Has evidence changed practice?: appropriateness of carotid endarterectomy after the clinical trials.

OBJECTIVE: To assess how appropriateness of and indications for carotid endarterectomy (CEA) have changed following the publication of several large international randomized controlled trials (RCTs) designed to rationalize use of CEA. METHODS: The New York Carotid Artery Surgery Study (NYCAS) is a population-based cohort study of all CEAs performed on elderly patients from January 1998 through June 1999 in New York State. Detailed clinical data were abstracted from medical charts to assess indications for and appropriateness of surgery using a list of 1,557 indications for CEA developed by national experts using RAND appropriateness methods. Deaths and strokes within 30 days of surgery were ascertained and confirmed by two physicians. RESULTS: Among the 9,588 patients, the mean age was 74.6 years and 93.6% had 70 to 99% carotid stenosis. Nearly three-quarters of patients (72.3%) underwent CEA for asymptomatic stenosis, 18.6% for TIA, and 9.1% for stroke. Overall, 87.1% of operations were done for appropriate reasons, 4.3% for uncertain reasons, and 8.6% for inappropriate reasons (vs 32% inappropriate before the RCTs, p < 0.0001). Among procedures judged inappropriate, the most common reasons were high comorbidity in asymptomatic patients (62.2%), operating after a major stroke (14.2%), or for minimal stenosis (10.5%). Among asymptomatic patients, those with high comorbidity had over twice the risk of death or stroke compared to those without high comorbidity (7.13% vs 2.69%, p < 0.0001). CONCLUSIONS: Since publication of the randomized controlled trials, there has been a reduction in the proportion of patients undergoing carotid endarterectomy (CEA) for inappropriate reasons. The shift toward many asymptomatic patients undergoing CEA is concerning because the net benefit from surgery for these patients is low and is reduced further for patients with high comorbidity.

Association of surgical specialty and processes of care with patient outcomes for carotid endarterectomy.

BACKGROUND AND PURPOSE: Because there is considerable variation in practice patterns and outcomes for carotid endarterectomy (CE), there is a need to study the processes of care that are associated with adverse outcomes. The purpose of this study was to examine the impact of processes of care and surgical specialty on adverse outcomes for CE. METHODS: A retrospective cohort study based on a voluntary CE registry containing 3644 patients undergoing CE between April 1, 1997, and March 31, 1999, in New York hospitals was used in the study. A multivariable statistical model was used to identify significant independent patient risk factors and to examine the association of processes of care and surgical specialty with outcomes after adjustment for differences in patient risk factors. RESULTS: The overall adverse outcome (in-hospital death or stroke) rate was 1.84%. After adjustment for differences in 7 patient risk factors that were significantly related to adverse outcomes, the use of >/=1 specific processes of care (eversion endarterectomy, protamine, or shunts) was found to be associated with lower odds of an adverse outcome relative to patients undergoing CE without the processes (OR=0.42, P=0.006). Similarly, patients undergoing surgery performed by vascular surgeons had lower odds of experiencing an adverse outcome (OR=0.36, P=0.009). Processes of care and surgical specialty were highly correlated with one another. CONCLUSIONS: Processes of care and surgical specialty are significant interrelated determinants of adverse outcome for CE.

Motor vehicle crashes in New York State: importance of accounting for emergency department deaths when assessing differences in in-hospital mortality by level of care.

