BACKGROUND: Pay for performance has increasingly become the subject of intense interest and debate, both of which have been heightened as the Centers for Medicare and Medicaid Services moves closer to adopting this approach for Medicare. Although many claims have been made for the effectiveness of this approach, the extent of its national penetration remains unknown. METHODS: We surveyed a sample of 252 health maintenance organizations (HMOs) (response rate, 96%) drawn from 41 metropolitan areas across the nation about use of pay for performance. We determined the prevalence of pay-for-performance programs, detailed the features of such programs, and examined the adoption of pay for performance as a function of the characteristics of both the health plans and markets. RESULTS: More than half the HMOs, representing more than 80% of persons enrolled, use pay for performance in their provider contracts. Of the 126 health plans with pay-for-performance programs, nearly 90% had programs for physicians and 38% had programs for hospitals. Use of pay for performance was statistically associated with geographic region, use of primary care providers (PCPs) as gatekeepers, use of capitation to pay PCPs, and whether the plans themselves received bonuses or penalties according to performance. CONCLUSIONS: Pay for performance is now commonly used by HMOs, especially those that are situated to assign responsibility for a particular patient to a PCP or medical group. As the design of Medicare with pay for performance moves forward, it will be important to leverage the early experience of pay for performance in the commercial market.

BACKGROUND: The Joint Commission on Accreditation of Healthcare Organizations and the Centers for Medicare and Medicaid Services recently began reporting on quality of care for acute myocardial infarction, congestive heart failure, and pneumonia. METHODS: We linked performance data submitted for the first half of 2004 to American Hospital Association data on hospital characteristics. We created composite scales for each disease and used factor analysis to identify 2 additional composites based on underlying domains of quality. We estimated logistic regression models to examine the relationship between hospital characteristics and quality. RESULTS: Overall, 75.9% of patients hospitalized with these conditions received recommended care. The mean composite scores and their associated interquartile ranges were 0.85 (0.81-0.95), 0.64 (0.52-0.78), and 0.88 (0.80-0.97) for acute myocardial infarction, congestive heart failure, and pneumonia, respectively. After adjustment, for-profit hospitals consistently underperformed not-for-profit hospitals for each condition, with odds ratios (ORs) ranging from 0.79 (95% confidence interval [CI], 0.78-0.80) for the congestive heart failure composite measure to 0.90 (95% CI, 0.89-0.91) for the pneumonia composite. Major teaching hospitals had better performance on the treatment and diagnosis composite (OR, 1.37; 95% CI, 1.34-1.39) but worse performance on the counseling and prevention composite (OR, 0.83; 95% CI, 0.82-0.84). Hospitals with more technology available, higher registered nurse staffing, and federal/military designation had higher performance. CONCLUSIONS: Patients are more likely to receive high-quality care in not-for-profit hospitals and in hospitals with high registered nurse staffing ratios and more investment in technology. Because payments and sources of payments affect some of these factors (eg, investments in technology and staffing ratios), policy makers should evaluate the effect of alternative payment approaches on quality.

A majority of employees can choose among health insurance plans of varying generosity. They may switch plans if prices, information, or their health status change. This paper analyzes switching behavior presumptively caused by changes in health status. We show that people who move to a less generous plan have lower medical spending prior to the switch than the average for the generous plan in which they started, while those who move to a more generous plan appear to anticipate higher spending, which they delay until after the switch. This transfer of costs from a less to a more generous plan increases the burden of adverse selection. Our data suggest that switching may be more important to the level of premiums than previously documented.

With the proliferation of efforts to report publicly the outcomes of healthcare providers and institutions, there is a growing need to define standards for the methods that are being employed. An interdisciplinary writing group identified 7 preferred attributes of statistical models used for publicly reported outcomes. These attributes include (1) clear and explicit definition of an appropriate patient sample, (2) clinical coherence of model variables, (3) sufficiently high-quality and timely data, (4) designation of an appropriate reference time before which covariates are derived and after which outcomes are measured, (5) use of an appropriate outcome and a standardized period of outcome assessment, (6) application of an analytical approach that takes into account the multilevel organization of data, and (7) disclosure of the methods used to compare outcomes, including disclosure of performance of risk-adjustment methodology in derivation and validation samples.

PURPOSE: The study investigated the determinants of warfarin use in patients with atrial fibrillation (AF). METHODS: We assembled a retrospective cohort of community-dwelling elderly patients (aged > or = 66 years) with AF using linked administrative databases. We identified the physicians responsible for the ambulatory care of these patients using physician service claims and compared patients who did and did not have an identifiable provider. For those patients with an identifiable provider, we assessed the association between patient, physician, and hospital factors and warfarin use. RESULTS: Our cohort consisted of 140,185 patients, of whom 116,200 (83%) had an identifiable cardiac provider. Patients without a provider were significantly more likely to have comorbid conditions that increase their risk of warfarin-associated bleeding. After adjustment for clinical factors, patients without a provider were significantly less likely to receive warfarin (odds ratio 0.37, 95% confidence interval: 0.36-0.38). Of patients with providers, 50,551 patients (43.5%) received warfarin within 180 days after hospital discharge. Warfarin use was positively associated with AF-associated stroke risk factors (eg, prior stroke, congestive heart failure) and negatively associated with warfarin-associated bleeding risk factors (eg, history of intracerebral hemorrhage). After controlling for patient and hospital factors, patients cared for by noncardiologist physicians with cardiology consultation were more likely to receive warfarin then patients treated in noncollaborative environments. CONCLUSIONS: Warfarin continues to be substantially underprescribed to patients who are at high risk for AF-associated cardioembolic stroke. Our findings highlight the need for targeted quality improvement interventions and suggest preferred models of AF care involving routine collaboration between cardiologists and other physicians.

