The uneven landscape of newborn intensive care services: variation in the neonatology workforce.

CONTEXT: In the past 30 years, the number of neonatologists has increased while total births have remained nearly constant. It is not known how equitably this expanded workforce is distributed. OBJECTIVE: To determine the geographic distribution of neonatologists in the United States. DATA SOURCES: 1996 American Medical Association physician masterfiles; 1999 survey of all U.S. neonatal intensive care units; 1995 American Hospital Association hospital survey; and 1995 U.S. vital records. MEASURES: The number of neonatologists and neonatal mid-level providers per live birth within 246 market-based regions. RESULTS: The neonatology workforce varied substantially across neonatal intensive care regions. The number of neonatologists per 10,000 live births ranged from 1.2 to 25.6 with an interquintile range of 3.5 to 8.5. The weakly positive correlation between neonatologists and neonatal mid-level providers per live birth is not consistent with substitution of neonatal mid-level providers for neonatologists (Spearman rank-correlation coefficient, 0.17; P < 0.01). There was no difference in the percentage of neonatal fellows in the lowest and highest workforce quintile (14% vs. 16%) or in the percentage of neonatologists engaged predominantly in research, teaching, or administration (14% in lowest and highest quintiles). CONCLUSIONS: The regional supply of neonatologists varies dramatically and cannot be explained by the substitution of neonatal mid-level providers or by the presence of academic medical centers. Further research is warranted to understand whether neonatal intensive care resources are located in accordance with risk and whether more resources improve newborn outcomes.

Are neonatal intensive care resources located according to need? Regional variation in neonatologists, beds, and low birth weight newborns.

OBJECTIVE: Despite marked growth in neonatal intensive care during the past 30 years, it is not known if neonatologists and beds are preferentially located in regions with greater newborn risk. This study reports the relationship between regional measures of intensive care capacity and low birth weight infants using newly developed market-based regions of neonatal intensive care. DESIGN: Cross-sectional small-area analysis of 246 neonatal intensive care regions (NICRs). DATA SOURCES: 1996 American Medical Association and American Osteopathic Association masterfiles data of clinically active neonatologists; 1999 American Academy of Pediatrics Section on Perinatal Pediatrics survey of directors of neonatal intensive care units in the United States with 100% response rate; 1995 linked birth/death data. RESULTS: The number of total births per neonatologist across NICRs ranged from 390 to 8197 (median: 1722) and the number of total births per intensive care bed ranged from 72 to 1319 (median: 317). The associations between capacity measures and low birth weight rates across NICRs were statistically significant but negligible (R(2): 0.04 for neonatologists; 0.05 for beds). NICRs in the quintile with the greatest neonatologist capacity (average of only 863 births per neonatologist) had very low birth weight (VLBW) rates of 1.5% while those in the quintile of lowest neonatologist capacity (average of 3718 births per neonatologist) had VLBW rates of 1.3%; a similar lack of meaningful difference in VLBW rates was noted across quintiles of intensive care bed capacity. Including midlevel providers and intermediate care beds to the analyses did not alter the findings. CONCLUSIONS: Neonatal intensive care capacity is not preferentially located in regions with greater newborn need as measured by low birth weight rates. Whether greater capacity affords benefits to the newborns remains unknown.

Has asthma medication use in children become more frequent, more appropriate, or both?

