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

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

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

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.

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.

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.