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Biomedical subjects

M E Miller

Publications and source records attributed to M E Miller.

At least 91 records · Page 5Linked to original sources
PubMed1995

Growth in Medicare's hospital outpatient care: implications for prospective payment.

Medicare hospital outpatient expenditures are growing rapidly. In response, Congress mandated implementation of a prospective payment system (PPS). The potential cost control effectiveness of a PPS is assessed in this paper by decomposing growth in charges into changes in beneficiaries, prices, case mix, encounters per beneficiary, services per encounter, and intensity per service. This paper examines aggregate growth rates and rates disaggregated by type of service, highlighting rapid growth in surgery and imaging services. Findings indicate that 69% of observed growth is attributable to factors that would be unaffected by an encounter-based PPS (i.e., beneficiaries, prices, case mix, and encounters per beneficiary). We conclude that effective cost containment may require implementation of direct volume controls in addition to a PPS.

Ambulatory Care↗
PubMed1995

Physicians practicing in hospitals: implications for a medical staff policy.

President Clinton's health reform package included a proposal that would limit Medicare payments to the medical staffs of hospitals whose inpatient physician service volume was systematically above national norms. Under this policy, it would be possible for a physician practicing in more than one hospital to be penalized in one and not the other. Physicians might direct their admissions to certain hospitals to avoid penalties, and thereby would threaten the viability of some hospitals. However, to engage in large-scale admission shifting, physicians must practice in multiple hospitals. Using a national database, we find that, on average, physicians are affiliated with 1.56 hospitals and that 62% are affiliated with one hospital. On average, 90% of a physician's admissions are in a single hospital. We also find that, in the average hospital, a relatively small percentage of physicians (20%) admit a majority (60%) of Medicare patients. We discuss policy implications.

Hospital-Physician Relations↗
PubMed1995

Service mix in the hospital outpatient department: implications for Medicare payment reform.

OBJECTIVE: To determine if implementation of a PPS for Medicare hospital outpatient department (HOPD) services will have distributional consequences across hospital types and regions, this analysis assesses variation in service mix and the provision of high-technology services in the HOPD. DATA: HCFA's 1990 claims file for a 5 percent random sample of Medicare beneficiaries using the HOPD was merged, by hospital provider number, with various HCFA hospital characteristic files. STUDY DESIGN: Hospital characteristics examined are urban/rural location, teaching status, disproportionate-share status, and bed size. Two analyses of HOPD services are presented: mix of services provided and the provision of high-technology services. The mix of services is measured by the percentage of services in each of 14 type-of-service categories (e.g., medical visits, advanced imaging services, diagnostic testing services). Technology provision is measured by the percentage of hospitals providing selected high-technology services. FINDINGS/CONCLUSIONS: The findings suggest that the role hospital types play in providing HOPD services warrants consideration in establishing a PPS. HOPDs in major teaching hospitals and hospitals serving a disproportionate share of the poor play an important role in providing routine visits. HOPDs in both major and minor teaching hospitals are important providers of high-technology services. Other findings have implications for the structure of an HOPD PPS as well. First, over half of the services provided in the HOPD are laboratory tests and HOPDs may have limited control over these services since they are often for patients referred from local physician offices. Second, service mix and technology provision vary markedly among regions, suggesting the need for a transition to prospective payment. Third, the organization of service supply in a region may affect service provision in the HOPD suggesting that an HOPD PPS needs to be coordinated with payment policies in competing sites of care (e.g., ambulatory surgical centers).

Aged↗
PubMed1994

Paradoxical influence of estrogenic hormones on platelet-endothelial cell interactions.