OBJECTIVE: Despite national initiatives to improve asthma medical treatment, the appropriateness of physician prescribing for children with asthma remains unknown. This study measures trends and recent patterns in the pediatric use of medications approved for reversible obstructive airway disease (asthma medications). DESIGN: Population-based longitudinal and cross-sectional analyses. Setting. A nonprofit staff model health maintenance organization located in the Puget Sound area of Washington state. PARTICIPANTS: Children 0 to 17 years of age enrolled continuously during any one of the years from 1984 to 1993 (N = 83 232 in 1993). PRIMARY OUTCOME MEASURES. Percent of enrollees filling prescriptions for asthma medications and fill rates by medication class and estimated duration of inhaled antiinflammatory medication use. RESULTS: Between 1984 and 1993, the frequency of asthma medication use increased: the percent of children filling any asthma medication prescription increased from 4. 0% to 8.1%, whereas the percent filling an inhaled antiinflammatory inhaler rose from 0.4% to 2.4%. In contrast, the intensity of inhaled antiinflammatory use decreased among users; 37% of users filled more than two inhalers during the year in 1984, and 29% in 1993. In high beta-agonist users (filling more than two beta-agonist inhalers each quarter per year), the estimated duration of inhaled antiinflammatory use increased slightly from a mean of 4.1 months per year in 1984-1986 to 5.0 months in 1991-1993; estimated duration of use in adolescents 10 to 17 years of age was approximately half that of children 5 to 9 years of age. CONCLUSIONS: The proportion of children using asthma medications increased substantially during the study period, but the use of inhaled antiinflammatory medication per patient remained low even for those using large amounts of inhaled beta-agonists. These findings suggest that most asthma medications were used by children with mild lower airway symptoms and that inhaled antiinflammatory medication use in children with more severe disease fell short of national guidelines.

Trends in pediatric asthma hospitalization rates: regional and socioeconomic differences.

OBJECTIVE: Asthma hospitalization rates continue to increase nationally for children despite efforts by the National Institutes of Health and specialty organizations to improve outcomes through the dissemination of practice guidelines. To understand the generalizability of national trends to regional populations, we studied childhood hospitalizations over a 10-year period in four northeastern states. DESIGN: Longitudinal analysis of hospitalization rates by patient residence and patient characteristics using state hospital discharge datasets. POPULATION: Age < 18 years residing in Maine, New Hampshire, Vermont, or New York state during the period 1985 to 1994. RESULTS: In multivariate analyses (controlling for age, sex, race/ethnicity, median household income, metropolitan status), we found that New York asthma hospitalization rates increased 3.8% per annum (95% confidence interval: 3.3, 4.2), whereas in New Hampshire, rates decreased 5.8% (95% confidence interval: 7.6, 4.1). Maine and Vermont rates did not change significantly during the study period. Increased asthma hospitalization rates were noted in black and Hispanic populations, in children residing in zip codes with lower median household incomes, and in those living in metropolitan areas. Hospitalization rates for nonasthma causes fell substantially. As a result, the proportion of hospital days attributed to childhood asthma increased in all population groups. CONCLUSIONS: Asthma discharge rates measured by the state of residence or socioeconomic characteristic do not necessarily parallel national trends. None of the current hypotheses offered to explain national trends in asthma hospitalization rates (changes in disease severity, diagnostic substitution, or differences in the supply and character of medical care) can be the sole explanation of these regional trends. Efforts intended to improve asthma outcomes may benefit a greater number of children by redirecting resources toward specific populations identified through state hospital discharge datasets.

The distance to community medical care and the likelihood of hospitalization: is closer always better?

OBJECTIVES: This study examined the influence that distance from residence to the nearest hospital had on the likelihood of hospitalization and mortality. METHODS: Hospitalizations were studied for Maine. New Hampshire, and Vermont during 1989 (adults) and for 1985 through 1989 (children) and for mortality (1989) in Medicare enrollees. RESULTS: After other known predictors of hospitalization (age, sex, bed supply, median household income, rural residence, academic medical center, and presence of nursing home patients) were controlled for, the adjusted rate ratio of medical hospitalization for residents living more than 30 minutes away was 0.85 (95% confidence interval [CI] = 0.82, 0.88) for adults and 0.78 (95% CI = 0.74, 0.81) for children, compared with those living in a zip code with a hospital. Similar effects were seen for the four most common diagnosis-related groups for both adults and children. The likelihood of hospitalization for conditions usually requiring hospitalization and for mortality in the elderly did not differ by distance. CONCLUSIONS: Distance to the hospital exerts an important influence on hospitalization rates that is unlikely to be explained by illness rates.

Benchmarking the US physician workforce. An alternative to needs-based or demand-based planning.

