) found that some aspects of primary care delivery had an important independent effect on reducing the odds of children dying in socially deprived areas. These processes included adequate referral mechanisms, continuity of care (being seen by the same provider at each visit), and being attended in a public facility designed to provide primary care. A study in Bolivia (Perry et al. 1998) found that a community-based approach to planning primary health care services in socially deprived areas lowered the mortality of children under age five compared with adjacent similar areas or the country as a whole. The Costa Rican primary care reforms, which were instituted first in the most socially deprived areas, illustrate the importance of primary care in reducing health disparities. These reforms included transferring the responsibility for providing health care from the Ministry of Health to the Costa Rican Social Security Fund (CCSS), expanding the number of primary care facilities—particularly in underserved areas—and reorganizing primary care into “integrated primary care teams” or EBAIS (equipos básicos de atención integral en salud), which consist of teams of health professionals assigned to a geographic region covering about 1,000 households (Rosero-Bixby 2004b). By 1985, Costa Rica's life expectancy reached 74 years, and infant mortality rates fell from 60 per 1,000 live births in 1970 to 19 per 1,000 live births, levels comparable to those in more developed countries. The improvements in primary health care were estimated to have reduced infant mortality by between 40 percent and 75 percent, depending on the particular study (Haines and Avery 1982; Klijzing and Taylor 1982; Rosero-Bixby 1986). For every five additional years after primary health care (PHC) reform, child mortality fell by 13 percent, and adult mortality fell by 4 percent. The study's quasi-experimental nature provided evidence of the power of PHC policies and provision of services to improve health, above and beyond improvements in social and economic indicators (which the longitudinal analyses controlled for) (Rosero-Bixby 2004a). Studies in other developing countries show the considerable potential of primary care to reduce the large disparities associated with socioeconomic deprivation. In seven African countries, the wealthiest 20 percent of the population receives well over three times as much financial benefit from overall government spending as does the poorest 20 percent of the population (40 percent versus 12 percent). For primary care services, the ratio of rich to poor in the distribution of government expenditures was notably lower (23 percent to the top group versus 15 percent to the lowest group) (Castro-Leal et al. 2000), leading one international expert to conclude that “from an equity perspective, the move toward primary care represents a clear step in the right direction” (Gwatkin 2001,720). An analysis of preventable deaths in children concluded that in the 42 countries accounting for 90 percent of child deaths worldwide, 63 percent could have been prevented by the full implementation of primary care. The primary care interventions included integrated care addressing the very common problems of diarrhea, pneumonia, measles, malaria, HIV/AIDS, preterm delivery, neonatal tetanus, and neonatal sepsis (Jones et al. 2003). Except in metropolitan areas, where a greater supply of primary care physicians alone may not be associated with reductions in disparities between African Americans and whites, the findings of fewer disparities by primary care were consistent across all types of studies and were particularly marked in studies examining the actual receipt of primary care services. Costs of CareIn addition to its relationship to better health outcomes, the supply of primary care physicians was associated with lower total costs of health services. Areas with higher ratios of primary care physicians to population had much lower total health care costs than did other areas, possibly partly because of better preventive care and lower hospitalization rates. This was demonstrated to be the case for the total U.S. adult population (Franks and Fiscella 1998), as well as among U.S. elderly living in metropolitan areas (Mark et al. 1996; Welch et al. 1993). Baicker and Chandra's (2004) analysis showed a linear decrease in Medicare spending along with an increase in the supply of primary care physicians, as well as better quality of care (as measured by 24 indicators concerning the treatment of six common medical conditions). In contrast, the supply of specialists was associated with more spending and poorer care. Care for illnesses common in the population, for example, community-acquired pneumonia, was more expensive if provided by specialists than if provided by generalists, with no difference in outcomes (Rosser 1996; Whittle et al. 1998). Consistent with the findings within countries, international comparisons of primary care showed that those countries with weaker primary care had significantly higher costs (r = .61, p < .001) (Starfield and Shi 2002). Rationale for the Benefits of Primary Care for HealthSix mechanisms, alone and in combination, may account for the beneficial impact of primary care on population health. They are (1) greater access to needed services, (2) better quality of care, (3) a greater focus on prevention, (4) early management of health problems, (5) the cumulative effect of the main primary care delivery characteristics, and (6) the role of primary care in reducing unnecessary and potentially harmful specialist care.
