James Hubbard

The Inflammatory Bowel Diseases and Ambient Air Pollution: A Novel Association

OBJECTIVES:The inflammatory bowel diseases (IBDs) emerged after industrialization. We studied whether ambient air pollution levels were associated with the incidence of IBD.METHODS:The health improvement network (THIN) database in the United Kingdom was used to identify incident cases of Crohns disease (n=367) or ulcerative colitis (n=591), and age- and sex-matched controls. Conditional logistic regression analyses assessed whether IBD patients were more likely to live in areas of higher ambient concentrations of nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter <10μm (PM10), as determined by using quintiles of concentrations, after adjusting for smoking, socioeconomic status, non-steroidal anti-inflammatory drugs (NSAIDs), and appendectomy. Stratified analyses investigated effects by age.RESULTS:Overall, NO2, SO2, and PM10 were not associated with the risk of IBD. However, individuals ≤23 years were more likely to be diagnosed with Crohns disease if they lived in regions with NO2 concentrations within the upper three quintiles (odds ratio (OR)=2.31; 95% confidence interval (CI)=1.25–4.28), after adjusting for confounders. Among these Crohns disease patients, the adjusted OR increased linearly across quintile levels for NO2 (P=0.02). Crohns disease patients aged 44–57 years were less likely to live in regions of higher NO2 (OR=0.56; 95% CI=0.33–0.95) and PM10 (OR=0.48; 95% CI=0.29–0.80). Ulcerative colitis patients ≤25 years (OR=2.00; 95% CI=1.08–3.72) were more likely to live in regions of higher SO2; however, a dose–response effect was not observed.CONCLUSIONS:On the whole, air pollution exposure was not associated with the incidence of IBD. However, residential exposures to SO2 and NO2 may increase the risk of early-onset ulcerative colitis and Crohns disease, respectively. Future studies are needed to explore the age-specific effects of air pollution exposure on IBD risk.

Postoperative Complications and Mortality Following Colectomy for Ulcerative Colitis

BACKGROUND & AIMS Complications after colectomy for ulcerative colitis (UC) have not been well characterized in large, population-based studies. We characterized postoperative in-hospital complications, stratified them by severity, and assessed independent clinical predictors, including use of immunosuppressants. METHODS We performed population-based surveillance using administrative databases to identify all adults (≥18 y) who had an International Classification of Diseases-9th/10th revisions code for UC and a colectomy from 1996 to 2009. All medical charts were reviewed. The primary outcome was severe postoperative complications, including in-hospital mortality. Logistic regression was used to assess predictors of complications after colectomy and then restricted to patients undergoing emergent or elective surgeries. RESULTS Of the 666 UC patients who underwent a colectomy, a postoperative complication occurred in 27.0% and the mortality rate was 1.5%. Independent predictors of postoperative complications were age (for patients >64 vs 18-34 y: odds ratio [OR], 1.95; 95% confidence interval [CI], 1.07-3.54), comorbidities (>2 vs none: OR, 1.89; 95% CI, 1.06-3.37), and admission status (emergent vs elective colectomy: OR, 1.62; 95% CI, 1.14-2.30). Significant risk factors for an emergent colectomy included time from admission to colectomy (>14 vs 3-14 d: OR, 3.32; 95% CI, 1.62-6.80) and a preoperative complication (≥1 vs 0: OR, 3.04; 95% CI, 1.33-6.91). A prescription of immunosuppressants before colectomies did not increase the risk for postoperative complications. CONCLUSIONS Postoperative complications frequently occur after colectomy for UC, predominantly among elderly patients with multiple comorbidities. Patients who were admitted to the hospital under emergency conditions and did not respond to medical treatment had worse outcomes when surgery was performed 14 or more days after admission.

A population-based study of pyogenic liver abscesses in the United States: incidence, mortality, and temporal trends.

