Biomedical subjects

M Pine

Publications and source records attributed to M Pine.

12 recordsLinked to original sources

PubMed1998

Laboratory values improve predictions of hospital mortality.

OBJECTIVE: To compare the precision of risk adjustment in the measurement of mortality rates using: (i) data in hospitals' electronic discharge abstracts, including data elements that distinguish between comorbidities and complications; (ii) these data plus laboratory values; and (iii) these data plus laboratory values and other clinical data abstracted from medical records. DESIGN: Retrospective cohort study. SETTING: Twenty-two acute care hospitals in St Louis, Missouri, USA. STUDY PARTICIPANTS: Patients hospitalized in 1995 with acute myocardial infarction, congestive heart failure, or pneumonia (n = 5966). MAIN OUTCOME MEASURES: Each patient's probability of death calculated using: administrative data that designated all secondary diagnoses present on admission (administrative models); administrative data and laboratory values (laboratory models); and administrative data, laboratory values, and abstracted clinical information (clinical models). All data were abstracted from medical records. RESULTS: Administrative models (average area under receiver operating characteristic curve=0.834) did not predict death as well as did clinical models (average area under receiver operating characteristic curve=0.875). Adding laboratory values to administrative data improved predictions of death (average area under receiver operating characteristic curve=0.860). Adding laboratory data to administrative data improved its average correlation of patient-level predicted values with those of the clinical model from r=0.86 to r=0.95 and improved the average correlation of hospital-level predicted values with those of the clinical model from r=0.94 for the administrative model to r=0.98 for the laboratory model. CONCLUSIONS: In the conditions studied, predictions of inpatient mortality improved noticeably when laboratory values (sometimes available electronically) were combined with administrative data that included only those secondary diagnoses present on admission (i.e. comorbidities). Additional clinical data contribute little more to predictive power.

Clinical Laboratory Information Systems↗

PubMed1997

Predictions of hospital mortality rates: a comparison of data sources.

BACKGROUND: Comparing hospital mortality rates requires accurate adjustment for patients' intrinsic differences. Commercial severity systems require either administrative data that omit vital clinical facts about patients' conditions at hospital admission or costly, time-consuming abstraction of medical records. The validity of supplementing administrative data with laboratory data has not been assessed. OBJECTIVE: To compare risk-adjusted mortality predictions using administrative data alone; administrative data plus laboratory values; and the combination of administrative, laboratory, and clinical data. DESIGN: Retrospective cohort study. SETTING: 30 acute care hospitals. PATIENTS: 46,769 patients hospitalized with acute myocardial infarction, cerebrovascular accident, congestive heart failure, or pneumonia. MEASUREMENTS: Each patient's probability of dying was estimated by using administrative data only (unrestricted administrative models), administrative data restricted to secondary diagnoses that are unlikely to be hospital-acquired complications (restricted administrative models), restricted administrative data plus laboratory data (laboratory models), and restricted administrative data plus laboratory and abstracted clinical data (clinical models). RESULTS: The unrestricted administrative models predicted death better than the restricted administrative models (average areas under the receiver-operating characteristic [ROC] curves, 0.87 and 0.75, respectively) and as well as the laboratory models and the clinical models (average areas under the ROC curves, 0.86 and 0.87, respectively). The good mortality predictions obtained by using the unrestricted administrative models result from inclusion of hospital-acquired complications that commonly precede death. The laboratory models ranked 93% of patients and 95% of hospitals in a manner similar to the clinical models; in comparison, rankings provided by the laboratory models were similar to those provided for 75% of patients and 69% of hospitals by the unrestricted administrative models and for 72% of patients and 77% of hospitals by the restricted administrative models. CONCLUSIONS: Adding laboratory data (often available electronically) to restricted administrative data sets can provide accurate predictions of inpatient death from acute myocardial infarction, cerebrovascular accident, congestive heart failure, or pneumonia. This alternative avoids the cost of data abstraction and the serious errors associated with using administrative data alone.

Adult↗

PubMed1996

Care of patients with upper gastrointestinal hemorrhage in academic medical centers: a community-based comparison.

BACKGROUND & AIMS: A common perception among purchasers is that academic medical centers are inefficient and overutilize technology; however, little empirical information exists. The aim of this study was to compare treatment and outcomes of patients with upper gastrointestinal hemorrhage admitted to major teaching hospitals and other hospitals in a large metropolitan area. METHODS: Data on 3801 consecutive eligible patients admitted to five major teaching hospitals and 25 other hospitals from 1991 to 1993 were obtained by review of medical records. Admission severity of illness was measured using validated multivariable models. RESULTS: Rates of upper endoscopy were somewhat lower among the 1004 patients discharged from fellowship hospitals, compared with the other 2797 patients (82.9% vs. 85.6%; P < 0.05), and the use of other procedures was similar. Although patients admitted to fellowship hospitals tended to have a higher severity of illness, both unadjusted (6.3 +/- 9.0 vs. 7.1 +/- 7.5 days; P < 0.01) and risk-adjusted length of stay were somewhat shorter. Mortality rates were similar between hospitals, and patients admitted to fellowship hospitals were somewhat less likely to be transfused. CONCLUSIONS: In patients with upper gastrointestinal hemorrhage, teaching hospitals do not appear to provide inefficient care or overutilize expensive treatments when compared with community facilities. These findings are noteworthy at a time when viability of academic centers and fellowship training is threatened.

