Kristin M. Sheffield

Allostatic Load Among Non-Hispanic Whites, Non-Hispanic Blacks, and People of Mexican Origin: Effects of Ethnicity, Nativity, and Acculturation

OBJECTIVES We investigated ethnic differences in allostatic load in a population-based sample of adults living in Texas City, TX, and assessed the effects of nativity and acculturation status on allostatic load among people of Mexican origin. METHODS We used logistic regression models to examine ethnic variations in allostatic load scores among non-Hispanic Whites, non-Hispanic Blacks, and people of Mexican origin. We also examined associations between measures of acculturation and allostatic load scores among people of Mexican origin only. RESULTS Foreign-born Mexicans were the least likely group to score in the higher allostatic load categories. Among individuals of Mexican origin, US-born Mexican Americans had higher allostatic load scores than foreign-born Mexicans, and acculturation measures did not account for the difference. CONCLUSIONS Our findings expand on recent research from the National Health and Nutrition Examination Survey with respect to ethnicity and allostatic load. Our results are consistent with the healthy immigrant hypothesis (i.e., newer immigrants are healthier) and the acculturation hypothesis, according to which the longer Mexican immigrants reside in the United States, the greater their likelihood of potentially losing culture-related health-protective effects.

Neighborhood Context and Cognitive Decline in Older Mexican Americans: Results From the Hispanic Established Populations for Epidemiologic Studies of the Elderly

In previous research on cognitive decline among older adults, investigators have not considered the potential impact of contextual variables, such as neighborhood-level conditions. In the present investigation, the authors examined the association between 2 neighborhood-context variables-socioeconomic status and percentage of Mexican-American residents-and individual-level cognitive function over a 5-year follow-up period (1993-1998). Data were obtained from the Hispanic Established Populations for Epidemiologic Studies of the Elderly, a longitudinal study of community-dwelling older Mexican Americans (n = 3,050) residing in the southwestern United States. Individual records were linked with 1990 US Census tract data, which provided information on neighborhood characteristics. Hierarchical linear growth-curve models and hierarchical logistic models were used to examine relations between individual- and neighborhood-level variables and the rate and incidence of cognitive decline. Results showed that baseline cognitive function and rates of cognitive decline varied significantly across US Census tracts. Respondents living in economically disadvantaged neighborhoods experienced significantly faster rates of cognitive decline than those in more advantaged neighborhoods. Odds of incident cognitive decline decreased as a function of neighborhood percentage of Mexican-American residents and increased with neighborhood economic disadvantage. The authors conclude that neighborhood context is associated with late-life cognitive function and that the effects are independent of individual-level risk factors.

Preoperative laboratory testing in patients undergoing elective, low-risk ambulatory surgery.

Background:Routine preoperative laboratory testing for ambulatory surgery is not recommended. Methods:Patients who underwent elective hernia repair (N = 73,596) were identified from the National Surgical Quality Improvement Program (NSQIP) database (2005–2010). Patterns of preoperative testing were examined. Multivariate analyses were used to identify factors associated with testing and postoperative complications. Results:A total of 46,977 (63.8%) patients underwent testing, with at least one abnormal test recorded in 61.6% of patients. In patients with no NSQIP comorbidities (N = 25,149) and no clear indication for testing, 54% received at least one test. In addition, 15.3% of tested patients underwent laboratory testing the day of the operation. In this group, surgery was done despite abnormal results in 61.6% of same day tests. In multivariate analyses, testing was associated with older age, ASA (American Society of Anesthesiologists) class >1, hypertension, ascites, bleeding disorders, systemic steroids, and laparoscopic procedures. Major complications (reintubation, pulmonary embolus, stroke, renal failure, coma, cardiac arrest, myocardial infarction, septic shock, bleeding, or death) occurred in 0.3% of patients. After adjusting for patient and procedure characteristics, neither testing nor abnormal results were associated with postoperative complications. Conclusions:Preoperative testing is overused in patients undergoing low-risk, ambulatory surgery. Neither testing nor abnormal results were associated with postoperative outcomes. On the basis of high rates of testing in healthy patients, physician and/or facility preference and not only patient condition currently dictate use. Involvement from surgical societies is necessary to establish guidelines for preoperative testing.

