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.