Introduced into clinical use in 1980, the ICD has become smaller and simpler to implant, while providing better methods to detect and treat sustained ventricular tachyarrhythmias (rapid, irregular heart beat). This study found that ICD use expanded more than 10-fold in clinical practice from 1987 to 1995, with improved mortality rates but high medical expenditures and rates of surgical revision. The investigators identified ICD recipients by use of the hospital discharge databases of Medicare beneficiaries for 1987 through 1995 and of California residents for 1991 through 1995. They linked the initial hospital admission for each ICD patient to previous and subsequent admissions and to mortality files to determine the outcomes of ICD use.

During the study period, over 31,000 ICDs were implanted in Medicare patients, most of whom had been hospitalized for heart attack, congestive heart failure, or ventricular tachycardia at that time or during the previous year. Between 1987 and 1995, the number of hospitals performing the procedure increased from roughly 100 to 500, and the volume of ICD implantations per hospital also rose. Patients who died within 30 days of implantation decreased from 6 to 2 percent, and mortality rates within a year of implantation fell from 19 to 11 percent. Mortality rates at 3 years declined as well, but less sharply, from 38 percent in 1987 to 33 percent in 1992.

Subsequent hospitalizations for ICD complications or surgical replacement were very common and within the first year remained about 5 percent. However, the rate of revision/replacement at 3 years declined from 34 percent from 1987 to 1989 to 18 percent for devices implanted from 1990 to 1992, largely as a result of fewer generator replacements due to improvements in device and battery life. Medicare expenditures for these patients within 30 days of ICD implantation have remained close to $40,000 in 1993 dollars, and 3-year expenditures averaged almost $50,000.

Objectives. Concerns have mounted about the complexities of the health care system potentially causing significant unintended adverse effects. With a major national interest in addressing patient safety issues, a wide spectrum of individuals and organizations are working toward developing methods and systems to detect, characterize, and report potentially preventable adverse events. One approach is to develop screening measures based on routinely collected administrative data, such as the patient safety indicators (PSIs) reported here. The purpose of the PSI project is to report 1) literature-based evidence on potential PSIs, 2) clinician panel review results of potential indicators, 3) empirical analyses on a subset of indicators, and 4) recommendations regarding potential PSIs.

Methods. A four-pronged strategy to collect validation data and descriptive information was used: 1) background literature review, 2) structured clinical panel reviews of candidate PSIs, 3) expert review of ICD-9-CM codes in candidate PSIs, and 4) empirical analyses of the potential candidate PSIs. Evidence from these four sources was used to modify and select the most promising indicators for use as a screening tool to provide an accessible and low-cost approach to identifying potential problems in the quality of care related to patient safety.

Main results. A review of previously reported measures in the literature, and of medical coding manuals, resulted in identification of over 200 ICD-9-CM codes representing potential patient safety problems. Most of these codes were grouped into clinically meaningful indicators either based on previous indicator definitions or on clinical and coding expertise. Based on literature review of the published evidence related to their validity, several potential PSIs were eliminated. Because of the limited validation literature available on PSIs and complications indicators from which many PSIs were derived, the research team conducted a clinical panel review process to assess the face validity and to guide refinements to the initial definitions of the 34 most promising PSIs. Response to a questionnaire by clinicians (i.e., physicians from a number of specialties, nurses, and pharmacists) for each indicator, augmented by coding review and initial empirical testing, provided the basis for selecting the indicators expected to be most useful for screening for potentially preventable adverse events. Twenty hospital level PSIs are recommended for implementation as the initial AHRQ PSI set (designated Accepted indicators).

Conclusions and future research. Future validation work should focus on the sensitivity and specificity of these indicators in detecting the occurrence of a complication; the extent to which failures in processes of care at the system or individual level are detected using these indicators; the relationship of these indicators with other measures of quality, such as mortality; and further explorations of bias and risk adjustment. Enhancements to administrative data are worth exploring in the context of further validation studies that utilize data from other sources. The current development and evaluation effort will best be augmented by a continuous communication loop between users of these measures, researchers interested in improving these measures, and policy makers with influence over the resources aimed at data collection and patient safety measurement.

The ethical case for the social insurance model will be strengthened as people realize that most health problems have at least in part a genetic basis. The efficiency case will benefit from recognition that employment-based insurance has high administrative costs but provides no advantages to society as a whole. The desire to exert more direct control over rising expenditures will provide an additional reason to introduce some form of national health insurance.

The timing of such a change, however, will depend largely on factors external to health care. Major changes in health policy are political acts undertaken for political purposes. This was true when Bismarck introduced national health insurance to the new German state in the 19th century. It was true when England adopted national health insurance after World War II; and it will be true in the United States as well. National health insurance will probably come to the United States after a major change in the political climate, the kind of change that often accompanies a war, a depression, or large scale civil unrest. Until then, the major effect of the new plans will be to make young and healthy workers better off at the expense of their older, sicker colleagues.

OBJECTIVE: In 1976, the Committee on Perinatal Health recommended that hospitals with no neonatal intensive care unit (NICU) or intermediate NICUs transfer high-risk mothers and infants that weigh 2000 g to a regional NICU. This standard was based on expert opinion and has not been validated carefully. This study evaluated the effect of NICU level and patient volume at the hospital of birth on neonatal mortality of infants with a birth weight (BW) of 2000 g.

METHODS: Birth certificates of 16 732 singleton infants who had a BW of 2000 g and were born in nonfederal hospitals in California in 1992 and 1993 were linked to death certificates and to discharge abstracts. The hospitals were classified by the level of NICU: no NICU, no intensive care; intermediate NICU, intermediate intensive care; community NICU, expanded intermediate intensive care; and regional NICU, tertiary intensive care. A logistic regression model that controlled for demographic risks, diagnoses, transfer, average NICU census, and NICU level was estimated using death within the first 28 days or first year of life if continuously hospitalized as the main outcome measure.

RESULTS: Compared with birth in a hospital with a regional NICU, risk-adjusted mortality of infants with BW of 2000 g was higher when birth occurred in hospitals with no NICU (odds ratio [OR]: 2.38; 95% confidence interval [CI]: 1.81-3.13), an intermediate NICU (OR: 1.92; 95% CI: 1.44-2.54), or a small (average census 15) community NICU (OR: 1.42; 95% CI: 1.14-1.76). Risk-adjusted mortality for infants who were born in hospitals with a large (average census > or =15) community NICU was not statistically different compared with those with a regional NICU (OR: 1.11; 95% CI: 0.87-1.43). Except for large community NICUs, all of these ORs are larger when the data are restricted to infants with BW of 1500 g or BW of 1250 g and smaller for BW between 1250 g and 1999 g and 1500 g and 1999 g. For large community NICUs, the results are similar for the smaller BW intervals and significant only for the larger BW interval.

CONCLUSIONS: These results support the recommendation that hospitals with no NICU or intermediate NICUs transfer high-risk mothers with estimated fetal weight of 2000 g to a regional NICU. For infants with BW of 2000 g, birth at a hospital with a regional NICU is associated with a lower risk-adjusted mortality than birth at a hospital with no NICU, intermediate NICU of any size, or small community NICU. Subsequent neonatal transfer to a regional NICU only marginally decreases the disadvantage of birth at these hospitals. The evidence for the few hospitals with large community NICUs is mixed. Although the data point to higher mortality in large community NICUs, they are not conclusive and additional study is needed on the mortality effects of large community NICUs. Greater efforts should be made to deliver infants with expected BW of 2000 g at hospitals with regional NICUs.