BACKGROUND: Choice of statistical methodology may significantly impact the results of provider profiling, including cardiac surgery report cards. Because of sample size and clustering issues, logistic regression may overestimate systematic interprovider variability, leading to false outlier classification. Theoretically, the use of hierarchical models should result in more accurate representation of provider performance. METHODS: Extensively validated and audited data were available for all 4,603 isolated coronary artery bypass grafting procedures performed at 13 Massachusetts hospitals during 2002. To produce the official Massachusetts cardiac surgery report card, a 19-variable predictor set and a hierarchical generalized linear model were employed. For the current study, this same analysis was repeated with the 14 predictors used in the New York Cardiac Surgery Reporting System. Two additional analyses were conducted using each set of predictor variables and applying standard logistic regression. For each of the four combinations of predictors and models, the point estimates of risk-adjusted 30-day mortality, 95% confidence or probability intervals, and outlier status were determined for each hospital. RESULTS: Overall unadjusted mortality for coronary bypass operations was 2.19%. For most hospitals, there was wide variability in the point estimates and confidence or probability intervals of risk-adjusted mortality depending on statistical model, but little variability relative to the choice of predictors. There were no hospital outliers using hierarchical models, but there was one outlier using logistic regression with either predictor set. CONCLUSIONS: When used to compare provider performance, logistic regression increases the possibility of false outlier classification. The use of hierarchical models is recommended.

BACKGROUND: Recent studies indicate that a routine invasive approach for patients with unstable angina (UA) and non-ST-segment elevation myocardial infarction (NSTEMI) yields improved outcomes compared with a conservative approach, but the optimal timing of this approach remains open to debate. METHODS AND RESULTS: We used day of hospital presentation as an instrumental variable to study the impact of timing of cardiac catheterization and revascularization therapy on acute outcomes (death, reinfarction, stroke, cardiogenic shock, or congestive heart failure) among patients with UA and NSTEMI. Between January 2001 and September 2003, 56,352 patients with UA or NSTEMI were treated at 310 US hospitals participating in the CRUSADE national quality improvement initiative. Weekend patients were defined as those who presented to the hospital between 5 PM on Friday and 7 AM on Sunday. All other patients were classified as weekday. Weekday patients were similar to weekend patients in terms of demographics, clinical characteristics, and the use of medical therapies in the first 24 hours. Although overall rates of cardiac catheterization and revascularization were similar for the 2 groups, median time to catheterization was significantly longer for weekend than for weekday patients (46.3 versus 23.4 hours, P<0.0001). This delay was not associated with increased in-hospital adverse events, including death (weekend 4.4% versus weekday 4.1%, P=0.23), recurrent MI (2.9% versus 3.0%, P=0.36), or their combination (6.6% versus 6.6%, P=0.86). These findings were not affected by risk adjustment or use of alternative definitions of weekend versus weekday presentation. When weekend presentation was used as the basis for an instrumental variable analysis, we found that catheterization within the first 12 hours of presentation was associated with a nonsignificant trend toward reduced in-hospital mortality (absolute risk reduction 1.9%; 95% CI 6.7% lower to 2.9% higher; P=0.43) that decreased with longer treatment delays. CONCLUSIONS: Although weekend presentation is associated with a delay in invasive management among patients with UA and NSTEMI, in the context of contemporary medical therapy, this does not increase adverse events. Weekend presentation appears to fulfill accepted criteria as an instrumental variable for studying the optimal timing of invasive management for acute coronary syndrome patients. Using weekend status as an instrumental variable, we found no significant benefit to early catheterization, although we could not exclude an important risk reduction, particularly for catheterization within 12 hours of presentation.

In the USA, mental health expenditures have been rising at a rate that exceeds other medical expenditures. To control these costs, insurance companies and governmental agencies responsible for health benefit plans have turned to managed care companies who review utilisation of services and who negotiate fee reductions with providers. In this study, we examined changes in patterns of care and per person expenditures among Medicaid enrollees with major mental illness. We found that after the introduction of managed care, per person expenditures were reduced by about 25%, accomplished primarily by limiting hospital admissions. We also found that admissions (and the associated costs) were not shifted to the Department of Mental Health, which funds state hospital long-term care for the indigent. Measures of continuity of care were unchanged during the study period. We conclude that managed care met its cost-containment goals without shifting costs to another state agency.

