Biomedical subjects
Publications and source records attributed to D C Angus.
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STUDY OBJECTIVES: To examine the applicability of a previously developed intensive care prognostic measure to a community-based sample of hospitals, and assess variations in severity-adjusted mortality across a major metropolitan region. DESIGN: Retrospective cohort study. SETTING: Twenty-eight hospitals with 38 ICUs participating in a community-wide initiative to measure performance supported by the business community, hospitals, and physicians. PATIENTS: Included in the study were 116,340 consecutive eligible patients admitted to medical, surgical, neurologic, and mixed medical/surgical ICUs between March 1, 1991, and March 31, 1995. MAIN OUTCOME MEASURES: The risk of hospital mortality was assessed using a previous risk prediction equation that was developed in a national sample, and a reestimated logistic regression model fit to the current sample. The standardized mortality ratio (SMR) (actual/predicted mortality) was used to describe hospital performance. RESULTS: Although discrimination of the previous national risk equation in the current sample was high (receiver operating characteristic [ROC] curve area = 0.90), the equation systematically overestimated the risk of death and was not as well calibrated (Hosmer-Lemeshow statistic, 2407.6, 8 df, p < 0.001). The locally derived equation had similar discrimination (ROC curve area = 0.91), but had improved calibration across all ranges of severity (Hosmer-Lemeshow statistic = 13.5, 8 df, p = 0.10). Hospital SMRs ranged from 0.85 to 1.21, and four hospitals had SMRs that were higher or lower (p < 0.01) than 1.0. Variation in SMRs tended to be greatest during the first year of data collection. SMRs also tended to decline over the 4 years (1.06, 1.02, 0.98, and 0.94 in years 1 to 4, respectively), as did mean hospital length of stay (13.0, 12.4, 11.6, and 11.1 days in years 1 to 4; p < 0.001). However, excluding the increasing (p < 0.001) number of patients discharged to skilled nursing facilities attenuated much of the decline in standardized mortality over time. CONCLUSIONS: A previously validated physiologically based prognostic measure successfully stratified patients in a large community-based sample by their risk of death. However, such methods may require recalibration when applied to new samples and to reflect changes in practice over time. Moreover, although significant variations in hospital standardized mortality were observed, changing hospital discharge practices suggest that in-hospital mortality may no longer be an adequate measure of ICU performance. Community-wide efforts with broad-based support from business, hospitals, and physicians can be sustained over time to assess outcomes associated with ICU care. Such efforts may provide important information about variations in patient outcomes and changes in practice patterns over time. Future efforts should assess the impact of such community-wide initiatives on health-care purchasing and institutional quality improvement programs.
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BACKGROUND AND OBJECTIVE: In this era of health-care reform, there is increasing need to monitor and control health-care resource consumption. This requires the development of measurement tools that are practical, uniform, reproducible, and of sufficient detail to allow comparison among institutions, among select groups of patients, and among individual patients. We explored the feasibility of generating an index of resource use based on the Therapeutic Intervention Scoring System (TISS) from hospital electronic billing data. Such an index is potentially comparable across institutions, allows assessment of care at many levels, is well understood by clinicians, and captures many of the resources relevant to the ICU. DESIGN: We developed an automated mapping of the hospital billing database into the different items of TISS and generated computerized active TISS scores on 1,372 ICU days. The computerized score was then validated by comparison to prospectively gathered active TISS scores by trained data collectors. SETTING: Eight ICUs within a university teaching institution. PATIENTS: We studied 1,229 general medical and surgical ICU patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Active TISS scores ranged from 0 to 31 points. The two scores were well correlated (R2=0.53) and highly calibrated (as assessed by regression of active TISS on mean computerized active TISS [R2=0.85]). The scores were identical on 756 days (55.6%) and differed by < or = 3 TISS points on an additional 387 (28.2%) days. Interreliability assessment suggested substantial agreement (kappa statistic=0.71). The discriminatory power of the computerized score to identify different levels of ICU resource use was excellent as assessed by area under the receiver operating characteristics curves at four threshold points (0.91, 0.87, 0.89, and 0.88). Performance of the computerized score was similar across medical, coronary, and surgical ICU patient groups. CONCLUSION: An automated algorithm can reproduce valid TISS scores from standard hospital billing data, allowing comparison of patients and groups of patients in order to better understand ICU resource use.