Association between cholecystectomy with vs without intraoperative cholangiography and risk of common duct injury.

IMPORTANCE Significant controversy exists regarding routine intraoperative cholangiography in preventing common duct injury during cholecystectomy. OBJECTIVE To investigate the association between intraoperative cholangiography use during cholecystectomy and common duct injury. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study of all Texas Medicare claims data from 2000 through 2009. We identified Medicare beneficiaries 66 years or older who underwent inpatient or outpatient cholecystectomy for biliary colic or biliary dyskinesia, acute cholecystitis, or chronic cholecystitis. We compared results from multilevel logistic regression models to the instrumental variable analyses. INTERVENTIONS Intraoperative cholangiography use during cholecystectomy was determined at the level of the patients (yes/no), hospitals (percentage intraoperative cholangiography use for all cholecystectomies at the hospital), and surgeons (percentage use for all cholecystectomies performed by the surgeon). Percentage of use at the hospital and percentage of use by surgeon were the instrumental variables. MAIN OUTCOMES AND MEASURES Patients with claims for common duct repair operations within 1 year of cholecystectomy were considered as having major common duct injury. RESULTS Of 92,932 patients undergoing cholecystectomy, 37,533 (40.4%) underwent concurrent intraoperative cholangiography and 280 (0.30%) had a common duct injury. The common duct injury rate was 0.21% among patients with intraoperative cholangiography and 0.36% among patients without it. In a logistic regression model controlling for patient, surgeon, and hospital characteristics, the odds of common duct injury for cholecystectomies performed without intraoperative cholangiography were increased compared with those performed with it (OR, 1.79 [95% CI, 1.35-2.36]; P < .001). When confounding was controlled with instrumental variable analysis, the association between cholecystectomy performed without intraoperative cholangiography and duct injury was no longer significant (OR, 1.26 [95% CI, 0.81-1.96]; P = .31). CONCLUSIONS AND RELEVANCE When confounders were controlled with instrumental variable analysis, there was no statistically significant association between intraoperative cholangiography and common duct injury. Intraoperative cholangiography is not effective as a preventive strategy against common duct injury during cholecystectomy.

Potentially Inappropriate Screening Colonoscopy in Medicare Patients: Variation by Physician and Geographic Region

IMPORTANCE Inappropriate use of colonoscopy involves unnecessary risk for older patients and consumes resources that could be used more effectively. OBJECTIVES To determine the frequency of potentially inappropriate colonoscopy in Medicare beneficiaries in Texas and to examine variation among physicians and across geographic regions. DESIGN, SETTING, AND PARTICIPANTS This retrospective cohort study used 100% Medicare claims data for Texas and a 5% sample from the United States from 2000 through 2009. We identified Medicare beneficiaries aged 70 years or older who underwent a colonoscopy from October 1, 2008, through September 30, 2009. MAIN OUTCOME MEASURES Colonoscopies were classified as screening in the absence of a diagnosis suggesting an indication for the procedure. Screening colonoscopy was considered potentially inappropriate on the basis of patient age or occurrence too soon after colonoscopy with negative findings. The percentage of patients undergoing potentially inappropriate screening colonoscopy was estimated for each colonoscopist and hospital service area. RESULTS A large percentage of colonoscopies performed in older adults were potentially inappropriate: 23.4% for the overall Texas cohort and 9.9%, 38.8%, and 24.9%, respectively, in patients aged 70 to 75, 76 to 85, or 86 years or older. There was considerable variation across the 797 colonoscopists in the percentages of colonoscopies performed that were potentially inappropriate. In a multilevel model including patient sex, race or ethnicity, number of comorbid conditions, educational level, and urban or rural residence, 73 colonoscopists had percentages significantly above the mean (23.9%), ranging from 28.7% to 45.5%, and 119 had percentages significantly below the mean (23.9%), ranging from 6.7% to 18.6%. The colonoscopists with percentages significantly above the mean were more likely to be surgeons, graduates of US medical schools, medical school graduates before 1990, and higher-volume colonoscopists than those with percentages significantly below the mean. Colonoscopist rankings were fairly stable over time (2006-2007 vs 2008-2009). There was also geographic variation across Texas and the United States, with percentages ranging from 13.3% to 34.9% in Texas and from 19.5% to 30.5% across the United States. CONCLUSIONS AND RELEVANCE Many colonoscopies performed in older adults may be inappropriate. The likelihood of undergoing potentially inappropriate colonoscopy depends in part on where patients live and what physician they see.