OBJECTIVE: To propose population-based benchmarking as an alternative to needs- or demand-based planning for estimating a reasonably sized, clinically active physician workforce for the United States and its regional health care markets. DESIGN: Cross-sectional analysis of 1993 American Medical Association and American Osteopathic Association physician masterfiles. POPULATION: The resident population of the 306 hospital referral regions in the United States. MAIN OUTCOME MEASURES: Per capita number of clinically active physicians by specialty adjusted for age and sex population differences and out-of-region health care utilization. The measured physician workforce was compared with 4 benchmarks: the staffing within a large (2.4 million members) health maintenance organization (HMO), a hospital referral region dominated by managed care (Minneapolis, Minn), a hospital referral region dominated by fee-for-service (Wichita, Kan), and the proposed "balanced" physician supply (50% generalists). RESULTS: The proportion of the US population residing in hospital referral regions with a higher per capita generalist workforce than the benchmark was 96% for the HMO benchmark, 60% for Wichita, and 27% for Minneapolis. The specialist workforce exceeded all 3 benchmarks for 74% of the population. The per capita workforce of generalists was not related to the proportion of generalists among regions (Pearson correlation coefficient=0.06; P=.26). CONCLUSIONS: Population-based benchmarking offers practical advantages to needs- or demand-based planning for estimating a reasonably sized per capita workforce of clinically active physicians. The physician workforce within the benchmarks of an HMO and health care markets indicates the varying opportunities for regional physician employment and services. The ratio of generalists to specialists does not measure the adequacy of the supply of the generalist workforce either nationally or for specific regions. Research measuring the relationship between physician workforces of different sizes and population outcomes will guide the selection of future regional benchmarks.

Theophylline in acute childhood asthma: a meta-analysis of its efficacy.

Although theophylline is a widely used drug for the treatment of acute childhood asthma, its efficacy has not been clearly established. This study constitutes a meta-analysis of published randomized clinical trials of theophylline in children hospitalized with acute asthma. We conducted a search of English language MEDLINE citations from 1966 to 1995 and analyzed the methods of each report meeting study criteria. We pooled similar clinical measures across studies if a test for homogeneity of effect size was non-significant. The six methodologically acceptable randomized clinical trials included a total of 164 children less than 18 years of age. Incomplete reporting of measures and variances was common. No study included children in intensive care settings. Using pooled results, pulmonary function parameters [forced expired volume in 1 second (FEV1), forced expired flow (FEF)] appeared better at 24 hours in the theophylline group, but the results did not reach statistical significance (mean effect difference, + 3.9% predicted values; pooled effect size, + 1.6 SDS; P = 0.25). A mean of 2.1 more albuterol treatments were administered in the theophylline group (pooled effect size, - 0.18 SDS; P = 0.02), and the mean hospital stay was slightly longer (mean effect difference, - 0.31 days; pooled effect size, - 0.18 SDS; P = 0.03). We conclude that currently available data do not indicate a significant beneficial effect of theophylline in children hospitalized with acute asthma. There is evidence for weak detrimental effects. Theophylline efficacy in intensive care unit settings remains unstudied.

Assessment tools: small area analysis.

Small area analysis, the examination of geographic variation in the medical care utilization of populations, provides a method for analyzing medical care resource use and can lead to improved medical care. Variations in rates of hospital admissions for most common causes of hospitalization are related to differences in the supply of medical care resources, such as hospital beds, and uncertainty in the outcomes of different diagnostic and therapeutic procedures. Introducing clinicians to practice variation can lead to process improvements. The article describes small area analysis and the limitations of this methodology.

Poisoned landscapes: the epidemiology of environmental lead exposure in Massachusetts children 1990-1991.

This research models the geographic variation in lead poisoning among children living in Massachusetts between 1990 and 1991. Elevated levels of blood lead, which reduce educational performance, arise because children are exposed to unnaturally concentrated sources of lead in the built environment. A Poisson regression model indicates that a large number of children with lead poisoning may be detected in towns with a high proportion of older housing, female headed households, African-Americans, and an industrial heritage. Our results suggest links between the processes of urbanization and industrialization in Massachusetts and today's lead poisoned landscapes.

Why are children hospitalized? The role of non-clinical factors in pediatric hospitalizations.

