Sankey V. Williams

Hospital and patient characteristics associated with death after surgery. A study of adverse occurrence and failure to rescue.

We asked if the factors that predict overall mortality following two common surgical procedures are different from those that predict adverse occurrences (complications) during the hospitalization or death after an adverse occurrence, which we refer to as “failure to rescue.” We examined 5,972 Medicare patients undergoing elective cholecystectomy or transurethral prostatectomy using three outcome measures: 1) the death rate (number of deaths/number of patients); 2) the adverse occurrence rate (number of patients who developed an adverse occurrence/number of patients); and 3) the failure rate (number of deaths in patients who developed an adverse occurrence/number of patients with an adverse occurrence). The death rate was associated with both hospital and patient characteristics. The adverse occurrence rate was associated primarily with patient characteristics. In contrast, failure to rescue was associated more with hospital characteristics, and was less influenced by patient admission severity of illness as measured by the MedisGroups score. We concluded that factors associated with hospital failure to rescue are different from factors associated with adverse occurrences or death. Understanding the reasons behind variation in mortality rates across hospitals should improve our ability to use mortality statistics to help hospitals upgrade the quality of care.

A Meta-analysis of Thromboembolic Prophylaxis Following Elective Total Hip Arthroplasty*

Background: Although several agents have been shown to reduce the risk of thromboembolic disease, there is no clear preference for thromboembolic prophylaxis in elective total hip arthroplasty. The purpose of this study was to define the efficacy and safety of the agents that are currently used for prophylaxis against deep venous thrombosis - namely, low-molecular-weight heparin, warfarin, aspirin, low-dose heparin, and pneumatic compression. Methods: A Medline search identified all randomized, controlled trials, published from January 1966 to May 1998, that compared the use of one of the prophylactic agents with the use of any other agent or a placebo in patients undergoing elective total hip arthroplasty. For a study to be included in our analysis, bilateral venography had to have been performed to confirm the presence or absence of deep venous thrombosis. Fifty-two studies, in which 10,929 patients had been enrolled, met the inclusion criteria and were included in the analysis. The rates of distal, proximal, and total (distal and proximal) deep venous thrombosis; symptomatic and fatal pulmonary embolism; minor and major wound-bleeding complications; major non-wound bleeding complications; and total mortality were determined for each agent in each study. The absolute risk of each outcome was determined by dividing the number of events by the number of patients at risk. A general linear model with random effects was used to calculate the 95 percent confidence interval of risk. A crosstabs of study by outcome was performed to test homogeneity (ability to combine studies). The risk of each outcome was compared among agents and between each agent and the placebo. Results: With prophylaxis, the risk of total (proximal and distal) deep venous thrombosis ranged from 17.7 percent (low-molecular-weight heparin) to 31.1 percent (low-dose heparin); the risk with prophylaxis with any agent was significantly lower than the risk with the placebo (48.5 percent) (p < 0.0001). The risk of proximal deep venous thrombosis was lowest with warfarin (6.3 percent) and low-molecular-weight heparin (7.7 percent), and again the risk with any prophylactic agent was significantly lower than the risk with the placebo (25.8 percent) (p < 0.0001). Compared with the risk with the placebo (1.51 percent), only warfarin (0.16 percent), pneumatic compression (0.26 percent), and low-molecular-weight heparin (0.36 percent) were associated with a significantly lower risk of symptomatic pulmonary embolism. There were no significant differences among agents with regard to the risk of fatal pulmonary embolism or of mortality with any cause. The risk of minor wound-bleeding was significantly higher with low-molecular-weight heparin (8.9 percent) and low-dose heparin (7.6 percent) than it was with the placebo (2.2 percent) (p < 0.05). Compared with the risk with the placebo (0.28 percent), only low-dose heparin was associated with a significantly higher risk of major wound-bleeding (2.56 percent) and total major bleeding (3.46 percent) (p < 0.0001). Conclusions: The best prophylactic agent in terms of both efficacy and safety was warfarin, followed by pneumatic compression, and the least effective and safe was low-dose heparin. Warfarin provided the lowest risk of both proximal deep venous thrombosis and symptomatic pulmonary embolism. However, there were no identifiable significant differences in the rates of fatal pulmonary embolism or death among the agents. Significant risks of minor and major bleeding complications were observed with greater frequency with certain prophylactic agents, particularly low-molecular-weight heparin (minor bleeding) and low-dose heparin (both major and minor bleeding).

