Reducing missed opportunities for immunizations. Easier said than done.

BACKGROUND: Missed opportunities for immunizations are associated with underimmunization of preschool-age children. Practice policies limiting immunizations to scheduled preventive visits and guidelines requiring legal guardians to sign consent forms for vaccinations are 2 factors contributing to missed opportunities. However, methods to change these policies have not been sufficiently evaluated.

OBJECTIVE: To measure the effectiveness of (1) changing practice policies to incorporate the new national standard to screen and vaccinate eligible children at all office visits and (2) eliminating legal guardian signature requirements.

DESIGN: A randomized controlled trial of 2 interventions: (1) changing practice policy and routine to have office nurses screen for immunization status at all visits, attach immunization reminder cards to medical charts for eligible patients, and have providers vaccinate eligible children ("no missed opportunities" intervention) and (2) changing practice guidelines to allow vaccinations without a legal guardian's signature. The first intervention was performed at both sites; the second only at the neighborhood health center (NHC).

SETTING: A Pediatric Continuity Clinic in a teaching hospital (hereafter referred to as Clinic), and an NHC.

PATIENTS: Enrolled in the trial were 1005 Clinic patients and 983 NHC patients, 0 to 2 years of age.

MAIN OUTCOME MEASURES: Missed opportunity rates, immunization rates, and rates of preventive services.

RESULTS: Eliminating the requirement for a legal guardian's signature had no effect on any of the outcome measures. The no missed opportunities intervention was partially effective. Study patients had slightly fewer missed opportunities than control patients at each site: (0.60 vs 0.90 per patient per year at the Clinic, P = .01; 1.1 vs 1.3 per patient per year at the NHC, P = .02). For study group patients, immunization reminder cards were attached to medical charts in only one third of vaccine-eligible visits; when attached, they markedly increased vaccination by providers (odds ratio for vaccinating at a visit was 6.9 comparing visits when immunization reminder cards were attached vs not attached). However, at the end of the study, immunization rates were similar for study and control groups at each site. The number of undervaccinated days was slightly lower for the no missed opportunities study group at the Clinic than for the control group (56 days vs 77 days, P < .001), but they were similar for both groups at the NHC. There were no differences in rates of preventive visits or screening tests between study and control groups.

CONCLUSIONS: The interventions evaluated to reduce missed opportunities did not increase immunization rates. The key problem was failure to screen for immunization status at all visits. More effective interventions will be needed to overcome barriers within busy primary care practices to substantially reduce missed opportunities.