OBJECTIVE: Pediatric medical discharge rates vary widely across hospital service areas, beyond differences explained by chance or disease incidence alone. This study examines the relationship between the characteristics of local medical services and the likelihood of hospitalization. DESIGN: Small area and population-based regression analysis. SETTING: The 72 hospital service areas of Maine, New Hampshire, and Vermont. STUDY POPULATION: The 589,290 (1989) children of Maine, New Hampshire, and Vermont < 15 years of age with 120,806 discharges during 1985 through 1989. MEASUREMENT AND MAIN RESULTS: Using logistic regression and controlling for community income, we found that children residing in zip codes with high per capita bed supply (4.0/1000) had 9% more discharges (odds ratio: 1.09; 99% confidence interval: 1.07, 1.11) compared with children in areas with low per capita bed supply (1.9/1000). Children living 30 minutes from the nearest hospital had 15% fewer medical discharges (odds ratio: 0.849; confidence interval: 0.830, 0.867) than those living in a zip code with a hospital. Residence in one of the three academic medical center hospital service areas resulted in 32% fewer discharges (odds ratio: 0.68; confidence interval: 0.66, 0.70). Similar and statistically significant (P < .01) results were noted for the most common nonperinatal diagnostic categories: asthma/bronchitis (diagnostic related group = 98) and gastroenteritis (diagnostic related group = 184). No effect was noted for femur fracture, a condition for which admission rates equal disease incidence. CONCLUSIONS: The supply and character of medical care are important influences on the likelihood of hospitalization for pediatric medical conditions for which outpatient alternatives are available.

Finding equilibrium in U.S. physician supply.

One essential component of health system reform is to bring the number of physicians in line with the needs of the population. The physician supply policies of prepaid group practice health maintenance organizations have been cited as one model to achieve this goal. Planning for physician supply should be an explicit public-sector activity and should not be left to the private sector, because some areas are not sufficiently populated to support competing providers under a managed competition scheme. A new model for planning for physician supply should include the following strategies: (1) erecting barriers to entry into medical practice; (2) encouraging early retirement; (3) restructuring economic incentives; (4) reallocating physicians to underserved areas in the United States and abroad; and (5) creating new areas of professional responsibility for physicians.

The marketplace in health care reform. The demographic limitations of managed competition.

BACKGROUND: The theory of managed competition holds that the quality and economy of health care delivery will improve if independent provider groups compete for consumers. In sparsely populated areas where relatively few providers are required, however, it is not feasible to divide the provider community into competing groups. We examined the demographic features of health markets in the United States to see what proportion of the population lives in areas that might successfully support managed competition. METHODS: The ratios of physicians to enrollees in large staff-model health maintenance organizations were determined as an indicator of the staffing needs of an efficient health plan. These ratios were used to estimate the populations necessary to support health organizations with various ranges of specialty services. Metropolitan areas with populations large enough to support managed competition were identified. RESULTS: We estimated that a health care services market with a population of 1.2 million could support three fully independent plans. A population of 360,000 could support three plans that independently provided most acute care hospital services, but the plans would need to share hospital facilities and contract for tertiary services. A population of 180,000 could support three plans that provided primary care and many basic specialty services but that shared inpatient cardiology and urology services. Health markets with populations greater than 180,000 would include 71 percent of the U.S. population; those with populations greater than 360,000, 63 percent; and those with populations greater than 1.2 million, 42 percent. CONCLUSIONS: Reform of the U.S. health care system through expansion of managed competition is feasible in medium-sized or large metropolitan areas. Smaller metropolitan areas and rural areas would require alternative forms of organization and regulation of health care providers in order to improve quality and economy.

Geographic barriers to child health services in rural northern New England: 1980 to 1989.

