Distribution and hypothalamic projection of tyrosine-hydroxylase containing neurons of the nucleus of the solitary tract in the pigeon.

The avian nucleus of the solitary tract has an extensive subnuclear organization. Several subnuclear cell groups can be distinguished on the basis of cytoarchitectonic criteria. In general, the subnuclei of the medial division of the nucleus of the solitary tract receive gastrointestinal afferents, whereas the subnuclei of the lateral division of the nucleus of the solitary tract receive cardiopulmonary afferents. Forebrain afferents to the nucleus of the solitary tract are segregated to medial and lateral subnuclei, which are located at the periphery of the nucleus. These peripheral subnuclei of the nucleus of the solitary tract are also the source of ascending axonal projections to the forebrain. In this study, the tyrosine hydroxylase (initial enzyme for catecholamine synthesis) content of the anteromedial hypothalamic projecting neurons of the nucleus of the solitary tract is determined by use of a combined retrograde fluorescent dye-immunofluorescence method. Fast Blue implanted into the anteromedial hypothalamus (in the region of the nucleus periventricularis magnocellularis) resulted in the retrograde labeling of neurons in the caudal two-thirds of the nucleus of the solitary tract. At levels rostral to the obex, dye-labeled cells were mostly observed in the dorsally located subnuclei medialis superficialis pars posterior and lateralis dorsalis pars posterior and in the ventrally located subnucleus medialis ventralis pars posterior. More centrally located subnuclei contained few labeled cells, if any. For example, subnucleus medialis intermedius pars posterior only had a few retrogradely labeled cells, whereas the centrally located subnucleus medialis dorsalis pars posterior was almost devoid of labeled cells. At levels caudal to the obex, many retrogradely labeled neurons of the nucleus of the solitary tract were observed. Neurons immunoreactively labeled for tyrosine hydroxylase were mostly found within subnuclei, which contain anteromedial hypothalamic projection neurons. In subnuclei medialis superficialis pars posterior and lateralis dorsalis pars posterior, 87% of the retrogradely dye-labeled cells were also immunoreactively labeled, whereas in the caudal nucleus of the solitary tract (at levels caudal to the obex), 68% of the retrogradely labeled cells were immunoreactively labeled. Not all tyrosine hydroxylase containing cells had projections to the implantation site in the anteromedial hypothalamus since only 40% of the immunoreactive cells in the caudal nucleus of the solitary tract and 59% of the immunoreactive cells in the subnucleus medialis superficialis pars posterior were retrogradely labeled with Fast Blue.(ABSTRACT TRUNCATED AT 400 WORDS)

Projections of the lateral hypothalamus and bed nucleus of the stria terminalis to the dorsal vagal complex in the pigeon.

The dorsal vagal complex is composed of the nucleus tractus solitarii (Nts) and the dorsal motor nucleus of the vagus (DMN X). In the pigeon, these nuclei are composed of cytoarchitectonically well-defined subnuclear groups, which have connections that are partially segregated to specific organs (Katz and Karten: J. Comp. Neurol. 218:42-73, '83b, J. Comp. Neurol. 242:397-414, '85). The present study sought to determine whether forebrain afferents to Nts-DMN X are differentially distributed to specific subnuclei and thereby modulate the functions of specific organs. Forebrain afferents to the dorsal vagal complex were determined by retrograde tracing techniques. Labeled perikarya were found in the bed nucleus of the stria terminalis (BNST), ventral paleostriatum, and stratum cellulare externum (SCE) of the lateral hypothalamus, and in the medial hypothalamus, nucleus periventricularis magnocellularis (PVM), which is the avian homologue to a portion of the mammalian paraventricular nucleus. The pattern of axonal distribution to Nts-DMN X subnuclei from the BNST-ventral paleostriatum and SCE were investigated by anterograde tracing techniques. These experiments revealed axonal projections distributed to specific Nts-DMN X subnuclei. However, there is a high degree of overlap of the axonal projections to Nts-DMN X subnuclei from BNST-ventral paleostriatum and SCE, as well as from PVM (Berk and Finkelstein: J. Comp. Neurol. 220:127-136, '83). Labeled fibers from BNST-ventral paleostriatum and SCE project heavily to Nts subnuclei medialis superficialis, lateralis dorsalis, and medialis ventralis and to DMN X subnucleus ventralis parvicellularis. Fewer labeled fibers were found in Nts subnucleus medialis intermedius and extremely sparse labeling was found in Nts subnucleus medialis dorsalis. The Nts and DMN X subnuclei that receive forebrain projections also have peripheral connections with the aortic nerve, crop, esophagus, glandular stomach, and caudal abdominal organs. Thus, the forebrain could modulate the functions of these segments of the cardiovascular and digestive systems.