BACKGROUND: Motor vehicle crashes (MVCs) are one of the leading causes of death in the nation and in New York State, particularly among younger adult males. It is important to study how to reduce mortality from MVCs. METHODS: Hospitalized victims of motor vehicle crashes in the 1994-1995 New York State Trauma Registry were identified for the study. A statistical model was used to calculate risk-adjusted mortality rates for groups of hospitals constituting each level of care (regional trauma center, area trauma center, noncenter). Levels of care were also compared with respect to the location of deaths in the hospital (emergency department, inpatient), and the time between emergency department admission and death for patients dying in the hospital. RESULTS: The risk-adjusted mortality rate for MVCs in patients in regional centers was higher, although not significantly higher (6.91%; 95% confidence interval [CI], 6.18%-7.70%) than for area centers (5.53%; 95% CI, 4.43%-6.82%) or for noncenters (5.83%; 95% CI, 4.70%-7.15%). However, regional centers admitted seriously injured trauma patients from the emergency department much more quickly than other levels of care. Whereas only 18% of all in-hospital deaths occurred in emergency departments of regional centers, the comparable percentages for area centers and noncenters were 39% and 46%, respectively. Also, 43% of all deaths in regional centers occurred within 24 hours of presentation to the emergency department, compared with 15% in area centers and 21% in noncenters. CONCLUSION: Risk-adjusted inpatient mortality rates for victims of MVCs may not yield a fair comparison of performance for different levels of care or for different hospitals because of differences in how quickly emergency department patients are admitted to the hospital. A more equitable way to assess hospital mortality rates may be to include emergency department deaths in addition to inpatient deaths.

Differential survival after coronary revascularization procedures among patients with renal insufficiency.

BACKGROUND: Acute myocardial infarction, cardiac arrest, and other cardiac events are the major cause of mortality among patients with renal insufficiency. Previous studies of interventions for coronary artery disease among patients with renal insufficiency have not controlled for potentially confounding factors such as coronary artery disease severity and left ventricular function. This study investigates the comparative survival for patients with renal insufficiency and coronary artery disease following coronary artery bypass graft (CABG) surgery as compared with percutaneous coronary artery intervention (PCI), while controlling for confounding factors. METHODS: This retrospective cohort study of patients undergoing CABG surgery or PCI discharged between 1993 and 1995 uses the New York Department of Health databases and Cox proportional hazards analyses to estimate the mortality risk associated with CABG as compared with PCI for patients with renal insufficiency. Renal function was categorized as creatinine <2.5 mg/dL (N = 58,329), creatinine > or =2.5 mg/dL (N = 840), and end-stage renal disease (ESRD) requiring dialysis (N = 407). RESULTS: Patients with either ESRD or serum creatinine > or =2.5 mg/dL had more severe coronary artery disease and a greater frequency of comorbid conditions as compared with patients with creatinine <2.5 mg/dL. Creatinine > or =2.5 mg/dL and ESRD were both associated with an increased mortality risk among all distributions of coronary artery disease anatomy. Among patients with ESRD, the risk ratio (RR) of mortality for patients undergoing CABG compared with PCI was 0.39 (95% CI, 0.22 to 0.67, P = 0.0006). Among patients with creatinine > or =2.5 mg/dL, CABG surgery did not convey a survival benefit over PCI (RR, 0.86, 95% CI, 0.56 to 1.33, P = 0.50). CONCLUSIONS: This study demonstrates a survival benefit among patients with ESRD undergoing CABG surgery as compared with PCI, while controlling for severity of coronary artery disease, left ventricular dysfunction, and other comorbid conditions. These results suggest that management decisions among patients with coronary artery disease should be made in the context of not only location and severity of coronary artery lesions, but also on the presence and severity of renal dysfunction.

Mortality and locomotion 6 months after hospitalization for hip fracture: risk factors and risk-adjusted hospital outcomes.

CONTEXT: Hip fracture is a common clinical problem that leads to considerable mortality and disability. A need exists for a practical means to monitor and improve outcomes, including function, for patients with hip fracture. OBJECTIVES: To identify and compare the importance of significant prefracture predictors of functional status and mortality at 6 months for patients hospitalized with hip fracture and to compare risk-adjusted outcomes for hospitals providing initial care. DESIGN: Prospective study with data obtained from medical records and through structured interviews with patients and proxies. SETTING AND PARTICIPANTS: A total of 571 adults aged 50 years or older with hip fracture who were admitted to 4 New York, NY, metropolitan hospitals between August 1997 and August 1998. MAIN OUTCOME MEASURES: In-hospital and 6-month mortality; locomotion at 6 months; and adverse outcomes at 6 months, defined as death or needing assistance to ambulate, compared by hospital, adjusting for patient risk factors. RESULTS: The in-hospital mortality rate was 1.6%. At 6 months, the mortality rate was 13.5%, and another 12.8% needed total assistance to ambulate. Laboratory values were strong predictors of mortality but were not significantly associated with locomotion. Age and prefracture residence at a nursing home were significant predictors of locomotion (P =.02 for both) but were not significantly associated with mortality. Adjustment for baseline characteristics either substantially augmented or diminished interhospital differences in outcomes. Two hospitals had 1 outcome (functional status or mortality) that was significantly worse than the overall mean while the other outcome was nonsignificantly better than average. CONCLUSIONS: Mortality and functional status ideally should be considered both together and individually to distinguish effects limited to one or the other outcome. Hospital performance for these 2 measures may differ substantially after adjustment, probably because different processes of care are important to each outcome.

