Mohammad Kamal Faridi

Reduced Risk of Acute Exacerbation of COPD After Bariatric Surgery: A Self-Controlled Case Series Study

BACKGROUND Obesity is common among individuals with COPD and associated with increased COPD morbidities. However, little is known about the impact of weight reduction on COPD‐related outcomes in patients who are obese. METHODS Using the population‐based ED and inpatient sample in three US states (California, Florida, and Nebraska), we performed a self‐controlled case series study of 481 adults who were obese (40‐65 years of age) with COPD who underwent bariatric surgery. The primary outcome was an ED visit or hospitalization for acute exacerbation of COPD (AECOPD) from 2005 through 2011. We compared each patient’s risk of the outcome during sequential 12‐month periods using presurgery months 13 through 24 as the reference period. RESULTS During the 13 to 24 months before bariatric surgery (ie, reference period), 28% (95% CI, 24%‐32%) of patients had an ED visit or hospitalization for AECOPD. In the subsequent 12‐month presurgery period, the risk did not change materially (31%; 95% CI, 27%‐35%), with an adjusted OR (aOR) of 1.16 (95% CI, 0.88‐1.53; P = .29). By contrast, during the first 12 months after bariatric surgery, the risk declined significantly (12%; 95% CI, 9%‐15%; aOR, 0.35; 95% CI, 0.25‐0.49; P < .001). Likewise, in the subsequent period of 13 to 24 months after bariatric surgery, the risk remained significantly low (13%; 95% CI, 11%‐17%; aOR, 0.39; 95% CI, 0.28‐0.55; P < .001). CONCLUSIONS The risk of an ED visit or hospitalization for AECOPD substantially decreased after bariatric surgery in patients who are obese. This observation suggests the effectiveness of substantial weight reduction on COPD morbidity.

Trends in 30-day readmission rates after COPD hospitalization, 2006–2012

BACKGROUND Reduction in 30-day readmission rate after chronic obstructive pulmonary disease (COPD)-related hospitalization is a national objective. However, little is known about trends in readmission rates in recent years, particularly in priority populations defined by the Agency for Healthcare Research and Quality (AHRQ)(e.g., the elderly, women, racial/ethnic minorities, low-income and rural populations, and populations with chronic illnesses). METHODS We conducted a retrospective cohort study using data from the State Inpatient Database of eight geographically-dispersed US states (Arkansas, California, Florida, Iowa, Nebraska, New York, Utah, and Washington) from 2006 through 2012. We identified all COPD-related hospitalizations by patients ?40 years old. The primary outcome was any-cause readmission within 30 days of discharge from the index hospitalization for COPD. RESULTS From 2006 to 2012, a total of 845,465 hospitalizations at risk for 30-day readmissions were identified. Overall, 30-day readmission rate for COPD-related hospitalization decreased modestly from 20.0% in 2006 to 19.2% in 2012, an 0.8% absolute decrease (OR 0.991, 95%CI 0.989-0.995, Ptrend<0.001). This modest decline remained statistically significant after adjusting for patient demographics and comorbidities (adjusted OR 0.981, 95%CI 0.977-0.984, Ptrend<0.001). Similar to the overall population, the readmission rate over the 7-year period remained persistently high in most of AHRQ-defined priority populations. CONCLUSIONS Our observations provide a benchmark for future investigation of the impact of Hospital Readmissions Reduction Program on readmissions after COPD hospitalization. Our findings encourage researchers and policymakers to develop effective strategies aimed at reducing readmissions among patients with COPD in an already-stressed healthcare system.