Efferent projections of the medial preoptic nucleus and medial hypothalamus in the pigeon.

The efferent projections of the medial preoptic nucleus (POM), anterior-medial hypothalamic area (AM), and the posteromedial hypothalamic nucleus (PMH) in the pigeon were traced by the autoradiographic technique. Similar and differential connections were noted from these regions. Projections from POM and AM-PMH were traced to nucleus septalis lateralis, nucleus dorsomedialis thalami, nucleus dorsolateralis anterior thalami (pars ventralis), posterior hypothalamic and medial mammillary areas, area ventralis tegmenti (Tsai), central gray of midbrain and nucleus intercollicularis and substantia grisea periventricularis of the midbrain. The density of silver grains in these regions differed with POM and AM-PMH injections. Other projections were observed exclusively from only one or two of the nuclear regions injected. Connections from POM and the rostral part of AM were seen to the median eminence, neurohypophysis, and the nucleus of anterior pallial commissure. Only cells of the anterior part of AM project fibers to nucleus septalis medialis. In the hypothalamus, projections from POM are concentrated in the periventricular region and in the preoptic-hypophyseal tract in the extreme lateral hypothalamus, while AM-PMH projections are heaviest in the medial hypothalamus and lateral preoptic area. A major difference in the connections of PMH from POM is the more substantial PMH projection to the midbrain. A prominent projection courses dorsolaterally and posteriorly from PMH toward nucleus ovoidalis and splits into two pathways: a lateral pathway which heavily innervates n. intercollicularis and the periventricular gray and a ventrolateral projection to the midbrain tegmentum. The projections described above provide anatomical substrates for neuroendocrine, autonomic, and behavioral functions.

Local and commissural neuropeptide-containing projections of the nucleus of the solitary tract to the dorsal vagal complex in the pigeon.

The neuropeptide content of neurons of the nucleus of the solitary tract (NTS), which have local and commissural projections to the dorsal motor nucleus of the vagus (DMNX) and to NTS, were demonstrated in the pigeon (Columba livia) by using a combined fluorescein-bead retrograde-transport-immunofluorescence technique. The specific peptides studied were bombesin, cholecystokinin, enkephalin, galanin, neuropeptide Y, neurotensin, and substance P. Perikarya immunoreactive for bombesin were located in medial tier subnuclei of NTS and the caudal NTS. Most galanin- and substance P-immunoreactive cells were found in subnucleus medialis ventralis. Cells immunoreactive for neuropeptide Y were found in the medial tier of NTS and in the lateral tier, especially in subnucleus lateralis dorsalis intermedius. The majority of enkephalin- and neurotensin-immunoreactive cells were found centrally in subnuclei medialis dorsalis and medialis intermedius. Cells immunoreactive for cholecystokinin were located in subnuclei lateralis dorsalis pars anterior, medialis superficialis, and the caudal NTS. Based on the presence of retrogradely labeled cells, numerous neurons of the medial tier of NTS, but extremely few lateral tier NTS neurons, had projections to the ipsilateral and contralateral DMNX and NTS. The number of retrogradely labeled NTS cells was always greater ipsilaterally than contralaterally. The percentages of peptide-immunoreactive NTS cells that projected to the ipsilateral and contralateral DMNX were in the ranges of 29-61% and 10-48%, respectively. The percentages of peptide-immunoreactive NTS cells that projected to the contralateral NTS ranged from 13 to 60%. Peptide-immunoreactive NTS cells that have local and commissural projections to DMNX and NTS may act as interneurons in vagovagal reflex pathways and in the integration of visceral sensory and forebrain input to NTS and DMNX.

Long descending projections of the hypothalamus in the pigeon, Columba livia.

