BACKGROUND AND PURPOSE:

• Asch et al. (JAMA Internal Medicine, 2020) examined the change in COVID-19 hospital mortality rates over the first 6 months of the pandemic

METHODS:

• Cohort study (January 1, 2020 to June 30, 2020)
• Participants
  • Adults admitted to a US hospital with COVID-19
• Exposures
  • Hospital characteristics
    • Size | Number of ICU beds | Academic and profit status | Hospital setting and regional characteristics | COVID-19 case burden
• Primary outcome
  • Hospital’s risk-standardized event rate (RSER) of 30-day in-hospital mortality or referral to hospice, with adjustment for patient-level characteristics
  • The authors examined whether hospital characteristics were associated with RSERs or their change over time
  • Subset analysis of patients admitted to hospitals that treated ≥10 COVID-19 patients

RESULTS:

• 38,517 adults | 955 hospitals
  • Mean (SD) age 70.2 (15.5) years | 51.0% women
• Mean (SD) hospital-level RSER: 11.8% (2.5%)
  • Mean RSER in the worst-performing quintile of hospitals: 15.65%
  • Mean RSER in the best-performing quintile of hospitals: 9.06%
  • Absolute difference 6.59 percentage points (95% CI, 6.38% to 6.80%); P < 0.001
• Mean RSERs improved in all but 1 of the 398 hospitals that treated ≥10 COVID-19 patients
  • 94% (376 hospitals) improved by at least 25%
  • The overall mean (SD) RSER declined from 16.6% (4.0%) to 9.3% (2.1%)
  • Absolute differences in rates of mortality or referral to hospice between the worst- and best-performing quintiles of hospitals decreased over time
    • January 1 to April 30: 10.54 percentage points (95% CI, 10.03% to 11.05%); P < 0.001
    • May 1 to June 30: 5.59 percentage points (95% CI, 5.33% to 5.86%); P <0 .001
• Higher county-level COVID-19 case rates were associated with worse RSERs
  • Case rate declines were associated with improvement in RSERs

CONCLUSION:

• Hospital mortality rates due to COVID-19 declined “sharply” during the first six months of the pandemic
  • 94% of hospitals had a relative mortality reduction of >25%
  • Accrued clinical experience and use of medications (e.g., dexamethasone) could account for some of this improvement
• Mortality rate declines were associated with decreased COVID-19 case loads at the county level
• The authors state

This study revealed that outcomes for patients with COVID-19 rely not only on individual-level risk factors, but also on the hospital where care is received

The association between high community COVID-19 case loads and both worse RSERs and greater improvement in RSERs suggests hospitals do worse when they are burdened with cases and is consistent with imperatives to flatten the curve

Learn More – Primary Sources:

Variation in US Hospital Mortality Rates for Patients Admitted With COVID-19 During the First 6 Months of the Pandemic

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