Potential Limitations of Interpretations of Effectiveness of Primary CareDespite the consistency of the findings from various types of studies, areas, and populations and the theoretical rationale for benefit of primary care on population health, it is possible that the results may be overinterpreted. Those countries and areas in which primary care is strongest (however measured) may be areas in which other social interventions (such as income supports and welfare policies that influence health) also are strongest. So far, the effort to identify the social policies that have a great influence on health has not been successful (Graham and Kelly 2004). Moreover, the mere presence of primary care physicians may not reflect the availability of primary care services to certain population groups. At least two of the reviewed analyses in urban counties showed that the supply of primary care physicians is less closely related to the health of urban African Americans than it is for urban whites or for African Americans in rural areas. This is likely due to the poorer distribution of primary care physicians in more deprived urban areas, with the consequently greater need to seek care in such places as hospital outpatient units and emergency rooms. Supporting this hypothesis are two lines of evidence. First, African Americans are more likely than whites to report having their regular source of care in a facility (such as a hospital) and to report a specialist as their regular source of care (Shi 1999). That is, primary care physicians in urban areas tend to locate in more socially advantaged areas (Weiner et al. 1982). As a result, hospital clinics with predominantly hospital-based physicians not trained to provide the important features of primary care become the “default” regular source of care. Second, even in the presence of adequate primary care resources, African Americans may be less likely than other racial and ethnic groups to use primary care when other resources (such as hospital clinics) are available; this has been demonstrated to be the case for the medical care of inner-city infants (Hoffmann, Broyles, and Tyson 1997). State-level analyses are not as susceptible to this type of possible error because primary care is more evenly distributed than is specialty care (Shi and Starfield 2001). If the supply of primary care physicians is less closely associated with health outcomes in urban African Americans than in whites because of difficulties in access to them, the demonstrated association between supply and health outcomes may actually underestimate the potential impact of primary care services, particularly for deprived populations. Moreover, the studies that use alternative measures of primary care, including relationships with a primary care physician and studies considering the adequacy of primary care health services delivery characteristics, all confirm the conclusion that care meeting the criteria for primary care is associated with the better health of those populations receiving it, with a greater impact in more deprived populations. Primary Care in the FutureWhat issues remain to be addressed in primary care to improve its contribution to the health of populations and equity in distribution of health? A pervasive U.S. focus on “access” to health services rather than on the type of health services has detracted from the need to ensure that services are provided in the most appropriate places. The existing national data health interview surveys combine various safety net providers into one group so that people receiving their care from hospital outpatient clinics are not distinguishable from those receiving care from primary care–oriented clinics. Combining primary care–focused community health centers with hospital emergency and outpatient departments as “safety net providers” masks the high positive contributions to the health of the former with the lesser primary care focus of the latter. Apart from the Community Health Center program of the federal Health Resources and Services Administration and the commitment of certain not-for-profit health care organizations to strong primary care (Weiner 2004), little or nothing has been done to ensure that other “regular sources of care” fulfill the criteria for good primary care. In most other industrialized countries, primary care physicians are clearly distinguished from other physicians, and where people receive care is easily identified as primary care or specialty care. Greater appreciation that it is primary care that plays a major role in ensuring access to appropriate health services should provide the rationale for better distinguishing primary care from specialty care in data on the use of health services in the United States. At the very least, primary care must be recognized as a distinct aspect of a health services system. There now are well-validated methods (e.g., see Shi, Starfield, and Xu 2001; Starfield et al. 1998) to assess both the presence and the characteristics of primary care, and all sources of data on use of health services should include at least a few of these measures. Understanding people's primary care experiences (rather than or in addition to their satisfaction), including the extent to which they receive the range of services appropriate to their needs and have the care they receive elsewhere coordinated and integrated, are important to evaluating the adequacy of health services. In contrast to the situation in primary care, for which intensive conceptual and methodologic study over the past several decades has clarified its most important aspects, professional specialty groups in the United States have made little if any attempt to define the practice of “specialism” or the circumstances that should lead to seeking care from specialists. Referrals to specialists apparently have three functions: short-term consultation for diagnosis or management, referral for long-term management of specific illnesses, and recurrent consultation for periodic management. A study of referrals from 80 office-based family practices showed that by far the most referrals for common conditions (over 50 percent of all referrals to most types of specialists) were expected to be for a short term (less than 12 months) and that for more than 50 percent, they were for consultation only (no direct intervention) (Starfield et al. 2002). Very little is known, however, about the relative frequency of these functions from the viewpoint of specialty practice. One report (Hewlett et al. 2005) indicated that about 75 percent of visits to a pulmonary specialty clinic were just for “checkups,” even though the patients’ primary care physicians, once they had access to the specialists’ reports, could just as easily perform this function and report the findings to the specialists. Such an approach to reducing the number of visits to specialists could lower the demand for a greater supply of specialists; it at least deserves to be tested. There is an urgent need for information about the indications for specialty care and about the impact on outcomes of excessive use of specialists. Major challenges to primary care practice concern (1) recognizing and managing comorbidity, (2) preventing the adverse effects of medical interventions, (3) maintaining a high quality of the important characteristics of primary care practice, and (4) improving equity in health services and in the health of populations (Starfield 2001).