Variation in the Use of Intraoperative Cholangiography During Cholecystectomy

BACKGROUND The role of intraoperative cholangiography (IOC) in prevention of common bile duct (CBD) injuries and the management of CBD stones is controversial, and current variation in use of IOC has not been well described. STUDY DESIGN Multilevel hierarchical models using data from the Texas Hospital Inpatient Discharge Public Use data files (2001 to 2008) were used to evaluate the percentage of variance in the use of IOC that was attributable to patient, surgeon, and hospital factors. RESULTS A total of 176,981 cholecystectomies were performed in 212 hospitals in Texas. There was wide variation in IOC use, ranging from 2.4% to 98.4% of cases among surgeons and 3.7% to 94.8% of cases among hospitals, even after adjusting for case mix differences. The percentage of variance in IOC use attributable to the surgeon was 20.7% and an additional 25.7% was attributable to the hospital. IOC use was associated with increased age, gallstone pancreatitis or CBD stones, Hispanic race, decreased illness severity, insurance, and later year of cholecystectomy. ERCP (24.0% vs 14.9%, p < 0.0001) and CBD exploration (1.63% vs 0.42%, p < 0.0001) were more commonly performed in patients undergoing IOC. CONCLUSIONS Uncertainty regarding the benefit of IOC leads to wide variation in use across surgeons and hospitals. The surgeon and hospital are more important determinants of IOC use than measured patient characteristics. Our study highlights the need for further evaluation of comparative effectiveness of IOC in the prevention of CBD injuries and retained stones, taking into account patient risk factors, surgeon skill, cost, and availability of local expertise.

Resection benefits older adults with locoregional pancreatic cancer despite greater short-term morbidity and mortality

OBJECTIVES: To evaluate time trends in surgical resection rates and operative mortality in older adults diagnosed with locoregional pancreatic cancer and to determine the effect of age on surgical resection rates and 2‐year survival after surgical resection.

Overuse of Preoperative Cardiac Stress Testing in Medicare Patients Undergoing Elective Noncardiac Surgery

Objective:To determine the frequency and predictors of cardiac stress testing before elective noncardiac surgery in Medicare patients with no indications for cardiovascular evaluation. Background:The American College of Cardiology/American Heart Association guidelines indicate that patients without class I (American Heart Association high risk) or class II cardiac conditions (clinical risk factors) should not undergo cardiac stress testing before elective noncardiac, nonvascular surgery. Methods:We used 5% Medicare inpatient claims data (1996–2008) to identify patients aged ≥ 66 years who underwent elective general surgical, urological, or orthopedic procedures (N = 211,202). We examined the use of preoperative stress testing in the subset of patients with no diagnoses consistent with cardiac disease (N = 74,785). Bivariate and multivariate analyses were used to identify predictors of preoperative cardiac stress testing. Results:Of the patients with no cardiac indications for preoperative stress testing, 3.75% (N = 2803) received stress testing in the 2 months before surgery. The rate of preoperative stress testing increased from 1.72% in 1996 to 6.44% in 2007 (P < 0.0001). A multivariate analysis adjusting for patient and hospital characteristics showed a significant increase in preoperative stress testing over time. Female sex [odds ratio (OR) 1.11; 95% CI: 1.02–1.21], presence of other comorbidities [OR 1.22; 95% confidence interval (CI): 1.09–1.35], high-risk procedure (OR 2.42; 95% CI: 2.04–2.89), and larger hospital size (OR 1.17; 95% CI: 1.03–1.32) were positive predictors of stress testing. Patients living in regions with greater Medicare expenditures (OR 1.24; 95% CI: 1.05–1.45) were also more likely to receive stress tests. Conclusions:In a 5% sample of Medicare claims data, 2803 patients underwent preoperative stress testing without any indications. When these results were applied to the entire Medicare population, we estimated that there are over 56,000 patients who underwent unnecessary preoperative stress testing. The rate of testing in patients without cardiac indications has increased significantly over time.