Predictors of mortality for patients undergoing cardiac valve replacements in New York State.

BACKGROUND: The objective of this study was to identify the mortality rates and significant independent risk factors for mortality for each of six valve replacement groups. METHODS: A total of 14,190 patients who underwent valve replacement in New York State from 1995 to 1997 were classified into six major groups and significant independent risk factors for inpatient mortality were identified for each of the groups using stepwise logistic regression. RESULTS: Mortality rates ranged from 3.33% for isolated aortic valve surgical procedures to 18.72% for multiple valve replacements with coronary artery bypass graft operations. The number of years in excess of age 55 was a significant multivariate predictor of mortality for all six groups of patients. Shock was a significant predictor for five of the six groups, and in each of those groups it was the risk factor with the highest odds ratio. CONCLUSIONS: Significant patient risk factors are relatively consistent across different types of valve replacement procedures. The probability of survival from valve surgical procedures is highly dependent on the patient's preoperative profile and the type of valve operation.

Short- and long-term mortality for patients undergoing primary angioplasty for acute myocardial infarction.

OBJECTIVES: The goal of this study was to learn more about the risk factors and short- and long-term outcomes for primary angioplasty. BACKGROUND: Primary angioplasty (direct angioplasty without antecedent thrombolytic therapy) has been an effective alternative to thrombolytic therapy for patients with acute myocardial infarction (AMI). However, most reported studies have been compromised by small sample sizes and short observation times. METHODS: New York's coronary angioplasty registry was used to identify New York patients undergoing angioplasty within 6 h of AMI between January 1, 1993 and December 31, 1996. Statistical models were used to identify significant risk factors for in-patient and long-term survival and to estimate long-term survival for all patients as well as various subsets of patients undergoing primary angioplasty. RESULTS: The in-hospital mortality rate for all primary angioplasty patients was 5.81%. When patients in preprocedural shock (who had a mortality rate of 45%) were excluded, the in-hospital mortality rate dropped to 2.60%. Mortality rates for all primary angioplasty patients at one year, two years and three years were 9.3%, 11.3% and 12.6%, respectively. Patients treated with stent placement did not have significantly lower risk-adjusted in-patient or two-year mortality rates. CONCLUSIONS: Primary angioplasty is a highly effective option for AMI.

A comparison of short- and long-term outcomes for balloon angioplasty and coronary stent placement.

OBJECTIVES: We sought to compare patient outcomes for coronary stent placement and balloon angioplasty. BACKGROUND: Since 1994, the number of patients treated only with balloon angioplasty has decreased nationally, whereas the use of coronary stents as an alternative has grown tremendously. The objectives of this study were to compare short- and long-term survival and subsequent revascularization rates for patients undergoing single-vessel balloon angioplasty and coronary stent placement. METHODS: New York's Coronary Angioplasty Registry was used to identify New York patients undergoing either balloon angioplasty or stent placement between July 1, 1994, and December 31, 1996. Statistical models were used to compare risk-adjusted short- and long-term survival and subsequent coronary artery bypass graft surgery (CABG) and percutaneous coronary interventions (PCIs). RESULTS: No significant differences were found in adjusted in-patient mortality, but patients who had balloon angioplasty were, on average, 1.36 times more likely to have died at any time during the two-year period after the index procedure (p = 0.003). The adjusted in-patient CABG rate was significantly higher for balloon angioplasty (2.72% vs. 1.66%, p<0.0001), and the adjusted two-year CABG rate was also significantly higher for balloon angioplasty (10.81% vs. 7.25%, p<0.001). The adjusted two-year rate for subsequent PCIs was also significantly higher for balloon angioplasty (19.6% vs. 14.3%, p<0.0001). Although measures were taken to eliminate or minimize the effect of selection bias, it should be noted that patients with stents were healthier at hospital admission than patients who had balloon angioplasty. CONCLUSIONS: Stent placement is associated with significantly lower risk-adjusted long-term mortality, CABG and subsequent PCI rates, as compared with balloon angioplasty.

