Impact of insulin sensitization on metabolic and fertility outcomes in women with polycystic ovary syndrome and overweight or obesity-A systematic review, meta-analysis, and meta-regression

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in reproductive-age women. This systematic review, meta-analysis, and meta-regression aims to compare the effect of insulin sensitizer pharmacotherapy on metabolic and reproductive outcomes in women with PCOS and overweight or obesity. We searched online databases MEDLINE via OVID, EMBASE, Clinicaltrials.gov, and EudraCT for trials published from inception to November 13, 2023. Inclusion criteria were double-blind, randomized controlled trials in women diagnosed with PCOS, body mass index (BMI) ≥ 25 kg/m2, which reported metabolic or reproductive outcomes. The intervention was insulin sensitization pharmacotherapy versus placebo or other agents. The primary outcomes were changes from baseline BMI, fasting blood glucose, and menstrual frequency. Nineteen studies were included in this review. Metformin had the most significant effect on the fasting plasma glucose and body mass index. Insulin sensitizer pharmacotherapy significantly reduced fasting plasma glucose, body mass index, fasting serum insulin, HOMA-IR, sex hormone binding globulin, and total testosterone, but the effect size was small. There was a lack of menstrual frequency and live birth data. The results indicate a role for insulin sensitizers in improving the metabolic and, to a lesser degree, reproductive profile in these women. Further research should examine insulin sensitizers' effects on objective measures of fecundity.

Quantitative trait loci for callus initiation and totipotency in maize (Zea mays L.)

Induction of embryogenic callus in culture is an important step in plant transformation procedures, but response is genotype specific and the genetics of the trait are not well understood. Quantitative trait loci (QTL) were mapped in a set of 126 recombinant inbred lines (RILs) of inbred H99 (high Type I callus response) by inbred Mo17 (low Type I callus response) that were evaluated over two years for Type I callus response. QTL were observed in a total of eleven bins on eight chromosomes, including eight QTL with main effects and three epistatic interactions. Many of the QTL were mapped to the same or bordering chromosomal bins as candidate genes for abscisic acid metabolism, indicating a possible role for the hormone in the induction of embryogenic callus, as has previously been indicated in microspore embryo induction. Further examinations of allelic variability for known candidate genes located near the observed QTL could be useful for expanding the understanding of the genetic basis of induction embryogenic callus. The QTL observed herein could also be used in a marker assisted selection (MAS) program to improve the response of agronomically useful inbreds, but only if the resources required for MAS are lower than those required for phenotypic selection.

Does the valve regulated release of urine from the bladder decrease encrustation and blockage of indwelling catheters by crystalline proteus mirabilis biofilms?

PURPOSE

We tested whether valve regulated, intermittent flow of urine from catheterized bladders decreases catheter encrustation.

MATERIALS AND METHODS

Laboratory models of the catheterized bladder were infected with Proteus mirabilis. Urine was allowed to drain continuously through the catheters or regulated by valves to drain intermittently at predetermined intervals. The time that catheters required to become blocked was recorded and encrustation was visualized by scanning electron microscopy.

RESULTS

When a manual valve was used to drain urine from the bladder at 2-hour intervals 4 times during the day, catheters required significantly longer to become blocked than those on continuous drainage (mean 62.6 vs 35.9 hours, p = 0.039). A similar 1.7-fold increase occurred when urine was drained at 4-hour intervals 3 times daily. Experiments with an automatic valve in which urine was released at 2 or 4-hour intervals through the day and night also showed a significant increase in mean time to blockage compared with continuous drainage (p = 0.001). Scanning electron microscopy confirmed that crystalline biofilm was less extensive on valve regulated catheters.

CONCLUSIONS

Valve regulated, intermittent flow of urine through catheters increases the time that catheters require to become blocked with crystalline biofilm. The most beneficial effect was recorded when urine was released from the bladder at 4-hour intervals throughout the day and night by an automatic valve.

