Early connections: effectiveness of a pre-call intervention to improve immunisation coverage and timeliness

Abstract

INTRODUCTION: Children who have missed or delayed immunisations are at greater risk of vaccine-preventable diseases and getting their first scheduled dose on time strongly predicts subsequent complete immunisation. Developing a relationship with an infant’s parents and general practice staff soon after birth followed by a systematic approach can reduce the number of delayed first immunisations. AIM: To assess the effectiveness of a general practice–based pre-call intervention to improve immunisation timeliness. METHODS: Clustered controlled trial of general practices in a large urban district randomised to either delivery of pre-call intervention to all babies at aged four weeks or usual care. RESULTS: Immunisation timeliness for infants receiving the primary series of immunisations among their nominated Auckland general practices was higher than expected at 98% for the six week event. The intervention was statistically but not clinically significant. Coverage was significantly lower among infants with no nominated practice which reduced overall coverage rate for the district. DISCUSSION: Pre-call letters with telephone follow-up are simple interventions to introduce into the practice management system and can be easily implemented as usual standard of care. Early identification of newborn infants, primary care engagement and effective systems including tracking of infants not enrolled in general practices has the greatest potential to improve immunisation coverage rates even further. KEYWORDS: Randomized controlled trial; immunization; vaccination; general practice; intervention studies