The relationship between managed care insurance and use of lower-mortality hospitals for CABG surgery.

CONTEXT: Explicit information about the quality of coronary artery bypass graft (CABG) surgery has been available for nearly a decade in New York State; however, the extent to which managed care insurance plans direct enrollees to the lowest-mortality CABG surgery hospitals remains unknown. OBJECTIVE: To compare the proportion of patients with managed care insurance and fee-for-service (FFS) insurance who undergo CABG surgery at lower-mortality hospitals. DESIGN: A retrospective cohort study of CABG surgery discharges from 1993 to 1996, using New York Department of Health databases and multivariate analysis to estimate the use of lower-mortality hospitals by patients with different types of health insurance. SETTING: Cardiac surgical centers in New York, of which 14 were classified as lower-mortality hospitals (mean rate, 2.1%) and 17 were classified as higher-mortality hospitals (mean rate, 3.2%). PATIENTS: A total of 58,902 adults older than 17 years who were hospitalized for CABG surgery. Patients were excluded if their CABG surgery was combined with any valve procedure or left ventricular aneurysm resection or if they were younger than 65 years and enrolled in Medicare FFS or Medicare managed care. MAIN OUTCOME MEASURE: Probability of a patient receiving CABG surgery at a lower-mortality hospital. RESULTS: Compared with patients with private FFS insurance (n = 18,905), patients with private managed care insurance (n=7169) and Medicare managed care insurance (n=880) were less likely to receive CABG surgery at a lower-mortality hospital (relative risk [RR] of surgery at a lower-mortality hospital compared with patients with private FFS insurance, 0.77; 95% confidence interval [CI], 0.74-0.81; P<.001; and RR, 0.61; 95% CI, 0.54-0.70; P<.001, respectively, after controlling for multiple potential confounding factors). Patients with Medicare FFS insurance used lower-mortality hospitals at rates more similar to those with private FFS insurance (n = 31,948; RR, 0.95; 95% CI, 0.91-0.98; P=.004). CONCLUSIONS: Patients in New York State with private managed care and Medicare managed care insurance were significantly less likely to use lower-mortality hospitals for CABG surgery compared with patients with private FFS insurance.

Predicting inpatient mortality for pediatric trauma patients with blunt injuries: a better alternative.

PURPOSE: The aim of this study was to identify significant independent predictors of inpatient mortality rates for pediatric victims of blunt trauma and to develop a formula for predicting the probability of inpatient mortality for these patients. METHODS: Emergency department and inpatient data from 2,923 pediatric victims of blunt injury in the New York State Trauma Registry in 1994 and 1995 were used to explore the relationship between patient risk factors and mortality rate. A stepwise logistic regression model with P<.05 was developed using survival status asthe dependent variable. Independent variables included are elements of the Pediatric Trauma Score (PTS), additional elements from the Revised Trauma Score (RTS), the motor response and eye opening components of the Glasgow Coma Scale (GCS), age-specific systolic blood pressure, the AVPU score, and 2 measures of anatomic injury severity (the Injury Severity Score [ISS] and the International Classification of Disease, Ninth Revision-based Injury Severity Score [ICISS]). RESULTS: The only significant independent predictors of severity that emerged were the ICISS, no motor response (best motor response = 1) from the GCS, and the unresponsive component from the AVPU score. The statistical model exhibited an excellent fit (C statistic = .964). The specificity associated with the prediction of inpatient mortality rate based on the presence of 1 or more of these risk factors was .926, and the sensitivity was .944. CONCLUSION: The best independent predictors of inpatient mortality rate for pediatric trauma patients with blunt injuries include variables not specifically contained in the PTS or the RTS: ICISS, no motor response (best motor response = 1) from the GCS, and the unresponsive component of the AVPU score.