Clinical practice guidelines: when the tool becomes the rule

This work provides a critical examination of the use of clinical practice guidelines to measure individual performance. The problems inherent in using a measure of central tendency derived from a distribution of individual performances are addressed, as is the translation of the collectively determined guidelines into a measurement instrument. It is suggested that every process on the distribution of processes used to determine the guideline must be considered equally legitimate representations of the process in question. It is further suggested that to accept as a standard of quality, a particular process simply because there is a minimum of variation between providers, is to ignore the importance of the linkage between process and outcome. The importance of an independent measure of quality based on outcomes is further emphasized by highlighting the tautological nature of analyses that include an input measure, such as nursing hours, in both the dependent variable and the list of independent variables. It is recommended that individual performance be evaluated within the tolerances of the distribution from which they were derived and not be held to some measure of central tendency of that distribution. The alternative is to use the measure of central tendency with plus or minus limits such as one, or more, standard deviations.

What price an additional day of life? A cost-effectiveness study of case management

OBJECTIVE

To examine the costs and benefits of a case-management program for an elderly, functionally impaired population in a managed care setting.

STUDY DESIGN

A post hoc, cost-effectiveness study of case management.

SUBJECTS AND METHODS

As part of a larger study, 317 elderly, functionally impaired clients were randomly assigned to a case-managed or regular-care group. During the 2-year study period, 34 clients in the case-managed and 43 clients in the regular-care group died. A post hoc analysis of the difference in average total cost per person, death rates, and average number of days of exposure per person were assessed to determine the cost per life saved and cost per additional day of life.

RESULTS

Although the average costs for the case-managed group were greater than the costs for the regular-care group, clients in the case-managed group lived an average of 106 days longer. The cost per additional day of life was $40. The difference in death rates was so small that, by extrapolation, the cost per life saved was over $42 million.

CONCLUSION

Although the case-management program was more costly when viewed from a purely fiscal perspective, it may very well be considered a success when its benefits are evaluated. The case-management program improved quality and was associated with prolonged life at a cost of $40 per day of additional life. Additional research involving other patient populations, study settings, and case-management models is warranted.

The relationship of impending death and age category to treatment intensity in the elderly

The purpose of this study was to isolate and quantify the age-related treatment intensity differential in elderly clients (n = 278) with functional disability in one managed care setting. For those who died during the study, treatment intensity changes for the last year and month of life were examined. The subjects were categorized into four age groups: 75-79 years; 80-84 years; 85-89 years and 90 + years, and a treatment intensity index was calculated for each group using a ratio of actual to expected costs. Indices of overall costs and cost per day for all clients, and also indices for the year and month prior to death for the deceased clients were calculated. The results clearly show that for all clients, the oldest age group was treated less intensively than the youngest age group. For the deceased clients, the older age group was treated less intensively than the youngest age group in the last year and month of life but, for all age groups, the intensity of treatment increased during the last month of life.

Case management and the cost of care in the last month of life: evidence from one managed care setting

Elderly, functionally disabled enrollees in a managed care organization were randomly assigned to case management or regular care. The service use and cost of care for the last month life for the case managed deceased is compared with that of the regular care group. The results suggest that contrary to general expectation, the managed care clients experienced greater use and costs of care in the last month of life.

The relationship between self-assessed health status, mortality, service use, and cost in a managed care setting

This article explores the extent to which Self-Assessed Health Status (SAH) can contribute to the development of capitation and premium rates by predicting mortality, service use, and service cost in an elderly population in a managed care setting. Those who rated their health as poor were three times as likely to die, and service use and cost were positively associated with those who rated their health as poor. Performance indices based on the ratio of actual-to-expected cost within each SAH category suggest a more aggressive treatment of those who rated their health as poor.

Case management of the elderly in a health maintenance organization: the implications for program administration under managed care

Kaiser Permanente initiated a two-year demonstration ambulatory case management program in its Ohio region to evaluate five outcomes: perceived health status, functional status, and satisfaction with care, service use, and service costs. Expected results were not consistently obtained for the five outcome measures. Treatment group members did not, however, experience the functional status impairments or decline in health status perceptions reported by the control group during the study period. The unexpected finding that costs were not affected may be attributed to the type of case management intervention used in the demonstration program. This study is broadly applicable to managed care settings facing the challenge of developing programs to minimize the risk for bearing the costs of the Medicare beneficiaries' overall health when all services are not covered. Managed care administrators should be favorably disposed to implementing a case management model with the potential for affecting functional status, the most significant predictor of expensive continuing care for this cohort of Medicare beneficiaries, while working to develop more effective protocols and resource control strategies.

