Hospital Staffing and Patient Outcomes After Private Equity Acquisition

Hospital Staffing and Patient Outcomes After Private Equity Acquisition
Authors: Kannan S, Bruch JD, Zubizarreta JR, Stevens J, Song Z
Journal: Annals of Internal Medicine, November 2025

Conclusions:

  • After private equity (PE) acquisition, hospitals cut ED and ICU staffing expenditures and FTEs; this was associated with higher ED mortality, more transfers from EDs/ICUs, and shorter ICU LOS.

  • Findings suggest reduced on-site capacity post-acquisition may shift acuity downstream (more transfers) and worsen ED outcomes for Medicare patients, while ICU mortality did not change.

EM practice takeaways:

  • Expect operational strain post-acquisition: anticipate leaner ED staffing and plan mitigation (boarding management, throughput, escalation pathways).

  • Watch quality signals: monitor ED mortality and transfer rates in dashboards; track case-mix and staffing changes to identify early harm.

Advocate for capacity safeguards: minimum staffing ratios, protected resuscitation coverage, and clear criteria for safe interfacility transfer.

Results:

  • Cohort/setting: 49 PE-acquired hospitals (1,007,529 ED visits; 121,080 ICU stays) vs 293 matched controls (6,179,854 ED; 760,377 ICU), 2009–2019.

  • Staffing & spend (relative to controls after acquisition):

    • ED salary expenditures: −18.2% (−$12.63 per inpatient bed day; 95% CI −$22.74 to −$2.52; p=0.015).

    • ICU salary expenditures: −15.9% (−$8.46 per inpatient bed day; 95% CI −$13.21 to −$3.72; p<0.001).

    • Hospital-wide FTEs: −11.6%; salary expenditures: −16.6%.

  • Patient outcomes (Medicare):

    • ED mortality: +7.0 deaths per 10,000 visits post-acquisition (baseline 52.4 → ~13.4% increase; p=0.009).

    • ICU mortality: no differential change.

    • Transfers to other acute-care hospitals: ED +4.2%, ICU +10.6%.

    • ICU length of stay: −0.2 days on average.

  • Sensitivity analyses: qualitatively similar.

Methods:

  • Matched difference-in-differences using 100% Medicare claims and Cost Report data (2009–2019).

  • Outcomes: ED/ICU salary spend, mortality, LOS, transfers; secondary: hospital-wide FTEs and salary.

  • Limitations: potential unmeasured confounding, generalizability to non-Medicare populations/other acquisitions.

Kannan, S., Bruch, J.D., Zubizarreta, J.R., Stevens, J. and Song, Z., 2025. Hospital staffing and patient outcomes after private equity acquisition. Annals of Internal Medicine, 178(11), pp.1529-1538.

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