An examination of the volume-mortality relationship for New York State trauma centers.

OBJECTIVES: New York State Trauma Registry data were analyzed to determine whether there is a significant relationship between the volume of trauma patients treated by a trauma center and its risk-adjusted inpatient mortality rate. METHODS: Stepwise logistic regression was used to identify significant independent predictors of mortality, their weights, and the probability of in-hospital mortality for each patient. These data were then used to calculate risk-adjusted mortality rates for various ranges of hospital volume. Ranges were identified on the basis of homogeneity of mortality rates, the number of hospitals in each range, and the number of patients in each range. Three volume measures were used: (1) total annual volume of trauma cases > or = 1200 and total annual volume > or = 240 for patients with Injury Severity Score (ISS) > or = 15 (equivalent to American College of Surgeons [ACS] criteria), (2) total annual volume of patients with ISS > or = 15, and (3) total annual volume of cases in the Registry (approximately, inpatients with ISS > or = 9). RESULTS: Results show that the 35 New York State trauma centers not meeting the ACS criteria had lower, but not significantly lower, observed and risk-adjusted mortality rates (7.62% and 8.25%, respectively) than the corresponding rates for the 8 New York State trauma centers that met the ACS criteria (9.36% and 8.83%, respectively). Regarding the other two criteria, hospital ranges representing lower annual volumes tended to have somewhat lower, although not significantly lower, observed and risk-adjusted mortality rates. For example, using a total annual volume for patients with ISS > or = 15, the risk-adjusted mortality rates for the volume ranges 1-150, 151-250, and 251+ were 7.78%, 9.23%, and 8.70%, respectively. CONCLUSIONS: We were unable to document an inverse relationship between hospital volume and inpatient mortality rate for trauma centers in New York State. Volume criteria should not be considered indicators of the quality of trauma care.

Accounting for intubation status in predicting mortality for victims of motor vehicle crashes.

BACKGROUND: Two of the important predictors of mortality for trauma patients are the Glasgow Coma Scale and the respiratory rate. However, for intubated patients, the verbal response component of the Glasgow Coma Scale and the respiratory rate cannot be accurately obtained. This study extends previous work that attempts to predict mortality accurately for intubated patients without using verbal response and respiratory rate. METHODS: The New York State Trauma Registry was used to identify 1994 and 1995 victims of motor vehicle crashes (MVCs). For the subset of patients who were not intubated, we developed two statistical models to predict mortality: one did not contain verbal response or respiratory rate, and the other contained a predicted verbal response. These were compared with a model that did include verbal response and respiratory rate. We also compared the predictive abilities of the first two models for all MVC patients (intubated and nonintubated) and determined the extent to which intubated patients were at increased risk of dying in the hospital after having adjusted for other predictors of mortality. RESULTS: For nonintubated patients, the statistical model without verbal response and the model with predicted verbal response had slightly better discrimination and worse calibration than the model that included verbal response and respiratory rate. Predicted verbal response did not improve the strength of the model without verbal response. For all MVC patients (intubated and nonintubated), predicted verbal response was not a significant predictor of mortality when used in combination with the other predictors. Intubation status was a significant predictor, with intubated patients having a higher probability of dying in the hospital than patients with otherwise identical risk factors. CONCLUSION: Inpatient mortality for intubated MVC patients can be accurately predicted without respiratory rate or verbal response. There appears to be no need for predicted verbal response to be part of the prediction formula, but intubation status is an important independent predictor of mortality and should be used in statistical models that predict mortality for MVC patients.

