Faculty Bibliography

Moving from a descriptive focus to a comprehensive analysis grounded in causal inference can be particularly daunting for disparities researchers. However, even a simple model supported by the theoretical underpinnings of causality gives researchers a better chance to make correct inferences about possible interventions that can benefit our most vulnerable populations. This commentary provides a brief description of how race/ethnicity and context relate to questions of causality, and uses a hypothetical scenario to explore how different researchers might analyze the data to estimate causal effects of interest. Perhaps although not entirely removed of bias, these causal estimates will move us a step closer to understanding how to intervene. (PsycINFO Database Record

BACKGROUND: Hospital care on weekends has been associated with delays in care, reduced quality, and poor clinical outcomes. OBJECTIVE: The purpose of this study was to evaluate the impact of a weekend hospital intervention on processes of care and clinical outcomes. The multifaceted intervention included expanded weekend diagnostic services, improved weekend discharge processes, and increased physician and care management services on weekends. DESIGN AND PATIENTS: This was an interrupted time series observational study of adult non-obstetric patients hospitalized at a single academic medical center between January 2011 and January 2014. The study included 18 months prior to and 19 months following the implementation of the intervention. Data were analyzed using segmented regression analysis with adjustment for confounders. MAIN MEASURES: The primary outcome was average length of stay. Secondary outcomes included percent of patients discharged on weekends, 30-day readmission rate, and in-hospital mortality rate. KEY RESULTS: The study included 57,163 hospitalizations. Following implementation of the intervention, average length of stay decreased by 13 % (95 % CI 10-15 %) and continued to decrease by 1 % (95 % CI 1-2 %) per month as compared to the underlying time trend. The proportion of weekend discharges increased by 12 % (95 % CI 2-22 %) at the time of the intervention and continued to increase by 2 % (95 % CI 1-3 %) per month thereafter. The intervention had no impact on readmissions or mortality. During the post-implementation period, the hospital was evacuated and closed for 2 months due to damage from Hurricane Sandy, and a new hospital-wide electronic health record was introduced. The contributions of these events to our findings are not known. We observed a lower inpatient census and found differences in patient characteristics, including higher rates of Medicaid insurance and comorbidities, in the post-Hurricane Sandy period as compared to the pre-Sandy period. CONCLUSIONS: The intervention was associated with a reduction in length of stay and an increase in weekend discharges. Our longitudinal study also illuminated the challenges of evaluating the effectiveness of a large-scale intervention in a real-world hospital setting.

BACKGROUND: Angiotensin converting enzyme inhibitors (ACEi) are widely used in the treatment of patients with hypertension. However, their efficacy in hypertensive blacks when compared with other antihypertensive agents is not well established. METHODS: Cohort study of patients using data from a clinical data warehouse of 434,646 patients from New York City's Health and Hospitals Corporation (HHC) from January 2004 - December 2009. Patients were divided into the following comparison groups: ACEi vs. Calcium Channel Blocker (CCB); ACEi vs. thiazide diuretics and ACEi vs. beta-blockers. Primary outcome was a composite of death, myocardial infarction or stroke. Secondary outcomes include the individual components and heart failure. RESULTS: In the propensity score matched ACEi vs. CCB comparison cohort (4,506 blacks in each group), ACEi was associated with higher risk of primary outcome (HR=1.45; 95% CI 1.19, 1.77; P=0.0003), myocardial infarction (HR=3.40; 95% CI 1.25, 9.22; P=0.02), stroke (HR=1.82; 95% CI 1.29, 2.57; P=0.001) and heart failure (HR=1.77; 95% CI 1.30, 2.42; P=0.0003) when compared with CCB. For the ACEi vs. thiazide diuretics comparison (5,337 blacks in each group), ACEi was associated with higher risk of primary outcome (HR=1.65; 95% CI 1.33, 2.05; P<0.0001), death (HR=1.35; 95% CI 1.03, 1.76; P=0.03), myocardial infarction (HR=4.00; 95% CI 1.34, 11.96; P=0.01), stroke (HR=1.97; 95% CI 1.34, 2.92; P=0.001) and heart failure (HR=3.00; 95% CI 1.99, 4.54; P<0.0001). For the ACEi vs. beta-blocker comparison, the outcomes between the groups were not significantly different. CONCLUSIONS: In a real-world cohort of hypertensive blacks, ACEi was associated with higher risk of cardiovascular events when compared with CCB or thiazide diuretics.

