The Effect of Hospital Isolation Precautions on Patient Outcomes and Cost of Care: A Multi-Site, Retrospective, Propensity Score-Matched Cohort Study

BACKGROUND: Isolation precautions have negative effects on patient safety, psychological well-being, and healthcare worker contact. However, it is not known whether isolation precautions affect certain hospital-related outcomes. OBJECTIVE: To examine the effect of isolation precautions on hospital-related outcomes and cost of care. DESIGN: Retrospective, propensity-score matched cohort study of inpatients admitted to general internal medicine (GIM) services at three academic hospitals in Toronto, Ontario, Canada between January 2010 and December 2012. PARTICIPANTS: Adult (≥18 years of age) patients on isolation precautions for respiratory illnesses and methicillin-resistant Staphylococcus aureus (MRSA) were matched to controls based on propensity scores derived from nine covariates: age, sex, Resource Intensity Weight, number of hospital readmissions within 90 days, total length of stay for hospital admissions within 90 days, site of admission, month of isolation, year of isolation, and Case Mix Group. MAIN MEASURES: Thirty-day readmission rates and emergency department visits, hospital length of stay, expected length of stay, adverse events, in-hospital mortality, patient complaints, and cost of care in Canadian doll ars (CAD). KEY RESULTS: A total of 17,649 non-isolated patients were admitted to the participating hospitals during the study period. We identified 1506 patients isolated for respiratory illnesses and 745 patients isolated for MRSA. Compared to non-isolated individuals, those on isolation precautions for respiratory illnesses stayed 17 % longer (95 % CI: 9 %, 25 %), stayed 9 % longer than expected (95 % CI: 3 %, 15 %), and had 23 % higher cost of care (95 % CI: 14 %, 32 %). Patients isolated for MRSA had similar outcomes, but they also had a 4.4 % higher (95 % CI: 1.4 %, 7.3 %) rate of readmission to hospital within 30 days. CONCLUSIONS: Isolation precautions are associated with adverse effects which may result in poorer hospital outcomes. Balancing the benefits for the many with the harms to the few will be a future challenge.