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1.
BMC Health Serv Res ; 16(1): 634, 2016 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-27821121

RESUMO

BACKGROUND: Approximately 29 million individuals are expected to enroll in health insurance using the Patient Protection and Affordable Care Act (ACA) Marketplace by 2022. Those seeking health insurance struggle to understand insurance options and choose a plan that best suits their needs. METHODS: We interviewed stakeholders to identify the challenges associated with the ACA Marketplace health insurance enrollment and elicited feedback about what to include in health insurance decision support tools. Interviews were transcribed and themes were identified using inductive thematic analysis. RESULTS: Stakeholders stated that consumers felt frustrated by unclear terminology, high plan costs, and complex calculations required to assess costs. Consumers felt anxious about making the wrong choice and being unable to change plans within a calendar year. Stakeholders recommended using plain language tables defining complex terms, grouping information, and using engaging graphics to communicate information about health insurance. Stakeholders thought that narratives of how others made decisions about insurance might be helpful to consumers, but recommended that they be tailored to the needs of specific consumers. CONCLUSION: Strategies that clarify health insurance terms using plain language and graphics, acknowledge concern associated with making the wrong choice, calculate and enable cost comparison, and tailor information to consumers' unique needs could benefit those enrolling in ACA Marketplace plans, Narratives developed should be simple and inclusive enough for diverse populations.


Assuntos
Comportamento de Escolha , Trocas de Seguro de Saúde , Compreensão , Tomada de Decisões , Feminino , Trocas de Seguro de Saúde/economia , Trocas de Seguro de Saúde/estatística & dados numéricos , Humanos , Cobertura do Seguro/economia , Seguro Saúde/economia , Entrevistas como Assunto , Masculino , Patient Protection and Affordable Care Act , Pesquisa Qualitativa , Estados Unidos
2.
Int J Clin Pract ; 63(1): 27-34, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19125990

RESUMO

OBJECTIVE: The ENDURANCE study evaluated the efficacy of vardenafil, a phosphodiesterase type 5 (PDE5) inhibitor, in men with erectile dysfunction (ED), by measuring the duration of erection leading to successful intercourse using a stopwatch as the assessment instrument. METHODS: This was a randomised, multicentre, double-blind, placebo-controlled, crossover study consisting of a 4-week treatment-free run-in phase after which patients were randomised to either fixed-dose vardenafil 10 mg or placebo (to be administered 60 min prior to intercourse) and entered the first of the two 4-week double-blind treatment periods, separated by a 1-week washout. The primary efficacy end-point was the stopwatch-assessed duration of erection, which was defined as the time from erection perceived hard enough for penetration until withdrawal from the partner's vagina leading to successful intercourse as measured by Sexual Encounter Profile Question 3 (SEP-3). Secondary efficacy end-points included SEP-2 and SEP-3 success rates, the erectile function domain of the International Index of Erectile Function, global assessment questionnaire, change from baseline in duration of erection and duration of erection not leading to successful intercourse. Safety was assessed by adverse events (AEs), laboratory samples, vital signs and ECGs. RESULTS: Of the 191 men included in the safety population, 40% had moderate ED and 33% had severe ED at baseline. The duration of erection (least squares mean +/- SE) leading to successful intercourse was longer with vardenafil than with placebo (12.81 +/- 1.00 min vs. 5.45 +/- 1.00 min; p < 0.001). The differences recorded for all secondary end-points were statistically significant in favour of vardenafil compared with placebo (p < 0.001), with the exception of duration of erection not leading to successful intercourse. Vardenafil was well tolerated in this study; the majority of AEs being mild-to-moderate in intensity. CONCLUSION: Vardenafil 10-mg therapy provided a statistically superior duration of erection leading to successful intercourse in men with ED compared with placebo.