Obesity and Severity of Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Rationale: Obesity is relatively common among individuals with chronic obstructive pulmonary disease (COPD). However, little is known about the association of obesity with severity of acute exacerbation of COPD and in‐hospital mortality. Objectives: To examine the association of obesity with markers of severity of acute exacerbation of COPD and in‐hospital mortality. Methods: This is a population‐based, retrospective cohort study using the 2012‐2013 State Inpatient Databases of seven U.S. states (Arkansas, Florida, Iowa, Nebraska, New York, Utah, and Washington). We included adults (aged ≥40 yr) hospitalized for acute exacerbation of COPD. Obesity, use of noninvasive positive pressure ventilation (NIPPV), and use of invasive mechanical ventilation were determined by International Classification of Diseases, Ninth Revision codes. To examine associations between obesity and each outcome (NIPPV, invasive mechanical ventilation, hospital length of stay (LOS), and in‐hospital mortality), we fit unadjusted and adjusted logistic regression models using generalized estimating equations to account for patient clustering within hospitals. We adjusted for age, sex, race/ethnicity, primary payer, median household income, patient residence, hospitalization year, chronic comorbidities, and hospital state. In the sensitivity analysis, we used stabilized inverse probability weighting to estimate the causal relation of obesity with outcomes in this observational study. Results: Of 187,647 patients hospitalized for an acute exacerbation of COPD, 17% were obese. Obesity was associated with increased use of both NIPPV (12.0% vs. 6.5%; adjusted odds ratio [OR] = 1.86; 95% confidence interval [CI] = 1.77‐1.95; P < 0.001) and invasive mechanical ventilation (3.5% vs. 2.8%; adjusted OR = 1.13; 95% CI = 1.04‐1.22; P = 0.003). Similarly, obese patients were more likely to have a hospital LOS of 4 days or longer (57.9% vs. 50.3%; adjusted OR = 1.37; 95% CI = 1.33‐1.41; P < 0.001). In contrast, obesity was associated with a lower in‐hospital mortality (0.9% vs. 1.4%; unadjusted OR = 0.63; 95% CI = 0.56‐0.72; P < 0.001). After adjusting for potential confounders, this association was no longer statistically significant (adjusted OR = 0.86; 95% CI = 0.75‐1.00; P = 0.06). Results were similar in sensitivity analyses using stabilized inverse probability weighting. Conclusions: In this population‐based study of adults hospitalized with an acute exacerbation of COPD, obesity was associated with increased use of noninvasive and invasive ventilation, increased hospital LOS, but was not associated with increased in‐hospital mortality.

The association of aspirin use with severity of acute exacerbation of chronic obstructive pulmonary disease: a retrospective cohort study

Little is known about the effect of long-term aspirin use on acute severity of COPD. We hypothesized that, in patients hospitalized for acute exacerbation of COPD (AECOPD), long-term aspirin use is associated with lower risks of disease severity (in-hospital death, mechanical ventilation use, and hospital length-of-stay). We conducted a retrospective cohort study using large population-based data from 2012 through 2013. Among 206,686 patients (aged ≥40 years) hospitalized for AECOPD, aspirin users had lower in-hospital mortality (1.0 vs. 1.4%; OR 0.60 [95% CI 0.50–0.72]; P < 0.001) and lower risk of invasive mechanical ventilation use (1.7 vs. 2.6%; OR 0.64 [95% CI 0.55–0.73]; P < 0.001) compared to non-users, while there was no significant difference in risks of non-invasive positive pressure ventilation use. Length-of-stay was shorter in aspirin users compared to non-users (P < 0.001). In sum, in patients with AECOPD, aspirin use was associated with lower rates of in-hospital mortality and invasive mechanical ventilation use, and shorter length-of-stay.

Association of Obesity With Severity of Heart Failure Exacerbation: A Population‐Based Study

Background Obesity and heart failure (HF) are important public health problems in the United States. Although studies have reported the association between obesity and higher chronic morbidity of HF, little is known about the relations of obesity with severity of HF exacerbation and in‐hospital mortality; therefore, we aimed to investigate the associations of obesity with severity of HF exacerbation and in‐hospital mortality. Methods and Results This retrospective cohort study of adults hospitalized for HF exacerbation used population‐based data sets (the State Inpatient Databases) of 7 US states from 2012 to 2013. The outcomes were acute severity measures—use of positive pressure ventilation and hospital length of stay—and in‐hospital mortality. We determined the associations between obesity and these outcomes, including adjustment for sociodemographic factors and comorbidities. We identified 219 465 patients hospitalized for HF exacerbation. Of those, 37 539 (17.1%) were obese. Obese patients had a significantly higher risk of positive pressure ventilation use compared with nonobese patients (13.6% versus 8.8%), with a corresponding adjusted odds ratio of 1.61 (95% confidence interval, 1.55–1.68; P<0.001). Likewise, obese patients were more likely to have hospital length of stay of ≥4 days compared with nonobese patients (62.5% versus 56.7%), with an adjusted odds ratio of 1.40 (95% confidence interval, 1.37–1.44; P<0.001). In contrast, obese patients had significantly lower in‐hospital mortality compared with nonobese patients (1.7% versus 3.3%), with an adjusted odds ratio of 0.87 (95% confidence interval, 0.80–0.95; P=0.002). Conclusions Based on large population‐based data sets of patients with HF exacerbation, obesity was associated with higher acute severity measures but lower in‐hospital mortality.

