Adverse inpatient outcomes during the transition to a new electronic health record system: observational study

Abstract

Objective: To assess the short term association of inpatient implementation of electronic health records (EHRs) with patient outcomes of mortality, readmissions, and adverse safety events.

Design: Observational study with difference-in-differences analysis.

Setting: Medicare, 2011-12.

Participants: Patients admitted to 17 study hospitals with a verifiable "go live" date for implementation of inpatient EHRs during 2011-12, and 399 control hospitals in the same hospital referral region.

Main outcome measures: All cause readmission within 30 days of discharge, all cause mortality within 30 days of admission, and adverse safety events as defined by the patient safety for selected indicators (PSI)-90 composite measure among Medicare beneficiaries admitted to one of these hospitals 90 days before and 90 days after implementation of the EHRs (n=28 235 and 26 453 admissions), compared with the control group of all contemporaneous admissions to hospitals in the same hospital referral region (n=284 632 and 276 513 admissions). Analyses were adjusted for beneficiaries' sociodemographic and clinical characteristics.

Results: Before and after implementation, characteristics of admissions were similar in both study and control hospitals. Among study hospitals, unadjusted 30 day mortality (6.74% to 7.15%, P=0.06) and adverse safety event rates (10.5 to 11.4 events per 1000 admissions, P=0.34) did not significantly change after implementation of EHRs. There was an unadjusted decrease in 30 day readmission rates, from 19.9% to 19.0% post-implementation (P=0.02). In difference-in-differences analysis, however, there was no significant change in any outcome between pre-implementation and post-implementation periods (all P≥0.13).

Conclusions: Despite concerns that implementation of EHRs might adversely impact patient care during the acute transition period, we found no overall negative association of such implementation on short term inpatient mortality, adverse safety events, or readmissions in the Medicare population across 17 US hospitals.

Fig 1 Unadjusted trends in patient outcome rates for 30 day mortality, 30 day readmission, and patient safety for selected indicators (PSI)-90 composite measure in 30 day intervals relative to implementation of electronic health records (EHRs) for each study hospital. 95% confidence intervals are shown, assuming normal distribution of rates given large sample size of admissions

Fig 2 Subgroup analyses for patient outcomes associated with admission to hospital during first 90 days of implementation of electronic health records (EHRs) versus prior 90 days. Analyses adjusted for age, sex, race, original reason for Medicare eligibility, major diagnostic category for admission, and length of stay (for patient safety for selected indicators (PSI)-90 outcome only). All analyses also use robust variance estimators to account for clustering of admissions within hospitals