Predictors of mortality in adult patients with blunt injuries in New York State: a comparison of the Trauma and Injury Severity Score (TRISS) and the International Classification of Disease, Ninth Revision-based Injury Severity Score (ICISS).

BACKGROUND: The purpose of this study was to determine the statistical model that best predicted mortality from blunt trauma using a contemporary population-based database. METHODS: 1994-1995 New York State Trauma Registry data for patients with blunt injuries were used to predict mortality using three statistical models: (1) the original Trauma and Injury Severity Score (TRISS) model based on Major Trauma Outcome Study data, (2) a new TRISS model whose coefficients were derived using New York data, and (3) the International Classification of Disease, Ninth Revision-based Injury Severity Score (ICISS) with predicted survival values obtained from the Agency for Health Care Policy and Research's Health Care Utilization Project. The models were compared with respect to discrimination (using the C statistic) and calibration (using the Hosmer-Lemeshow [H-L] statistic). In addition, the models were tested to see how well they predicted outcomes for each of the three mechanisms of blunt injury. RESULTS: The ICISS model had a significantly higher C statistic (0.878) and a better H-L statistic (29.38) for predicting mortality for all adult patients with blunt injuries. The original TRISS model had very poor calibration (H-L = 687.38). None of the three models predicted mortality accurately for victims of motor vehicle crashes or victims of low falls. When separate models were developed for all motor vehicle crashes, low falls, and other blunt injuries, the ICISS and New York TRISS models both fit well, although the calibration was marginal in most cases. The ICISS model had a statistically significantly higher C statistic for other blunt injuries and for motor vehicle crashes. The New York TRISS model had better calibration for low falls. CONCLUSIONS: The ICISS has promise as an alternative to TRISS, but many more comparative studies need to be undertaken using updated TRISS coefficients. Models should also be developed for mechanisms of injury, not just for blunt and penetrating injuries.

Access to coronary artery bypass surgery by race/ethnicity and gender among patients who are appropriate for surgery.

OBJECTIVE: The study sought to determine if there were race/ethnicity or gender differences in access to coronary artery bypass graft (CABG) surgery among patients who have been designated as appropriate and as necessary for that surgery according to the RAND methodology. METHODS: RAND appropriateness and necessity criteria were used to identify a race/gender stratified sample of postangiography patients who would benefit from coronary artery bypass graft surgery. These patients were tracked for 3 months to determine if they had undergone coronary artery bypass graft surgery in New York State. Subjects were a total of 1,261 postangiography patients in eight New York hospitals in 1994 to 1996. Measures included percentages of patients for whom coronary artery bypass graft surgery was appropriate and necessary undergoing surgery by race/ethnicity and gender, as well as multivariate odds ratios for race/ethnicity and gender. RESULTS: After controlling for age, payer, number of vessels diseased, and presence of left main disease, African-American and Hispanic patients were found to be significantly less likely to undergo coronary artery bypass graft surgery than white non-Hispanic patients (respective odds ratios 0.64 and 0.60). When "necessity" was used as a criterion instead of "appropriateness," significant differences in access for African-American patients remained. The gatekeeper physician recommended surgery only 10% of the time that patients did not undergo "appropriate" coronary artery bypass graft surgery, and this percentage did not vary significantly by race/ethnicity or gender of the patient. CONCLUSIONS: Even after controlling for appropriateness and necessity for coronary artery bypass graft surgery in a prospective study, African-American patients had significant access problems in obtaining coronary artery bypass graft surgery. These problems appeared not to be related to patient refusals.

A comparison of three-year survival after coronary artery bypass graft surgery and percutaneous transluminal coronary angioplasty.

