Assessing response bias from missing quality of life data: The Heckman method

BACKGROUND: The objective of this study was to demonstrate the use of the Heckman two-step method to assess and correct for bias due to missing health related quality of life (HRQL) surveys in a clinical study of acute coronary syndrome (ACS) patients. METHODS: We analyzed data from 2,733 veterans with a confirmed diagnosis of acute coronary syndromes (ACS), including either acute myocardial infarction or unstable angina. HRQL outcomes were assessed by the Short-Form 36 (SF-36) health status survey which was mailed to all patients who were alive 7 months following ACS discharge. We created multivariable models of 7-month post-ACS physical and mental health status using data only from the 1,660 survey respondents. Then, using the Heckman method, we modeled survey non-response and incorporated this into our initial models to assess and correct for potential bias. We used logistic and ordinary least squares regression to estimate the multivariable selection models. RESULTS: We found that our model of 7-month mental health status was biased due to survey non-response, while the model for physical health status was not. A history of alcohol or substance abuse was no longer significantly associated with mental health status after controlling for bias due to non-response. Furthermore, the magnitude of the parameter estimates for several of the other predictor variables in the MCS model changed after accounting for bias due to survey non-response. CONCLUSION: Recognition and correction of bias due to survey non-response changed the factors that we concluded were associated with HRQL seven months following hospital admission for ACS as well as the magnitude of some associations. We conclude that the Heckman two-step method may be a valuable tool in the assessment and correction of selection bias in clinical studies of HRQL

Variation in contrast-associated acute kidney injury prophylaxis for percutaneous coronary intervention: Insights from the Veterans Affairs Clinical Assessment, Reporting, and Tracking (CART) program

BACKGROUND: Contrast-Associated Acute Kidney Injury (CA-AKI) is a serious complication associated with percutaneous coronary intervention (PCI). Patients with chronic kidney disease (CKD) have an elevated risk for developing this complication. Although CA-AKI prophylactic measures are available, the supporting literature is variable and inconsistent for periprocedural hydration and N-acetylcysteine (NAC), but is stronger for contrast minimization. METHODS: We assessed the prevalence and variability of CA-AKI prophylaxis among CKD patients undergoing PCI between October 2007 and September 2015 in any cardiac catheterization laboratory in the VA Healthcare System. Prophylaxis included periprocedural hydration with normal saline or sodium bicarbonate, NAC, and contrast minimization (contrast volume to glomerular filtration rate ratio ≤ 3). Multivariable hierarchical logistic regression models quantified site-specific prophylaxis variability. As secondary analyses, we also assessed CA-AKI prophylaxis measures in all PCI patients regardless of kidney function, periprocedural hydration in patients with comorbid CHF, and temporal trends in CA-AKI prophylaxis. RESULTS: From 2007 to 2015, 15,729 patients with CKD underwent PCI. 6928 (44.0%) received periprocedural hydration (practice-level median rate 45.3%, interquartile range (IQR) 35.5-56.7), 5107 (32.5%) received NAC (practice-level median rate 28.3%, IQR 22.8-36.9), and 4656 (36.0%) received contrast minimization (practice-level median rate 34.5, IQR 22.6-53.9). After adjustment for patient characteristics, there was significant site variability with a median odds ratio (MOR) of 1.80 (CI 1.56-2.08) for periprocedural hydration, 1.95 (CI 1.66-2.29) for periprocedural hydration or NAC, and 2.68 (CI 2.23-3.15) for contrast minimization. These trends were similar among all patients (with and without CKD) undergoing PCI. Among patients with comorbid CHF (n = 5893), 2629 (44.6%) received periprocedural hydration, and overall had less variability in hydration (MOR of 1.56 (CI 1.38-1.76)) compared to patients without comorbid CHF (1.89 (CI 1.65-2.18)). Temporal trend analysis showed a significant and clinically relevant decrease in NAC use (64.1% of cases in 2008 (N = 1059), 6.2% of cases in 2015 (N = 128, p = \u3c 0.0001)) and no significant change in contrast-minimization (p = 0.3907). CONCLUSIONS: Among patients with CKD undergoing PCI, there was low utilization and significant site-level variability for periprocedural hydration and NAC independent of patient-specific risk. This low utilization and high variability, however, was also present for contrast minimization, a well-established measure. These findings suggest that a standardized approach to CA-AKI prophylaxis, along with continued development of the evidence base, is needed

Association Between Chronic Kidney Disease and Rates of Transfusion and Progression to End‐Stage Renal Disease in Patients Undergoing Transradial Versus Transfemoral Cardiac Catheterization—An Analysis From the Veterans Affairs Clinical Assessment Reporting and Tracking (CART) Program