OBJECTIVES:Few population-based studies have evaluated pyogenic liver abscess (PLA) in North America. We assessed the incidence of PLA and evaluated predictors of mortality.METHODS:We used the Nationwide Inpatient Sample to identify all patients with discharges for PLA (ICD-9 572.0) between 1994 and 2005. Multivariable logistic regression analysis was performed to determine whether mortality was associated with patient and hospital characteristics including comorbidities, interventions, and bacterial cultures. We determined the annual incidence for PLA in the US population and assessed for temporal changes using generalized linear regression models.RESULTS:We identified 17,787 PLA discharges for an overall incidence of PLA of 3.6 (95% confidence interval (CI): 3.5–3.7) per 100,000 population. From 1994 to 2005, the annual average percent increase in incidence was 4.1% (95% CI: 3.4–4.8; P<0.0001). In-hospital mortality was 5.6% (95% CI: 5.3–6.0). Mortality was associated with older age (65–84 vs. 18–34: odds ratio (OR)=2.28 (1.48–3.51)); Medicaid (OR=1.74 (1.36–2.23)) and Medicare (OR=1.48 (1.18–1.85) vs. private insurance; and comorbidities such as cirrhosis (OR=2.48 (1.85–3.31)), chronic renal failure (OR=1.99 (1.28–3.09)), and cancer (OR=2.32 (1.97–2.73)). Patients who underwent percutaneous liver aspiration (OR=0.45 (0.39–0.52)) had lower mortality, whereas surgical drainage (OR=0.87 (0.68–1.10)) and endoscopic retrograde cholangiopancreatography (OR=0.73 (0.52–1.03)) were not associated with mortality. The most commonly recorded bacterial infections were Streptococcus species (29.5%) and Escherichia coli (18.1%). Patients with bacteremia or septicemia (OR=3.88 (3.36–4.48)) had an increased risk of death.CONCLUSIONS:The incidence of PLA is increasing and is associated with significant mortality that is attributable to several modifiable risk factors.

Decreasing Colectomy Rates for Ulcerative Colitis: A Population-Based Time Trend Study

OBJECTIVES:Colectomy rates for ulcerative colitis (UC) have been inconsistently reported. We assessed temporal trends of colectomy rates for UC, stratified by emergent vs. elective colectomy indication.METHODS:From 1997 to 2009, we identified adults hospitalized for a flare of UC. Medical charts were reviewed. Temporal changes were evaluated using linear regression models to estimate the average annual percent change (AAPC) in surgical rates. Logistic regression analysis compared: (i) UC patients responding to medical management in hospital to those who underwent colectomy; (ii) UC patients who underwent an emergent vs. elective colectomy; and (iii) temporal trends of drug utilization.RESULTS:From 1997 to 2009, colectomy rates significantly dropped for elective colectomies with an AAPC of −7.4% (95% confidence interval (CI): −10.8%, −3.9%). The rate of emergent colectomies remained stable with an AAPC of −1.4% (95% CI: −4.8%, 2.0%). Azathioprine/6-mercaptopurine prescriptions increased from 1997 to 2009 (odds ratio (OR)=1.15; 95% CI: 1.09–1.22) and infliximab use increased after 2005 (OR=1.68; 95% CI: 1.25–2.26). A 13% per year risk adjusted reduction in the odds of colectomy (OR=0.87; 95% CI: 0.83–0.92) was observed in UC patients responding to medical management compared with those who required colectomy. Emergent colectomy patients had a shorter duration of flare (<2 weeks vs. 2–8 weeks, OR=5.31; 95% CI: 1.58–17.81) and underwent colectomy early after diagnosis (<1 year vs. 1–3 years, OR=5.48; 95% CI: 2.18–13.79).CONCLUSIONS:From 1997 to 2009, use of purine anti-metabolites increased and elective colectomy rates in UC patients decreased significantly. In contrast, emergent colectomy rates were stable, which may have been due to rapid progression of disease activity.

Predicting in-hospital mortality in patients with cirrhosis: Results differ across risk adjustment methods†