Controversies abound in the literature about the safety and efficacy of tamoxifen and estrogen. We studied the effect of these 2 hormonal agents on factors involved in in vitro thrombogenesis: platelets and endothelial cells. Endothelial cells were derived from human umbilical veins and platelets were obtained from premenopausal and postmenopausal women, women on oral contraceptives, postmenopausal women on hormone replacement therapy, men, and patients with breast cancer who had been taking adjuvant tamoxifen for more than 1 year. The interaction of platelets with endothelial cell matrix was measured in 2 systems: 1) in a flow chamber at low shear rate and, 2) with 51Cr labeled platelets in a "static" culture system. In the static system, platelets from women on tamoxifen exhibited decreased platelet adherence to endothelial cell matrix whether they were grown in tamoxifen or control conditions, when compared to platelets from premenopausal women. When flow (25 sec-1) was added these differences were negated. Neither tamoxifen nor 17 beta estradiol had an effect on endothelial cell proliferation or platelet aggregation. Adhesion of platelets at low shear was not altered when platelet rich plasma was incubated with tamoxifen nor when endothelial cells were grown in tamoxifen. In contrast, incubation of platelets in 17 beta estradiol decreased platelet adhesion at low shear rate, however, there was no effect on platelet adhesion when endothelial cells were grown in 17 beta estradiol. We conclude that in early stages of thrombus formation as measured in vitro, tamoxifen may not have a detrimental effect and estrogen may be protective.

Blood Platelets↗
PubMed1994

Physician profiling. An analysis of inpatient practice patterns in Florida and Oregon.

BACKGROUND: Physician profiling is a method of cost control that focuses on patterns of care instead of on specific clinical decisions. It is one cost-control method that takes into account physicians' desire to curb the intrusion of administrative mechanisms into the clinical encounter. To provide a concrete example of profiling, we analyzed the inpatient practice patterns of physicians in Florida and Oregon. METHODS: Data for 1991 from Medicare's National Claims History File were used to profile 12,720 attending physicians in Florida and 2589 in Oregon. For each attending physician, we determined the total relative value of all physicians' services delivered during each patient's hospital stay. Relative value was measured in relative-value units (RVUs), according to the resource-based relative-value scale used by Medicare in determining payments to physicians. The mean number of RVUs per admission was then adjusted for the physician's case mix according to the patients' assigned diagnosis-related groups. The influence of the physician's specialty and of selected types of services (such as imaging and endoscopy) was also examined. RESULTS: Florida physicians used markedly more resources, on average, than their colleagues in Oregon (46 vs. 30 case-mix-adjusted RVUs per admission). The difference was apparent for all specialties and all types of service. To illustrate the profiling data potentially available to the medical staffs of individual hospitals, we examined specific data on individual attending physicians and for various types of service for three hospitals' staffs. Despite similar overall profiles that fell below the national mean, each staff had a different practice pattern and would require different efforts to improve efficiency. CONCLUSIONS: In an effort to encourage further debate, we have described one method of physician profiling. Profiling data help identify and characterize differences in practice style to which individual physicians or hospital staffs can respond. Because profiling is not based on rigid rules, it is a cost-containment strategy that can easily accommodate legitimate exceptions; it is therefore preferable to methods in which the appropriateness of each clinical decision is judged separately.

Cost Control↗
PubMed1994

Statistical prediction of the locus of endoproteolytic cleavage of the nascent polypeptide in glycosylphosphatidylinositol-anchored proteins.

Existing methods of identifying the cleavage site of the nascent polypeptide and the C-terminal residue to which the glycosylphosphatidylinositol (GPI) anchor is attached in mature GPI-anchored proteins are technically difficult and labour-intensive. We tested the hypothesis that it was possible to predict this locus using data from the cDNA-deduced amino acid sequence and amino acid composition of GPI-anchored proteins. We employed a statistical approach which allowed repeated chi 2 comparisons between the proportions of residual amino acids in the major body of the cDNA-deduced polypeptide (minus the N-terminal signal peptide) after repeated computer-generated progressive exoproteolysis from its C-terminus one amino acid at a time and the fixed proportion of amino acids obtained from amino acid analysis of the mature GPI-anchored protein. Initial comparison of the two parameters invariably revealed a relatively high chi 2 statistic which progressively lowered to a minimum point at which the amino acid proportions of progressively exoproteolysed polypeptide and fixed endoproteolysed polypeptides of the mature GPI-anchored protein were in closest agreement. This objectively defined and unique minimum point of closest agreement accurately identified the locus of post-translational endoproteolytic cleavage of the nascent polypeptide in several tissue-specific single-gene-encoded GPI-anchored proteins. Thus the C-terminal amino acid to which the GPI anchor is attached can be rapidly identified using data from the cDNA sequence and the amino acid composition of proteins suspected to be GPI-anchored.

