To investigate the effect on immunization levels of retrospective written feedback to residents regarding missed immunization opportunities.
Randomized trial with control group.
Pediatric resident continuity clinic in an urban hospital-based primary care clinic.
Thirty-two postgraduate level 2 and postgraduate level 3 pediatric residents.
Monthly retrospective written feedback mailed to residents detailing their missed immunization opportunities and appointment failure rates over a 12-month period beginning in February 1997.
Main Outcome Measures
The immunization level of 2-year-old children in the resident clinic was the main outcome of interest. Secondary outcomes included missed immunization opportunity rates and appointment failure rates.
Postintervention immunization levels were 71.4% (95% confidence limits [CLs]: 63.2%, 78.7%) for patients from the intervention group and 68.5% (95% CLs: 60.8%, 75.4%) for patients from the control group. The immunization level for patients of both groups who had fewer than 2 visits during the second year of life was 47.2% (95% CLs: 38.2%, 56.3%). This compares with an immunization level of 78.1% (95% CLs: 66.0%, 87.5%) for patients from both groups who had 2 visits during the second year of life, and with an immunization level of 88.2% (95% CLs: 81.0%, 93.4%) for patients of both groups who had more than 2 visits during the second year of life (P<.001).
In this setting, written retrospective feedback to residents was an ineffective strategy for improving immunization levels. Adequate follow-up during the second year of life is critical in achieving high immunization levels.