Risk‐adjusted health outcomes are often used to measure the quality of hospital care, yet the optimal approach in patients with liver disease is unclear. We sought to determine whether assessments of illness severity, defined as risk for in‐hospital mortality, vary across methods in patients with cirrhosis. We identified 258,731 patients with cirrhosis hospitalized in the Nationwide Inpatient Sample between 2002 and 2005. The performance of four common risk adjustment methods (the Charlson/Deyo and Elixhauser comorbidity algorithms, Disease Staging, and All Patient Refined Diagnosis Related Groups [APR‐DRGs]) for predicting in‐hospital mortality was determined using the c‐statistic. Subgroup analyses were conducted according to a primary versus secondary diagnosis of cirrhosis and in homogeneous patient subgroups (hepatic encephalopathy, hepatocellular carcinoma, congestive heart failure, pneumonia, hip fracture, and cholelithiasis). Patients were also ranked according to the probability of death as predicted by each method, and rankings were compared across methods. Predicted mortality according to the risk adjustment methods agreed for only 55%–67% of patients. Similarly, performance of the methods for predicting in‐hospital mortality varied significantly. Overall, the c‐statistics (95% confidence interval) for the Charlson/Deyo and Elixhauser algorithms, Disease Staging, and APR‐DRGs were 0.683 (0.680–0.687), 0.749 (0.746–0.752), 0.832 (0.829–0.834), and 0.875 (0.873–0.878), respectively. Results were robust across diagnostic subgroups, but performance was lower in patients with a primary versus secondary diagnosis of cirrhosis. Conclusion: Mortality analyses in patients with cirrhosis require sensitivity to the method of risk adjustment. Because different methods often produce divergent severity rankings, analyses of provider‐specific outcomes may be biased depending on the method used. (HEPATOLOGY 2008.)

Postoperative complications following colectomy for ulcerative colitis: A validation study

BackgroundUlcerative colitis (UC) patients failing medical management require colectomy. This study compares risk estimates for predictors of postoperative complication derived from administrative data against that of chart review and evaluates the accuracy of administrative coding for this population.MethodsHospital administrative databases were used to identify adults with UC undergoing colectomy from 1996–2007. Medical charts were reviewed and regression analyses comparing chart versus administrative data were performed to assess the effect of age, emergent operation, and Charlson comorbidities on the occurrence of postoperative complications. Sensitivity, specificity, and positive/negative predictive values of administrative coding for identifying the study population, Charlson comorbidities, and postoperative complications were assessed.ResultsCompared to chart review, administrative data estimated a higher magnitude of effect for emergent admission (OR 2.52 [95% CI: 1.80–3.52] versus 1.49 [1.06–2.09]) and Charlson comorbidities (OR 2.91 [1.86–4.56] versus 1.50 [1.05–2.15]) as predictors of postoperative complications. Administrative data correctly identified UC and colectomy in 85.9% of cases. The administrative database was 37% sensitive in identifying patients with ≥ 1Charlson comorbidity. Restricting analysis to active comorbidities increased the sensitivity to 63%. The sensitivity of identifying patients with at least one postoperative complication was 68%; restricting analysis to more severe complications improved the sensitivity to 84%.ConclusionsAdministrative data identified the same risk factors for postoperative complications as chart review, but overestimated the magnitude of risk. This discrepancy may be explained by coding inaccuracies that selectively identifying the most serious complications and comorbidities.

Morbidity and mortality following coronary artery bypass graft surgery in patients with cirrhosis: a population-based study

Background: The risk of cardiac surgery in patients with cirrhosis is poorly defined. Our objective was to describe outcomes of coronary artery bypass graft (CABG) surgery in cirrhotic patients from a population‐based perspective.

Inflammatory bowel disease patients who leave hospital against medical advice: predictors and temporal trends.

Background: Leaving hospital against medical advice (AMA) may have consequences with respect to health‐related outcomes; however, inflammatory bowel disease (IBD) patients have been inadequately studied. Thus, we determined the prevalence of self‐discharge, assessed predictors of AMA status, and evaluated time trends. Methods: We analyzed the 1995–2005 Nationwide Inpatient Sample (NIS) to identify 93,678 discharges with a primary diagnosis of IBD admitted to the hospital emergently and did not undergo surgery. We described the proportion of IBD patients who left AMA. Predictors of AMA status were evaluated using a multivariate logistic regression model and temporal trend analyses were performed with Poisson regression models. Results: Between 1995 and 2005, 1.31% of IBD patients left hospitals AMA. Crohns disease (CD) patients were more likely to leave AMA (adjusted odds ratio [aOR], 1.53; 95% confidence intervals [CI]: 1.30–1.79). Characteristics associated with leaving AMA included: ages 18–34 (aOR, 7.77, 95% CI: 4.34–13.89); male (aOR, 1.75; 95% CI: 1.55–1.99); Medicaid (aOR, 4.55; 95% CI: 3.81–5.43) compared to private insurance; African Americans (aOR, 1.34; 95% CI: 1.09–1.64) compared to white; substance abuse (aOR, 2.75; 95% CI: 2.14–3.54); and psychosis (aOR, 1.55; 95% CI: 1.13–2.14). The incidence rates of self‐discharge for CD patients were stable (P > 0.05) between 1995 and 1999, while they significantly (P < 0.0001) increased after 1999. In contrast, AMA rates for UC patients remained stable during the study period. Conclusions: Approximately 1 in 76 IBD patients admitted emergently for medical management leave the hospital AMA. These were primarily disenfranchised patients who may lack adequate outpatient follow‐up.