Defining the utility of clinically acceptable variations in evidence-based practice guidelines for evaluation of quality improvement activities

This study examines the utility of systematically accounting for acceptable physician variations in guideline application. The results argue against assuming that even seemingly noncontentious guideline protocol offer a threshold of variation similar to conventional Continuous Quality Improvement (CQI) assessment standards. Findings also suggest that health service organizations can derive greater benefits from expending the resources necessary to standardize guidelines if compliance with both the medical review criteria, and the guidelines as originally constructed, is monitored as part of the evaluation activity.

Using collectively-derived standards to evaluate individual performance: a cautionary note on clinical practice guidelines

The purpose of this work is to demonstrate the problem of evaluating an individual physician's performance relative to practice guidelines which have typically been derived from group consensus or some measure of central tendency. It is argued that when evaluated against a set of criteria derived at the macro-level, an individual physician's performance may justifiably vary due to the patient characteristics or the evolving process of care. It is also argued that it is not necessarily true that costs are reduced when practice variation is reduced. The results indicate that there are cost reduction in areas not targeted by the guidelines, suggesting a possible 'spillover effect' due to the increased vigilance in monitoring provider performance. The results also provide some evidence of increased costs following a reduction in variation. Caution should be exercised when evaluating individual physician performance relative to guidelines established at the aggregate level. Acceptable individual physician performance should be judged within the upper and lower boundaries of the implicit distribution of physicians' performances from which the established guidelines generated.

Utilization of hospital services by the elderly: geriatric crisis in one Canadian single payer system

As the number and proportion of elderly persons in the Canadian population increase, utilization of health services by the elderly becomes a growing concern for health service insurers, financial managers and policy makers, as well as for care providers. The purpose of this paper is to present the results of a study to analyse the use of hospital services by the elderly in Alberta since the introduction of a universal single payer health care insurance system in 1970. The study period coincides with the implementation of publicly-financed comprehensive medical and hospital insurance programmes for all Alberta residents, making it possible to perform historical and population-based utilization analyses. Thus the data used for the study included all hospital discharge abstracts generated by all Alberta hospitals from 1971 to 1991. Trends in hospital service utilization by the elderly in terms of total number of separations, patient-days, and per case measures such as average length of stay as well as per capita utilization rates were reviewed to identify utilization patterns over the study period. Further, relative per capita utilization measures, in comparison with the base year (1971), age group 15-44, male, metropolitan residents, were derived and historical trends identified. A series of regression analyses were carried out to estimate the effects of age, sex and origin on utilization rates. In addition, for the period of 1984-1991, Diagnosis Related Groups (DRG) case weights were used to measure per capita and per case rates and to analyse historical relative utilization rates over the 8-year period. In general, there has been a significant decline in hospital utilization by Albertans under the publicly-financed single payer system, but utilization rates for elderly have remained high, resulting in high relative utilization rates in comparison with other age groups. It was also noted that per capita utilization rates for rural residents were substantially higher than urban residents. It appears that these higher utilization rates by the elderly and rural residents in combination with tight bed and financial control by the government have been causing significant bed shortage problems for non-elderly elective patients in urban areas.

The relationship between resource constraints and physician problem solving. Implications for improving the process of care

OBJECTIVES

Research suggests that physicians will engage in more vigilant problem-solving under conditions of resource constraints than under conditions of resource slack. Increased vigilance related to physicians' clinical strategies enhances care by disposing physicians toward more optimal care choices. The authors examine whether pressures for clinical resource constraints encourage increased and sustained vigilance in problem-solving among cardiologists treating acute myocardial infarction.

METHODS

The physician problem-solving process is reconstructed from the medical records of all eligible cases of acute myocardial infarction treated by the physician sample set over a 6-year period. The sample period encompasses phases of both resource slack and resource constraints. The Herfindahl index is used to measure the relative amount of vigilant problem-solving activity exhibited in each of five major tactical areas of the physician care strategies in each year of the study.

RESULTS

The results support the hypothesis that resource constraints initially promote a shift to increased vigilance in physician problem-solving. Only one of the five major tactical areas, however, is characterized by sustained vigilance over time. The other areas are, instead, associated with a substantial reduction in vigilant activity after the initial peak period.

CONCLUSIONS

The results suggest that resource constraints do set the stage for improved clinical decision-making. Sustained vigilance, however, appears to apply only to those portions of the care strategy for which the physician can draw a clear link between optimizing clinical activity and reducing resource consumption. For those portions of the care strategy for which the physician cannot establish a clear link, ongoing pressures to conserve resources results in reduced vigilance and a potential reduction in quality of clinical decision-making.