Association between primary care practice characteristics and emergency department use in a medicaid managed care organization.

Background:Many patients use emergency departments (EDs) for primary care. Previous studies have found that patient characteristics affect ED utilization. However, such studies have led to few policy changes. Objectives:We sought to determine whether Medicaid patients’ ED use is associated with characteristics of their primary care practices. Research Design:This was a cohort study. Subjects:A total of 57,850 patients, assigned to 353 primary care practices affiliated with a Medicaid HMO, were included. Measures:Predictor variables were characteristics of primary care practices, which were measured by visiting each practice. The outcome variable was ED use adjusted for patient characteristics. Results:On average, patients made 0.80 ED visits/person/yr. Patients from practices with more than 12 evening hours/wk used the ED 20% less than patients from practices without evening hours. A higher ratio of the number of active patients per clinician-hour of practice time was associated with more ED use. When more Medicaid patients were in a practice, these patients used the ED more frequently. Other factors associated with ED use included equipment for the care of asthma and presence of nurse practitioners and physician assistants. Discussion:Modifiable characteristics of primary care practices were associated with ED use. Because the observational design of this study does not allow definitive conclusions about causality, future studies should include intervention trials to determine whether changing practice characteristics can reduce ED use. Conclusions:Improving primary care access and scope of services may reduce ED use. Focusing on systems issues rather than patient characteristics may be a more productive strategy to improve appropriate use of emergency medical care.

Factors affecting decisions to seek treatment for sick children in Kerala, India

The purpose of this study was to measure the effects of social and economic variables, disease-related variables, and child gender on the decisions of parents in Kerala, India, to seek care for their children and on their choice of providers in the allopathic vs. the alternative system. A case-control analysis was done using data from the Kerala section of the 1996 Indian National Family Health Survey, a cross-sectional survey of a probability sample of households conducted by trained interviewers with a close-ended questionnaire. Of the 469 children who were eligible for this study because they had at least one common symptom suggestive of acute respiratory illness or diarrhea during the 2 weeks before the interview, 78 (17%) did not receive medical care, while the remaining 391 (83%) received medical care. Of the 391 children who received medical care, 342 (88%) received allopathic medical care, and 48 (12%) received alternative medical care. In multivariable analyses, parents chose not to seek medical care for their children significantly more often when the illness was mild, the child had a specific diagnosis, the mother had previously made fewer antenatal visits, and the family had a higher economic status. When parents sought medical care for their children, care was sought significantly more often in the alternative provider system when the child was a boy, the family lived in a rural area, and the family had a lower social class. We conclude that, in Kerala, disease severity and economic status predict whether children with acute respiratory infection or diarrhea are taken to medical providers. In contrast, most studies of this issue carried out in other populations have identified economic status as the primary predictor of medical system utilization. Also in Kerala, the gender of the child did not influence whether or not the child was taken for treatment but did influence whether care was sought in the alternative or the allopathic system.

Market reform in New Jersey and the effect on mortality from acute myocardial infarction.

OBJECTIVE To determine whether mortality rates for patients with acute myocardial infarction (AMI) changed in New Jersey after implementation of the Health Care Reform Act, which reduced subsidies for hospital care for the uninsured and changed hospital payment to price competition from a rate-setting system based on hospital cost. DATA SOURCES/STUDY SETTING Patient discharge data from hospitals in New Jersey and New York from 1990 through 1996 and the Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS). STUDY DESIGN A comparison between states over time of unadjusted and risk-adjusted mortality and cardiac procedure rates. DATA COLLECTION Discharge data were obtained for 286,640 patients with the primary diagnosis of AMI admitted to hospitals in New Jersey or New York from 1990 through 1996. Records of 364,273 NIS patients were used to corroborate time trends. PRINCIPAL FINDINGS There were no significant differences in AMI mortality among insured patients in New Jersey relative to New York or the NIS. However, there was a relative increase in mortality of 41 to 57 percent among uninsured New Jersey patients post-reform, and their rates of expensive cardiac procedures decreased concomitantly. CONCLUSIONS The introduction of hospital price competition and reductions in subsidies for hospital care of the uninsured were associated with an increased mortality rate among uninsured New Jersey AMI patients. A relative decrease in the use of cardiac procedures in New Jersey may partly explain this finding. Additional studies should be done to identify whether other market reforms have been associated with changes in the quality of care.