In recent years, several factors have led to increasing focus on the meaning of appropriateness of care and clinical performance in the intensive care unit (ICU). The emergence of new and expensive treatment modalities, a deeper reflection on what constitutes a desirable outcome, increasing financial pressure from cost containment efforts, and new attitudes regarding end-of-life decisions are reshaping the delivery of intensive care worldwide. This quest for a measure of ICU performance has led to the development of severity adjustment systems that will allow standardised comparisons of outcome and resource use across ICUs. These systems, for many years used only in the research setting, have evolved to become sophisticated, computer-based decision-support tools, in some instances commercially developed, and capable of predicting a diverse set of outcomes. Their application has broadened to include ICU performance assessment, individual patient decision-making, and pre- and post-hoc risk stratification in randomised trials. In this paper, we review the popular scoring systems currently in use; design issues in the development and evaluation of new scoring systems; current applications of scoring systems; and future directions.
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Though there are reasonable data to suggest that certain countries, such as the United States, spend considerably more money on the provision of critical care services than others, there is little information regarding the added benefits accrued with this additional expense. Studies to date have suggested little if no difference in outcome but have been limited in their size, design, and choice of outcome measures. Furthermore, significant underlying societal priorities and philosophy may dictate that the optimal critical care delivery system is different for different countries. With the increasing availability of large patient databases, however, it will be more feasible in the future to design and conduct assessments of critical care delivery systems between countries taking appropriate account of the choice of study design, definition of at-risk populations, and choice of valuable measures of output and cost. The results of such assessments will hopefully drive wiser decision making in the design and management of critical care delivery systems worldwide.
BACKGROUND: Previous studies have shown "beat-to-beat" variation in systemic BP with high-frequency jet ventilation (HFJV). However, it is not clear if such changes are paralleled by changes in cardiac output. OBJECTIVE: To characterize the effect of HFJV near or equal to the heart rate (HR) on beat-to-beat cardiac output in an adult human subject with ARDS. DESIGN: Case study. SETTING: ICU, university teaching hospital. PATIENTS: One patient with end-stage liver disease complicated by sepsis, severe pancreatitis, ARDS, and multisystem organ failure. METHODS: The patient was intubated, sedated, paralyzed, and ventilated with controlled mechanical ventilation (CMV). Ventilatory mode was then switched to HFJV at fixed frequencies (f) near but not equal to the HR (f= 100, 110, and 120 beats/min; HR=108/min). HFJV was then synchronized to the ECG such that f and HR were equal. Continuous cardiac output (COc) was monitored during change of ventilator mode from CMV to fixed-rate HFJV to synchronized HFJV, then followed through progressive delays in jet triggering within the cardiac cycle during the synchronous HFJV mode. COc was monitored by arterial pulse-contour analysis, allowing assessment of beat-to-beat changes in cardiac output. MEASUREMENTS AND MAIN RESULTS: A cyclic variation in COc equal to the beat frequency difference between f and HR was observed (harmonic interaction) during fixed-rate HFJV. This COc oscillation was abolished during synchronous HFJV. COc was significantly greater during systolic synchronous HFJV as compared to diastolic synchronous HFJV or fixed-rate HFJV (10.1 to 9.0 [p<0.05] and to 8.6 [p<0.05] L/min, systolic synchronous to diastolic synchronous and to fixed-rate HFJV, respectively). CONCLUSIONS: This study demonstrates instantaneous variations in cardiac output in a human subject with fixed rates of HFJV near to the HR in humans. These variations are abolished by synchronous HFJV but cardiac output was dependent on the timing of the HFJV inspiration in relation to the cardiac cycle. COc is a potentially valuable method to monitor sudden changes in cardiac output and facilitate attempts to maximize cardiac output during synchronized HFJV.