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139058/1/jah32090-sup-0001-TablesS1-S4.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139058/2/jah32090_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139058/3/jah32090.pd

Acute Kidney Injury Risk Prediction in Patients Undergoing Coronary Angiography in a National Veterans Health Administration Cohort with External Validation

Background: Acute kidney injury (AKI) occurs frequently after cardiac catheterization and percutaneous coronary intervention. Although a clinical risk model exists for percutaneous coronary intervention, no models exist for both procedures, nor do existing models account for risk factors prior to the index admission. We aimed to develop such a model for use in prospective automated surveillance programs in the Veterans Health Administration. Methods and Results: We collected data on all patients undergoing cardiac catheterization or percutaneous coronary intervention in the Veterans Health Administration from January 01, 2009 to September 30, 2013, excluding patients with chronic dialysis, end‐stage renal disease, renal transplant, and missing pre‐ and postprocedural creatinine measurement. We used 4 AKI definitions in model development and included risk factors from up to 1 year prior to the procedure and at presentation. We developed our prediction models for postprocedural AKI using the least absolute shrinkage and selection operator (LASSO) and internally validated using bootstrapping. We developed models using 115 633 angiogram procedures and externally validated using 27 905 procedures from a New England cohort. Models had cross‐validated C‐statistics of 0.74 (95% CI: 0.74–0.75) for AKI, 0.83 (95% CI: 0.82–0.84) for AKIN2, 0.74 (95% CI: 0.74–0.75) for contrast‐induced nephropathy, and 0.89 (95% CI: 0.87–0.90) for dialysis. Conclusions: We developed a robust, externally validated clinical prediction model for AKI following cardiac catheterization or percutaneous coronary intervention to automatically identify high‐risk patients before and immediately after a procedure in the Veterans Health Administration. Work is ongoing to incorporate these models into routine clinical practice

Renin-Angiotensin-Aldosterone System Inhibitor Use and Mortality in Pulmonary Hypertension: Insights from the Veterans Affairs Clinical Assessment Reporting and Tracking Database

Background The renin-angiotensin-aldosterone system (RAAS) contributes to pulmonary hypertension (PH) pathogenesis. Although animal data suggest that RAAS inhibition attenuates PH, it is unknown if RAAS inhibition is beneficial in PH patients. Research Question Is RAAS inhibitor use associated with lower mortality in a large cohort of patients with hemodynamically confirmed PH? Study Design and Methods We used the Department of Veterans Affairs Clinical Assessment Reporting and Tracking Database to study retrospectively relationships between RAAS inhibitors (angiotensin converting enzyme inhibitors [ACEIs], angiotensin receptor blockers [ARBs], and aldosterone antagonists [AAs]) and mortality in 24,221 patients with hemodynamically confirmed PH. We evaluated relationships in the full and propensity-matched cohorts. Analyses were adjusted for demographics, socioeconomic status, comorbidities, disease severity, and comedication use in staged models. Results ACEI and ARB use was associated with improved survival in unadjusted Kaplan-Meier survival analyses in the full cohort and the propensity-matched cohort. This relationship was insensitive to adjustment, independent of pulmonary artery wedge pressure, and also was observed in a cohort restricted to individuals with precapillary PH. AA use was associated with worse survival in unadjusted Kaplan-Meier survival analyses in the full cohort; however, AA use was associated less robustly with mortality in the propensity-matched cohort and was not associated with worse survival after adjustment for disease severity, indicating that AAs in real-world practice are used preferentially in sicker patients and that the unadjusted association with increased mortality may be an artifice of confounding by indication of severity. Interpretation ACEI and ARB use is associated with lower mortality in veterans with PH. AA use is a marker of disease severity in PH. ACEIs and ARBs may represent a novel treatment strategy for diverse PH phenotypes

Sex-based differences in veterans with pulmonary hypertension: Results from the veterans affairs-clinical assessment reporting and tracking database

Women have an increased risk of pulmonary hypertension (PH) but better survival compared to men. Few studies have explored sex-based differences in population-based cohorts with PH. We sought to determine whether sex was associated with hemodynamics and survival in US veterans with PH (mean pulmonary artery pressure [mPAP] ≥ 25 mm Hg) from the Veterans Affairs Clinical Assessment, Reporting, and Tracking database. The relationship between sex and hemodynamics was assessed with multivariable linear mixed modeling. Cox proportional hazards models were used to compare survival by sex for those with PH and precapillary PH (mPAP ≥ 25 mm Hg, pulmonary artery wedge pressure [PAWP] ≤ 15 mm Hg and pulmonary vascular resistance [PVR] > 3 Wood units) respectively. The study population included 15,464 veterans with PH, 516 (3%) of whom were women; 1,942 patients (13%) had precapillary PH, of whom 120 (6%) were women. Among those with PH, women had higher PVR and pulmonary artery pulse pressure, and lower right atrial pressure and PAWP (all p <0.001) compared with men. There were no significant differences in hemodynamics according to sex in veterans with precapillary PH. Women with PH had 18% greater survival compared to men with PH (adjusted HR 0.82, 95% CI 0.69–0.97, p = 0.020). Similarly, women with precapillary PH were 29% more likely to survive as compared to men with PH (adjusted HR 0.71, 95% CI 0.52–0.98, p = 0.040). In conclusion, female veterans with PH have better survival than males despite higher pulmonary afterload