Assuntos
Coito , Disfunção Erétil/tratamento farmacológico , Imidazóis/uso terapêutico , Ereção Peniana/efeitos dos fármacos , Inibidores de Fosfodiesterase/uso terapêutico , Piperazinas/uso terapêutico , Adulto , Estudos Cross-Over , Método Duplo-Cego , Humanos , Imidazóis/efeitos adversos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Inibidores de Fosfodiesterase/efeitos adversos , Piperazinas/efeitos adversos , Índice de Gravidade de Doença , Sulfonas/efeitos adversos , Sulfonas/uso terapêutico , Inquéritos e Questionários , Fatores de Tempo , Resultado do Tratamento , Triazinas/efeitos adversos , Triazinas/uso terapêutico , Dicloridrato de Vardenafila , Adulto Jovem
3.
Vision Res ; 46(6-7): 1057-69, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16289208

RESUMO

In four experiments, observers were required to discriminate interval or ordinal differences in slant, tilt, or curvedness between designated probe points on randomly shaped curved surfaces defined by shading, texture, and binocular disparity. The results reveal that discrimination thresholds for judgments of slant or tilt typically range between 4 degrees and 10 degrees; that judgments of one component are unaffected by simultaneous variations in the other; and that the individual thresholds for either the slant or tilt components of orientation are approximately equal to those obtained for judgments of the total orientation difference between two probed regions. Performance was much worse, however, for judgments of curvedness, and these judgments were significantly impaired when there were simultaneous variations in the shape index parameter of curvature.


Assuntos
Percepção de Profundidade/fisiologia , Discriminação Psicológica/fisiologia , Percepção de Forma/fisiologia , Humanos , Julgamento/fisiologia , Orientação , Estimulação Luminosa/métodos , Psicometria , Limiar Sensorial/fisiologia , Disparidade Visual/fisiologia , Visão Binocular/fisiologia
4.
Cancer Res ; 53(18): 4172-4, 1993 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-8364911

RESUMO

We have determined the specificity of mutations produced by nickel(II), a known human carcinogen, in a forward mutation assay and also used a sensitive reversion assay to show that Ni(II), like iron and copper, can produce tandem double CC-->TT mutations, a hallmark of damage to DNA by either UV irradiation or oxygen free radicals. A reduction in mutation frequencies by the addition of oxygen radical scavengers also supports the involvement of reactive oxygen species in DNA damage and mutagenesis by Ni(II). Mutagenesis by Ni(II) is enhanced by the addition of both hydrogen peroxide and a tripeptide glycyl-glycyl-L-histidine. The enhancement of mutagenesis of Ni(II) by the tripeptide indicates that these complexes could serve to localize Ni(II) in nuclei and mediate DNA damage and mutagenesis via the generation of short-lived oxygen free radicals. These data suggest that Ni(II) carcinogenesis may proceed via the generation of active oxygen species and furthermore provide a model for nickel carcinogenesis based on the binding of Ni(II) to nuclear proteins.


Assuntos
Dano ao DNA , Mutação , Níquel/toxicidade , Espécies Reativas de Oxigênio/toxicidade , Sequência de Aminoácidos , Sequência de Bases , Radicais Livres , Dados de Sequência Molecular
5.
Genetics ; 160(4): 1599-608, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11973313

RESUMO

Therapeutic intervention for atherosclerosis has predominantly concentrated on regulating cholesterol levels; however, these therapeutics are not efficacious for all patients, suggesting that other factors are involved. This study was initiated to identify mechanisms that regulate atherosclerosis predisposition in mice other than cholesterol level regulation. To do so we performed quantitative trait locus analysis using two inbred strains that each carry the atherosclerosis phenotype-sensitizing Apoe deficiency and that have been shown to have widely disparate predilection to atherosclerotic lesion formation. One highly significant locus on chromosome 10 (LOD = 7.8) accounted for 19% of the variance in lesion area independent of cholesterol. Two additional suggestive loci were identified on chromosomes 14 (LOD = 3.2) and 19 (LOD = 3.2), each accounting for 7-8% of the lesion variance. In all, five statistically significant and suggestive loci affecting lesion size but not lipoprotein levels were identified. Many of these were recapitulated in an independent confirmatory cross. In summary, two independently performed crosses between C57BL/6 and FVB/N Apoe-deficient mice have revealed several previously unreported atherosclerosis susceptibility loci that are distinct from loci linked to lipoprotein levels.