OBJECTIVE: To determine whether insurance status (managed care vs traditional commercial and Medicare) influences resource consumption (as measured by length of stay [LOS]) in the intensive care unit (ICU). DESIGN: Retrospective analysis of the 1992 Massachusetts state hospital discharge database, using prospectively developed and validated risk-stratification models. SETTING: All nonfederal hospitals in Massachusetts. SUBJECTS: Of all adult hospitalizations where an ICU stay was incurred (n=104270), we selected those covered by 1 of 4 payer groups (n=88050): (1) commercial fee-for-service (patients aged <65 years); (2) commercial managed care (patients aged <65 years); (3) traditional Medicare (patients aged >/=65 years); and (4) Medicare-sponsored managed care (patients aged >/=65 years). MAIN OUTCOME MEASURE: Mean ICU LOS. ANALYSIS: The ICU LOS regression models were constructed using split-halves validation to adjust for differences in age, sex, severity of illness, diagnosis, discharge status, and payer. Separate models were constructed for those younger than 65 years and those aged 65 years or older. Robustness of the models was explored using goodness of fit and correlation. The effect of payer on hospital mortality was also explored using logistic regression. Observed minus predicted mean ICU LOS and mortality rates were correlated with managed care penetration at the hospital level. RESULTS: The ICU LOS models performed well (R2=0.84 and R2L [likelihood ratio statistic]=0.92 for the development set, and R2=0.83 and R2L=0.89 for the validation set). Significant covariables affecting LOS included age, severity of principal illness, comorbidity, reason for admission, and discharge status (P<.001 for each). Among the cohort younger than 65 years (n=27805), although unadjusted mean ICU LOS was shorter (2.9 vs 3.43 days; P<.05) for those covered by managed care organizations, payer status had no independent effect on ICU LOS (P=.48). Among those older than 65 years, there was neither a difference in unadjusted ICU LOS (3.94 vs 3.88 days; P>/=.05) nor an independent effect of payer on ICU LOS (P=.35). Unadjusted mortality was lower among managed care patients (3.9% vs 5.1% in patients aged <65 years [P<.05] and 8.7% vs 12.1% in patients aged > or = 65 years [P<.05]). Age, severity of principal diagnosis, comorbidity, and reason for admission significantly influenced mortality (P<.001). After controlling for these factors with the mortality model (R2L=0.92 and 0.89, C statistic [12 df]=8.45 and 17.58, and P=.75 and .13 [where a large P reflects good agreement] for the development and validation sets, respectively), payer continued to have a small but significant effect on mortality (odds ratios ranging from 1.67 at 0.1% probability of death to 1.11 at 30% probability of death.) Managed care penetration among the commercially insured varied across hospitals (n=82) from 0% to 68%. There was no correlation between managed care penetration and either ICU LOS (R2=0.04; P=.09) or mortality (R2=0.0; P=.88). CONCLUSIONS: Though patients covered under managed care consume fewer ICU resources, this appears to be primarily attributable to a difference in patient-related factors. Thus, as managed care case mix changes in the future to include sicker and older patients, the initial advantages of reduced resource consumption may diminish.
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OBJECTIVES: To review the various outcomes from cardiopulmonary resuscitation (CPR), the factors that influence these outcomes, the costs associated with CPR, and the application of cost-analyses to CPR. DATA SOURCES: Data used to prepare this article were drawn from published articles and work in progress. STUDY SELECTION: Articles were selected for their relevance to the subjects of CPR and cost-analysis by MEDLINE keyword search. DATA EXTRACTION: The authors extracted all applicable data from the English literature. DATA SYNTHESIS: Cost-analysis studies of CPR programs are limited by the high variation in resources consumed and attribution of cost to these resources. Furthermore, cost projections have not been adjusted to reflect patient-dependent variation in outcome. Variation in the patient's underlying condition, presenting cardiac rhythm, time to provision of definitive CPR, and effective perfusion all influence final outcome and, consequently, influence the cost-effectiveness of CPR programs. Based on cost data from previous studies, preliminary estimates of the cost-effectiveness of CPR programs for all 6-month survivors of a large international multicenter collaborative trial are $406,605.00 per life saved (range $344,314.00 to $966,759.00), and $225,892.00 per quality-adjusted-life-year (range $191,286.00 to $537,088.00). CONCLUSIONS: Reported outcome from CPR has varied from reasonable rates of good recovery, including return to full employment to 100% mortality. Appropriate CPR is encouraged, but continued widespread application appears extremely expensive.
PURPOSE: This study was performed to compare the effect of entry criteria, patient population, and study design on outcome and projected cost-effectiveness of human anti-endotoxin antibody (HA-1A). MATERIALS AND METHODS: Patients with suspected or documented gram-negative bacteremia (GNB) with sepsis syndrome or shock received HA-1A during an open-label protocol. The patient characteristics and outcome measures of this series were compared with those of a placebo-controlled randomized clinical trial (RCT) of HA-1A. Both data sets were subjected to three published cost-effectiveness models of anti-endotoxin therapy, which were derived from RCT data. RESULTS: One hundred thirty-one patients (43 with gram-negative bacteremia) received HA-1A during a 19-month open-label protocol. Comparison with the RCT results demonstrated greater severity of illness and higher 28-day mortality in the open-label protocol. When projected for open-label recipients, HA-1A was considerably less cost-effective than in the original projections based on RCT-derived data. This reduction in cost-effectiveness was consistent across all three models and their respective sensitivity analyses. CONCLUSIONS: Extrapolating cost-effectiveness from RCT-derived analyses to open-label usage may yield widely inaccurate projections because of only small differences in patient population and the drug administration protocol.
