Estimating the effect of the 2005 change in BCG policy in England: a retrospective cohort study, 2000 to 2015

A retrospective audit of neonatal BCG vaccination in Grampian, Scotland

Bacillus Calmette-Guerin (BCG) vaccine confers protection against tuberculosis (TB) and works most effectively when given to infants. Scotland runs a risk-based program in which BCG vaccine is offered to infants whose parent or grandparent was born in a high incidence country for TB. BCG vaccination records for all infants born in Grampian from 1st January 2019 to 31st December 2021 were reviewed from Nov 2022 to Feb 2023. Three electronic databases were examined, i.e. BadgerNet, Scottish Immunisation Recall System and TrakCare. Data were analyzed using Microsoft Excel 2013. Out of a total of 16,078 live births in the 3-year study period, 2060 met the criteria for offering BCG vaccination. The uptake level was 93% in 2019, 89% in 2020 (in the midst of the COVID-19 pandemic) and 93% in 2021. Audit results demonstrated higher uptake than the 85% key performance indicator target within the 2018 Scottish TB Framework and improvement in vaccination rates as compared to earlier rates of 86% in 2012 and 90% in 2013 in Grampian. Strengthening electronic systems and enhancing awareness regarding TB and the BCG vaccine can further progress BCG vaccination uptake.

Reassessing the evidence for universal school-age BCG vaccination in England and Wales: re-evaluating and updating a modelling study

OBJECTIVES

In 2005, England and Wales switched from universal BCG vaccination against tuberculosis (TB) disease for school-age children to targeted vaccination of neonates. We aimed to recreate and re-evaluate a previously published model, the results of which informed this policy change.

DESIGN

We recreated an approach for estimating the impact of ending the BCG schools scheme, correcting a methodological flaw in the model, updating the model with parameter uncertainty and improving parameter estimates where possible. We investigated scenarios for the assumed annual decrease in TB incidence rates considered by the UK's Joint Committee on Vaccination and Immunisation and explored alternative scenarios using notification data.

SETTING

England and Wales.

OUTCOME MEASURES

The number of vaccines needed to prevent a single notification and the average annual additional notifications caused by ending the policy change.

RESULTS

The previously published model was found to contain a methodological flaw and to be spuriously precise. It greatly underestimated the impact of ending school-age vaccination compared with our updated, corrected model. The updated model produced predictions with wide CIs when parameter uncertainty was included. Model estimates based on an assumption of an annual decrease in TB incidence rates of 1.9% were closest to those estimated using notification data. Using this assumption, we estimate that 1600 (2.5; 97.5% quantiles: 1300, 2000) vaccines would have been required to prevent a single notification in 2004.

CONCLUSIONS

The impact of ending the BCG schools scheme was found to be greater than previously thought when notification data were used. Our results highlight the importance of independent evaluations of modelling evidence, including uncertainty, and evaluating multiple scenarios when forecasting the impact of changes in vaccination policy.

Ensuring Prevention Science Research is Synthesis-Ready for Immediate and Lasting Scientific Impact

When seeking to inform and improve prevention efforts and policy, it is important to be able to robustly synthesize all available evidence. But evidence sources are often large and heterogeneous, so understanding what works, for whom, and in what contexts can only be achieved through a systematic and comprehensive synthesis of evidence. Many barriers impede comprehensive evidence synthesis, which leads to uncertainty about the generalizability of intervention effectiveness, including inaccurate titles/abstracts/keywords terminology (hampering literature search efforts), ambiguous reporting of study methods (resulting in inaccurate assessments of study rigor), and poorly reported participant characteristics, outcomes, and key variables (obstructing the calculation of an overall effect or the examination of effect modifiers). To address these issues and improve the reach of primary studies through their inclusion in evidence syntheses, we provide a set of practical guidelines to help prevention scientists prepare synthesis-ready research. We use a recent mindfulness trial as an empirical example to ground the discussion and demonstrate ways to ensure the following: (1) primary studies are discoverable; (2) the types of data needed for synthesis are present; and (3) these data are readily synthesizable. We highlight several tools and practices that can aid authors in these efforts, such as using a data-driven approach for crafting titles, abstracts, and keywords or by creating a repository for each project to host all study-related data files. We also provide step-by-step guidance and software suggestions for standardizing data design and public archiving to facilitate synthesis-ready research.