Filling gaps in all-cause and cause-specific mortality and disability data are essential for improving Global Burden of Disease estimation: descriptive study of missing data by country and region

Abstract

BackgroundThe Global Burden of Disease (GBD) Study provides detailed information about leading causes of premature mortality and disability to help policy makers assess health in their countries. GBD is also a massive and rigorous audit of country data collection systems. Globally, major challenges are posed by missing data on mortality and causes of death and disability, which creates substantial uncertainty in GBD estimates for numerous causes in many countries. This study aims to identify gaps in data sources that are important to fill to improve estimation of disease burden; gaps exist because data are either not collected or not being made available for research. MethodsThe data used in this study were derived from the GBD Study 2010 (GBD 2010), which compiled secondary data from literature reviews, internet searches, and correspondence and consultations with researchers, staff of national statistics institutes and ministries of health, and other experts. Frequently, literature reviews were not the primary source of data on causes of death and disability. FindingsIn general, data on mortality and causes of death were sparsest in countries with the fewest resources. Vital registration data with medical certification of causes of death were available from 130 countries. Regions with the greatest data gaps were sub-Saharan Africa and parts of Asia. Cause of death data from verbal autopsy were available only for 486 site-years from 66 countries, just 10% (47 site-years) of which were nationally representative. Gaps in sources of disability data were even more profound. Hospital discharge data coded in International Classification of Disease and Injuries (ICD) formats 9 and 10 were available for just 43 countries, and outpatient data were only available for the USA and Canada. InterpretationThe GBD 2010 is a powerful starting point for evidence-based policy making. However, the accuracy of future GBD updates will be enhanced by improvements and expansion in data collection, which will strengthen future decision making and will be essential for monitoring progress toward the Millennium Development Goals and any health-related post-2015 goals. Gaps in mortality and cause of death data could be remedied through increased investment in vital registration and verbal autopsy data collection, particularly in low-resource settings. Training physicians in ICD coding and medical certification is crucial for strengthening the quality of vital registration data. Our findings about disability data scarcity highlight the importance of addressing these gaps, particularly in countries where GBD 2010 has documented the fastest epidemiological transitions. FundingBill & Melinda Gates Foundation.