Observation unit impact on ED admission for asthma.

The hypothesis that the use of an observation unit (OU) in the emergency department (ED) results in monetary savings by lowering the hospital admission rate for asthma was studied in a retrospective comparative cohort at an urban university county hospital. All acute asthmatic patients seen in the ED during a 22-month period were included. Preobservation patients were seen before the OU opened (n = 834); postobservation patients were treated afterward (n = 390). Postobservation patients in the experimental group meeting standard criteria were admitted to the OU. Fisher's exact test and the binomial distribution were used to analyze proportions of patients admitted. Median charges were compared with the Mann-Whitney test. The difference between groups in hospital admission rate was only 2.7% and was not significant (P = .25). However, 5.3% less patients were admitted directly to the hospital (P = .01), and 6.7% less patients were discharged directly from the ED (P = .005). The OU produced no demonstrable cost savings. The use of an OU for asthmatic patients results in lower initial discharge rates from the ED and does not reduce eventual hospital admission appreciably.