An atypical T-cell lymphosarcoma in a calf with bovine immunodeficiency-like virus infection

An 11-month-old Holstein calf experimentally infected with bovine immunodeficiency-like virus (BIV) developed T-cell lymphosarcoma 5 months postinoculation, concurrent with progressive monocytosis. Tumors were found in the thymus, multiple lymph nodes, and brain. Tumor cells were CD2+, CD4-, CD8-T cells. Infectious BIV could be recovered from splenic tissue and blood mononuclear cells. Bovine leukemia virus was not present. Because this calf was part of an ongoing experiment on the pathogenesis of BIV infection, immune function data were also available both before and after lymphosarcoma developed. Neutrophil and monocyte function were normal, but lymphocyte blastogenesis was enhanced before the development of lymphosarcoma. Follicular hyperplasia in lymphoid tissues was also seen. This case raises the possibility that BIV infection may cause or be associated with some cases of atypical T-cell lymphosarcoma, without evidence of immune suppression at the time of tumor onset.

Quality of life improvement in patents with osteoarthritis: the potential for office-based assessment

OBJECTIVE

This study presents the initial findings from our evaluation of the Nottingham Health Profile, a short and simple quality of life instrument, to determine its ease and robustness as a routine office tool for evaluating changes in the quality of life for arthritis patients undergoing joint replacement.

METHODS

Thirty-five patients awaiting total joint replacement surgery were asked to complete the Nottingham Health Profile at their pre-operative clinic. A post-joint replacement evaluation profile, with a self-addressed stamped envelope, was mailed to each participant 3-4 months post-surgery. The profile was self-administered on both occasions.

RESULT

The follow-up response rate was 69%. The t-test for the paired difference of related populations was used to determine pre-test and post-test changes. Significant improvement was found in the profile's 6 subscales, with energy, pain, and physical mobility significant at the 0.001 level, emotion and social isolation significant at the 0.005 level, and sleep significant at the 0.05 level. The before and after comparison of the profile's global self-assessment of health was not significant.

CONCLUSION

Preliminary findings suggest that the Nottingham Health Profile is a useful office tool for the routine assessment of intervention-related changes in quality of life. The instrument was easy to self-administer and was associated with a mail return response rate consistent with other investigations using the profile. Even with a small sample size, the profile rendered data consistent with large-scale research evaluations of changes in quality of life for joint replacement patients. The finding that patients' global health status measures did not change despite improvements in quality of life subscales indicates that the instrument reliably netted out the quality of life benefits of the arthritis-related intervention from the patients' total burden of illness.

Variation in outpatient procedure rates in Canadian teaching hospitals

OBJECTIVE

To determine the variation in the rate at which specific procedures are performed on an outpatient basis in Canadian teaching hospitals.

DESIGN

An index of outpatient activity was developed using the ratio of expected-to-actual performance, with the expected performance representing empirical, exogenous criteria.

SETTING

Canadian teaching hospitals.

RESULTS

The index indicated whether the hospital, or group of hospitals, of interest is equally, more, or less active than the comparison group. The results show that Canadian teaching hospitals were 3% less active than Canadian nonteaching hospitals and Alberta teaching hospitals were 22% less active than all Canadian teaching hospitals. Individual teaching hospitals in Alberta were 21% more, 40% less, 9% less, 44% less, 8% less, 39% less, 20% less, and 2% less active than all other Alberta teaching hospitals.

CONCLUSIONS

If variation in the use of less costly treatment modalities represents variation in quality as in Donabedian's unifying model, the results show considerable variation in quality across the generally accepted leaders in the medical care field. By comparing teaching hospitals with other teaching hospitals the difference in the patient severity level is minimized. The decision regarding the delivery modality represents only one decision in the complex decision matrix faced by physicians in the treatment episode. Given the considerable variation demonstrated in this study, the task of developing protocol, standards, or guidelines in order to reduce variation over the total treatment episode will be enormous.