An autoradiographic analysis was performed on the descending projections of nucleus periventricularis magnocellularis (PVM) of the hypothalamus in the pigeon. A PVM-medullospinal pathway was observed coursing posteriorly through the lateral hypothalamus, ventrolateral midbrain tegmentum, and into the spinal lemniscus (ls) in the ventrolateral pons and medulla. In the pons, some fibers course dorsomedially from ls and terminate at the lateral border of the locus coeruleus. At medullary levels, fibers from ls sweep dorsomedially in the plexus of Horsley and project to certain regions of the nucleus of the solitary tract (NTS) and the dorsal motor nucleus of the vagus (NX). Specifically, PVM fibers project heavily into NTS subnuclei medialis superficialis, medialis ventralis, and lateralis (sulcalis) dorsalis as well as into the ventral parvocellular subnucleus of NX. Fibers in ls were traced caudally into the lateral funiculus as far as upper cervical levels of the spinal cord. Although autoradiographs of lower cervical or thoracic spinal cord sections were not available, PVM fibers do descend to thoracic spinal cord levels, as evidenced by the retrograde transport of horseradish peroxidase. In addition to the medullospinal pathway, the autoradiographs demonstrated PVM projections to septum, diencephalon, and midbrain. Labeled PVM fibers are found in the lateral septal nucleus, nucleus of the anterior pallial commisure, dorsomedial thalamic nucleus, dorsolateral anterior thalamic nucleus (pars ventralis), median eminence, medial and lateral hypothalamus, medial mammillary area, and nucleus intercollicularis and central gray of the midbrain. The projection of fibers to medullospinal regions and median eminence suggests that PVM is homologous to the mammalian paraventricular nucleus. These projections to specific subnuclei of NTS and NX denote hypothalamic control over certain autonomic functions.

Ascending projections of the mammillary region in the pigeon: emphasis on telencephalic connections.

The ascending projections of the mammillary region of the hypothalamus and adjacent posterolateral hypothalamus were investigated by autoradiographic and horseradish peroxidase histochemical techniques. Analysis of the anterograde data revealed that the main contingent of mammillary fibers ascends in the medial forebrain bundle (MFB) in the lateral hypothalamic area. These fibers distribute to a number of telencephalic regions via three pathways. (1) Fibers course dorsomedially into the medial and lateral parts of the septum and continue into the hippocampus with a dense terminal field in the parahippocampal area. (2) Laterally coursing fibers project to area corticoidea dorsolateralis, area temporo-parieto-occipitalis, cortex piriformis, and the posterior part of archistriatum. (3) The fibers remaining in the MFB ascend into the "ventral paleostriatum," olfactory tubercle, and into the lateral and ventral borders of the rostral portion of lobus parolfactorius (LPO). Numerous fibers leave the LPO region and course dorsally into the deep layer of the Wulst, hyperstriatum dorsale (HD). Many fibers continue dorsolaterally through the HD and enter an unnamed region of the dorsolateral telencephalon (lateral to the vallecula) at the level of the olfactory bulb. Retrograde transport experiments revealed that the perikarya of origin-of-fiber projections to the parahippocampal area and to the rostral, dorsolateral telencephalon reside not only in nucleus mammillaris lateralis but also in posterolateral hypothalamic cells rostral and dorsal to this nucleus. The projection of these hypothalamic cells to the hippocampal formation and many other telencephalic regions in birds suggests that these cells are similar to the mammalian supramammillary nucleus and posterolateral hypothalamus rather than the mammillary nuclei.

Nucleus of the solitary tract and dorsal motor nucleus of the vagus nerve of the pigeon: localization of peptide and 5-hydroxytryptamine immunoreactive fibers.

The distribution of peptide and serotonin fibers in the nucleus of the solitary tract (NTS) and the dorsal motor nucleus of the vagus nerve (DMNX) in the pigeon (Columba livia) was investigated immunocytochemically. This information was correlated with the viscerotopic organization of the nuclei and with central NTS circuitry to suggest the role of the neurochemical containing fibers in the regulation of organ function. The distribution of fibers containing cholecystokinin (CCK), calcitonin gene-related peptide (CGRP), enkephalin (ENK), neuropeptide Y (NPY), neurotensin (NT), substance P (SP), somatostatin (SS), vasoactive intestinal peptide (VIP), and 5-hydroxytryptamine (5-HT) was determined. Each substance had a distinct distribution within the subnuclei of NTS-DMNX, but certain generalities can be deduced. In the DMNX, fibers immunoreactive for ENK, NT, and SP were found in greatest concentration, while CGRP and 5-HT immunoreactive fibers were the least dense. This suggests that ENK, NT, and SP may have a significant modulatory effect on gastrointestinal functions. In the NTS overall, ENK, NT, SP, and VIP fibers were found in high density, CCK, NPY, SS, and 5-HT fibers were found in moderate density, and CGRP fibers were found in low density. However, some individual NTS subnuclei were found to contain moderate to high concentrations of each of the substances, including CGRP. Fibers containing CCK, ENK, NT, SP, SS, and VIP in the medial dorsal NTS subnuclei may regulate gastroesophageal functions. The caudal part of subnucleus lateralis parasolitarius did not contain most of the substances, which suggests that pulmonary function is not modulated by these neurochemicals. The boundaries of a subnucleus could sometimes be demarcated by a change in density of immunoreactive fibers between adjacent subnuclei. This was particularly evident in NTS subnuclei medialis dorsalis anterior centralis and lateralis parasolitarius, and in DMNX subnucleus posterior dorsalis magnocellularis. The selective distribution of peptide and serotonin immunoreactive fibers in various subnuclei of NTS-DMNX suggests that these substances may be differentially involved in neural circuits that mediate cardiovascular and gastrointestinal functions.