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As public concern for quality control of medical care at the beginning of this century forced regulations on medical licensing of physicians, the forces of change in health care are again substantial, this time driven by concerns for cost and access. Our experience at the University of Pittsburgh Medical Center leads us to believe that well-trained physician extenders will play a valuable role in improving efficiency and effectiveness in the care of critically ill patients. We have developed a method for training and supervision. Graded practice supervision, with physician-led professional review, is considered a reasonable goal. We propose that the appropriate degree of supervision in any given area can be determined by: a) careful development of training programs; b) careful assessment of the individual's practice with the target patient population; and c) application of a review process that is sensitive in that population. Issues surrounding the independent practice and reimbursement of acute care nurse practitioners (ACNPs) are not resolved. These issues should be addressed by joint position statements that are based on objective documentation of the safe, effective performance of ACNPs, and on the incorporation of routine performance measurements with continued medical or joint evaluation of the quality review system. Guidelines regarding the evolving roles of ACNPs should be established by professional associations and state or national boards of both nursing and medical practice. Critical care physician and nursing leaders should lead such initiatives.
Cleveland Health Quality Choice (CHQC) is a unique community-based program designed to provide more efficient delivery of healthcare services through routine collection and dissemination of selected patient interventions and outcomes. This effort, coordinated by a consortium of business, hospital, and medical leaders, provides comparative public data on hospital performance. In the ICU, this effort involves collection of Acute Physiology and Chronic Health Evaluation (APACHE) III, as well as severity and prognostic data. To date, results suggest that a higher percentage of patients admitted to the ICU are at low risk of death or adverse outcome when compared with a national benchmark using APACHE III. Risk-adjusted mortality rates are lower and length of stay is shorter than predicted. CHQC demonstrates that cooperative public efforts, undertaken by groups with often divergent interests and using objective risk estimates, can provide useful data for hospital quality improvement activities and market-based health reform efforts.
Critical care medicine is a field of medicine using the highest concentration of expensive diagnostic and life-support technology for the benefit of a single individual. Conventional use of this resource and specialty is clearly understood, despite the fact that it is not necessarily comparable among different institutions. Some of the major issues in using critical care as a medical tool during extraordinary stress on the hospital, and the potential for using it in unconventional environments outside an established institution, have been reviewed. It is clear that the expertise and multidisciplinary approach can be of great use in disaster response, and a national effort toward integrating critical care into overall medical response is in progress.
In catastrophic disasters such as major earthquakes in densely populated regions, effective Life-Supporting First-Aid (LSFA) and basic rescue can be administered to the injured by previously trained, uninjured survivors (co-victims). Administration of LSFA immediately after disaster strikes can add to the overall medical response and help to diminish the morbidity and mortality that result from these events. Widespread training of the lay public also may improve bystander responses in everyday emergencies. However, for this scheme to be effective, a significant percentage of the lay population must learn in eight basic steps of LSFA. These have been developed by the International Resuscitation Research Center in collaboration with the World Association for Emergency and Disaster Medicine, the City of Pittsburgh Department of Public Safety, and the American Red Cross (Pennsylvania chapter). They include: 1) scene survey; 2) airway control; 3) rescue breathing (mouth-to-mouth); 4) circulation (chest compressions; may be omitted for disasters, but should be retained for everyday bystander response); 5) abdominal thrusts for choking (may be omitted for disasters, but retained for everyday bystander response); 6) control of external bleeding; 7) positioning for shock; and 8) call for help.
INTRODUCTION: The 1991 earthquake in the Limón area of Costa Rica presented the opportunity to examine the effectiveness of a decade of disaster preparedness. HYPOTHESIS: Costa Rica's concentrated work in disaster preparedness would result in significantly better management of the disaster response than was evident in earlier disasters in Guatemala and Nicaragua, where disaster preparedness largely was absent. METHODS: Structured interviews with disaster responders in and outside of government, and with victims and victims' neighbors. Clinical and epidemiologic data were collected through provider agencies and the coroner's office. RESULTS: Medical aspects of the disaster response were effective and well-managed through a network of clinic-based radio communications. Nonmedical aspects showed confusion resulting from: 1) poor government understanding of the roles and responsibilities of the central disaster coordinating agency; and 2) poor extension of disaster preparedness activities to the rural area that was affected by the earthquake. CONCLUSION: To be effective, disaster preparedness activities need to include all levels of government and rural, as well as urban, populations.