Decreasing mortality from acute biliary diseases that require endoscopic retrograde cholangiopancreatography: a nationwide cohort study.

BACKGROUND & AIMS The management of acute biliary diseases often involves endoscopic retrograde cholangiopancreatography (ERCP), but it is not clear whether this technique reduces mortality. We investigated whether mortality from acute biliary diseases that require ERCP has been reduced over time and explored factors associated with mortality. METHODS We conducted a cohort study using the Nationwide Inpatient Sample (1998-2008). We identified hospitalizations for choledocholithiasis, cholangitis, and acute pancreatitis that involved ERCP. Multivariate analyses were used to determine the effects of time period, patient factors, hospital characteristics, features of the ERCP procedure, and types of cholecystectomies on mortality, length of stay, and costs. RESULTS From 1998 to 2008 there were 166,438 admissions for acute biliary conditions that met the inclusion criteria, corresponding to more than 800,000 patients nationwide. During this interval, mortality decreased from 1.1% to 0.6% (adjusted odds ratio [aOR], 0.7; 95% confidence interval [CI], 0.6-0.8), diagnostic ERCPs decreased from 28.8% to 10.0%, hospitals performing fewer than 100 ERCPs per year decreased from 38.4% to 26.9%, open cholecystectomies decreased from 12.4% to 5.8%, and unsuccessful ERCPs decreased from 6.3% to 3.2% (P < .0001 for all trends). Unsuccessful ERCP (aOR, 1.7; 95% CI, 1.4-2.2), open cholecystectomy (aOR, 3.4; 95% CI 2.7-4.3), cholangitis (aOR, 1.9; 95% CI, 1.5-2.3), older age, having Medicare health insurance, and comorbidity were associated with increased mortality. CONCLUSIONS In-hospital mortality from acute biliary conditions requiring ERCP in the United States has decreased over time. Reductions in the rate of unsuccessful ERCPs and open cholecystectomies are associated with this trend.

Characteristics of Patients With Cirrhosis Who Are Discharged From the Hospital Against Medical Advice

BACKGROUND & AIMS Patients discharged from hospital against medical advice are at risk of adverse health outcomes. The frequency and predictors of self-discharge in cirrhotic patients have not been examined. METHODS By using the 1993-2005 US Nationwide Inpatient Sample, we identified 581,380 cirrhotic patients who had been admitted to hospitals. The proportion discharged against medical advice and predictors of self-discharge were analyzed by using regression models with adjustments for clinical factors, including illness severity. RESULTS Of the patients with cirrhosis identified, 2.8% left their hospital against medical advice. Self-discharge was most common in patients with alcoholic cirrhosis (4.2%) and hepatitis B or C ( approximately 3%) and least common among those with chronic cholestasis (0.4%). Independent predictors of self-discharge included male sex, younger age, non-private insurance, and admission to urban, nonteaching hospitals. Patients undergoing surgery and those with more comorbidities were less likely to leave against medical advice, whereas those with human immunodeficiency virus, drug and alcohol abuse, or psychosis were more likely to leave against medical advice. Self-discharge was less common among patients with hepatic decompensation (odds ratio [OR], 0.79; 95% confidence interval [CI], 0.76-0.82), primary liver cancer (OR, 0.49; 95% CI, 0.41-0.59), or prior transplantation (OR, 0.37; 95% CI, 0.25-0.55). Length of stay and hospital charges were lower in patients discharged against medical advice (P < .0001). CONCLUSIONS Approximately 1 in 36 hospitalized cirrhotic patients leave hospital against medical advice. Self-discharge is most common among patients with alcoholic cirrhosis, lower socioeconomic status, psychiatric disorders, substance abuse, and less severe liver disease. These findings might assist in the prevention of self-discharge and, ultimately, improve health outcomes in patients with cirrhosis.