Academic Medical Centers↗

PubMed1993

Data about mortality.

Explore the source record for details and available documents.

Data Interpretation, Statistical↗

PubMed1991

Using clinical variables to estimate the risk of patient mortality.

The Health Care Financing Administration (HCFA) uses information from hospital bills, such as age, sex, and diagnoses, to estimate statistical models for the probability, or risk, of death during and after hospital stays. The average risk estimates (expected death rates) are compared with the actual death rates to identify potentially poor quality of care. However, the methods have been criticized as inadequate and an often cited reason is the failure to incorporate risk factors for mortality that are known from clinical research. This hypothesis was tested using a stratified, random sample of 41,963 Medicare patients in 84 hospitals. Many clinical measurements were abstracted for testing as possible risk factors, and a few (26) were identified as useful predictors of death using logistic regression. The estimated regressions accounted for 39% of the variation in mortality, a standard severity classification accounted for 29%, and a relatively simple classification of patients into 17 groups, based on diagnoses, accounted for 17%. The logistic regressions yielded more accurate estimated mortality rates than the severity classification, which in turn was superior to the estimation methods used by HCFA. The HCFA methods were found to be biased in identifying outlier hospitals and this bias can be removed or ameliorated by using clinical risk factors to predict mortality. It is possible to estimate the risk of death more accurately using clinical risk factors and to measure the quality of care.

Centers for Medicare and Medicaid Services, U.S.↗

PubMed1982

Clinical relevance of verapamil plasma levels in stable angina pectoris.

Plasma levels of verapamil and norverapamil were evaluated in 77 patients who received oral verapamiL for treatment of angina pectoris. There was a sixfold interpatient variation in verapamil plasma concentrations, but plasma concentrations were linearly related to doses of the drug (240 to 480 mg/day) in the same patient (r = 0.81). Plasma concentrations of norverapamil, the major active metabolite of verapamil, were similar to those of verapamil. Although verapamil produced a significant improvement in exercise tolerance in most patients, the increase in exercise time was not related to plasma levels of the drug; however, most patients with improvement had plasma levels exceeding 100 ng/ml. An increase in the dose of verapamil from 320 to 480 mg daily produced a substantial (71%) increase in plasma levels of the drug but no significant increase in exercise tolerance (4%). The average increase in the P-R interval with 480 mg of verapamil in these 77 patients was small (8%) (161 +/- 18 to 174 +/- 22 ms); on.y six patients had first-degree heart block. These minor effects on atrioventricular conduction were noted despite plasma verapamil concentrations in 76 patients that exceeded 100 ng/ml, a level that successfully converts supraventricular tachycardias after intravenous drug administration. We differences between the effects of oral and intravenous verapamil on atrioventricular conduction may be the result of stereoselective hepatic inactivation of verapamil's I-isomer. Determination of plasma levels of verapamil is of limited value in the management of patients with angina pectoris, but may be useful in the identification of nonresponders with plasma levels less than 100 ng/ml who may benefit from a further increment in drug dose.

Administration, Oral↗

PubMed1978

Mechanical circulatory support in postoperative cardiogenic shock.

A 38-year-old white woman had cardiogenic shock after elective mitral valve replacement and was unresponsive to pressor drugs and intra-aortic balloon counterpulsation. A left ventricular assist device (left ventricle to ascending aorta) was implanted 16 hours after the initial operation and provided circulatory support for 8 days. Improvement in the patient's own cardiac performance was documented, and there were no complications attributable to the assist device. However, intercurrent medical problems resulted in clinical deterioration on the fifth day after operation, and the patient died 8 days after operation. The findings in this patient suggest a potential role for this left ventricular assist device in future cases of acute, intractable, but potentially reversible myocardial failure.

Acute Kidney Injury↗

PubMed1976

The use of drug concentration measurements in studies of the therapeutic response to propranolol.