Assuntos
Apolipoproteínas E/deficiência , Arteriosclerose/genética , Predisposição Genética para Doença , Animais , Apolipoproteínas E/genética , Colesterol/sangue , Feminino , Frequência do Gene , Lipídeos/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Característica Quantitativa Herdável
6.
Mech Ageing Dev ; 115(3): 127-38, 2000 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-10906508

RESUMO

Previously it was shown in young-adult muscles that eccentric contractions (EC) produce a significant (24 h) depolarization of the resting membrane potential (RMP), and that in-vitro (Gd(3+)) and in-vivo (streptomycin) blockade of stretch activated ion channels (SAC) result in a partial repolarization of the RMP. The portion of the depolarization not restored by SAC blockade is believed to be from sarcolemmal injury. A second exposure to EC results in less depolarization and a more rapid recovery of the RMP. Aged muscles were subjected to the same EC protocol to test the hypotheses that: (1) Aged muscles will experience a more significant and prolonged depolarization of the RMP following EC. (2) The depolarization in aged muscles will occur by a greater contribution from membrane damage, rather than the opening of SAC. (3) The aged muscles will demonstrate a reduced capacity to adapt to EC, and will experience a similar degree of depolarization following repeated exposures to EC. The results indicate a significantly greater and longer lasting depolarization in aged compared to young-adult muscles. Blocking SAC did not produce a repolarization of the RMP in aged muscles. Aged muscles had a significantly reduced adaptive response to EC compared to young-adult. It is speculated that the different response in aged muscles results from a reduced number of functional SAC.


Assuntos
Envelhecimento/fisiologia , Músculo Esquelético/fisiologia , Adaptação Fisiológica , Animais , Feminino , Gadolínio/farmacologia , Técnicas In Vitro , Canais Iônicos/antagonistas & inibidores , Canais Iônicos/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Modelos Biológicos , Contração Muscular/fisiologia , Músculo Esquelético/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Estreptomicina/farmacologia
7.
Mech Ageing Dev ; 83(3): 185-200, 1995 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-8583836

RESUMO

We tested the hypothesis that exposure to eccentric (lengthening) contractions results in greater damage and more prolonged recovery in aged rat muscle (32 months) than in adult muscle (6 months), and that the adaptation usually associated with a single exposure to eccentric exercise is reduced in the aged muscle. Experiments were performed using a new rat model for aging studies. Fisher 344/Brown Norway F1 Hybrid. An ankle flexor, the tibialis anterior (TA), was subjected to a series of 24 eccentric contractions in situ and contractile function was assessed 1, 2, 5 and 14 days following. Eccentric exercise produced a similar reduction in maximum specific twitch and tetanic tension in the aged and adult muscles at 1 and 2 days postexercise. Adult muscles recovered by 5 days, while aged TA remained significantly impaired. Aged TA was fully restored by 14 days. Exercise adaptation was tested by subjecting the TA to a second exercise 14 days following the first. Contractile function was determined 2 days following the second exercise. Adult TA maintained its pre-exercise specific force following the second exercise, while aged TA again showed a significant reduction. Thus, a single exposure to eccentric exercise produced complete adaptation in the adult TA, but not in the aged muscles.


