Effectiveness and cost of immunization recall at school-based health centers

Effectiveness of recall for immunizations has not been examined in the setting of school-based health centers (SBHCs). We assessed (1) immunization rates achieved with recall among sixth-grade girls (demonstration study); (2) effectiveness of recall among sixth-grade boys (randomized controlled trial [RCT]); and (3) cost of conducting recall in SBHCs.

During October 2008 through March 2009, in 4 Denver public SBHCs, we conducted (1) a demonstration study among 265 girls needing ≥ 1 recommended adolescent vaccine and (2) an RCT among 264 boys needing vaccines, with half randomized to recall and half receiving usual care. Immunization rates for recommended adolescent vaccines were assessed 6 months after recall. First dose costs were assessed by direct observation and examining invoices.

At the end of the demonstration study, 77% of girls had received ≥ 1 vaccine and 45% had received all needed adolescent vaccines. Rates of receipt among those needing each of the vaccines were 68% (160/236) for tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine, 57% (142/248) for quadrivalent meningococcal conjugate vaccine, and 59% (149/253) for the first human papillomavirus vaccine. At the end of the RCT, 66% of recalled boys had received ≥ 1 vaccine and 59% had received all study vaccines, compared with 45% and 36%, respectively, of the control group (P < .001). Cost of conducting recall ranged from $1.12 to $6.87 per recalled child immunized.

SBHC-based recall was effective in improving immunization rates for all adolescent vaccines, with effects sizes exceeding those achieved with younger children in practice settings.