Routine portable chest radiographs in the medical intensive care unit : Effects and costs

OBJECTIVE To determine the effects and net costs of routine chest radiographs in a medical intensive care unit (ICU). DESIGN A prospective, cohort study. A survey of experts in critical care and pulmonary diseases was undertaken to assess the effect of routine radiographs on patient management. SETTING Medical ICU of a university hospital. PATIENTS Eighty randomly selected patients admitted to a medical ICU. Two hundred fourteen experts were surveyed; 118 (55%)/214 responded. MEASUREMENTS AND MAIN RESULTS Daily interviews with medical ICU clinicians were conducted to assess the radiographic findings in the routine radiographs and actions taken based on these findings. Experts evaluated the findings, their importance, the actions taken, and the probability of complications if the actions had not been taken at that time. Experts also predicted increases in length of stay associated with these complications. Presence of radiographic findings, changes in management because of the findings, net costs of routine chest radiographs, cost per finding that prompted an action, and expected changes in length of stay resulting from the actions were also assessed. Seventy-two (33%) of 221 routine radiographs (95% confidence interval: 25% to 39%) had findings, of which 44 (61%) were judged important, and 18 (8%, 95% confidence interval: 5% to 12%) prompted actions. Experts predicted that each action averted, on average, 2.1 +/- 1.7 days (SD) in the medical ICU. Mean savings per routine radiograph was

Discharge motor fim-function related groups

98. Net savings from routine chest radiographs remained after sensitivity analysis for expected change in length of stay, percentage of patients with routine radiographs, and percentage of routine radiographs that produce changes in management. CONCLUSION The policy of obtaining routine chest radiographs in the medical ICU is effective and results in net savings.

How many intensive care beds are enough

OBJECTIVE To develop a patient classification system that groups patients achieving similar functional outcome scores by discharge from medical rehabilitation. DESIGN Patient groups were developed using a recursive partitioning algorithm and clinical input. Results were validated in a separate set of patient records. SETTING Two hundred fifty-two free-standing rehabilitation hospitals and distinct part units that participate in the Uniform Data System for Medical Rehabilitation. PATIENTS The 84,492 rehabilitation inpatients discharged in 1992 were grouped into 20 impairment categories. MAIN OUTCOME MEASURE Discharge score on the motor subscale of the Functional Independence Measure (FIM). RESULTS In the Discharge Motor FIM-Function Related Groups (DMF-FRGs) system, patients are first classified into one of 20 impairment categories and then into FRGs by their admission motor FIM scores. Some FRGs are also subdivided on the basis of admission cognitive FIM scores and age. The entire system consists of 139 patient groups that explain 63% of the variation in motor FIM discharge scores in the validation data set. Nontraumatic brain injury and joint replacement DMF-FRGs are provided as examples. CONCLUSION Clinicians can use the DMF-FRGs to identify groups of patients whose motor FIM scores at discharge are below, within, or above nationally established ranges of values for the purpose of outcomes management, guideline development, and quality improvement. The DMF-FRGs can also be considered in the design of an outcome-based payment system for medical rehabilitation.

Clinical Guidelines for Using Two Dichotomous Tests

Rapid changes in technology have forced many hospitals to consider changes in the size of their ICUs. One method of predicting intensive care bed needs creates a mathematical model of the unit which simulates the units operation. This report describes a model that provided information to a physician group charge with deciding how many beds to include in a proposed expansion of one hospitals ICU. As the total number of beds in the simulated unit increased from 7 to 15, the model predicted a linear increase in the number of empty beds and a nonlinear decrease in the number of prematurely discharged patients. Based on the results, the group chose to leave the units size unchanged at 11 beds. The immediate result was to facilitate planning by providing quantitative estimates of the consequences of different choices. The long-term result was an ICU whose size accommodated patient needs despite changing demand for services.

Applying quantitative methods to the prediction of full functional recovery in adult rehabilitation patients

Building on the threshold model developed by Pauker and Kassirer for a single test, the authors describe a decision analytic model for two tests with dichotomous outcomes. The model includes ten decision strategies that differ depending on which tests are performed, whether the tests are performed together or in sequence, and the definition of a positivity criterion used to make the treatment decision when the test results disagree. Formulas derived from the model are used to compute the preferred option as a function of disease probability and to calculate test and test-treatment thresholds. General guidelines developed from the model can be used without calculation to identify relative preferences for alternative options and to predict threshold effects. Key words: decision analytic model; tests with dichotomous outcomes. (Med Decis Making 6:68-78, 1986)