School-based immunization policy compliance in preschools of Karachi, Pakistan: An explanatory sequential mixed-method study

Background Healthcare providers in schools play a crucial role in ensuring student wellness and maintaining effective communication with parents regarding their children's health. In 2022, the Government of Pakistan introduced the national school-based immunization policy, but the factors affecting policy compliance and the role of preschool healthcare providers in it are still unexplored. Thus, the study aims to assess the implementation of the school-based immunization policy in preschools, considering the presence of preschool healthcare providers and other factors that may influence policy compliance. Methods The study used an explanatory sequential mixed-method design. It included all preschools in Karachi that met the defined eligibility criteria. Preschools were surveyed using systematic sampling, with data obtained from preschool administrators through structured questionnaires. Subsequently, administrators were approached for in-depth interviews. Descriptive statistics and multiple linear regression along with thematic framework analysis were used to analyze quantitative and qualitative data respectively. The findings from both datasets were triangulated. Results A total of 223 preschools were surveyed and 9 in-depth interviews were conducted with preschool administrators. The survey revealed that 97 (43.5%) of the preschools relied on manual vaccination record-keeping methods, consistent with 3 out of 9 preschools found in in-depth interviews. 179 (80.3%) administrators reported that parents cooperate with school management in vaccinating their child(ren) at preschool, consistent with qualitative findings. 200 (89.7%) administrators were unaware of EPI, consistent with 7 out of 9 in-depth interviews. A significant mean difference (3.91; 95% CI 2.15–5.66) in compliance scores was observed between preschools with and without healthcare providers. The final model included the vaccination records storage method (β 5.05; 95% CI 3.47–6.63), parents’ cooperation (β 1.32; 95% CI 0.16–2.49), and a statistically significant interaction between the presence of preschool healthcare providers and awareness of EPI among preschool administrators at a p-value < 0.1. Conclusion The healthcare providers in preschools facilitate school-based immunization policy compliance, while the absence of staff training for vaccination record-keeping and supporting vaccination drives impedes compliance. Understanding and addressing these factors can optimize policy compliance.