Meta-analyzing surveillance studies to estimate the burden of vaccine-preventable infectious disease

Article type
Authors
Thumburu KK1, Jaiswal N1, Agarwal A1, Jindal I1, Singh M2, Bharti B2, Mathew JL2
1ICMR Advanced Centre for Evidenced Based Child Health, Advanced Pediatric Centre, PGIMER,Chandigarh, India
2Department of Pediatrics, Advanced Pediatric Centre, PGIMER, Chandigarh, India
Abstract
Background:
The policy-makers and epidemiologists usually estimate the infectious disease burdens due to a specific organism by using statistical remodelling or extrapolation of the data from different settings. Though proven for usefulness, these are complex and difficult to replicate. For this reason there is a need to create strategies to make it simple and easy to replicate.

Objectives:
To describe a simpler method of using the data available from surveillance of infectious diseases.

Methods:
A systematic review and meta-analysis was carried out on surveillance studies to discuss the impact of the clinical evidence available. The proportions were calculated from individual studies: a) proportion of invasive pneumococcal diseases (IPD) from suspected children (< 12 years), b) proportion of invasive pneumococcal disease from confirmed invasive bacterial disease, and c) meta-regression analysis was carried to find out the effect of confounding factors using Stata/MP-12 2 core. Pooling the proportions separately obtained provided an estimate size to inform about the proportion of patients affected with IPD.

Results:
The pooled proportions from 22 included studies show an effect size 3.57 (95% CI 2.66 to 4.49), when the proportions of IPD from suspected patients were pooled. An effect size of 23.74 (95% CI 17.47 to 30.01) was obtained when the proportion of IPD among confirmed bacterial diseases were pooled. The results thus obtained show that a high proportion of bacterial diseases are pneumococcal diseases. The meta-regression showed a trend towards significance when different diagnostic methods were used (OR 1.09, 95% CI 0.99 to 1.21).

Conclusions:
The meta-analysis of surveillance studies could be a useful method for policy-makers in cases where data from clinical trials are not available.

Acknowledgement: Indian Council of Medical Research, New Delhi, India