Profitable and unprofitable DRGs: the implications for access

Given a choice, hospitals would prefer to admit a patient with the potential to contribute to an accounting profit and prefer not to admit a patient with the potential to contribute to an accounting loss. It is suggested that if all hospitals found the same DRGs to be unprofitable, access to inpatient care would be denied those patient types. A set of 509 hospitals was stratified according to bedsize, Medicare load, type of control, teaching status and geographic location. The 10 most and 10 least profitable DRGs were identified for each hospital category and a Spearman's rank order correlation was used to determine the similarity or dissimilarity across hospital category. The results indicate that the more alike hospitals are in terms of bedsize, Medicare load and teaching status, the more alike are the DRGs that are determined to be unprofitable (or profitable). Conversely, the less alike they were on these characteristics, the less alike were the unprofitable (or profitable) DRGs. There were no differences evident when the hospitals were classified according to type of control or geographic location. These results are generally encouraging in terms of potential access but disturbing in terms of possible further financial threat to rural hospitals.

Case mix management: a cautionary note

Using data from a study that involved 500 U.S. acute care hospitals, the author examines the relationship between the profitability of Diagnostic Related Groups (DRGs) and their DRG weight, and the similarity/difference of the most/least profitable DRGs across hospital types. Hospital administrators are cautioned that to engage in case mix management, they must use a management information system that provides the data necessary for determining the cost of treating each patient type within their own institution, not information derived from other facilities or other systems.

The impact of diagnosis related group profitability on the skimming and dumping of psychiatric diagnosis related groups

Psychiatric DRGs are identified in terms of their relative profitability within each hospital of a 386 hospital cohort. It is then determined whether hospitals admitted more of the more profitable and fewer of the less profitable patients over the period 1983-1987 (skimming). Also determined is whether hospitals discharged more of the less profitable to other short term hospitals over the same period of time (dumping). The findings generally indicate that this did not happen.

Identification of a hypervariable region in the long terminal repeat of equine infectious anemia virus

An avirulent, field-derived isolate of equine infectious anemia virus (EIAV), designated MA-1, was molecularly cloned, and the complete nucleotide sequence was determined for the 3' half of the viral genome. Comparisons between MA-1 and the prototype Wyoming strain of EIAV identified a 66-nucleotide stretch between CAAT (-91) and TATAA (-25) in the U3 region of the long terminal repeat, where sequence divergence was as high as 39.3%. The polymerase chain reaction was used to amplify and clone long terminal repeat sequences from Th-1, the in vivo parental stock of MA-1. Results indicated that the nucleotide sequences of MA-1 and Th-1 clones were less variable than was observed between MA-1 and Wyoming. However, MA-1 and Th-1 markedly differed in the types of enhancer sequences located in the hypervariable region. These results suggest that variation in lentivirus regulatory sequences may be important in EIAV host cell tropism and pathogenesis.

A reassessment of hospital product and productivity changes over time

Were the changes found in the first year of the prospective payment system (PPS) one-time changes that attenuated as hospitals gained familiarity with the system? The results of this research show that, over time, discharges to home (self-care) continued to decrease, discharges to home health agencies continued to increase, but transfers and discharges to skilled nursing facilities or intermediate care facilities accounted for an increasing share of total discharges. After a dramatic decrease in the first year, the use of laboratory tests, diagnostic tests, and X-rays returned, over time, almost to pre-PPS levels.

Were hospitals selective in their product and productivity changes? The top 50 DRGs after PPS

Five separate hospital products are identified based on the concept of the amount of disease remission achieved by the hospital. The parameters of this concept are illness level on admission and discharge location. In a cohort of 646 nonfederal, short-term hospitals over the period 1980-1984, changes in the hospital product are examined separately in the 50 diagnosis-related groups (DRGs) with the greatest volume of Medicare discharges. Productivity changes, as defined by the number of certain inputs, are also examined. In both sets of analyses, patient severity level is controlled for by indexing to the base year (1980) case mix. The purpose of this study was to examine whether the dramatic product and productivity changes following implementation of the prospective payment system, as found in our earlier work, were across-the-board changes or the result of selective changes, specific to certain DRGs or products. The results suggest that the changes were an across-the-board phenomenon. Policy implications are discussed.

