OPV. Children considered eligible for OPV3 immunization had not yet been immunized with OPV3 before the beginning of the study; had been immunized with OPV2 by 3 months before the end of the study period; and were at least 3.5 months old by 1 month before the end of the study period. Children considered eligible for OPV4 immunization had not been immunized with OPV4 by the beginning of the study; had been immunized with OPV3 before age 4 years; and were at least 4 years old by 1 month before the end of the study.
Results
A total of 977 charts were reviewed. At the LFHC, 637 charts were reviewed; at the BGFHC, 340 charts were reviewed. Among these 977 children, 448 had been assigned to the intervention group, and 529 had been assigned to the control group. The intervention group did not differ from the control group in mean age at the midpoint of the study (39.1 months vs 38.1 months, respectively; P = .33). The age distribution in each group is provided in Table 2. No statistically significant association was noted between assignment to group and FHC site. At the LFHC, 47% of children had been assigned to the intervention group, and at the BGFHC, 44% of children had been assigned to the intervention group (P = .35).
The intervention and control groups were compared with regard to the timeliness of receipt of DTP3, DTP4, DTP5, HEPB3, MMR1, OPV3, and OPV4 vaccinations as well as completeness of immunization for age. “Up to date for age” was defined as receipt of all immunizations as recommended by the 1995 Childhood Immunization Schedule for the child’s age at the end of the study period. Results of this comparison are shown in Table 3. Among the subgroup of children eligible to receive DTP4 vaccination during the study period (n = 224), 51% of the intervention group vs 36% of the control group received DTP4 vaccination on time (P = .03). For the subgroup of children eligible to receive MMR1 vaccination during the study period (n = 238), 42% of the intervention group compared with 26% of the control group received MMR1 on time (P = .01). For the subgroup of children eligible to receive OPV3 vaccination during the study period (n = 200), 70% of the intervention group compared with 56% of the control group received OPV3 vaccination on time (P = .04). For DTP3, DTP5, HEPB3, and OPV4 vaccination, no statistically significant difference was noted between intervention and control groups in the percent of children receiving vaccinations on time. Neither was there a statistically significant difference between the intervention and control groups for “up to date for age” (85% vs 80%; P = .09).
The total number of office visits during the study period did not differ between the 2 groups; both the intervention and control groups had a mean of 4 ± 0.1 visits during the study period. The groups also did not differ in the number appointments canceled or number of appointments not kept. A total of 54% of children received at least 1 immunization during the study period; there was no difference between the intervention and control groups (56% and 54%, respectively, P = .51).
Discussion
We found that a nurse-initiated prompt increased on-time vaccinations for DTP4, OPV3, and MMR1 by 14% to 16% by decreasing the number of missed opportunities for vaccination. Multiple studies show missed opportunities to vaccinate at acute care visits for mild illnesses.3,6,20-22 Reasons for such missed opportunities include practice policies against vaccination at acute care visits, time limitations of acute care visits, focus on the initial agenda of the visit, concern about parental expectations, or overly cautious interpretation of contraindications.23 Overcoming missed opportunities to vaccinate can involve a reminder prompt for the clinician as well as clinician education that vaccines may be given during mild acute illness and during most chronic illnesses. The Standards for Pediatric Immunization Practice urge that “providers utilize all clinical encounters to screen for needed vaccines and, when indicated, immunize children.”24
Several educational materials-including the Standards for Pediatric Immunization Practice, the Guide to Contraindications to Childhood Vaccinations, and the Teaching Immunization for Medical Education (TIME) project24-26-address missed opportunities. Gyorkos et al11 found that provider-oriented strategies, primarily chart reminders, increased pooled influenza vaccination rates by 18% (95% CI, 16-20) and pneumococcal vaccination rates by 7.5% (95% CI, 3-12). Other data show increases in pneumococcal vaccination rates of 10% and 41% and in influenza vaccine of 47%.14-16 In 1 private practice, a systematic health maintenance protocol resulted in 95% of patients being offered vaccination compared with 45% of controls.27 The Task Force on Community Preventive Services found that provider reminders and recall systems improved vaccination coverage and strongly recommends their use.17 Prompts have increased use of some other preventive services such as smoking cessation counseling as well as mammography and colorectal cancer screening.16,28-30