Amino Acid Sequence↗
PubMed1994

Bromide pharmacokinetics in cystic fibrosis.

OBJECTIVE: Individuals with cystic fibrosis (CF) have altered kinetics for a number of drugs, most often an increased volume of distribution (Vd) per body weight and increased clearance per body weight. To further evaluate those differences, we studied bromide kinetics (Vd, elimination rate constant, and clearance) and body mass index in eight adults with mild-to-moderate forms of CF, 21 obligate carriers of the CF gene, and 21 healthy controls. Bromide distribution approximates the extracellular fluid volume and bromide is excreted unchanged by the kidney. DESIGN: Individuals were given a single oral dose of bromide (50 mg/kg), and serum bromide concentrations were measured over 4 weeks. Bromide pharmacokinetics (Vd, elimination rate constant, and clearance) were determined using a one-compartment model with first-order kinetics. Body mass index was determined for each individual. RESULTS: Individuals with CF had a significantly greater lean body mass per kilogram as estimated by body mass index compared with individuals in the obligate carrier and control groups. The mean (+/- SD) Vd per kilogram for the CF group (311 +/- 29 mL/kg) was significantly greater than that of the obligate carrier group (261 +/- 26 mL/kg) and the control group (274 +/- 30 mL/kg). However, the mean (+/- SD) Vd per square meter for the three groups was similar. The mean elimination rate constant for the CF group (3.55 +/- 0.98 x 10(-3)/h) was significantly greater compared with the mean elimination rate constant for the obligate carrier group (2.55 +/- 0.36 x 10(-3)/h) and the control group (2.58 +/- 0.49 x 10(-3)/h). The mean (+/- SD) clearance per kilogram was also significantly greater for the CF group (1095 +/- 283 microL/kg per hour) compared with the obligate carrier group (664 +/- 100 microL/kg per hour) and the control group (700 +/- 115 microL/kg per hour). CONCLUSIONS: These findings indicate that individuals with CF have a greater Vd per kilogram for bromide and drugs that distribute in the extracellular fluid volume because of their greater lean body mass per kilogram. The findings also suggest that individuals with CF have a greater renal clearance of bromide and presumably of other anionic drugs excreted by the kidney. The results emphasize the importance of body composition in drug disposition.

Adolescent↗
PubMed1994

Predictors of unsafe injecting drug use.

This paper reports on the incidence of unsafe injecting and the factors which influence this practice in a sample of 1245 Sydney injecting drug users (IDUs). Using a needle and syringe after someone else at some time in the last six months was reported in 41.6% of the sample. Taking into account those who claimed always to clean used needles with virucidal methods, 32.9% had placed themselves at risk of HIV infection from shared needles in the six months prior to interview.Seven factors were predictive of unsafe behaviour. These were (a) the amount spent per week on drugs, (b) the number of times a single needle was used prior to disposal, (c) having shared with a person who is now HIV infected, (d) having a regular sexual partner, (e) the proportion of times high, stoned or drunk when injecting, (f) being part of a group that injects together and (g) having been in prison.

Journal Article↗
PubMed1994

Predictors of HIV status among injecting drug users and health promotion.

Two consecutive samples one year apart of injecting drug users (n = 754 and n = 345) were collected in Sydney, Australia and analysed for predictors of Human Immunodeficiency Virus (HIV) prevalence. Data indicated that similar variables were associated with HIV infection in both waves of the study. Risks for HIV infection included number of injections in last typical using month, acceptance of used injecting equipment from other injecting drug users (IDUs) who were known to be infected either before or after the sharing occurred, having sex with people known to be infected with HIV, and sexual orientation. It was not possible to determine whether sexual or equipment sharing with known HIV infected people preceded or followed HIV infection. These data confirm that predictors of HIV prevalence in Sydney are similar to those found in overseas studies and that sexual orientation appears to be the most powerful predictor. These data suggest both that sexual contact is an important route of infection in IDUs, and that sexual risks for HIV infection in IDUs need to be emphasised.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Proposals to control high-cost hospital medical staffs.