A comparison of the resource intensity of inpatients in urban and rural nonteaching hospitals

PL 98-21 mandated a prospective payment system based on diagnosis related groups (DRGs) for all Medicare inpatients. The predetermined payment for each DRG is intended to reflect the resources used to treat patients within the DRG. Eventually, the system will allow for one payment level for each DRG in rural hospitals and a higher payment level for the same DRG in urban hospitals. This represents an equitable approach, provided there is not a predominance of high severity cases in rural hospitals and that higher costs in urban hospitals are reflective of higher priced exogenous factors beyond the control of the hospital. Equitability also requires that DRGs capture the resource intensity of treatment for a given classification of patients, equally for urban and rural patients. This work compares the pediatric population of urban hospitals without a pediatric residency program with that of rural hospitals in terms of major diagnostic category, DRG, disease severity, length of stay, and charges. It also compares the capacity of DRGs to explain the variation in resource consumption in urban and rural hospitals. A sample of 116,721 discharges from 130 urban hospitals and a sample of 54,073 discharges from 97 rural hospitals are used in this work. The results indicate that there is no difference in the patient populations of these two hospital groups. The results also indicate that DRGs explain only 50 percent of the variance in the resource variables, but this obtains equally for both populations.

The effect of PPS on hospital product and productivity

The results suggest that Prospective Payment System (PPS) prompted a reduction in the proportion of Medicare patients that were discharged, for whom the hospital considered the episode of care to be completed. The results also show a reduction in the proportion of patients discharged dead. When controlling for patient type, the results support the findings, but the magnitude of the change that might be attributed to PPS is somewhat smaller. Proportional changes in the input measures for all patients were next considered. The results indicate that fewer diagnostic tests, fewer laboratory tests, and fewer x-rays were used in 1984. Laboratory tests showed the most dramatic decrease. LOS decreased, but the drug input remained fairly constant. A productivity index that reflects the change in the input measure while controlling for patient type was developed. The results provide strong evidence of a productivity increase in all products for Medicare patients. The drug input did not contribute to the productivity increase. The 50 most frequent DRGs for Medicare patients were examined separately for productivity changes by product. The results further support the findings of an increase in productivity.

Spectrophotometric and liquid chromatographic identification of 3,4-methylenedioxyphenylisopropylamine and its N-methyl and N-ethyl homologs

3,4-Methylenedioxyphenylisopropylamine (MDA) is an hallucinogenic drug that somewhat resembles lysergic acid diethylamide (LSD) in its effects. Recently, widespread abuse of the N-methyl homolog (MDMA) of MDA has led to federal control. This article reports on the synthesis of the N-ethyl homolog (MDEA) of MDA as well as spectrophotometric and chromatographic methods for identification of the 3 homologs.

Should children's hospitals have special consideration in reimbursement policy?

Children's hospitals were excluded indefinitely from the prospective payment system until a methodology for their reimbursement could be developed. Special consideration in reimbursement policy could be made for children's hospitals if their patients were generally more resource intensive than the pediatric patients of other hospitals. The resource intensity of patients in children's hospitals was compared with pediatric patients in other hospital groups. The results indicate that the patient population of children's hospitals is similar to the pediatric patient population of university hospitals and considerably different from the pediatric patient populations of the urban and rural hospitals.

Minimum optimum scale of federally qualified health maintenance organizations

From a policy standpoint it is important to identify the level of output at which average cost per unit is at its lowest. If minimum optimum scale is achieved at a very high output level, it would suggest that monopoly conditions should be allowed to prevail. If, however, minimum optimum scale is achieved at a low level of output, more organizations would be able to survive, allowing for competition in the marketplace. Using data published by the Office of Health Maintenance Organizations, the relationship between size and average cost was examined in federally qualified staff, group, and Independent Practice Association (IPA) health maintenance organizations (HMOs) and minimum optimum scale was identified for each organization. The findings support the hypothesis that least cost size is achieved at the lowest level of output in IPA HMOs. The hypothesis that minimum optimum scale would be achieved at a lower level of output in group rather than in staff HMOs was not supported. This may be due to the practice of some staff HMOs of employing part-time, salaried providers and purchasing unique services from other providers.

A reconsideration of economies of scale in the health care field

The Health Care Financing Administration has demonstrated an interest in the economies of scale phenomenon as it might apply to reimbursement methodologies. This paper provides a critical evaluation of the economies of scale research methodology and a critical review of both the analytical (LRAC estimates) and the implied economies of scale (spreading fixed costs) literature. Given that estimates of Minimum Optimum Scale are based on individual coefficients generated by a regression model, this work illustrates the danger inherent in this approach and examines the volatility of the coefficient values and their dependence upon model specification. The ambiguity present in the literature addressing the LRAC estimates is thereby explained. An evaluation of the implied economies of scale literature reveals that average fixed costs decrease with increasing levels of output. This should not be a surprise to anyone. The notion of economies of scale is implied in this literature but never addressed. It is suggested in this work that the means to better standardize the output of the hospital industry, the sine qua non of economies of scale research, is now available in various methodologies of patient grouping.