The Relevance of PolicyThe relatively poor performance of the United States on major health indicators, despite per capita health care expenditures that are much higher than those of any other country, is a pressing concern for policymakers, the business community (which has, historically, paid for much of the health insurance in the country), and, ultimately, taxpayers. Efforts to improve the system to achieve better health at lower cost are rapidly becoming imperative. Primary care offers an effective and efficient approach to achieve that goal. Evidence of the benefits of a health system with a strong primary care base is abundant and consistent. These benefits are not limited to one or only a few aspects of health but, rather, extend to the major causes of death and disorders as well as to reducing disparities in health across major population subgroups, including racial and ethnic minorities as well as socially deprived adults and children. Federally qualified community health centers (CHCs) currently serve more than 3,600 urban and rural communities, which are typically low-income inner-city or resource-poor rural communities. But they serve only one-quarter of all people living below the poverty level, one in seven people living under 200 percent of poverty level, and one of eight uninsured Americans (Proser, Shin, and Hawkins 2005). Expansion of the CHC network well beyond the current supply is one appropriate strategy. Other policy strategies would strengthen primary care on a broader level (Starfield and Simpson 1993). These include (but are not limited to) changes in the method of reimbursing primary care physicians and, particularly, better reimbursement rates for primary care services for both common conditions and for the important primary care delivery characteristics. Establishing a more rational basis for referrals and improving the coordination between primary care and specialist physicians would make primary care practice more challenging and intellectually rewarding. States could encourage a better distribution of physicians (both primary care and specialists) by tailoring their licensing policies to health needs in different areas or by providing financial incentives for practicing in underserved areas, as is done in some other countries. Incentives for training primary care practitioners could be improved by reorienting federal support for graduate medical education toward training primary care physicians. Similarly, loan forgiveness for primary care practitioners could be expanded. Reducing the amount of paperwork needed to file claims and encouraging the creation of electronic medical records would greatly reduce the tedium of record keeping in practice and, at the same time, make time to improve the self-monitoring of the quality of care. Bonus payments for team practice could enhance the comprehensiveness of primary care. Special recognition of best primary care practices could enhance public recognition of the importance of primary care and its characteristics. Finally, offering more funds for research on primary care, including the support of collaborative practice-based networks (Lanier 2005; Wasserman, Slora, and Bocian 2003), would help meet the intellectual challenges of expanding our knowledge base for the practice of both primary care and specialty care. AcknowledgmentsThis work was funded in part by the Bureau of Health Professions, U.S. Department of Health and Human Services. The authors gratefully acknowledge the advice of Dr. Neil Holtzman in writing this article. References
Articles from The Milbank Quarterly are provided here courtesy of Milbank Memorial Fund Which of the following mechanisms to reduce or control healthcare costs will have an impact on hit?Which of the following mechanisms to reduce or control healthcare costs will have an impact on HIT? Facility coordination of care across the continuum of care by greater investment in information technology.
What was one of the main purposes of the first computer systems?Early computers were meant to be used only for calculations. Simple manual instruments like the abacus have aided people in doing calculations since ancient times. Early in the Industrial Revolution, some mechanical devices were built to automate long tedious tasks, such as guiding patterns for looms.
What percentage of organizations have an information systems steering committee?As shown in Figure 2 from our full report, IT Steering Committee Adoption and Best Practices, 72% of organizations currently have these committees, which is slightly down from last year. Nevertheless, steering committees remain one of the most highly adopted best practices that we study.
|