Nigericin, in the concentration range (10(-6) M or higher) at which it uncouples intact mitochondria, was found to increase the conductance of black lipid membranes (BLM) by several orders of magnitude. The dependence of the membrane conductance on pH and K+ concentration suggests a mechanism for the transfer of charge mediated by this ionophore based on a mobile dimer with both nigericin molecules protonated and complexed with one K+. This charged complex accounts for the uncoupling effect observed in intact mitochondria.

During the "respiratory adaptation" of Bacillus coagulans, it was possible to dissociate the kinetics of cytochrome a and a3 synthesis with carbon monoxide. The synthesis of cytochrome a3 is preferentially repressed when the pH of the incubation medium is pH 6.5 instead of pH 5.5. However, though the total synthesis of tetrapyrrole compounds is the same at both pH values, the excretion of coproporphyrin III is much increased at pH 6.5. Bacillus coagulans, sensitive to the "glucose effect", shows the "pH effect" only in the presence of high glucose concentrations. The repression of the oxidase complex synthesis by a slight increase of the extracellular pH appears directly related to the increase of the extracellular coproporphyrin III.

It has been established that H+ secretion can be maintained in frog stomach in the absence of exogenous CO2 by using a nutrient bathing fluid containing 25 mM H2PO4 (pH approximately equal to 4.5) or by lowering the pH of a nonbuffered nutrient solution to about 3.0-3.6. Exogenous CO2 in the presence of these nutrient solutions uniformly caused a marked decrease in H+ secretion, PD, adn short-circuit current (Isc) and an increase in transmucosal resistance (R). Elevation of nutrient [k+] to 83 mM reduced R significantly but transiently without change in H+ when nutrient pH less than 5.0, whereas R returned to base line and H+ increased when nutrient pH greater than 5.0. Acidification of the nutrient medium in the presence of exogenous CO2 results in inhibition of the secretory pump, probably by decreasing intracellular pH, and also interferes with conductance at the nutrient membrane. Removal of exogenous CO2 from standard bicarbonate nutrient solution reduced by 50% the H+, PD, and Isc without change in R; K+-free nutrient solutions reverse these changes in Isc and PD but not in H+. The dropping PD and rising R induced by K+-free nutrient solutions in 5% CO2 - 95% O2 are returned toward normal by 100% O2. Our findings support an important role for exogenous CO2 in maintaining normal acid-base balance in frog mucosa by acting as an acidifying agent.

The extracellular proteinase of Staphylococcus aureus strain V8 was used to digest the NADP-specific glutamate dehydrogenase of Neurospora crassa. Of 35 non-overlapping peptides expected from the glutamate content of the polypeptide chain, 29 were isolated and substantially sequenced. The sequences obtained were valuable in providing overlaps for the alignment of about two-thirds of the sequences found in tryptic peptides [Wootton, J. C., Taylor, J, G., Jackson, A. A., Chambers, G. K. & Fincham, J. R. S. (1975) Biochem. J. 149, 739-748]. The blocked N-terminal peptide of the protein was isolated. This peptide was sequenced by mass spectrometry, and found to have N-terminal N-acetylserine by Howard R. Morris and Anne Dell, whose results are presented as an Appendix to the main paper. The staphylococcal proteinase showed very high specificity for glutamyl bonds in the NH4HCO3 buffer used. Partial splits of two aspartyl bonds, both Asp-Ile, were probably attributable to the proteinase. No cleavage of glutaminyl or S-carboxymethylcysteinyl bonds was found. Additional experimental detail has been deposited as Supplementary Publication SUP 50053 (5 pages) with the British Library (Lending Division), Boston Spa, Wetherby, W. Yorkshire LS23 7BQ, U.K, from whom copies may be obtained under the terms given in Biochem. J. (1975) 1458 5.

(--)-alpha-Bisabolol has a primary antipeptic action depending on dosage, which is not caused by an alteration of the pH-value. The proteolytic activity of pepsin is reduced by 50 percent through addition of bisabolol in the ratio of 1/0.5. The antipeptic action of bisabolol only occurs in case of direct contact. In case of a previous contact with the substrate, the inhibiting effect is lost.

Adrenaline-induced gastric ulceration was studied in rats. Adrenaline in high doses caused gastric ulcer, which was completely blocked by pretreatment with alpha-blockers (phenoxybenzamine, dibenamine), but not by pretreatment with propranolol or atropine, nor by vagotomy, hypophysectomy or adrenalectomy. After successive administration of adrenaline, once daily for 7 days, however, no gastric ulcer was observed. Recovery from the ulcerogenic action of adrenaline was seen after 4 weeks withdrawal. Pretreatment with a small dose of adrenaline inhibited the ulcerogenic action of a high dose of adrenaline. Pretreatment with reserpine, pyrogallol or iproniazid inhibited the action of adrenaline. It is concluded that adrenaline has a biphasic effect on gastric ulceration, the ulcerogenic action is due to its alpha-action and antiulcerogenic effect is due to development of tachyphylaxis.