Variation in the use of observation status evaluation in Massachusetts acute care hospitals, 2003-2006

Background: Observation evaluation is an alternate pathway to inpatient admission following Emergency Department (ED) assessment.

Aims: We aimed to describe the variation in observation use and charges between acute care hospitals in Massachusetts from 2003 to 2006.

Methods: Retrospective pilot analysis of hospital administrative data. Patients discharged from a Massachusetts hospital between 2003 and 2006 after an observation visit or inpatient hospitalization for six emergency medical conditions, grouped by the Clinical Classification System (CCS), were included. Patients discharged with a primary obstetric condition were excluded. The primary outcome measure, "Observation Proportion" (pOBS), was the use of observation evaluation relative to inpatient evaluation (pOBS = n Observation/(n Observation + n Inpatient). We calculated pOBS, descriptive statistics of use and charges by the hospital for each condition.

Results: From 2003 to 2006 the number of observation visits in Massachusetts increased 3.9% [95% confidence interval (CI) 3.8% to 4.0%] from 128,825 to 133,859, while inpatient hospitalization increased 1.29% (95% CI 1.26% to 1.31%) from 832,415 to 843,617. Nonspecific chest pain (CCS 102) was the most frequently observed condition with 85,843 (16.3% of total) observation evaluations. Observation visits for nonspecific chest pain increased 43.5% from 2003 to 2006. Relative observation utilization (pOBS) for nonspecific chest pain ranged from 25% to 95% across hospitals. Wide variation in hospital use of observation and charges was seen for all six emergency medical conditions.

Conclusions: There was wide variation in use of observation across six common emergency conditions in Massachusetts in this pilot analysis. This variation may have a substantial impact on hospital resource utilization. Further investigation into the patient, provider and hospital-level characteristics that explain the variation in observation use could help improve hospital efficiency.