Several health care reform bills would limit Medicare payments to high-cost medical staffs, that is, physicians in hospitals with a high volume of physician services per admission. In a given year, Medicare's payment to the physicians on each hospital's medical staff could not collectively exceed a limit defined as a certain percentage above the national median. Limits of various forms are used in other parts of the Medicare program. This policy would combine cost containment incentives with a clear organizational structure. In addition, medical staffs could be provided with detailed information on their practice styles.

Cost Control↗
PubMed1994

A comparison of HIV risk between women and men who inject drugs.

Although there is growing evidence of differences between women and men who inject drugs (IDUs) in terms of level of risk for HIV infection, very little research has been conducted specifically addressing the risk practices of women IDUs. This study formed part of a national study of HIV infection risks in IDUs and the purpose of the present analysis was an exploration of gender differences in HIV risk practices, focusing on the HIV risk practices of IDU women. 1,245 IDUs from the inner city area of Sydney took part in this study. Of these, 908 were men and 331 were women. Notable results were that female respondents were more likely to report sharing needles, they injected heroin more times in a typical using month and were more likely to have shared with someone they later found out was HIV seropositive. Female respondents also reported more sexual partners than men, were more likely to engage in prostitution, and were more likely to have sexual partners who were themselves IDUs. The results provide support for the proposition that women who inject drugs may be at greater risk of HIV infection through both their drug taking and their sexual practices. Further research is needed to explore the reasons underlying the risk practices of women who inject drugs and an understanding of these factors needs to be incorporated into HIV risk-reduction and drug harm-reduction policies and programs.

Adolescent↗
PubMed1993

Geographic variation in expenditures for physicians' services in the United States.

BACKGROUND: The national volume-performance standard recently implemented by Medicare does not account for geographic variation in expenditures for physicians' services. To study this variation, we examined expenditures for physicians' services in all metropolitan areas in the United States. METHODS: We used Medicare claims data for 1989 to measure rates of service use for beneficiaries living in the 317 U.S. metropolitan statistical areas (MSAs). The variables investigated were rates of admission to the hospital, payments to physicians for inpatient care per admission and per beneficiary, payments to physicians for outpatient care per beneficiary, and overall payments to physicians per beneficiary. Expenditures were measured in terms of allowed charges as adjusted to reflect prevailing charges in each MSA. Rates of use were adjusted for age and sex, with the exception of the variable for payments to physicians for inpatient care per admission, which was adjusted for case mix. RESULTS: Expenditures for the delivery of physicians' services to Medicare beneficiaries varied markedly among MSAs, with those for the areas with the lowest and the highest rates differing at least twofold on each measure. The measures for specific areas varied in parallel: areas with high rates of admission tended to have high levels of payment to physicians for inpatient care per admission, and areas with high payments for inpatient services tended to have high payments for outpatient services. Expenditures were not related to the number of physicians per capita but were lower in MSAs with a high proportion of primary care practitioners. The variation persisted when the 25 largest MSAs were examined; for total payments to physicians per beneficiary, there was a twofold difference between the area with the lowest rate and that with the highest, San Francisco ($872) and Miami ($1,874). The states with the highest overall payments to physicians per beneficiary were Florida, Louisiana, and Michigan. CONCLUSIONS: The marked variation among metropolitan areas in payments to physicians underscores the lack of consensus among physicians about which services are required. Moreover, the practice style in a given community appears to be influenced not by the aggregate supply of physicians but rather by the mixture of primary care physicians and specialists.

Ambulatory Care↗
PubMed1993

Physician inpatient order writing on microcomputer workstations. Effects on resource utilization.

