Case Sampling vs Universal Review for Evaluating Hospital Postoperative Mortality in US Surgical Quality Improvement Programs

Care Fragmentation, Social Determinants of Health, and Postoperative Mortality in Older Veterans

INTRODUCTION

Veterans Affairs Surgical Quality Improvement Program (VASQIP) benchmarking algorithms helped the Veterans Health Administration (VHA) reduce postoperative mortality. Despite calls to consider social risk factors, these algorithms do not adjust for social determinants of health (SDoH) or account for services fragmented between the VHA and the private sector. This investigation examines how the addition of SDoH change model performance and quantifies associations between SDoH and 30-d postoperative mortality.

METHODS

VASQIP (2013-2019) cohort study in patients ≥65 y old with 2-30-d inpatient stays. VASQIP was linked to other VHA and Medicare/Medicaid data. 30-d postoperative mortality was examined using multivariable logistic regression models, adjusting first for clinical variables, then adding SDoH.

RESULTS

In adjusted analyses of 93,644 inpatient cases (97.7% male, 79.7% non-Hispanic White), higher proportions of non-veterans affairs care (adjusted odds ratio [aOR] = 1.02, 95% CI = 1.01-1.04) and living in highly deprived areas (aOR = 1.15, 95% CI = 1.02-1.29) were associated with increased postoperative mortality. Black race (aOR = 0.77, CI = 0.68-0.88) and rurality (aOR = 0.87, CI = 0.79-0.96) were associated with lower postoperative mortality. Adding SDoH to models with only clinical variables did not improve discrimination (c = 0.836 versus c = 0.835).

CONCLUSIONS

Postoperative mortality is worse among Veterans receiving more health care outside the VA and living in highly deprived neighborhoods. However, adjusting for SDoH is unlikely to improve existing mortality-benchmarking models. Reduction efforts for postoperative mortality could focus on alleviating care fragmentation and designing care pathways that consider area deprivation. The adjusted survival advantage for rural and Black Veterans may be of interest to private sector hospitals as they attempt to alleviate enduring health-care disparities.

Social Determinants of Health and Surgical Desirability of Outcome Ranking in Older Veterans

Importance

Evaluating how social determinants of health (SDOH) influence veteran outcomes is crucial, particularly for quality improvement.

Objective

To measure associations between SDOH, care fragmentation, and surgical outcomes using a Desirability of Outcome Ranking (DOOR).

Design, Setting, And Participants

This was a cohort study of US veterans using data from the Veterans Affairs (VA) Surgical Quality Improvement Program (VASQIP; 2013-2019) limited to patients aged 65 years or older with inpatient stays between 2 and 30 days, merged with multiple data sources, including Medicare. Race and ethnicity data were retrieved from VASQIP, Medicare and Medicaid beneficiary summary files, the Veterans Health Administration Corporate Data Warehouse, and the United States Veterans Eligibility Trends and Statistics file. Data were analyzed between September 2023 and February 2024.

Exposure

Living in a highly deprived neighborhood (Area Deprivation Index >85), race and ethnicity used as a social construct, rurality, and care fragmentation (percentage of non-VA care days).

Main Outcomes and Measures

DOOR is a composite, patient-centered ranking of 26 outcomes ranging from no complication (1, best) to 90-day mortality or near-death complications (6, worst). A series of proportional odds regressions was used to assess the impact of SDOH and care fragmentation adjusted for clinical risk factors, including presentation acuity (presenting with preoperative acute serious conditions and urgent or emergent surgical procedures).

Results

The cohort had 93 644 patients (mean [SD] age, 72.3 [6.2] years; 91 443 [97.6%] male; 74 624 [79.7%] White). Veterans who identified as Black (adjusted odds ratio [aOR], 1.06; 95% CI, 1.02-1.10; P = .048) vs White and veterans with higher care fragmentation (per 20% increase in VA care days relative to all care days: aOR, 1.01; 95% CI, 1.01-1.02; P < .001) were associated with worse (higher) DOOR scores until adjusting for presentation acuity. Living in rural geographic areas was associated with better DOOR scores than living in urban areas (aOR, 0.93; 95% CI, 0.91-0.96; P < .001), and rurality was associated with lower presentation acuity (preoperative acute serious conditions: aOR, 0.88; 95% CI, 0.81-0.95; P = .001). Presentation acuity was higher in veterans identifying as Black, living in deprived neighborhoods, and with increased care fragmentation.

Conclusions and Relevance

Veterans identifying as Black and veterans with greater proportions of non-VA care had worse surgical outcomes. VA programs should direct resources to reduce presentation acuity among Black veterans, incentivize veterans to receive care within the VA where possible, and better coordinate veterans' treatment and records between care sources.

Case Sampling for Evaluating Hospital Postoperative Morbidity in US Surgical Quality Improvement Programs

Importance

US surgical quality improvement (QI) programs use data from a systematic sample of surgical cases, rather than universal review of all cases, to assess and compare risk-adjusted hospital postoperative complication rates. Given decreasing postoperative complication rates over time and the types of cases eligible for abstraction, it is unclear whether case sampling is robust for identifying hospitals with higher than expected complications.

Objective

To compare the assessment of hospital 30-day complication rates derived from sampling strategy used by some US surgical QI programs relative to universal review of all cases.

Design, Setting, and Participants

This US hospital-level analysis took place from January 1, 2016, through September 30, 2020. Data analysis was performed from July 1, 2022, through December 21, 2022. Quarterly, risk-adjusted, 30-day complication observed to expected (O-E) ratios were calculated for each hospital using the sample (n = 502 730) and universal review (n = 1 725 364). Outlier hospitals (ie, those with higher than expected mortality) were identified using an O-E ratio significantly greater than 1.0. Patients 18 years and older who underwent a noncardiac operation at US Department of Veterans Affairs (VA) hospitals with a record in the VA Surgical Quality Improvement Program (systematic sample) and the VA Corporate Data Warehouse surgical domain (100% of surgical cases) were included.

Main Outcome Measure

Thirty-day complications.

Results

Most patients in both the representative sample and the universal sample were men (90.2% vs 91.2%) and White (74.7% vs 74.5%). Overall, 30-day complication rates were 7.6% and 5.3% for the sample and universal review cohorts, respectively (P < .001). Over 2145 hospital quarters of data, hospitals were identified as an outlier in 15.0% of quarters using the sample and 18.2% with universal review. Average hospital quarterly complication rates were 4.7%, 7.2%, and 7.4% for outliers identified using the sample only, universal review only, and concurrent identification in both data sources, respectively. For nonsampled cases, average hospital quarterly complication rates were 7.0% at outliers and 4.4% at nonoutliers. Among outlier hospital quarters in the sample, 54.2% were concurrently identified with universal review. For those identified with universal review, 44.6% were concurrently identified using the sample.

Conclusion

In this observational study, case sampling identified less than half of hospitals with excess risk-adjusted postoperative complication rates. Future work is needed to ascertain how to best use currently collected data and whether alternative data collection strategies may be needed to better inform local QI efforts.