Carotid endarterectomy trends in the patterns and outcomes of care at academic medical centers, 1990 through 1995.

OBJECTIVE: To evaluate whether the patterns of inpatient care and patient characteristics have changed for patients undergoing a carotid endarterectomy across a group of academic medical centers from 1990 through 1995. If changes occurred, we investigated whether they had an impact on patient outcomes. DESIGN: Retrospective evaluation of patients undergoing a carotid endarterectomy using a hospital discharge data set compiled by the Academic Medical Center Consortium. SETTING: Ten academic medical centers. PATIENTS: A total of 7019 hospital admissions for patients who had 1 carotid endarterectomy performed as a principal procedure from January 1990 to December 1995. MAIN OUTCOME MEASURES: Trends in patient demographics, comorbidities, length of stay, days in the intensive care unit, and inpatient cerebral arteriogram use were determined. Patient outcomes included inpatient mortality, discharge to an institution, 30-day readmission rate, and selected diagnoses (postoperative hemorrhage, infection, or seizure; acute myocardial infarction; or cranial nerve palsy) and postprocedure diagnostic tests (computed tomography and magnetic resonance imaging of the head and electroencephalogram) indicative of complications. RESULTS: Over the 6-year study period, the number of carotid endarterectomies performed more than doubled and the percentage of hospital admissions for patients 65 years or older increased from 65% to 75%. The mean and median length of stay halved and the percentage of admissions with transfers to the intensive care unit decreased from 56% to 26% of cases. In addition, the percentage of cases with a cerebral arteriogram during the same admission but prior to the day of the carotid endarterectomy decreased from 52% to 27%. There were no trends in inpatient mortality, discharge to an institution, or 30-day readmission rate. There were no significant trends indicative of poorer quality of care as measured by the frequency of secondary diagnoses or postprocedure diagnostic test use. CONCLUSIONS: Despite dramatic changes that have occurred in patient characteristics and in hospital management practices for patients undergoing a carotid endarterectomy from 1990 to 1995, we were unable to detect any measurable impact on patient outcomes. These data have implications for monitoring and evaluating the impact of systemwide change on the overall quality of care for patients undergoing a carotid endarterectomy.

Inpatient costs of specific cerebrovascular events at five academic medical centers.

We estimated the hospital costs for patients with different cerebrovascular events and applied patient and administrative variables to explain the variance of the cost estimates with particular attention to the relationship between patient age and cost. The study sample was drawn from an administrative data set of all hospital discharges from five academic medical centers for the 1992 calendar year. Using International Classification of Diseases (ICD-9-CM) primary diagnosis codes, cases were classified into cerebrovascular subgroups: subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), ischemic cerebral infarction (ICI), and transient ischemic attack (TIA). The ICD-9-driven data file was supplemented with billing data containing inpatient charges reported in UB-82 format. Costs were imputed by applying Medicare charge-to-cost ratios and regional wage adjustments to the billing data. We estimated relationships between inpatient costs and a number of demographic and administrative variables. A statistically significant difference was found between cerebrovascular subgroups for both the mean cost per discharge (p<0.01) and the mean cost of an inpatient day (p<0.01). The mean cost per discharge for each subgroup was as follows: SAH, $39,994 (n=218); ICH, $21,535 (n=258); ICI, $9,882 (n=908); TIA, $4,653 (n=303). Likewise, the mean cost per inpatient day was as follows: SAH, $2,215; ICH, $1,396; ICI, $1,036; TIA, $1,117. Length of stay as a measure of resource use was strongly predictive of inpatient cost, explaining 72 to 82% of the variation in cost. Demographic variables (i.e., age, gender, race, insurance status), however, revealed virtually no predictive power, accounting for less than 10% of the variance in each of the four subgroups. There are substantial differences in the patient-level cost of hospital services for stroke-related events. After controlling for the type of cerebrovascular event, basic demographic variables and insurance status (including Medicare) contribute little to the total cost of inpatient care. More important factor include stroke severity, social factors, and clinical practice variations.

The consistency of estimates obtained through central-location sampling: analysis of the Partnership for a Drug-Free America Attitude Tracking Study.

To evaluate the reliability and validity of estimates of drug use obtained through multiple-site central-location sampling, data from the Partnership Attitude Tracking Study (PATS), collected annually beginning in 1987, are tracked longitudinally and compared with data collected through traditional household interviews. Comparisons with demographic estimates from Current Population Surveys indicate that central-location sampling can provide a broadly representative sample of the adult population. However, there is some coverage bias in central-location sampling, most notably in the underrepresentation of adults who do not have high school diplomas. Sample estimates obtained from central-location sampling are consistent over time. Basic demographic characteristics of the samples--education, income, marital status, and area of residence--vary by less than 5% across the four waves of the tracking study. Prevalence estimates of self-reported drug use demonstrate an even higher degree of consistency over time. Comparisons of PATS and National Household Survey of Drug Abuse data and the Monitoring the Future data indicate a higher level of drug use and a lower level of perceived risk of occasional use among PATS respondents. While the trends in use and perceived risk reported in all studies are similar, we suggest that perceived threats to confidentiality and anonymity often result in significant underreporting of drug use, particularly in household surveys. Sample estimate differences are attributed to sampling and measurement error. Some discrepancy in prevalence estimates is associated with the fact that the PATS sample is not a true probability sample; as a result, the sampling error of the overall study cannot be estimated precisely. It is also likely that the difference in estimates between the studies is a product of the decreased measurement error of PATS methodology. In central-location sampling, respondents are completely anonymous and may feel more comfortable in providing honest answers about illicit activities such as drug use. The potential applications of this methodology are discussed.

Sociodemographic and attitudinal correlates of alcohol and other drug use among children and adolescents: analysis of a large-scale attitude tracking study.

Data from the Partnership Attitude Tracking Study are analyzed to provide a greater understanding of the contributing factors to alcohol and other drug use among children and adolescents. The data were collected from children (ages 9 to 12) and teenagers (ages 13 to 17) in central locations (usually shopping malls) located in 100 primary sampling units across the United States. The analysis, which primarily employed stepwise multiple regression for model estimation, reinforced the importance of friends use, perceived risk, and tobacco and alcohol use in predicting marijuana use. An exposure model, which included antidrug advertisements, was a particularly powerful model. Implications of the findings are discussed.

Fenoprofen-induced immune hemolysis. Difficulties in diagnosis and complications in compatibility testing.

A 70-year-old man developed severe immune intravascular hemolysis and renal failure following ingestion of fenoprofen, a nonsteroidal, anti-inflammatory drug. The patient's red blood cells were sensitized with both IgG and C3d. The serum reacted with normal red blood cells in the presence and absence of the drug. Addition of albumin to the serum inhibited the reactivity with both neat and drug-treated serum. These atypical serologic findings for drug-related immune hemolytic anemia were explained by (1) the measurement of fenoprofen by high performance liquid chromatography (HPLC) in the neat serum; and (2) solid-phase adsorption studies showing that albumin can bind drug, leading to the disappearance of agglutination when albumin is added. This case demonstrates the utility of drug levels and adsorption techniques to confirm the diagnosis of drug-induced immune hemolytic anemia despite the anomalous serologic results which obscured the diagnosis and management of the patient.