Nancy J. O. Birkmeyer

Hospital Complication Rates With Bariatric Surgery in Michigan

CONTEXT Despite the growing popularity of bariatric surgery, there remain concerns about perioperative safety and variation in outcomes across hospitals. OBJECTIVE To assess complication rates of different bariatric procedures and variability in rates of serious complications across hospitals and according to procedure volume and center of excellence (COE) status. DESIGN, SETTING, AND PATIENTS Involving 25 hospitals and 62 surgeons statewide, the Michigan Bariatric Surgery Collaborative (MBSC) administers an externally audited, prospective clinical registry. We evaluated short-term morbidity in 15,275 Michigan patients undergoing 1 of 3 common bariatric procedures between 2006 and 2009. We used multilevel regression models to assess variation in risk-adjusted complication rates across hospitals and the effects of procedure volume and COE designation (by the American College of Surgeons or American Society for Metabolic and Bariatric Surgery) status. MAIN OUTCOME MEASURE Complications occurring within 30 days of surgery. RESULTS Overall, 7.3% of patients experienced perioperative complications, most of which were wound problems and other minor complications. Serious complications were most common after gastric bypass (3.6%; 95% confidence interval [CI], 3.2%-4.0%), followed by sleeve gastrectomy (2.2%; 95% CI, 1.2%-3.2%), and laparoscopic adjustable gastric band (0.9%; 95% CI, 0.6%-1.1%) procedures (P < .001). Mortality occurred in 0.04% (95% CI, 0.001%-0.13%) of laparoscopic adjustable gastric band, 0 sleeve gastrectomy, and 0.14% (95% CI, 0.08%-0.25%) of the gastric bypass patients. After adjustment for patient characteristics and procedure mix, rates of serious complications varied from 1.6% (95% CI, 1.3-2.0) to 3.5% (95% CI, 2.4-5.0) (risk difference, 1.9; 95% CI, 0.08-3.7) across hospitals. Average annual procedure volume was inversely associated with rates of serious complications at both the hospital level (< 150 cases, 4.1%; 95% CI, 3.0%-5.1%; 150-299 cases, 2.7%; 95% CI, 2.2-3.2; and > or = 300 cases, 2.3%; 95% CI, 2.0%-2.6%; P = .003) and surgeon level (< 100 cases, 3.8%; 95% CI, 3.2%-4.5%; 100-249 cases, 2.4%; 95% CI, 2.1%-2.8%; > or = 250 cases, 1.9%; 95% CI, 1.4%-2.3%; P = .001). Adjusted rates of serious complications were similar in COE and non-COE hospitals (COE, 2.7%; 95% CI, 2.5%-3.1%; non-COE, 2.0%; 95% CI, 1.5%-2.4%; P = .41). CONCLUSIONS The frequency of serious complications among patients undergoing bariatric surgery in Michigan was relatively low. Rates of serious complications are inversely associated with hospital and surgeon procedure volume, but unrelated to COE accreditation by professional organizations.

Meta-Analysis Comparing the Effectiveness and Adverse Outcomes of Antifibrinolytic Agents in Cardiac Surgery

Background— Since the 1980s, antifibrinolytic therapies have assisted surgical teams in reducing the amount of blood loss. To date, however, serious questions remain regarding the safety and effectiveness of these agents. Methods and Results— We conducted a meta-analysis to compare aprotinin, ϵ-aminocaproic acid, and tranexamic acid with placebo and head to head on 8 clinical outcomes from 138 trials. Published randomized controlled trial data were collected from OVID/PubMed. Outcomes included total blood loss, transfusion of packed red blood cells, reexploration, mortality, stroke, myocardial infarction, dialysis-dependent renal failure, and renal dysfunction (0.5-mg/dL increase in creatinine from baseline). All agents were effective in significantly reducing blood loss by 226 to 348 mL and the proportion of patients transfused with packed red blood cells over placebo. Only high-dose aprotinin reduced the rate of reexploration (relative risk, 0.49; 95% CI, 0.33 to 0.73). There were no significant risks or benefits for any agent for mortality, stroke, myocardial infarction, or renal failure. However, high-dose aprotinin significantly increased the risk of renal dysfunction (relative risk, 1.47; 95% CI, 1.12 to 1.94), 12.9% versus 8.4%. Compared head to head, high-dose aprotinin demonstrated significant reduction in total blood loss over ϵ-aminocaproic acid (−184 mL; 95% CI, −256 to −112) and tranexamic acid (−195 mL; 95% CI, −286 to −105). There were no significant differences among any agent when compared head to head on other outcomes. Conclusions— All antifibrinolytic agents were effective in reducing blood loss and transfusion. There were no significant risks or benefits for mortality, stroke, myocardial infarction, or renal failure. However, high-dose aprotinin was associated with a statistically significant increased risk of renal dysfunction.

