Perioperative comparative effectiveness research.

The goal of comparative effectiveness research (CER) is to improve effectiveness, efficacy and efficiency in health care. While CER seems to present a major opportunity to introduce accountability into health care by identifying and promoting best practices in medicine, many issues surrounding CER remain poorly understood by clinicians and researchers, including what study designs are most appropriate for such research and what analytic tools are most helpful. The goal of this review is therefore to provide background and definitions of what constitutes CER and to discuss the various study designs and their strengths and weaknesses in achieving the stated goals of CER, while relating them to examples relevant to perioperative research. We provide a brief outline of the types of analytic methods particularly useful for CER and connect the reader to references for their practice. Finally, we assess the role of CER in perioperative research and provide some thoughts on future paths.

Demographics, outcomes, and risk factors for adverse events associated with primary and revision total hip arthroplasties in the United States.

We conducted a study to analyze nationally representative data on patient and health care system characteristics and in-hospital outcomes associated with primary and revision total hip arthroplasties in the United States. Between 1990 and 2004, there were an estimated 2,748,187 hospital discharges after total hip arthroplasty. The risk factors we identified for procedure-related complications and in-hospital mortality included revision procedures, increased age, and male sex. Compared with smaller hospital capacity (number of beds), large hospital capacity was associated with a decreased odds ratio for complications but an increased risk for in-hospital mortality. Additional studies are warranted to determine causal relationships.

National trends in anterior cervical fusion procedures.

STUDY DESIGN: Population-based database analysis. OBJECTIVE: To analyze trends in patient- and healthcare-system-related characteristics, utilization and outcomes associated with anterior cervical spine fusions. SUMMARY OF BACKGROUND DATA: Anterior cervical decompression and spine fusion (ACDF) is one of the most commonly performed surgical procedures of the spine. However, few data analyzing trends in patient- and healthcare-system-related characteristics, utilization and outcomes exist. METHODS: Data from 1990 to 2004 collected in the National Hospital Discharge Survey were accessed. ACDF procedures were identified. Five-year periods of interest (POI) were created for temporal analysis and changes in the prevalence and utilization of this procedure as well as in patient- and healthcare-system-related variables were examined. The changes in the occurrence of procedure-related complications were evaluated. RESULTS: An estimated total of 771,932 discharges after ACDF were identified. Temporally, an almost 8-fold increase in total prevalence was accompanied by a similar increase in utilization (23/100.000 civilians/POI to 157/100.000/civilians/POI). The highest increase in utilization was observed in those > or =65 years (28-fold). Average age increased from 47.2 years to 50.5 years over time. Length of hospital stay decreased from 5.17 days to 2.38 days. Overall procedure-related complication rates decreased from 4.6% to 3.03%. The prevalence of hypertension, diabetes mellitus, hypercholesterolemia, obesity, pulmonary, and coronary artery increased over time among patients undergoing ACDF. CONCLUSION: Despite limitations inherent to secondary analysis of large databases, we identified a number of significant changes in the utilization, demographics, and outcomes associated with ACDF, which can be used to assess the effect of changes in medical care, direct health care resources, and future research. The effect of the increased prevalence of comorbidities on medical practice remains to be evaluated. Further studies are necessary to evaluate causal relationships.

Risk factors for perioperative mortality after lower extremity arthroplasty: a population-based study of 6,901,324 patient discharges.

The goal of this study was to provide nationally representative data on characteristics of patients who died after hip and knee arthroplasty and to determine risk factors for such outcome. Using national in-patient data collected between 1990 and 2004, we identified a cumulative in-hospital mortality rate of 0.35% among an estimated 6,901,324 procedures. The strongest independent risk factors for in-hospital mortality were pulmonary embolism and cerebrovascular complications, which increased the odds for a fatal outcome by approximately 40-fold. Preoperative risk factors for in-hospital mortality were revision total hip arthroplasty, advanced age, and the presence of a number of comorbid diseases, predominantly dementia, renal, and cerebrovascular disease. Our results can be used to identify patients at risk for fatal outcome and implement interventions to reduce such risk.

Risk factors for pulmonary embolism after hip and knee arthroplasty: a population-based study.