Assuntos
Envelhecimento/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Condicionamento Físico Animal , Adaptação Fisiológica , Animais , Feminino , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos F344
8.
J Immunol Methods ; 256(1-2): 77-87, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11516757

RESUMO

The concentration of the immunosuppressive drugs cyclosporine A (CSA) and FK506 in biological fluids is routinely determined by antibody-based assays, which for several reasons do not give accurate information on the actual level of immunosuppression in the patient. To alleviate this problem, we developed a functional reporter gene assay which uses the enhancer fragment of the interleukin-2 promoter region driving the expression of the green fluorescent protein (GFP). This construct was stably transfected in the Jurkat human T lymphoblastoid cell line. Upon stimulation of the cell recipient, the GFP was produced and evaluated by flow cytometry. Immunosuppressants acting via inhibition of interleukin-2 synthesis, such as CSA or FK506, inhibited the production of GFP in a dose-dependent manner. This assay can be performed within a working day with a good reproducibility and was more sensitive than the antibody-based assays, since its detection limit was as low as 10 ng/ml for CSA and 0.5 ng/ml for FK506. We used it for the follow up of drug level present in the blood of transplanted patients, and compared the results with those obtained with the antibody-based assay routinely carried out in our hospital. The conclusions suggest that this assay is a valuable alternative to the presently available assays for the measurement of the immunosuppressive activity found in body fluids.


Assuntos
Ciclosporina/sangue , Citometria de Fluxo/métodos , Imunossupressores/sangue , Interleucina-2/genética , Proteínas Luminescentes/genética , Tacrolimo/sangue , Anticorpos Monoclonais/imunologia , Relação Dose-Resposta a Droga , Genes Reporter , Glucocorticoides/farmacologia , Proteínas de Fluorescência Verde , Humanos , Células Jurkat , Transplante de Rim , Proteínas Luminescentes/metabolismo , Metilprednisolona/farmacologia , Regiões Promotoras Genéticas , Proteínas Recombinantes de Fusão/metabolismo
9.
Mayo Clin Proc ; 75(11): 1124-32, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11075741

RESUMO

OBJECTIVE: To determine the relative efficacy and safety of cerivastatin and pravastatin in patients with type II hypercholesterolemia. PATIENTS AND METHODS: In this prospective, double-blind, parallel-group study, hypercholesterolemic patients were randomized to treatment with cerivastatin, 0.3 mg (n=250) or 0.4 mg (n=258), or pravastatin, 20 mg (n=266) or 40 mg (n=256), for 8 weeks. RESULTS: Cerivastatin, 0.3 mg, was significantly more effective than pravastatin, 20 mg, in reducing low-density lipoprotein (LDL) cholesterol from baseline (-29.6% vs -26.8%; P=.008). Cerivastatin, 0.4 mg, was significantly more effective than pravastatin, 40 mg, in reducing LDL cholesterol (-34.2% vs -30.3%; P<.001). A larger proportion of cerivastatin-treated patients had greater than 40% reductions in LDL cholesterol than those receiving pravastatin (11.1% vs 6.0%). The percentage of patients who achieved the National Cholesterol Education Program (NCEP) target was 71.3% with cerivastatin, 0.3 mg, compared with 67.5% with pravastatin, 20 mg, and 74.0% with cerivastatin, 0.4 mg, compared with 71.1% with pravastatin, 40 mg (no significant difference). Cerivastatin, 0.3 mg, reduced total cholesterol to a greater extent than did pravastatin, 20 mg (P<.03). Both agents reduced triglycerides and increased high-density lipoprotein cholesterol to a similar degree (no significant differences). Cerivastatin and pravastatin were well tolerated. CONCLUSIONS: Cerivastatin, 0.3 mg and 0.4 mg, showed greater efficacy than pravastatin, 20 mg and 40 mg, respectively, in lowering LDL cholesterol. Cerivastatin is safe and effective for patients with hypercholesterolemia who require aggressive LDL cholesterol lowering to achieve NCEP-recommended targets.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipercolesterolemia/tratamento farmacológico , Hipolipemiantes/uso terapêutico , Pravastatina/uso terapêutico , Piridinas/uso terapêutico , Adolescente , Adulto , Idoso , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Feminino , Humanos , Hipercolesterolemia/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Triglicerídeos/sangue
10.
Opt Express ; 4(8): 270-86, 1999 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-19396284

