Influenza vaccinations of Washington state Medicare beneficiaries seen by physiatrists in the outpatient setting in 1994.

Objective: To compare influenza vaccination billing rates for patients seen by physiatrists with those of four other specialties: neurology, rheumatology, family practice, and internal medicine.
Design: Retrospective cohort analysis using Medicare billing data.
Patients: 234,164 Medicare outpatients seen in Washington state between September 1 and December 31, 1994.
Results: Based on Medicare's billing data, only 6 of 99 physiatrists ordered vaccinations, and they immunized only 159 (6%) of the patients seen. An additional 1,109 (42%) patients seen by physiatrists were vaccinated by other physicians. Physiatric patients were less likely to have been vaccinated than those seen by internists, family practitioners, or rheumatologists (p < .002), but equally likely as those seen by neurologists (p = .07). A significantly smaller percentage of physiatrists ordered vaccinations than all other specialties (p < .04). Utilizing pre-existing survey data, the misclassification rate (those immunized but not billed) was estimated at 22% of our original cohort. Thus, approximately 800 patients, one third of those seeing physiatrists, may not have been immunized. We estimated the increase in hospitalization costs to be $117 per nonvaccinated patient (total >$90,000).
Conclusions: Missed opportunities for vaccination by physiatrists appear to be more frequent than in other specialties and have potentially large health and economic costs.