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Biomedical subjects

H Krakauer

Publications and source records attributed to H Krakauer.

At least 55 records · Page 3Linked to original sources
PubMed1991

National outcomes of cataract extraction. Endophthalmitis following inpatient surgery.

We analyzed the likelihood of rehospitalization for endophthalmitis in 338,141 Medicare beneficiaries over age 65 years who were admitted to US hospitals for cataract extraction in 1984. This cohort represents approximately one half of all persons who underwent cataract extraction under the Medicare program in 1984. Extracapsular extraction was performed in 195,587 (58%) of cases, intracapsular cataract extraction in 99,971 (30%), and phacoemulsification in 28,474 (8%). The risk of rehospitalization for endophthalmitis in the year following surgery was 0.17% for intracapsular cataract extraction compared with 0.12% for extracapsular extraction or phacoemulsification (P less than .002). The risk of endophthalmitis at 1 month was higher for intracapsular cataract extraction than for extracapsular extraction or phacoemulsification (0.11% vs 0.085%), although the difference did not reach statistical significance. Cataract surgery accompanied by anterior vitrectomy increased the 1-month risk of rehospitalization for endophthalmitis to 0.41%, more than a four-fold increase over that for cataract surgery alone (0.09%; P less than .05). The rates of endophthalmitis at 1 year were 0.58% and 0.13%, respectively, for cataract surgery with anterior vitrectomy and cataract surgery alone (P less than .0001). No significant differences in the rate of rehospitalization for endophthalmitis were observed based on the use of an intraocular lens, age, or race. Endophthalmitis within 1 year of surgery was 1.2 times more frequent in men than in women (0.16% vs 0.13%; P = .03). Overall, the likelihood of postoperative endophthalmitis from a national sample is consistent with case series previously reported.

Actuarial Analysis↗
PubMed1991

A method for the quantitative analysis and standardization of interleukin-1 bioactivity.

A method is presented for the reproducible quantitation of the biological activity of interleukin 1 (IL-1). This method provides diagnostic tools which give insights into the qualitative aspects of the binding of IL-1 and of the resulting activation of the responder thymocytes; for example, whether the lymphokine and/or the responder population is heterogeneous, or whether a threshold level exists. It establishes under what circumstances the assumptions on which it is based are reasonably adhered to and, consequently, quantitative estimation in the manner it prescribes is justified. It also gives a simple way to calculate both the maximal response attainable for each preparation in an assay and the dilution of a particular preparation that would produce a half-maximal response, the accepted unit of activity of IL-1. This empirical technique provides an improved means of comparing the activities of various preparations of IL-1 in bioassays using various stocks of responder cells and reagents. It should also be applicable to the evaluation of the biological activity of lymphokines in general.

Animals↗
PubMed1991

Epidemiologic oversight of the medical care provided to Medicare beneficiaries.

The Health Care Financing Administration is charged by law with the assurance of the quality of the medical care rendered to Medicare beneficiaries, a function carried out through the Peer Review Organizations. To guide and support this activity, a programme of epidemiologic surveillance of the health of such persons has been devised and is being implemented. Its focus is on the objective measures of health-mortality, morbidity, disability and expenditures for health care. Its principal components are analyses of trends in those measures over time and of their variations among geographic areas, as problem-finding techniques, and evaluations of the comparative effectiveness of strategies of management of patients, as problem-solving tools. Examples of the feasibility and utility of this strategy include an evaluation of the longitudinal impact of administrative changes undertaken in 1983-1984, the assessment of variations in patient mortality rates among hospitals, the characterization of the management of patients with ischemic heart disease, and a demonstration of a methodology for the observational evaluation of revascularization in various types of patients hospitalized for acute myocardial infarction. The objectives of the programme are the improvement of review of medical practices as carried out by the Peer Review Organizations, assistance to clinicians in the management of patients, and guidance to planners in the allocation of resources.

Aged↗
PubMed1991

Mortality and reoperation following prostatectomy: outcomes in a Medicare population.

Data from a series of pilot projects undertaken by the Health Care Financing Administration and seven peer review organizations were used to evaluate the outcomes of prostatectomy. Outcomes in both the original random sample of 3,641 patients and subsample of 2,617 patients that had a diagnosis of benign prostatic hyperplasia and did not have a diagnosis of prostatic carcinoma were examined. Patients undergoing a transurethral resection had increased probabilities of reoperation and mortality. However, the increased risk associated with having a transurethral resection was not statistically significant after controlling for other variables associated with mortality.

Aged↗
PubMed1991

National outcomes of cataract extraction. I. Retinal detachment after inpatient surgery.

Rehospitalization for retinal detachment (RD) was studied in 338,141 Medicare beneficiaries older than 65 years of age who were undergoing inpatient cataract extraction in 1984. Extracapsular cataract extraction (ECCE) was performed in 60% of patients, intracapsular cataract extraction (ICCE) in 31%, and phacoemulsification in 9%. The risk of rehospitalization for RD within 4 years of ICCE was 1.55% over 1.5 times the risk associated with ECCE (0.9%). The risk of RD after phacoemulsification was 1.17%. Cataract surgery accompanied by anterior vitrectomy was associated with a 5.0%, likelihood of RD at 4 years, which is 4.5 times greater than that for cataract surgery alone (1.12%). White patients were 1.7 times more likely to be rehospitalized for RD than were black patients (1.15% versus 0.67%; P less than 0.001). In both races, younger patients were more likely to be rehospitalized for RD than were older patients (P less than 0.001). While the increased rate of RD after ICCE versus ECCE confirms previously held clinical beliefs, the increase in the risk following phacoemulsification (P less than 0.0001) has not been reported previously.

Aged↗
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.↗
PubMed1989

Hospital characteristics and mortality rates.

The Health Care Financing Administration (HCFA) publishes hospital mortality rates each year. We undertook a study to identify characteristics of hospitals associated with variations in these rates. To do so, we obtained data on 3100 hospitals from the 1986 HCFA mortality study and the American Hospital Association's 1986 annual survey of hospitals. The mortality rates were adjusted for each hospital's case mix and other characteristics of its patients. The mortality rate for all hospitalizations was 116 per 1000 patients. Adjusted mortality rates were significantly higher for for-profit hospitals (121 per 1000) and public hospitals (120 per 1000) than for private not-for-profit hospitals (114 per 1000; P less than 0.0001 for both comparisons). Osteopathic hospitals also had an adjusted mortality rate that was significantly higher than average (129 per 1000; P less than 0.0001). Private teaching hospitals had a significantly lower adjusted mortality rate (108 per 1000) than private nonteaching hospitals (116 per 1000; P less than 0.0001). Adjusted mortality rates were also compared for hospitals in the upper and lower fourths of the sample in terms of certain hospital characteristics. The mortality rates were 112 and 121 per 1000 for the hospitals in the upper and lower fourths, respectively, in terms of the percentage of physicians who were board-certified specialists (P less than 0.0001), 112 and 120 per 1000 for occupancy rate (P less than 0.0001), 113 and 120 per 1000 for payroll expenses per hospital bed (P less than 0.0001), and 113 and 119 per 1000 for the percentage of nurses who were registered (P less than 0.0001).

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