RESUMO

Images produced in six different geometries with diffuse optical tomography simulations of tissue have been compared using a finite element-based algorithm with iterative refinement provided by the Newton-Raphson approach. The source-detector arrangements studied include (i) fan-beam tomography, (ii) full reflectance and transmittance tomography, as well as (iii) sub-surface imaging, where each of these three were examined in a circular and a flat slab geometry. The algorithm can provide quantitatively accurate results for all of the tomographic geometries investigated under certain circumstances. For example, quantitatively accurate results occur with sub-surface imaging only when the object to be imaged is fully contained within the diffuse projections. In general the diffuse projections must sample all regions around the target to be characterized in order for the algorithm to recover quantitatively accurate results. Not only is it important to sample the whole space, but maximal angular sampling is required for optimal image reconstruction. Geometries which do not maximize the possible sampling angles cause more noise artifact in the reconstructed images. Preliminary simulations using a mesh of the human brain confirm that optimal images are produced from circularly symmetric source-detector distributions, but that quantitatively accurate images can be reconstructed even with a sub-surface imaging, although spatial resolution is modest.

11.
Opt Express ; 1(13): 391-403, 1997 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-19377563

RESUMO

The instrument development and design of a prototype frequency-domain optical imaging device for breast cancer detection is described in detail. This device employs radio-frequency intensity modulated near-infrared light to image quantitatively both the scattering and absorption coefficients of tissue. The functioning components of the system include a laser diode and a photomultiplier tube, which are multiplexed automatically through 32 large core fiber optic bundles using high precision linear translation stages. Image reconstruction is based on a finite element solution of the diffusion equation. This tool for solving the forward problem of photon migration is coupled to an iterative optical property estimation algorithm, which uses a Levenberg-Marquardt routine with total variation minimization. The result of this development is an automated frequency-domain optical imager for computed tomography which produces quantitatively accurate images of the test phantoms used to date. This paper is a description and characterization of an automated frequency-domain computed tomography scanner, which is more quantitative than earlier systems used in diaphanography because of the combination of intensity modulated signal detection and iterative image reconstruction.

12.
Pediatr Infect Dis J ; 7(3): 229-38, 1988 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3282216

RESUMO

This paper presents the results of a randomized, double-blind, placebo-controlled study of the efficacy of chlorpheniramine in relieving the symptoms and attenuating the pathophysiologic correlates of a rhinovirus "common cold." Forty healthy, adult, nonatopic subjects were randomly assigned to one of two treatment groups: active drug and placebo. On study Day 0, all subjects were challenged intranasally with rhinovirus type 39 (dose = 100 TCID50). Subjects were cloistered from Day 2 to Day 7, at which time they were treated with either chlorpheniramine or placebo. From 3 days before challenge to study Day 19, subjects had nasal patency assessed by rhinomanometry, eustachian tube function assessed by the 9-step test and sonotubometry, middle ear pressure assessed by tympanometry and nasal clearance assessed by the dyed-saccharin technique. Symptom diaries were maintained throughout the period of follow-up. During cloister, symptoms also were scored by interview, nasal secretions were quantified and nasal washings were performed for viral culture. Results showed that 19 (95%) subjects in the active-treatment group and 18 (90%) subjects in the placebo-treatment group shed virus. Symptomatic colds were observed in 63% of the active-treated and 83% of the placebo-treated subjects. Symptoms increased on Day 1 and peaked at Days 4 to 5. Detrimental changes in other measured functions consistent with those previously reported were observed. During the period of treatment, significant differences in the average symptom scores favoring the active-treatment group were observed for sneezing. Also, weight of expelled secretions was greater and mucociliary clearance rate less on some cloister days for the placebo-treated group. No significant differences between treatment groups in the objective measures of nasal congestion or the response of the middle ear and eustachian tube were documented.