Pulmonary embolism (PE) is a cause of death after total hip and knee arthroplasty (THA, TKA). We characterised the patient population suffering from in-hospital PE and identified perioperative risk factors associated with PE using nationally representative data. Data from the National Hospital Discharge Survey between 1990 and 2004 on patients who underwent primary or revision THA/TKA in the United States were analysed. Multivariate regression analysis was performed to determine if perioperative factors were associated with increased risk of in-hospital PE. An estimated 6,901,324 procedures were identified. The incidence of in-hospital PE was 0.36%. Factors associated with an increased risk for the diagnosis of PE included: revision THA, female gender, dementia, obesity, renal and cerebrovascular disease. An increased association with PE was found among patients with diagnosis of Adult Respiratory Distress Syndrome (ARDS), psychosis (confusion), and peripheral thrombotic events. Our findings may be useful in stratifying the individual patient's risk of PE after surgery.

Trends in bilateral total knee arthroplasties: 153,259 discharges between 1990 and 2004.

UNLABELLED: Information regarding national trends in bilateral TKAs is needed for a rational allocation of resources, policy making, and research. Therefore, we analyzed data from the National Hospital Discharge Survey to elucidate temporal changes in the demographics, comorbidity profiles, hospital stay, and in-hospital complications of patients undergoing bilateral TKAs in the United States. We created three 5-year periods: 1990-1994, 1995-1999, 2000-2004. Procedure, healthcare system, and patient-related variables were analyzed for an estimated 153,259 discharges. Use of bilateral TKAs more than doubled for the entire civilian population and almost tripled among the female population, with the steepest increase seen during the last two study periods. A decline of nearly 50% in the use of bilateral TKAs in patients 85 years and older was seen between the second and third study periods. The prevalence of coronary artery disease and pulmonary disease increased from the first to the second study periods but decreased from the second to the third. The changes in the variables studied may reflect a recently acquired reluctance to perform bilateral TKAs in elderly patients with cardiopulmonary comorbidities. Additional studies are necessary to identify other causal relationships and define the impact of these changes on various aspects of the healthcare system. LEVEL OF EVIDENCE: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Trends in demographics, comorbidity profiles, in-hospital complications and mortality associated with primary knee arthroplasty.

We analyzed the National Hospital Discharge Survey to elucidate temporal changes in the demographics, comorbidities, hospital stay, in-hospital complications, and mortality of patients undergoing primary total knee arthroplasties (TKAs) in the United States. Three 5-year periods were created (1990-1994, 1995-1999, and 2000-2004), and temporal changes were analyzed. The number of TKAs performed increased by 125% for the 3 periods. The increasing proportion of younger patients was accompanied by a concomitant decrease of Medicare-insured patients. Length of stay decreased from 8.44 to 4.18 days. An increase in the proportion of discharges to long-term and short-term care facilities and in procedures performed in small hospitals was noted. Although the prevalence of procedure-related complications decreased over time, comorbidities increased. Despite a decrease in mortality from the first to the second study period (0.50% vs 0.21%), a slight increase was noticed more recently (0.28%). We identified significant changes in most variables studied.

Trends in mortality, complications, and demographics for primary hip arthroplasty in the United States.

To determine trends in characteristics of total hip arthroplasty (THA) in the United States, the National Hospital Discharge Survey (NHDS) was analyzed from 1990 to 2004 for trends in in-hospital mortality and complications, length of hospital stay, demographics, and comorbidities. The number of THAs performed increased by 158%, whereas mortality rates remained low and slightly decreased (from 0.32% to 0.29%). Prevalence of procedure-related complications decreased over time, and length of stay decreased from an average of 8.7 days to 4.5 days. These improvements occurred despite an increase in comorbidities in patients. An increase in both the proportion of discharges to long- and short-term care facilities and in the proportion of procedures performed in smaller hospitals was noted. Multiple temporal changes in outcomes and demographics for THA were found. These changes have implications for clinical care and allocation of health resources.

In-hospital complications and mortality of unilateral, bilateral, and revision TKA: based on an estimate of 4,159,661 discharges.