Despite substantial recent increases in the number of rural physicians, it is unknown whether rural children still face significant barriers to medical care. To address this question, we determined travel times in 1980 and in 1989 to child health services for the rural pediatric population of northern New England--the area with the highest per-capita primary care physician supply of any non-metropolitan region in the United States. The study population in 1989 included 363,443 children living in 936 nonmetropolitan towns. The study revealed important spatial relationships in health service supply and demand not identified using other methods of assessing physician availability. Although travel times to physicians decreased slightly during the decade, we found that 15.5 percent of the children in our population were more than 30 minutes from pediatricians in 1989, and travel time to emergency rooms was more than 30 minutes for 9.9 percent of the children. In contrast, only 1.8 percent of children faced excessive travel times to family/general practitioners. While towns with pediatricians were likely to also have a family physician or an emergency room, the majority of towns with family physicians had neither a pediatrician nor an emergency room. Towns with poor geographic access to pediatricians and emergency rooms had low population densities and were distant from metropolitan areas. The analysis indicates that even in rural areas of high physician supply, access to pediatricians and emergency rooms for many children remains limited, and family physicians are the dominant medical providers for children.(ABSTRACT TRUNCATED AT 250 WORDS)

Organization of ascending spinal projections in Caiman crocodilus.

Ascending spinal projections in the caiman (Caiman crocodilus) were demonstrated with Nauta and Fink-Heimer methods following hemisections of the third spinal segment in a series of twelve animals. These results were compared with earlier data in the literature obtained from a turtle, a snake, and a lizard using the same experimental and histological procedures. The results show remarkable similarities considering that each species represents a different reptilian order with different evolutionary history and habitat. However, the caiman displays several important peculiarities. Although the dorsal funiculus of the caiman contains the largest number of ascending spinal projections of the four species examined, this funiculus has not differentiated into cuneate and gracile fasciculi as is the case in the tegu lizard. The ventro-lateral ascending spinal projections follow a fundamentally similar general morphologic pattern in the four species with only minor variations. The anatomical arrangement in the caiman and tegu lizard appears most similar in the high cervical and the medullary regions; however, this is not the case in midbrain and thalamic regions where considerably more extensive projections are seen in the caiman. In the caiman an extensive spinal connection to the ventro-lateral nucleus of the dorsal thalamus is present; this connection is reminiscent of the mammalian spinal projection to the ventro-basal complex. The caiman has in common with the other three reptilian species a small projection to another dorsal thalamic region that is apparently homologous to the mammalian intralaminar nuclei, which are the destination of the mammalian paleospinothalamic tract.

Absence of sprouting by retinogeniculate axons after chronic focal lesions in the adult cat retina.

Focal lesions were placed in the retina of adult cats in order to denervate partially the laminae of the lateral geniculate nucleus (LGN). Retinogeniculate projections were assessed after survival times of from 5 days to 2 years by means of either reduced silver staining for degeneration or autoradiographic labelling. Filling of the lesion-denervated zones by 'sprouts' from the intact retinofugal fibers was not observed, even in the brains of animals with long-term lesions. It was concluded that the retinogeniculate projection in adult cat does not display any significant ability to sprout into denervated regions.

The ventral lateral geniculate nucleus, pars lateralis of the rat. Synaptic organization and conditions for axonal sprouting.

The synaptic organization of the pars lateralis portion of the ventral lateral geniculate nucleus is similar to that of other thalamic nuclei. There are four types of synaptic knobs (RL, RS, F1, F2). RL knobs are large and irregularly shaped, contain round synaptic vesicles and make multiple asymmetrical junctions. They are found primarily in "synaptic islands" making contact with gemmules, spines, small dendrites, and other synaptic profiles containing pleiomorphic synaptic vesicles (F2). Smaller RS knobs contain round vesicles and make asymmetrical junctions with the same type of elements as RL knobs, with the exception of the F2 profiles, but are seldom found in synaptic islands. F1 knobs contain flattened synaptic vesicles and form symmetrical junctions with F2 knobs, gemmules, spines, and small-medium dendrites in synaptic islands, throughout the neuropil, and on the proximal dendrites and soma of the largest type of neuron. F2 knobs are irregularly shaped, contain pleiomorphic synaptic vesicles and make symmetrical junctions primarily with gemmules and spines in synaptic islands. They are postsynaptic to RL and F1 knobs. Occipital decortication indicates that cortical terminals are of the RS type. Bilateral enucleation indicates that retinal terminals are of both the FL and RS type. The large amount of geographic overlap of retinal and cortical terminals on gemmules, spines, and small dendrites found in the neuropil outside of synaptic islands logically would maximize axonal sprouting between these two sources.