BACKGROUND: Clinical trial evidence suggests poorer outcomes in blacks compared with whites when treated with an angiotensin-converting enzyme (ACE) inhibitor-based regimen, but this has not been evaluated in clinical practice. OBJECTIVES: This study evaluated the comparative effectiveness of an ACE inhibitor-based regimen on a composite outcome of all-cause mortality, stroke, and acute myocardial infarction (AMI) in hypertensive blacks compared with whites. METHODS: We conducted a retrospective cohort study of 434,646 patients in a municipal health care system. Four exposure groups (Black-ACE, Black-NoACE, White-ACE, White-NoACE) were created based on race and treatment exposure (ACE or NoACE). Risk of the composite outcome and its components was compared across treatment groups and race using weighted Cox proportional hazard models. RESULTS: Our analysis included 59,316 new users of ACE inhibitors, 47% of whom were black. Baseline characteristics were comparable for all groups after inverse probability weighting adjustment. For the composite outcome, the race treatment interaction was significant (p = 0.04); ACE use in blacks was associated with poorer cardiovascular outcomes (ACE vs. NoACE: 8.69% vs. 7.74%; p = 0.05) but not in whites (6.40% vs. 6.74%; p = 0.37). Similarly, the Black-ACE group had higher rates of AMI (0.46% vs. 0.26%; p = 0.04), stroke (2.43% vs. 1.93%; p = 0.05), and congestive heart failure (3.75% vs. 2.25%; p < 0.0001) than the Black-NoACE group. However, the Black-ACE group was no more likely to develop adverse effects than the White-ACE group. CONCLUSIONS: ACE inhibitor-based therapy was associated with poorer cardiovascular outcomes in hypertensive blacks but not in whites. These findings confirm clinical trial evidence that hypertensive blacks have poorer outcomes than whites when treated with an ACE inhibitor-based regimen.

We performed a retrospective cohort study of patients with chronic obstructive lung disease (COPD) on long-term oxygen treatment (LTOT) who received invasive mechanical ventilation for COPD exacerbation. Of the 4791 patients, 23% died in the hospital, and 45% died in the subsequent 12 months. 67% of patients were readmitted at least once in the subsequent 12 months, and 26.8% were discharged to a nursing home or skilled nursing facility within 30 days. We conclude that these patients have high mortality rates, both in-hospital and in the 12 months postdischarge. If patients survive, many will be readmitted to the hospital and discharged to nursing home. These potential outcomes may support informed critical care decision making and more preference congruent care.

BACKGROUND: On October 2012, Hurricane Sandy struck New York City, resulting in unprecedented damages, including the temporary closure of Bellevue Hospital Center and its primary care office-based buprenorphine program. OBJECTIVES: At 6 months, we assessed factors associated with higher rates of substance use in buprenorphine program participants that completed a baseline survey one month post-Sandy (i.e. shorter length of time in treatment, exposure to storm losses, a pre-storm history of positive opiate urine drug screens, and post-disaster psychiatric symptoms). METHODOLOGY: Risk factors of interest extracted from the electronic medical records included pre-disaster diagnosis of Axis I and/or II disorders and length of treatment up to the disaster. Factors collected from the baseline survey conducted approximately one month post-Sandy included self-reported buprenorphine supply disruption, health insurance status, disaster exposure, and post-Sandy screenings for PTSD and depression. Outcome variables reviewed 6 months post-Sandy included missed appointments, urine drug results for opioids, cocaine, and benzodiazepines. RESULTS: 129 (98%) patients remained in treatment at 6 months, and had no sustained increases in opioid-, cocaine-, and benzodiazepine-positive urine drug tests in any sub-groups with elevated substance use in the baseline survey. Contrary to our initial hypothesis, diagnosis of Axis I and/or II disorders pre-Sandy were associated with significantly less opioid-positive urine drug findings in the 6 months following Sandy compared to the rest of the clinic population. CONCLUSION: These findings demonstrate the adaptability of a safety net buprenorphine program to ensure positive treatment outcomes despite disaster-related factors.