OBJECTIVES: The purpose of this study was to compare 3-year risk-adjusted survival in patients undergoing coronary artery bypass graft (CABG) surgery and percutaneous transluminal coronary angioplasty. BACKGROUND: Coronary artery bypass graft surgery and angioplasty are two common treatments for coronary artery disease. For referral purposes, it is important to know the relative pattern of survival after hospital discharge for these procedures and to identify patient characteristics that are related to survival. METHODS: New York's CABG surgery and angioplasty registries were used to identify New York patients undergoing CABG surgery and angioplasty from January 1, 1993 to December 31, 1995. Mortality within 3 years of undergoing the procedure (adjusted for patient severity of illness) and subsequent revascularization within 3 years were captured. Three-year mortality rates were adjusted using proportional hazards methods to account for baseline differences in patients' severity of illness. RESULTS: Patients with one-vessel disease with the one vessel not involving the left anterior descending artery (LAD) or with less than 70% LAD stenosis had a statistically significantly longer adjusted 3-year survival with angioplasty (95.3%) than with CABG surgery (92.4%). Patients with proximal LAD stenosis of at least 70% had a statistically significantly longer adjusted 3-year survival with CABG surgery than with angioplasty regardless of the number of coronary vessels diseased. Also, patients with three-vessel disease had a statistically significantly longer adjusted 3-year survival with CABG surgery regardless of proximal LAD disease. Patients with other one-vessel or two-vessel disease had no treatment-related differences in survival. CONCLUSIONS: Treatment-related survival benefit at 3-years in patients with ischemic heart disease is predicted by the anatomic extent and specific site of the disease, as well as by the treatment chosen.

Laparoscopic and open cholecystectomy in New York State: mortality, complications, and choice of procedure.

BACKGROUND: With the advent of laparoscopic cholecystectomy patient outcomes and choice of procedure (laparoscopic vs open) are of vital interest. The purpose of this study was to examine the mortality and complication rates for patients undergoing laparoscopic and open cholecystectomy in New York State and to test for differences among hospital peer groups and regions of the state in the tendency to use the laparoscopic approach. METHODS: A population-based, retrospective cohort study of laparoscopic and open cholecystectomy was conducted in which data were analyzed on all 30,968 patients who underwent cholecystectomy as a principal procedure in New York State in 1996. RESULTS: A total of 78.7% of the 30,968 patients who underwent cholecystectomy as a principal procedure in New York State in 1996 underwent laparoscopic cholecystectomy. The mortality rate was lower for laparoscopic cholecystectomy than for the open procedure (0.23% vs 1.90%, P < .0001) and remained significantly lower after patient characteristics related to patient survival (odds ratio 0.34, P < .0001) were controlled for. The prevalence rate of the 8 most common complications among cholecystectomy patients was also much lower among patients undergoing laparoscopic cholecystectomy. Patients undergoing cholecystectomy in public hospitals, Bronx County, and Kings County were found to be significantly less likely to have laparoscopic procedures, and patients undergoing cholecystectomy on Long Island were found to be significantly more likely to have laparoscopic procedures than were other patients in the state. CONCLUSIONS: There are reasonably large differences among hospitals, hospital groups, and regions of the state in the type of cholecystectomy used, even after adjustment for differences in patient comorbidities and indications for type of procedure.

Relationship between provider volume and mortality for carotid endarterectomies in New York state.

BACKGROUND AND PURPOSE: The objective of this study was to assess the relationship between each of 2 provider volume measures for carotid endarterectomies (CEs) (annual hospital volume and annual surgeon volume) and in-hospital mortality. New York's Statewide Planning and Research (SPARCS) administrative database was used to identify all 28 207 patients for whom carotid endarterectomy was the principal procedure performed in New York State hospitals between January 1, 1990, and December 31, 1995. METHODS: A statistical model was developed to predict in-hospital mortality using age, admission status, and several conditions found to be associated with higher-than-average mortality. This model was then used to calculate risk-adjusted mortality rates for various intersections of hospital and surgeon volume ranges. RESULTS: Risk-adjusted in-hospital mortality ranged from 1.96% (95% confidence interval, 1.47 to 2.57) for patients having surgeons with annual CE volumes of <5 in hospitals with annual CE volumes of /=5 in hospitals with annual CE volumes of >100. These 2 rates were statistically different. CONCLUSIONS: We conclude that the in-hospital mortality rates for carotid endarterectomies performed by surgeons with extremely low annual volumes (<5) and for hospitals with low volumes (