Association of Bariatric Surgery With Risk of Infectious Diseases: A Self-Controlled Case Series Analysis

Background Although emerging data demonstrate that obesity is a risk factor for infectious diseases, no study has investigated the relationship of bariatric surgery with the risk of infectious diseases among obese adults. Methods We conducted a self-controlled case series analysis using data from the State Emergency Department Database and State Inpatient Database of 3 US states (California, Florida, and Nebraska) from 2005 through 2011. We included obese adults who underwent bariatric surgery as an instrument of weight reduction. Primary outcomes were emergency department (ED) visit or hospitalization for skin and soft-tissue infection (SSTI), respiratory infection, intra-abdominal infection, or urinary tract infection (UTI). Results Among 56277 obese adults who underwent bariatric surgery, compared to presurgery months 13-24 as the reference period, the risk of ED visit or hospitalization in the 0- to 12-month postsurgery period decreased significantly for SSTI (aOR, 0.85 [95% confidence interval {CI}, .76-.95]) and respiratory infection (aOR, 0.82 [95% CI, .75-.90]) and remained significantly low in the 13- to 24-month postsurgery period (aORs, 0.77 [95% CI, .68-.86] and 0.75 [95% CI, .68-.82], respectively). By contrast, the risk increased significantly in the 0- to 12-month postsurgery period for intra-abdominal infection (aOR, 2.09 [95% CI, 1.78-2.46]) and UTI (aOR, 1.93 [95% CI, 1.74-2.15]) and remained high in the 13- to 24-month postsurgery period (aORs, 1.29 [95% CI, 1.09-1.54] and 1.31 [95% CI, 1.17-1.47], respectively). Conclusions We found a divergent risk pattern in the risk of 4 common infectious diseases after bariatric surgery. The risk of SSTI and respiratory infection decreased after bariatric surgery whereas that of intra-abdominal infection and UTI increased.

Association Between Obesity and Acute Severity Among Patients Hospitalized for Asthma Exacerbation

BACKGROUND Although studies have demonstrated relations between obesity and incident asthma, little is known about the association of obesity with acute severity in adults hospitalized for asthma exacerbation. OBJECTIVES To investigate the association of obesity with acute severity of asthma exacerbation. METHODS This is a retrospective cohort study using population-based data of 8 geographically diverse US states from 2010 through 2013. We included adults (age 18-54 years) hospitalized for asthma exacerbation. The outcome measures were markers of acute severity-use of mechanical ventilation (defined by noninvasive positive pressure ventilation and/or invasive mechanical ventilation) and hospital length of stay. To determine the association of obesity with each outcome, we fit multivariable models adjusting for patient-level confounders (eg, age, sex, race/ethnicity, primary insurance, quartiles for household income, residential status, and comorbidities) and potential patient clustering within hospitals. RESULTS Among the 72,086 patients hospitalized for asthma exacerbation, 24% were obese. Obesity was associated with a significantly higher risk of any mechanical ventilation use (8.3% vs 5.0%; adjusted odds ratio [OR], 1.77; 95% CI, 1.63-1.92; P < .001) driven by the higher risk of noninvasive positive pressure ventilation use (7.2% vs 3.4%; adjusted OR, 2.14; 95% CI, 1.96-2.35; P < .001). Likewise, obese patients were more likely to have a hospital length of stay of 3 or more days compared with nonobese patients (59.4% vs 46.5%; adjusted OR, 1.37; 95% CI, 1.32-1.43; P < .001). These findings were consistent with stratifications by age, sex, and race/ethnicity. CONCLUSIONS In this population-based study of adults hospitalized for asthma exacerbation, obesity was associated with higher acute severity.