Assuntos
Clorfeniramina/uso terapêutico , Resfriado Comum/tratamento farmacológico , Testes de Impedância Acústica , Adulto , Ensaios Clínicos como Assunto , Resfriado Comum/fisiopatologia , Método Duplo-Cego , Orelha Média/efeitos dos fármacos , Tuba Auditiva/efeitos dos fármacos , Feminino , Humanos , Masculino , Manometria , Depuração Mucociliar/efeitos dos fármacos , Muco/efeitos dos fármacos , Nariz/efeitos dos fármacos , Distribuição Aleatória , Espirro/efeitos dos fármacos
13.
J Appl Physiol (1985) ; 88(1): 91-101, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10642367

RESUMO

We tested the hypothesis that eccentric contractions activate mechanosensitive or stretch-activated ion channels (SAC) in skeletal muscles, producing increased cation conductance. Resting membrane potentials and contractile function were measured in rat tibialis anterior muscles after single or multiple exposures to a series of eccentric contractions. Each exposure produced a significant and prolonged (>24 h) membrane depolarization in exercised muscle fibers. The magnitude and duration of the depolarization were related to the number of contractions. Membrane depolarization was due primarily to an increase in Na(+) influx, because the estimated Na(+)-to-K(+) permeability ratio was increased in exercised muscles and resting membrane potentials could be partially repolarized by substituting an impermeant cation for extracellular Na(+) concentration. Neither the Na(+)/H(+) antiport inhibitor amiloride nor the fast Na(+) channel blocker TTX had a significant effect on the depolarization. In contrast, addition of either of two nonselective SAC inhibitors, streptomycin or Gd(3+), produced significant membrane repolarization. The results suggest that muscle fibers experience prolonged depolarization after eccentric contractions due, principally, to the activation of Na(+)-selective SAC.


Assuntos
Canais Iônicos/metabolismo , Mecanorreceptores/metabolismo , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Condicionamento Físico Animal/fisiologia , Amilorida/farmacologia , Animais , Cátions/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Feminino , Gadolínio/farmacologia , Canais Iônicos/antagonistas & inibidores , Meglumina/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/fisiologia , Músculo Esquelético/citologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/lesões , Potássio/metabolismo , Ratos , Ratos Sprague-Dawley , Sódio/metabolismo , Bloqueadores dos Canais de Sódio , Canais de Sódio/metabolismo , Trocadores de Sódio-Hidrogênio/antagonistas & inibidores , Trocadores de Sódio-Hidrogênio/metabolismo , Estreptomicina/farmacologia , Tetrodotoxina/farmacologia
14.
Health Aff (Millwood) ; 17(6): 170-80, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9916367

RESUMO

Concern about the variation in rates paid to Medicare managed care plans across the United States led to the passage of major reforms of formulas for setting these rates as part of the Balanced Budget Act (BBA) of 1997. However, observers have focused much more on the variation in the rates per se than on the disparity in benefits offered by these plans and in the premiums they charge. This analysis shows that there is considerable variation in the range of risk plans available to Medicare beneficiaries, the premiums charged, and the benefits offered and that the variation is strongly related to the payment made by the Health Care Financing Administration (HCFA) on behalf of the beneficiary and to the beneficiary's area of residence.