Obesity and Risk of Adverse Outcomes Associated With Coronary Artery Bypass Surgery

Background—Obesity is frequently cited as a risk factor for adverse outcomes of major surgery. The results of prior studies of the relationship between obesity and risk of adverse outcomes of coronary artery bypass grafting (CABG) have been contradictory because of insufficient power to assess relatively infrequent outcomes or data to adjust for confounding factors. Methods and Results—Data on patient age, sex, height, weight, medical history, current clinical status, and treatment factors were assessed prospectively among 11 101 consecutive patients undergoing CABG. Body mass index (BMI) was used as the measure of obesity and was categorized as nonobese (1st to 74th percentiles), obese (75th to 94th percentiles), or severely obese (95th to 100th percentiles). Adverse outcomes occurring in-hospital, including mortality, intraoperative/postoperative cerebrovascular accident (CVA), postoperative bleeding, and sternal wound infection, were defined prospectively. Associations between obesity and postoperative...

Outcomes After Transhiatal and Transthoracic Esophagectomy for Cancer

BACKGROUND Although single-center series evaluating esophagectomy for cancer have demonstrated that this operation can be performed safely and with excellent outcomes, controversy remains regarding the comparable oncologic efficacy of the transhiatal and transthoracic approaches. This study was performed to determine outcomes after transhiatal and transthoracic esophagectomy for patients undergoing resection nationwide. METHODS Using the Surveillance, Epidemiology, and End Results-Medicare linked database (1992 to 2002), we identified registered patients undergoing esophagectomy for esophageal cancer. We evaluated operative mortality, late survival, and length of stay while adjusting for patient characteristics, tumor grade, and stage. As a surrogate for postoperative quality of life, we also assessed subsequent need for anastomotic dilation. RESULTS Of 868 patients undergoing either approach, for whom distinct Current Procedural Technology codes could be identified, 225 underwent transhiatal and 643 received transthoracic esophagectomy. Lower operative mortality rate was observed after a transhiatal than transthoracic approach (6.7% versus 13.1%, p = 0.009). Observed 5-year survival was higher for patients undergoing transhiatal rather than transthoracic esophagectomy (30.5% versus 22.7%, p = 0.02). After adjusting for differences in tumor stage, patient, and provider factors, this survival advantage was no longer statistically significant (adjusted hazard ratio for mortality, 0.95, 95% confidence interval: 0.75 to 1.20). Patients undergoing transhiatal esophagectomy were more likely to require endoscopic dilatation within 6 months of surgery (43.1% versus 34.5% for transthoracic operations, p = 0.02). CONCLUSIONS In the largest population-based study to date assessing long-term outcome after esophagectomy for esophageal cancer, transhiatal esophagectomy confers an early survival advantage, but long-term survival does not appear to differ according to surgical approach.

Risks of Morbidity and Mortality in Dialysis Patients Undergoing Coronary Artery Bypass Surgery

Background—Although dialysis patients are undergoing CABG with increasing frequency, large studies specifically comparing patient characteristics and procedure-related risks in this population have not been performed. Methods and Results—We conducted a regional prospective cohort study of 15 500 consecutive patients undergoing CABG in northern New England from 1992 to 1997. We used multiple logistic regression analysis to examine associations between preoperative dialysis-dependent renal failure and postoperative events and to adjust for potentially confounding variables. The 279 dialysis-dependent renal failure patients (1.8%) were 4.4 times more likely to experience in-hospital mortality than were other CABG patients (12.2% versus 3.0%, respectively;P <0.001). Dialysis-dependent renal failure patients were older and had more comorbidities and more severe cardiac disease than did other CABG patients. After adjusting for these factors in multivariate analysis, however, dialysis-dependent renal failure patients remained 3.1 times more likely to die after CABG (adjusted odds ratio [OR] 3.1, 95% CI 2.1 to 4.7;P <0.001). Dialysis-dependent renal failure patients compared with other CABG patients also had a substantially increased risk of postoperative mediastinitis (3.6% versus 1.2%, respectively; adjusted OR 2.4, 95% CI 1.2 to 4.7;P =0.011) and postoperative stroke (4.3% versus 1.7%, respectively; adjusted OR 2.1, 95% CI 1.1 to 3.9;P =0.016), even after controlling for potentially confounding variables. Risks of reexploration for bleeding were similar for patients with and without dialysis-dependent renal failure. Conclusions—Preoperative dialysis-dependent renal failure is a strong independent risk factor for in-hospital mortality and mediastinitis after CABG.

The comparative effectiveness of sleeve gastrectomy, gastric bypass, and adjustable gastric banding procedures for the treatment of morbid obesity.