The role of perceived price in physicians' demand for diagnostic tests

This research examines the extent of physicians implicit price knowledge and its role in the physicians' demand for diagnostic tests. In particular, it examines the effect of perceived price on the quantity of test ordered. A group of 36 second and third-year residents and 23 clinical faculty members in three family practice centers affiliated with the Family Medicine Department of Wayne State University were randomly assigned to either a control group or an experimental group. They were asked to review four case studies and indicate on a test order form the tests they would order. The experimental group used a test order form that included the actual test prices and the control group used the same form but without the prices included. Subsequent to this, the control group (those without actual price information) was asked to estimate the price of all tests listed. Physicians' implicit price knowledge was measured by the number of underestimates, overestimates, and correct estimates and correlated with the total number of tests ordered. The results show the following tendencies: 1) physicians generally incorrectly estimate prices; 2) they tend to underestimate rather than overestimate; 3) they tend to underestimate the higher priced tests and overestimate the lower priced tests; 4) the greater the propensity to underestimate, the greater the number of tests ordered; 5) the greater the propensity to overestimate, the fewer the number of tests ordered; and 6) the greater the propensity to correctly estimate, the fewer the number of tests ordered. The results indicate that in the absence of actual prices, perceived prices enter the physicians' demand function and that physicians' demand for diagnostic tests might be categorized as rational.

An integrated theory of provider behavior in Health Maintenance Organizations

It has been consistantly demonstrated in the literature that reduced medical care expenditures for Health Maintenance Organization (HMO) enrollees results from reduced hospital utilization. The cause of such behavior on the part of the HMO provider has generally been attributed to the prepayment or capitation method of financing the delivery of medical care or to the organization dynamics. This paper suggests that the problem with trying to attribute the cause of reduced hospitalization to either the payment mechanism or group dynamics is that the latter is a manifestation of the former. That is, peer review activities emerge as the result of fixed budget financing and emanate from the entity at risk. The task then becomes one of understanding the relationship between risk, incentive, behavior, and the identification of the entity at risk. Using the risk model, it can be seen that, depending on the entity perceiving the risk, controls on provider behavior can be implicit or explicit. It can also be seen that, depending on the magnitude of the perceived risk, controls can be stringently or loosely applied, or nonexistent. Much of the ambiguity in the literature regarding HMO provider behavior can be explained by the risk model developed in this work.

The effects of price information on physicians' test-ordering behavior. Ordering of diagnostic tests

This research evaluated the effects of providing physicians with information about the prices of diagnostic tests on their subsequent test-ordering behavior. The study population consisted of 36 second- and third-year residents and 23 clinical faculty in three family practice centers affiliated with the Department of Family Medicine at Wayne State University School of Medicine, Detroit, Michigan. Study participants were asked to review four case studies, each describing ambiguous symptoms, and to indicate on an attached test order form the tests they would order for each patient. Subjects were randomly assigned either to a group that received test order forms on which to prices of diagnostic tests were printed (price-information group) or to a group that received test order forms with no prices indicated (control group). The study results show that for each of the four cases, the average number of diagnostic tests ordered was significantly lower in the price-information group than in the control group. Our findings also show an average reduction in the cumulative cost of tests ordered per patient of 31.1 per cent related to the provision of price information is discussed and reviewed in light of other approaches that have been developed to modify physician behavior in ordering diagnostic tests.

Specialty choice of black medical school graduates

The choice of specialty by black U.S. citizens serving in residencies as of September 1977 is compared with the choice pattern of all physicians certified by specialty boards as of December 31, 1977. It is suggested that the choice pattern of all board-certified physicians represents a random choice, free from systematic bias. By comparing the choice patterns, it can be determined whether there is evidence of systematic bias which might suggest the presence of exogenous biasing forces. The results of the analysis indicate that the choice patterns of black residents are almost identical to the choice pattern of all physicians certified by specialty boards. The implication of this is that the choice of black U.S. citizens can be considered to be as free from biasing forces as is the choice of all board-certified physicians.