Assuntos
Acessibilidade aos Serviços de Saúde , Benefícios do Seguro , Programas de Assistência Gerenciada/economia , Medicare/organização & administração , Idoso , Serviços Contratados , Honorários e Preços , Reforma dos Serviços de Saúde , Humanos , Programas de Assistência Gerenciada/organização & administração , Medicare/economia , Gestão de Riscos , Participação no Risco Financeiro , Estados Unidos
15.
Health Aff (Millwood) ; 16(5): 172-80, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9314688

RESUMO

As Medicare beneficiary enrollment in managed care plans increases, and as Congress considers relying on capitation for achieving savings in the program, the question of finding a fair and equitable formula for determining the monthly payment to managed care plans has become increasingly salient. This DataWatch focuses on one dimension of using previous expenditures to determine annual capitation rates: the effects of historic volatility in total expenditures. Annual changes in adjusted average per capita cost (AAPCC) rates are especially dramatic in rural counties, with those not adjacent to urban areas experiencing the greatest volatility. This pattern of annual change may discourage managed care organizations from entering markets, even when the rate in any given year may appear to be favorable for accepting risk.


Assuntos
Capitação , Programas de Assistência Gerenciada/economia , Medicare/economia , Serviços de Saúde Rural/economia , Custos de Cuidados de Saúde , Humanos , Programas de Assistência Gerenciada/estatística & dados numéricos , Medicare/estatística & dados numéricos , Estados Unidos
16.
Med Phys ; 27(12): 2693-700, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11190952

RESUMO

Near-infrared (NIR) diffuse tomography is emerging as a medical imaging modality for obtaining information related to tissue hemoglobin concentration and oxygen saturation and may be used for characterizing diseased tissues such as breast cancer. The optimal methodology for NIR image reconstruction remains an ongoing research problem with several new approaches being demonstrated in recent years. However, a comparison of reconstruction methods is problematic because tools for the objective assessment of image quality have yet to be clearly defined for this type of nonlinear reconstruction problem. Contrast-detail analysis has become an accepted assessment tool to quantify x-ray mammography image quality, and in this study it has been applied to a prototype NIR diffuse tomography system that is being evaluated for breast cancer characterization. The minimum detectable levels of contrast have been defined for different sizes of objects, and the minimum contrasts which can be accurately reconstructed have also been determined for the same object sizes. In general, objects 8 mm and larger in diameter can be accurately reconstructed and detected for most absorption contrasts which are observed in human tissues (i.e., greater than 1% contrast in absorption). Objects as small as 2 mm can be detected with high contrast (i.e., near 100%), but cannot be accurately reconstructed. Within the size range of 2 mm to 8 mm, there is an inverse correlation between contrast and detail size which is characteristic of the total noise in the system. This analysis provides an objective method for assessing detection and characterization limits and can be applied to future improvements in hardware system architecture as well as reconstruction algorithms.


Assuntos
Processamento de Imagem Assistida por Computador , Raios Infravermelhos , Tomografia/instrumentação , Tomografia/métodos , Algoritmos , Neoplasias da Mama/diagnóstico , Feminino , Humanos , Modelos Estatísticos , Imagens de Fantasmas , Sensibilidade e Especificidade , Raios X
17.
Health Serv Res ; 36(4): 733-50, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11508637

RESUMO

OBJECTIVE: To examine the effect of adjusted average per capita cost (AAPCC) rate and volatility on Medicare risk plan enrollment at the county level. DATA SOURCES: Secondary data from the Health Care Financing Administration's office of managed care and other sources were merged to create comprehensive data on all Medicare risk plans in 3,069 of the 3,112 U. S. counties in December 1996. STUDY DESIGN: A two-step least squares regression was estimated to examine the effects of AAPCC rate and volatility, commercial HMO enrollment, market factors, and characteristics of the county population on Medicare HMO enrollment. The model was also used to simulate the effects of the Balanced Budget Act of 1997. Data from the Health Care Financing Administration were merged with other sources at the county level. The Federal Information Processing Standards code and a crosswalk file matching that code with the county name linked the data across sources. PRINCIPLE FINDINGS: The AAPCC rate has a small positive effect on the probability of Medicare HMO availability and enrollment. However, commercial HMO enrollment has a much stronger positive effect on Medicare HMO enrollment. Volatility has a negative effect on the probability of any Medicare HMO enrollment. CONCLUSIONS: The results suggest that payment changes enacted as part of the Balanced Budget Act will have a limited effect on Medicare HMO enrollment, especially in rural areas. Other policy changes are needed to stimulate Medicare HMO enrollment.