Distribution, parabrachial region projection, and coexistence of neuropeptide and catecholamine cells of the nucleus of the solitary tract in the pigeon.

The chemical nature of the cells of the nucleus of the solitary tract (NTS) that project to the parabrachial nucleus (PB) was investigated in the pigeon by the use of fluorescent bead retrograde tracer and immunofluorescence for the detection of substance P (SP), leucine-enkephalin (LENK), cholecystokinin (CCK), neurotensin (NT), somatostatin (SS), and tyrosine hydroxylase (TH). Cells immunoreactive for CCK were located in subnuclei lateralis dorsalis pars anterior (LDa) and medialis superficialis pars posterior, and caudal NTS (cNTS); 22-26.5% of these cells were double-labeled bilaterally. Immunoreactive SP cells were found in ventral NTS subnuclei; 24-25% of these cells were double-labeled bilaterally. Cells immunoreactive for LENK and NT were concentrated in the anterior NTS; 5.5-7.5% of the LENK cells were double-labeled bilaterally, while 11% (ipsilateral) and 21% (contralateral) of the NT immunoreactive cells were double-labeled. Many SS immunoreactive cells were found in peripherally located subnuclei; 5.5-6.5% of these cells were double-labeled bilaterally. Catecholamine cells were distributed in LDa, peripheral subnuclei, and cNTS; 23% of these cells were double-labeled ipsilaterally and 8.5% contralaterally. A two-color double-labeling immunofluorescence technique revealed many cells immunoreactive for both NT and LENK, only a rare cell immunoreactive for both SS and SP, and no cells immunoreactive for both TH and SP. Cells immunoreactive for SP, CCK, NT, and TH are major contributors to NTS projections to PB. The confinement of these substances to specific NTS subnuclei, which receive visceral sensory information from specific organs, may contribute to the chemical encoding of ascending visceral information.

The localization of vasotocin and neurophysin neurons in the diencephalon of the pigeon, Columba livia.

Vasotocin (VT)- and neurophysin (NP)-synthesizing neurons were demonstrated by immunocytochemistry in the diencephalon of the pigeon, Columba livia. Three diencephalic regions contain VT-NP cells: (1) periventricular preoptic area and hypothalamus, including nucleus periventricularis magnocellularis (PVM); (2) lateral preoptic area and hypothalamus; and (3) dorsal diencephalon. The immunoreactive cells in each of these three regions were divided into groups based on cytology and topography. No differences were found in the location of VT and NP cell groups. The periventricular region contains three continuous cell groups (P1-P3) extending from the posteroventral preoptic area to the anterodorsal hypothalamus and PVM. The lateral region has two cell groups composed of medium- to large-sized cells associated with the quintofrontal tract (L1) or with the optic tract (L2), while a third group (L3) lies between these two cell groups. Two accessory cell groups reside in the dorsolateral hypothalamus; L4 contains scattered cells of varied size, whereas L5 has small- to medium-sized cells clumped together. The dorsal diencephalic cell groups are found in the following locations: (1) lateral and dorsal to the lateral forebrain bundle (DD1); (2) in the area ventral to the dorsomedial anterior thalamic nucleus and dorsolateral to PVM (DD2); and (3) at the dorsolateral border of nucleus rotundus (DD3). To avoid potentially inaccurate mammalian homologies, the cell group nomenclature denotes topographic position. Nevertheless, the presence of VT-NP cells in PVM and projections to the brainstem and spinal cord suggest a homology between PVM and some of the parvocellular subnuclei of the mammalian paraventricular nucleus.

Regular source of care and the minority aged.