Prenatal and postnatal tobacco smoke exposure and risk of severe bronchiolitis during infancy

BACKGROUND Maternal prenatal smoking has adverse effects on the growing fetus including those of respiratory nature. Although postnatal smoke exposure is a risk factor for respiratory infections, the effects of prenatal smoking independent of postnatal smoke exposure are less established. We hypothesized that both maternal prenatal smoking, and postnatal smoke exposure are risk factors for severe bronchiolitis during infancy. METHODS We performed a case-control study of 1353 children born between 1996 and 2011 at a single teaching hospital. Cases were admitted to the same hospital for bronchiolitis during infancy. Maternal prenatal smoking was collected from birth records. Postnatal smoke exposure was collected from review of electronic health records. Multivariable logistic regression was used to evaluate the independent associations of the two smoking variables with severe bronchiolitis. RESULTS 6% of cases were exposed to maternal prenatal smoking, compared with 4% of controls (P = 0.10). Postnatal smoke exposure was present in the households of 17% of cases compared with 3% of controls (P < 0.001). In a multivariable model with both smoking variables and adjustment for 10 covariates, maternal prenatal smoking was not a significant risk factor for severe bronchiolitis (adjusted OR = 1.02, 95%CI 0.56-1.84). By contrast, postnatal smoke exposure was associated with >300% increased odds (adjusted OR 4.19, 95%CI 2.51-6.98). CONCLUSIONS Although maternal prenatal smoking has many known adverse effects, it was not associated with increased odds of severe bronchiolitis in either unadjusted or multivariable analyses. Postnatal smoke exposure was a consistently strong risk factor. Our findings support ongoing efforts to decrease infant exposure to ambient smoke.

Age-related differences in the rate and diagnosis of 30-day readmission after hospitalization for acute ischemic stroke

Background Little is known about the association between age and readmission within 30 days after hospitalization for acute ischemic stroke. Aim To examine the age-related differences in rate and principal reason of 30-day readmissions in patients hospitalized for acute ischemic stroke. Methods In this retrospective, population-based cohort study using State Inpatient Databases from eight US states, we identified all adults hospitalized for acute ischemic stroke. We grouped the patients into four age categories: < 65, 65–74, 75–84, and ≥85 years. Outcomes were any-cause readmission within 30 days of discharge from the index hospitalization for acute ischemic stroke and the principal diagnosis of 30-day readmission. Results We identified 620,788 hospitalizations for acute ischemic stroke. The overall 30-day readmission rate was 16.6% with an increase with advanced age. Compared to patients aged <65 years, the readmission rate was significantly higher in age 65–74 years (OR 1.19; 95% CI 1.16–1.21), in age 75–84 years (OR 1.29; 95% CI 1.27–1.31), and in ≥ 85 years (OR 1.24; 95% CI 1.22–1.27; all P<0.001). There was heterogeneity in the age-readmission rate association between men and women (Pinteraction < 0.001). Overall, 45.8% of readmissions were assigned stroke-related conditions or rehabilitation care. Compared to younger adults, older adults were more likely to present with non-stroke-related conditions (46.1% in < 65 years, 50.6% in 65–74 years, 57.1% in 75–84 years, and 62.9% in ≥ 85 years; P<0.001). Conclusions Advanced age was associated with a higher 30-day readmission rate after acute ischemic stroke. Compared with younger adults, older adults were more likely to be readmitted for non-stroke-related conditions.

Association of obstructive sleep apnoea with acute severity of chronic obstructive pulmonary disease exacerbation: a population-based study: Brief Communications

Little is known about the association of obstructive sleep apnoea (OSA) with the severity of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This retrospective cohort study investigated the association of coexistent OSA with acute severity markers (i.e. invasive positive pressure ventilation (IPPV) use and hospital length of stay (LOS)) among adults hospitalised for AECOPD. Patients with coexistent OSA had a significantly higher risk of IPPV use and prolonged hospital LOS compared to those without OSA.