Cardiac Rehabilitation Participation and Mortality After Percutaneous Coronary Intervention: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program.

Background Cardiac rehabilitation (CR) is strongly recommended after percutaneous coronary intervention (PCI), but it is underused. We sought to evaluate CR participation variation after PCI and its association with mortality among veterans. Methods and Results Patients undergoing PCI between 2007 and 2011 were identified in the Veterans Affairs Clinical Assessment, Reporting, and Tracking database and followed up until January 25, 2017. We excluded patients who died within 30&nbsp;days of PCI and calculated the percentage participating in ≥1 outpatient CR visits within 12&nbsp;months after PCI. We constructed multivariable hierarchical logistic regression models for CR participation, clustered by facility. We estimated propensity scores for CR participation, matched participants and nonparticipants by propensity score, calculated mortality rates, and estimated the association with mortality using Cox proportional hazards models. Participation in CR after PCI was 6.9% (2986/43&nbsp;319) and varied significantly by PCI facility (range, 0%-36%). After 6.1&nbsp;years median follow-up, CR participants had a 33% lower mortality rate than all nonparticipants (3.8 versus 5.7 deaths/100 person-years; hazard ratio, 0.67; 95% confidence interval, 0.61-0.75; P&lt;0.001) and a 26% lower mortality rate than 2986 propensity-matched nonparticipants (3.8 versus 5.1 deaths/100 person-years; hazard ratio, 0.74; 95% confidence interval, 0.65-0.84; P&lt;0.001). Participants attending ≥36 sessions had the lowest mortality rate (2.4 deaths/100 person-years; hazard ratio, 0.47; 95% confidence interval, 0.36-0.60; P&lt;0.001). Conclusions CR participation after PCI among veterans is low overall, with significant facility-level variation. CR participation is associated with lower mortality rates in veterans. Additional efforts are needed to promote CR participation after PCI among veterans

Transitions of Care Among Patients Undergoing Percutaneous Coronary Intervention for Stable Angina: Insights From the Veterans Affairs Clinical Assessment Reporting and Tracking Program

Background Effective transitions from the procedural to outpatient setting are essential to ensure high‐quality cardiovascular care across health care systems, particularly among patients undergoing invasive cardiac procedures. We evaluated the association of postprocedural follow‐up visits and antiplatelet prescriptions with clinical outcomes among patients undergoing percutaneous coronary intervention for stable angina at community or Veterans Affairs (VA) hospitals. Methods and Results Patients who actively received care within the VA Healthcare System and underwent percutaneous coronary intervention for stable angina at a community or VA hospital between October 1, 2015, and September 30, 2019, were identified. We compared mortality for patients receiving community or VA care, and among subgroups of community‐treated patients by the presence of a postprocedural follow‐up visit within 30 days or prescription for antiplatelet (P2Y12) medication within 120 days of the procedure. Among 12 837 patients who survived the first 30 days, 5133 were treated at community hospitals, and 7704 were treated in the VA. Prescriptions for antiplatelet therapy were less common for those treated in the community (85%) compared with the VA at 1 year (95%; hazard ratio [HR], 0.46; 95% CI, 0.44–47). Compared with VA‐treated patients, the hazards for death were similar for patients treated in the community with a follow‐up visit (HR, 1.17; 95% CI, 0.97–1.40) or with a fill for an antiplatelet therapy (HR, 1.08; 95% CI, 0.90–1.30). However, patients treated in the community without a follow‐up visit had an 86% (HR, 1.86; 95% CI, 1.40–2.48) increased hazard of death, and those without antiplatelet prescription fill had a 144% increased hazard of death (HR, 2.44; 95% CI, 1.85–3.21) compared with all VA‐treated patients. Conclusions Patients treated at community facilities have a decreased chance of receiving antiplatelet prescriptions after percutaneous coronary intervention with a concordant increased hazard of mortality, emphasizing the importance of transitions of care across health care systems when assessing cardiovascular quality