Data from the National Medical Care Expenditure Survey are used to examine the access of elderly minorities to a regular source of medical care. The findings suggest that such elderly persons are about as likely as the white elderly to have a routine point of entry into the medical care system. There are, however, difference in the type of setting at which care is received. Compared with the elderly population of whites, the elderly population of minorities is more likely to have a regular source of care in an institutional setting and less likely to have a regular source of care that provides house calls or emergency services. The absence of a usual source of care may be a contributing factor to the difference in use of health services between the white and the nonwhite elderly populations.

The concentration of health care expenditures, revisited.

In two previous publications, we described the distribution of health care expenditures among the civilian, noninstitutionalized U.S. population, specifically in terms of the share of aggregate expenditures accounted for by the top spenders in the distribution. Our focus revealed considerably skewed distribution, with a relatively small proportion of the population accounting for a large share of expenditures. In this paper we update our previous tabulations (last computed using data more than a decade old) with new data from the 1996 Medical Expenditure Panel Survey (MEPS). Our findings show that the skewed concentration of health care expenditures has remained very stable; 5 percent of the population accounts for the majority of health expenditures.

Access to care: how much difference does Medicaid make?

Using the 1994 Robert Wood Johnson Foundation National Access to Care Survey, we examine the likelihood of having a usual source of care, inability to obtain needed care, and number of physician visits for persons with private insurance, Medicaid coverage, and no insurance. Inability to obtain services is surprisingly consistent: For each service, Medicaid enrollees were about half as likely as uninsured persons and about twice as likely as privately insured persons were to report difficulty. For other access measures, access for those on Medicaid more closely resembles that of the privately insured than that of the uninsured.

The concentration of health expenditures: an update.

An earlier study tracing trends in health spending from 1928 to 1980 found health expenditures concentrated among the top 1 percent of those spending money for health care. In an update to that study, the authors found that that trend toward concentration has increased. In 1987 the tope 1 percent of spenders accounted for 30 percent of health spending, up from 26 percent in 1970 and 29 percent in 1980. In contrast, the bottom half of the population in terms of spending accounted for only 3 percent of total spending in 1987. The average expenditure for the top 1 percent of spenders in 1987 was $47,331. Nearly half of those top spenders in 1987 were elderly. Also, more than 16 percent were black, up from nearly 10 percent in 1980.

Ability to obtain health care: recent estimates from the Robert Wood Johnson Foundation National Access to Care Survey.

This DataWatch presents findings on Americans' ability to obtain health care. Data from the 1994 National Access to Care Survey sponsored by The Robert Wood Johnson Foundation suggest that earlier studies have underestimated the access problems facing Americans by not asking about supplementary services such as prescription drugs, eyeglasses, dental care, and mental health care or counseling. Using this more inclusive definition of health care needs, we estimate that 16.1 percent of Americans were unable to obtain at least one service they believed they needed. While income is highly correlated with unmet need, most persons reporting access problems are not poor.

Health care use among undocumented Latino immigrants.

Using data from a 1996/1997 survey of undocumented Latino immigrants in four sites, we examine reasons for coming to the United States, use of health care services, and participation in government programs. We find that undocumented Latinos come to this country primarily for jobs. Their ambulatory health care use is low compared with that of all Latinos and all persons nationally, and their rates of hospitalization are comparable except for hospitalization for childbirth. Almost half of married undocumented Latinos have a child who is a U.S. citizen. Excluding undocumented immigrants from receiving government-funded health care services is unlikely to reduce the level of immigration and likely to affect the well-being of children who are U.S. citizens living in immigrant households.

An autoradiographic determination of the efferent projections of the suprachiasmatic nucleus of the hypothalamus.

The efferent projections of the suprachiasmatic nucleus of the hypothalamus (SCN) have been investigated by the use of the anterograde autoradiographic technique. The majority of the fiber connections from SCN are to hypothalamic nuclei. The dorsal and periventricular parvocellular divisions of the paraventricular nucleus (PVN) and the medial part of the dorsomedial hypothalamic nucleus receive dense fiber projections. Also, fibers about the medial parvocellular division of PVN. Many descending fibers course into the retrochiasmatic area and pass to the ventral and medial borders of the ventromedial hypothalamic nucleus, as well as through the central zone of this nucleus. A few fibers at the lateral border of the ventromedial hypothalamic nucleus sweep dorsomedially into the posterior hypothalamic area and midbrain central gray. The major extrahypothalamic projection is to the periventricular thalamic nucleus.

Efferent connections of the lateral hypothalamic area of the rat: an autoradiographic investigation.

