121: High Adherence with RSV Immunoprophylaxis Dosing Schedule in a Centrally Managed Provincial RSV Program

Abstract

Passive immunization against RSV requires monthly doses to maintain adequate serologic levels to prevent RSV-related hospitalization. Up to five IM doses may be provided during the RSV season. Although patients enrolled into a RSV prophylaxis program are already pre-selected because of underlying risk factors, and self-selected by parental agreement to immunoprophylaxis, ensuring adherence to the monthly dosing schedule and the total number of doses remains a challenge. To review the adherence to dosing schedule and number of doses for patients enrolled in a provincial RSV Prophylaxis Program. The Manitoba RSV Prophylaxis Program (MB RSVP) coordinates RSV immunoprophylaxis for all patients in the province of Manitoba. This centralized program manages all aspects of RSV immunoprophylaxis including patient enrolment and medication ordering. One benefit of this centralized program is tracking of doses received and subsequent dose schedule for all enrolled patients. The MB RSVP provides phone calls reminding patients and health care providers (HCP) of upcoming palivizumab doses. Anonymized data for three seasons (2011–14) were analyzed. Adherence was evaluated by number of doses received during the season and by adherence to the dosing schedule. The optimum number of doses a patient should receive was calculated from the date of first dose given to the end of the RSV prophylaxis season. Compliance with dosing schedule is calculated based on the provincial standardized dosing interval of 28 days with exception of 35 days between the fourth and fifth doses. Over the three seasons, 857 paediatric patients received at least one dose of palivizumab. 74.8% of patients received the expected number of doses during the season and 24% received less than expected. Overall, 58.4% of all doses were provided exactly according to schedule. (either exactly at 28 days interval, or exactly at 35 days interval between 4th and 5th doses). 81.1% of doses were given within a ± 3 day window around the scheduled date, 93% within ± 7 day window. Only 13.5% of all doses were given ≥4 days after schedule. Factors impacting adherence included parent or HCP non-compliance, patient death, loss-to-follow-up, relocation outside of province, vacation/travel, repair of cardiac lesion, and withdrawal of consent. A centralized provincial RSV prophylaxis program with central tracking of dosing schedule and regular phone reminder to parents and heath care providers is highly successful in ensuring adherence to both dosing schedule and total number of doses.