Objective:To evaluate the comparative effectiveness of sleeve gastrectomy (SG), laparoscopic gastric bypass (RYGB), and laparoscopic adjustable gastric banding (LAGB) procedures. Background:Citing limitations of published studies, payers have been reluctant to provide routine coverage for SG for the treatment of morbid obesity. Methods:Using data from an externally audited, statewide clinical registry, we matched 2949 SG patients with equal numbers of RYGB and LAGB patients on 23 baseline characteristics. Outcomes assessed included complications occurring within 30 days, and weight loss, quality of life, and comorbidity remission at 1, 2, and 3 years after bariatric surgery. Results:Matching resulted in cohorts of SG, RYGB, and LAGB patients that were well balanced on baseline characteristics. Overall complication rates among patients undergoing SG (6.3%) were significantly lower than for RYGB (10.0%, P < 0.0001) but higher than for LAGB (2.4%, P < 0.0001). Serious complication rates were similar for SG (2.4%) and RYGB (2.5%, P = 0.736) but higher than for LAGB (1.0%, P < 0.0001). Excess body weight loss at 1 year was 13% lower for SG (60%) than for RYGB (69%, P < 0.0001), but was 77% higher for SG than for LAGB (34%, P < 0.0001). SG was similarly closer to RYGB than LAGB with regard to remission of obesity-related comorbidities. Conclusions:With better weight loss than LAGB and lower complication rates than RYGB, SG is a reasonable choice for the treatment of morbid obesity and should be covered by both public and private payers.

How A Regional Collaborative Of Hospitals And Physicians In Michigan Cut Costs And Improved The Quality Of Care

There is evidence that collaborations between hospitals and physicians in particular regions of the country have led to improvements in the quality of care. Even so, there have not been many of these collaborations. We review one, the Michigan regional collaborative improvement program, which was paid for by a large private insurer, has yielded improvements for a range of clinical conditions, and has reduced costs in several important areas. In general and vascular surgery alone, complications from surgery dropped almost 2.6 percent among participating Michigan hospitals-a change that translates into 2,500 fewer Michigan patients with surgical complications each year. Estimated annual savings from this one collaborative are approximately

Rates of advanced spinal imaging and spine surgery.

20 million, far exceeding the cost of administering the program. Regional collaborative improvement programs should become increasingly attractive to hospitals and physicians, as well as to national policy makers, as they seek to improve health care quality and reduce costs.

Hospital quality and the cost of inpatient surgery in the United States.

Study Design. Small area analysis. Objectives. To determine the association between the rates of advanced spinal imaging and spine surgery across geographic areas. Summary of Background Data. The rates of spine surgery in the United States have increased along with a concurrent rise in the use of advanced spinal imaging: CT and MRI. Spine surgery rates vary six-fold across geographic areas of the United States. Differences in patient populations and health care supply have explained only about 10% of this variation. Methods. We used a random 5% sample of Medicare’s National Claims History Part B files for 1996 and 1997 to determine procedure rates across 306 Hospital Referral Regions. We analyzed the association between spinal imaging and spine surgery using linear regression. Main outcome measures were rates of procedures and coefficients of determination (R2). Results. The rates of advanced spinal imaging (CT and MRI combined) varied 5.5-fold across geographic areas. Areas with higher rates of MRI had higher rates of spine surgery overall (r = 0.46) and spinal stenosis surgery specifically (r = 0.37). The rates of advanced spinal imaging accounted for 22% of the variability in overall spine surgery rates (R2 = 0.22, P < 0.001) and 14% of the variability in lumbar stenosis surgery rates (R2 = 0.14, P < 0.001). A simulation model showed that MRIs obtained in the patients undergoing surgery accounted for only a small part of the correlation between MRI and total spine surgery rates. Conclusions. A significant proportion of the variation in rates of spine surgery can be explained by differences in the rates of advanced spinal imaging. The indications for advanced spinal imaging are not firmly agreed on, and the appropriateness of many of these imaging studies has been questioned. Improved consensus on the use and interpretation of advanced spinal imaging studies could have an important effect on variation in spine surgery rates. Spine 2003;28:616–620

Predicting risk for serious complications with bariatric surgery: results from the Michigan Bariatric Surgery Collaborative.

Context:Payers, policy makers, and professional organizations have launched a variety of initiatives aimed at improving hospital quality with inpatient surgery. Despite their obvious benefits for patients, the likely impact of these efforts on health care costs is uncertain. In this context, we examined relationships between hospital outcomes and expenditures in the US Medicare population. Methods:Using the 100% national claims files, we identified all US hospitals performing coronary artery bypass graft, total hip replacement, abdominal aortic aneurysm repair, or colectomy procedures between 2005 and 2007. For each procedure, we ranked hospitals by their risk- and reliability-adjusted outcomes (complication and mortality rates, respectively) and sorted them into quintiles. We then examined relationships between hospital outcomes and risk-adjusted, 30-day episode payments. Results:There was a strong, positive correlation between hospital complication rates and episode payments for all procedures. With coronary artery bypass graft, for example, hospitals in the highest complication quintile had average payments that were