Factors Associated with Missed Opportunities for Simultaneous Administration of the Fourth Dose of Pneumococcal Conjugate Vaccine for Children in the United States.

: An important standard for childhood immunization is simultaneous administration of all age-eligible doses of vaccines. Vaccination coverage for ≥4 doses of pneumococcal conjugate vaccine (PCV) for children 19-35 months has not achieved the Healthy People 2020 objective of 90% in the United States, and the fourth dose of PCV is commonly missed in the series. Research has not been conducted on the factors associated with missed opportunities for simultaneous administration of the fourth dose of PCV. A missed opportunity for simultaneous administration of the fourth dose of PCV is characterized as failing to administer an age-appropriate fourth dose of PCV to children when in the same provider visit the children did receive other age-eligible vaccines. During the period of 2008-2015, 4.5% to 7.8% of young children in the United States experienced missed opportunities for simultaneous administration of the fourth dose of PCV; across all selected factors, the proportion of missed opportunities varied from 4.1% to 11.3%. The timeliness of the first through the third doses of PCV vaccination, and age group of mothers were factors significantly related to missed opportunities for simultaneous administration of the fourth dose of PCV; the adjusted prevalence ratios ranged from 1.2 to 2.0. Missed opportunities could be reduced by provider implementation of systems to ensure that all recommended vaccines are offered at each visit. Systems tools providers could use to reduce missed opportunities include patient recall, provider reminders, standing orders, extended office hours, and use of immunization information systems (IIS).