Assuntos
Capitação , Comportamento do Consumidor/estatística & dados numéricos , Programas de Assistência Gerenciada/estatística & dados numéricos , Medicare Part C/organização & administração , Idoso , Centers for Medicare and Medicaid Services, U.S. , Comportamento do Consumidor/economia , Geografia , Pesquisa sobre Serviços de Saúde , Humanos , Benefícios do Seguro , Análise dos Mínimos Quadrados , População Rural , Estados Unidos , População Urbana
18.
Health Serv Res ; 27(4): 453-79, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1399652

RESUMO

While interest in publicly funded home care for the disabled elderly is keen, basic policy issues need to be addressed before an appropriate program can be adopted and financed. This article presents findings from a study in which the cost implications of anticipated behavioral responses (for example, caregiver substitution) are estimated. Using simulation techniques, the results demonstrate that anticipated behavioral responses would likely add between $1.8 and $2.7 billion (1990 dollars) to the costs of a public home care program. Results from a variety of cost simulations are presented. The data base for the study was the 1982 National Long-Term Care Survey.


Assuntos
Pessoas com Deficiência , Custos de Cuidados de Saúde , Serviços de Saúde para Idosos/economia , Serviços de Assistência Domiciliar/economia , Atividades Cotidianas , Idoso , Cuidadores/psicologia , Coleta de Dados , Feminino , Financiamento Governamental/economia , Financiamento Governamental/tendências , Previsões , Custos de Cuidados de Saúde/tendências , Pesquisa sobre Serviços de Saúde , Serviços de Saúde para Idosos/estatística & dados numéricos , Serviços de Saúde para Idosos/tendências , Nível de Saúde , Serviços de Assistência Domiciliar/estatística & dados numéricos , Serviços de Assistência Domiciliar/tendências , Humanos , Masculino , Marketing de Serviços de Saúde/economia , Marketing de Serviços de Saúde/tendências , Análise de Regressão , Fatores Socioeconômicos , Estados Unidos
19.
IEEE Trans Med Imaging ; 18(12): 1188-93, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10695531

RESUMO

This paper extends basic concepts of statistical hypothesis testing and confidence intervals to images generated by a new procedure for near infrared spectroscopic tomography being developed for use in breast cancer diagnosis. By estimating the covariance matrix of the pixels of an image from data used in the image reconstruction process, confidence maps for statistical tests on individual pixels and confidence intervals for entire images are displayed as an aid to research and clinical personnel interpreting possibly noisy images. The methods are applied to simulated and phantom-based images.


Assuntos
Neoplasias da Mama/diagnóstico , Espectroscopia de Luz Próxima ao Infravermelho , Tomografia/métodos , Simulação por Computador , Intervalos de Confiança , Diagnóstico Diferencial , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imagens de Fantasmas
20.
Health Care Financ Rev ; 19(1): 145-60, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-10179996

RESUMO

The number of persons without health insurance is increasing. Although research has focused on the uninsured poor and the duration of spells without health insurance, less attention has been paid to the dynamics of spells without health insurance among those in poverty. Here it is shown that the typical uninsured spell is longer for the uninsured poor (roughly 8.3 months) than for the uninsured non-poor (roughly 6 months) and that the duration of spells has increased over time. In addition, more than 40 percent of the uninsured at a point in time are chronically uninsured and poor or near-poor.


Assuntos
Pessoas sem Cobertura de Seguro de Saúde/estatística & dados numéricos , Pobreza/estatística & dados numéricos , Adolescente , Adulto , Idoso , Demografia , Feminino , Pesquisas sobre Atenção à Saúde , Política de Saúde , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Estados Unidos/epidemiologia
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