The dose of propranolol which produces the optimal therapeutic effect in patients with angina pectoris has been found to vary widely among patients. Because the plasma concentration of propranolol also differs markedly due to interpatient variability in absorption it seemed possible that this might be the reason for the wide range of effective doses in angina and that plasma propranolol might provide a useful guide to therapeutic response. To examine this possibility we selected ten patients with coronary artery disease complicated by angina and studied them at varying propranolol doses to a maximum of 320 mg/day. Exercise capacity was tested on a treadmill and plasma propranolol concentration was measured by gas liquid chromatography. In seven normal subjects beta-blockade was quantified precisely as inhibition of exercise tachycardia and was related to plasma propranolol levels at various doses. Maximal beta-blockade occurred at 100 ng/ml of plasma propranolol, but the dose response curve of blockade was relatively flat and the ED50 of plasma propranolol was 8+/-1 ng/ml. In the patients maximal therapeutic benefit from propranolol occurred at 30+/-7 ng/ml and at a dose of 144 mg/day. This resulted in an increase in exercise capacity from an estimated 12-7+/-0-8 ml/kg/min of oxygen consumption during control to 17-2+/-1-1 ml/kg/min on the drug. Thus, there was a wide variation of both dose and concentration among these patients at the maximum therapeutic response. However, when plasma propranolol was related to pharmacologic activity, the maximum therapeutic response was observed between 64 and 98% of total blockade. These studies indicated the extent of beta-blockade necessary to produce an effective therapeutic response in angina, but demonstrate that plasma drug levels provide no practical guide to therapy in patients with angina pectoris. A further study was conducted measuring plasma propranolol in twenty hypertensive patients to investigate the fall in blood pressure in relations to the change in plasma renin activity and the inhibition of cardiac adrenergic receptors. The inhibition of plasma renin closely resemble the response seen in heart rate inhibition in that the maximum response is seen at 100 ng/ml and the ED50 was 11 ng/ml. In contrast propranolol is shown only to begin to have a significant effect on blood pressure at a plasma level of 30 ng/ml and the effect becomes progressively greater as the plasma level increases. This suggests that the hypotensive effect of propranolol may be dissociated from the beta-blocking effects of cardiac and renin releasing receptors.

Angina Pectoris↗

PubMed1976

Homograft and prosthetic aortic valve replacement: a comparative study.

Homograft aortic valve replacement was done in 103 patients and prosthetic aortic valve replacement in 106 between January 1962 and December 1973. Patients who received homograft and prosthetic valves were compared with respect to age, sex, preoperative functional impairment, infection, dyspnea, angina, hemodynamics, chest X-ray, electrocardiogram, associated operations, early and late mortality, and valve failure. Combined total mortality was 28% (12% operative, 8% first postoperative year, 8% late). Ten percent of valve required replacement. One year after operation, 70% of survivors were asymptomatic, 27% were improved, and 3% were unchanged or between homograft and prosthetic valve replacement. Valve-related failure and infections were more common after homograft aortic valve replacement. Emboli, hemorrhage, and hemolysis were commoner after prosthetic valve replacement. Fungal infections occurred in five homograft patients but in no patient with a prosthetic aortic valve. Severe properative symptoms or recent endocarditis was associated with greater mortality and valve failure in both the homograft and the prosthetic series. Increased mortality and failure was also seen in patients with either preoperative aortic regurgitation with high left ventricular end-diastolic pressure and low cardiac index, or aortic stenosis with cardiomegaly or roentgenographic evidence of congestive heart failure. Therefore, in two series of patients at equal risk, mortality and valve failure were similar for homograft and prosthetic aortic valve replacement.

Adolescent↗

PubMed1975

Correlation of plasma propranolol concentration with therapeutic response in patients with angina pectoris.

The therapeutic response to propranolol was evaluated in patients with documented coronary artery disease at doses varying from 40 to 320 mg/day. Therapeutic response was quantified by evaluating exercise performance on a treadmill and then related to plasma propranolol concentration. Plasma propranolol was defined in terms of beta-adrenergic blockade by comparison with dose (concentration) response curves in normal subjects. Individual therapeutic benefit occurred at doses which averaged 144 +/- 21 mg/day and at concentrations which averaged 30 +/- 7 ng/ml. There was a wide variation between both dose and concentration among the patients at maximum therapeutic response, but when the plasma propranolol was related to pharmacologic activity, the maximum therapeutic response was observed between 64 to 98% of total blockade. Despite the increased exercise performance in these patients, the double product of heart rate and systolic blood pressure was always less, suggesting either an alteration of the relation between myocardial oxygen consumption and the double product during propranolol or a reduction on oxygen delivery to the myocardium as the result of beta-adrenergic blockade of the coronary vasculature.

Administration, Oral↗

PubMedDate not supplied

Severity-of-illness systems. An overview for medical directors--Part two.

In Part One of this article in the March-April 1990 issue of Physician Executive, the authors explored severity-of-illness systems that relied on administrative data for their formulation. In the second part of the article, the authors deal with systems that use clinical and/or physiologic data as their basis.

Clinical Medicine↗

PubMedDate not supplied

Severity-of-illness systems. An overview for medical directors--Part one.

To a baseball fan, the weight of a player's bat is not very important, and the grace with which it is swung has only slightly more appeal. Both these factors matter far less than how often and with what results the bat meets the ball. Similarly, in today's competitive health care environment, the medical director has to focus on results. Not only external demands from constituencies such as insurers, payers, consumers, and regulators, but also internal pressures for sound management decisions require accurate information about the outcomes of care. In this two-part article, the authors examine the contributions that severity-of-illness systems can make to outcomes monitoring.

Centers for Medicare and Medicaid Services, U.S.↗