UNLABELLED: Patients undergoing bilateral total knee arthroplasty (BTKA) may have higher complication rates and mortality than those undergoing a unilateral procedure (UTKA). To evaluate this hypothesis, we analyzed nationally representative data collected for the National Hospital Discharge Survey on discharges after BTKA, UTKA, and revision TKA (RTKA) between 1990 and 2004. The demographics, comorbidities, in-hospital stay, complications, and mortality of each procedure were compared. An estimate of 4,159,661 discharges (153,259 BTKAs; 3,672,247 UTKAs; 334,155 RTKAs) were included. Patients undergoing BTKA were younger (1.5 years) and had a lower prevalence of comorbidities for hypertension (versus UTKA), diabetes, pulmonary disease, and coronary artery disease (versus UTKA and RTKA). The length of hospitalization was 5.8 days for BTKA, 5.3 for UTKA, and 5.4 for RTKA. Despite similar length of hospitalization, the prevalence of procedure-related complications was higher for BTKA (12.2%) compared with UTKA (8.2%) and RTKA (8.7%). In-hospital mortality was highest for patients undergoing BTKA (BTKA, 0.5%; UTKA, 0.3%; RTKA, 0.3%). Patients undergoing BTKA had a 1.6 times higher rate of procedure-related complications and mortality compared with those undergoing UTKA. Outcomes for patients undergoing RTKA for most variables were similar to those for UTKA. BTKA, advanced age, and male gender were independent risk factors for complications and mortality after TKA. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Trends in lung surgery: United States 1988 to 2002.

BACKGROUND: Reports on the temporal evolution in lung resection are limited. To elucidate temporal changes in the demographics of lung resections, we analyzed nationally representative data that were collected for the National Hospital Discharge Survey from 1988 to 2002. METHODS: Data collected between 1988 and 2002 were analyzed. Patients with International Classification of Diseases, ninth revision, clinical modification, procedure codes for lung resection were included in the sample. Three 5-year time periods were created (1988 to 1992, 1993 to 1997, and 1998 to 2002) to simplify the temporal analysis. Changes in the prevalence of procedures, age, gender, race, length of care, mortality, disposition status, and distribution by hospital size were evaluated. Trends in procedure-related complications were analyzed. RESULTS: Between 1988 and 2002, a total of 512,758 lung resections were performed. Comparing the earliest to the most recent time period, we found increases in the average age (61.1 years [range, 1 to 89 years] vs 63.2 years [range, 1 to 91 years], respectively), in the proportion of patients who were female (40.1% vs 49.6%, respectively), and in the proportion of Medicare/Medicaid patients (43.8% vs 49%/4.7% vs 6.7%, respectively). Decreases in the average length of stay (12.9 days [range, 1 to 358 days] vs 9.1 days [range, 1 to 175 days], respectively) and in the proportion of patients discharged to their primary residence (86% vs 79.5%, respectively) were seen. The proportion of patients who had undergone lobectomies compared to other types of lung resection increased. Mortality rates were 5% vs 5.4%, respectively, while the frequency of complications decreased. CONCLUSION: We identified temporal changes in lung resection surgery that may help in the construction of health-care policies to address the changing needs of and financial burdens on the health-care system.

Do race, gender, and source of payment impact on anesthetic technique for inguinal hernia repair?

STUDY OBJECTIVE: To evaluate the potential differences in the type of anesthesia provided to patients of different race, gender, and source of payment undergoing inguinal hernia repair (IHR). DESIGN: Retrospective cohort study. SETTING: Ambulatory surgical centers/National Survey of Ambulatory Surgery. PATIENTS: 5810 patients older than 14 years who underwent IHR in an ambulatory surgical center. INTERVENTIONS: Inguinal hernia repair under different types of anesthesia. MEASUREMENTS: The association of race, gender, and source of payment with different types of anesthesia for IHR as determined by multivariate regression analysis. RESULTS: Significant discrepancies in the use of various anesthetics between patients of different race, gender, and source of payment were found. Patients identified as black and those of other minority groups were significantly more likely to receive general anesthesia compared with those identified as white (odds ratio [OR] 2.76, confidence interval [CI] 1.96-3.88 and OR 1.66, CI 1.14-2.42, respectively). Those identified as black were less likely to receive epidural anesthesia compared with their white counterparts (OR 0.36, CI 0.14-0.95). Women were less likely than men to undergo IHR with epidural anesthesia (OR 0.5, 95% CI 0.3-0.85). CONCLUSION: Significant discrepancies in the use of various anesthetics for IHR between patients of different race, gender, and insurance status were found. Despite limitations inherent to secondary data analysis, the findings raise the possibility that nonmedical factors may influence anesthetic management.