Current trends in preoperative biliary stenting in patients with pancreatic cancer

BACKGROUND Sufficient evidence suggests that preoperative biliary stenting is associated with increased complication rates after pancreaticoduodenectomy. METHODS Surveillance, Epidemiology, and End Results (SEER) and linked Medicare claims data (1992-2007) were used to identify patients with pancreatic cancer who underwent pancreaticoduodenectomy. We evaluated trends in the use of preoperative biliary stenting, timing of physician visits relative to stenting, and time to surgical resection and symptoms in stented and unstented patients. RESULTS Pancreaticoduodenectomy was performed in 2,573 patients, and 52.6% of patients underwent preoperative biliary stenting (N = 1,354). Of these, 75.3% underwent endoscopic stenting only, 18.9% received a percutaneous stent, and 5.8% underwent both procedures. The overall stenting rate increased from 29.6% of patients between 1992 and 1995 to 59.1% between 2004 and 2007 (P < .0001). Preoperative stenting was more common in patients with jaundice, cholangitis, pruritus, or coagulopathy (P < .05 for all). Of stented patients, 77.7% had had a stent placed prior to seeing a surgeon. Stenting prior to surgical consultation was associated with longer indwelling stent time compared to stenting after surgical consultation (37.3 vs 27.0 days, P < .0001). In addition, stented patients had longer times from surgeon visit to pancreatectomy than those who had not received stents (24.2 days vs 17.2 days, P < .0001). CONCLUSION Use of preoperative biliary stenting doubled between 1992 and 2007 despite evidence that stenting is associated with increased perioperative infectious complications. The majority of stenting occurred prior to surgical consultation and is associated with significant delay in time to operation. Surgeons should be involved early in order to prevent unnecessary stenting and improve outcomes.

Implementation of a Critical Pathway for Complicated Gallstone Disease: Translation of Population-Based Data into Clinical Practice

BACKGROUND Evidence-based guidelines recommend cholecystectomy during initial hospitalization for complicated gallstone disease. Previous studies and quality initiative data from our institution demonstrated that only 40% to 75% of patients underwent cholecystectomy on index admission. STUDY DESIGN In January 2009, we implemented a critical pathway to improve cholecystectomy rates for all patients emergently admitted for acute cholecystitis, mild gallstone pancreatitis, or common bile duct stones. We compared cholecystectomy rates during initial hospitalization, time to cholecystectomy, length of initial stay, and readmission rates in prepathway (January 2005 to February 2008) and postpathway patients (January 2009 to May 2010). RESULTS Demographic and clinical characteristics were similar between prepathway (n = 455) and postpathway patients (n = 112). Cholecystectomy rates during initial hospitalization increased from 48% to 78% after pathway implementation (p < 0.0001). There were no differences in operative mortality or operative complications between the 2 groups. For patients undergoing cholecystectomy on initial hospitalization, the mean length of stay decreased after pathway implementation (7.1 days to 4.5 days; p < 0.0001), primarily due to a decrease in the time from admission to cholecystectomy (4.1 days to 2.1 days; p < 0.0001). Thirty-three percent of prepathway and 10% of postpathway patients required readmission for gallstone-related problems or operative complications (p < 0.0001), and each readmission generated an average of