OBJECTIVE: To assess the effects on health care resource utilization of a network of microcomputer workstations for writing all inpatient orders. DESIGN: Randomized controlled clinical trial. SETTING: Inpatient internal medicine service of an urban public hospital. SUBJECTS: A total of 5219 internal medicine patients and the 68 teams of house officers, medical students, and faculty internists who cared for them. INTERVENTION: Microcomputer workstations, linked to a comprehensive electronic medical record system, for writing all inpatient orders. MAIN OUTCOME MEASURES: Total inpatient charges for each admission and charges for specific categories of orders. A time-motion study of selected interns assessed the ordering system's time consumption. RESULTS: Intervention teams generated charges that were $887 (12.7%) lower per admission than did control teams (P = .02). Significant reductions (P < .05) were demonstrated separately for bed charges, diagnostic test charges, and drug charges. Reductions of similar proportion and statistical significance were found for hospital costs. The mean length of stay was 0.89 day shorter for intervention resident teams (P = .11). Interns in the intervention group spent an average of 33 minutes longer (5.5 minutes per patient) during a 10-hour observation period writing orders than did interns in the control group (P < .0001). CONCLUSIONS: A network of microcomputer workstations for writing all inpatient orders significantly lowered patient charges and hospital costs. This would amount to savings of more than $3 million in charges annually for this hospital's medicine service and potentially tens of billions of dollars nationwide. However, the system required more physician time than did the paper charts. Research at other sites and system advances to reduce time requirements are warranted.

Computer Communication Networks↗
PubMed1993

Platelet adhesion at low shear rate: study of a normal population.

The use of oral contraceptives (OCs) has been associated with vascular complications. The mechanism(s) by which OCs predispose to thrombotic events remains unclear. Recent studies have demonstrated that postmenopausal (PM) women who take estrogen replacement therapy (ERT) have a decreased incidence of myocardial infarction compared to those who do not take ERT. This study was undertaken to determine if healthy individuals have differences in platelet adhesion depending on hormonal status. Men, PM women taking ERT, PM women not taking ERT, OC users, and premenopausal women not taking any medications were studied. Platelet studies were performed in a Hele-Shaw flow chamber at a low shear rate using platelet-rich plasma. The platelet adhesion process to subendothelial components: fibronectin, collagen I and collagen III was recorded using a 35 mm camera mounted on an inverted microscope. Photographs were taken at 30 second intervals for a total of 12 minutes and analyzed using a modified computer program which provided a numerical account of platelet adhesion. OC users had significantly higher platelet adherence to fibronectin, collagen I and collagen III compared to all other groups. All other study groups had similar platelet adhesion independent of hormonal status. These findings suggest that OCs cause increased platelet adhesion in some individuals and this may be one of the mechanisms by which OCs contribute to thrombotic events.

Adult↗
PubMed1993

Requiring physicians to respond to computerized reminders improves their compliance with preventive care protocols.

OBJECTIVE: To improve compliance with computer-generated reminders to perform fecal occult blood testing (FOBT), mammography, and cervical Papanicolaou (Pap) testing. DESIGN: Six-month prospective, randomized, controlled trial. SETTING: Academic primary care general internal medicine practice. SUBJECTS: Thirty-one general internal medicine faculty, 145 residents, and 5,407 patients with scheduled visits who were eligible for any of the three cancer screening protocols. INTERVENTION: Primary care teams of internal medicine residents and faculty received either routine computer reminders (control) or the same remainders to which they were required to circle one of four responses: 1) "done/order today," 2) "not applicable to this patient," 3) "patient refused," or 4) "next visit." RESULTS: Intervention physicians complied more frequently than control physicians with all remainders combined (46% vs 38%, respectively, p = 0.002) and separately with remainders for FOBT (61% vs 49%, p = 0.0007) and mammography (54% vs 47%, p = 0.036) but not cervical Pap testing (21% vs 18%, p = 0.2). Intervention residents responded significantly more often than control residents to all reminders together and separately to reminders for FOBT and mammography but not Pap testing. There was no significant difference between intervention and control faculty, but the compliance rate for control faculty was significantly higher than the rate for control residents for all reminders together and separately for FOBT but not mammography or Pap testing. The intervention's effect was greatest for patients > or = 70 years old, with significant results for all tests, together and singly, for residents but not faculty. Intervention physicians felt that the reminders were not applicable 21% of the time (due to inadequate data in patient's electronic medical records) and stated that their patients refused 10% of the time. CONCLUSIONS: Requiring physicians to respond to computer-generated reminders improved their compliance with preventive care protocols, especially for elderly patients for whom control physicians' compliance was the lowest. However, 100% compliance with cancer screening remainders will be unattainable due to incomplete data and patient refusal.

Adult↗