The efferent projections of the lateral hypothalamic area (LHA) at mid-tuberal levels were examined with the autoradiographic tracing method. Connections were observed to widespread regions of the brain, from the telencephalon to the medulla. Ascending fibers course through LHA and the lateral preoptic area and lie lateral to the diagonal band of Broca. Fibers sweep dorsally into the lateral septal nucleus, cingulum bundle and medial cortex. Although sparse injections are found to the ventromedial hypothalamic nucleus, a prominent pathway courses to the dorsal and medial parvocellular subnuclei of the paraventricular nucleus. Labeled fibers in the stria medullaris project to the lateral habenular nucleus. The central nucleus of the amygdala is encapsulated by fibers from the stria terminalis and the ventral amygdalofugal pathway. The substantia innominata, nucleus paraventricularis of the thalamus, and bed nucleus of the stria terminalis also receive LHA fibers. Three descending pathways course to the brainstem: (1) periventricular system, (2) central tegmental tract (CTT), and (3) medial forebrain bundle (MFB). Periventricular fibers travel to the ventral and lateral parts of the midbrain central gray, dorsal raphe nucleus, and laterodorsal tegmental nucleus of the pons. Dorsally coursing fibers of CTT enter the central tegmental field and the lateral and medial parabrachial nuclei. The intermediate and deep layers of the superior colliculus receive some fibers. Fibers from CTT leave the parabranchial region by descending in the ventrolateral pontine and medullary formation; some of these fibers sweep dorsomedially into the nucleus tractus solitarius, dorsal motor nucleus of the vagus, and nucleus commissuralis. From MFB, fibers descend into the ventral tegmental area and to the border of the median raphe and raphe magnus nuclei.

National probability samples in studies of low-prevalence diseases. Part I: Perspectives and lessons from the HIV cost and services utilization study.

OBJECTIVE: To examine the trade-offs inherent in selecting a sample design for a national study of care for an uncommon disease, and the adaptations, opportunities and costs associated with the choice of national probability sampling in a study of HIV/AIDS. SETTING: A consortium of public and private funders, research organizations, community advocates, and local providers assembled to design and execute the study. DESIGN: Data collected by providers or collected for administrative purposes are limited by selectivity and concerns about validity. In studies based on convenience sampling, generalizability is uncertain. Multistage probability sampling through households may not produce sufficient cases of diseases that are not highly prevalent. In such cases, an attractive alternative design is multistage probability sampling through sites of care, in which all persons in the reference population have some chance of random selection through their medical providers, and in which included subjects are selected with known probability. DATA COLLECTION AND PRINCIPAL FINDINGS: Multistage national probability sampling through providers supplies uniquely valuable information, but will not represent populations not receiving medical care and may not provide sufficient cases in subpopulations of interest. Factors contributing to the substantial cost of such a design include the need to develop a sampling frame, the problems associated with recruitment of providers and subjects through medical providers, the need for buy-in from persons affected by the disease and their medical practitioners, as well as the need for a high participation rate. Broad representation from the national community of scholars with relevant expertise is desirable. Special problems are associated with organization of the research effort, with instrument development, and with data analysis and dissemination in such a consortium. CONCLUSIONS: Multistage probability sampling through providers can provide unbiased, nationally representative data on persons receiving regular medical care for uncommon diseases and can improve our ability to accurately study care and its outcomes for diseases such as HIV/AIDS. However, substantial costs and special circumstances are associated with the implementation of such efforts.

Choice of health plan: implications for access and satisfaction.

In this article, the authors examine why low-income persons choose a managed care plan and the effects of choice on access and satisfaction, using data from the 1995-96 Kaiser/Commonwealth Five-State Low-Income Survey. Two-thirds of those choosing a managed care plan cited costs or benefits as their primary reason. Logistic regressions indicate that choice of plan had a neutral or positive effect on access and satisfaction. Medicaid enrollees with choice were less likely than those without to have difficulty obtaining particular services, more likely to rate plan quality highly, and less likely to report major problems with plan rules.

Health care use by Hispanic adults: financial vs. non-financial determinants.

The purpose of this article is to assess the relative effects of financial and cultural factors, namely language spoken, on health care use by Hispanic adults. Using a national sample, we examine the determinants of having a usual source of care (USOC), use of physician visits, and likelihood of having blood pressure checked. Multivariate analysis reveals the following: Monolingual Spanish speakers were not significantly different from English speakers for the three dependent variables; having private insurance or Medicaid was positively related to all three dependent variables. We conclude that financial factors--primarily insurance--remain as the paramount barriers to care.