What contributes to delays? The primary care determinants of immunisation timeliness in New Zealand

Abstract

Introduction: Delay in receipt of the first vaccine dose in the primary series is one of the strongest and most consistent predictors of subsequent incomplete immunisation. Aim: To describe the on-time immunisation delivery of New Zealand infant scheduled vaccines by primary care practices and identify characteristics of practices, health professionals and patients associated with delays in receipt of infant immunisations. Methods: Timeliness of immunisation delivery and factors associated with timely immunisation were examined in 124 randomly selected primary care practices in two large regions of New Zealand. Results: A multiple regression model of demographic, practice, nurse, doctor and caregiver association explained 68% of the variance in immunisation timeliness between practices. Timeliness was higher in practices without staff shortages (ß-coefficient -0.0770, p= 0.01), where nurses believed parental apathy (ß-coefficient 0.0819, p=0.008) or physicians believed parental access (ß-coefficient 0.109, p=0.002) was a barrier, and lower in practices with Maori governance (ß-coefficient -0.0868, p=0.05), higher social deprivation (ß-coefficient -0.0643, <0.001) and where caregivers received immunisation-discouraging information (ß-coefficient -0.0643, p=0.04). Discussion: Interventions supporting practice teams and providers in primary care settings could produce significant improvements in immunisation timeliness.