Poor data produce poor models: children with developmental disabilities deserve better – Authors' reply
Authors: Bolajoko O Olusanya, Adrian C Davis, Nicholas J Kassebaum
Journal: The Lancet Global Health (2019)

In commenting on our study,1Global Research on Developmental Disabilities CollaboratorsDevelopmental disabilities among children younger than 5 years in 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Glob Health. 2018; 6: e1100-e1121Summary Full Text Full Text PDF PubMed Scopus (263) Google Scholar Diane Damiano and Hans Forssberg aptly acknowledge the lifelong disabilities faced by many beneficiaries of under-5-survival programmes and the need for baseline data to monitor interventions under the Sustainable Development Goal (SDG) era. Our Global Burden of Disease (GBD) study1Global Research on Developmental Disabilities CollaboratorsDevelopmental disabilities among children younger than 5 years in 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Glob Health. 2018; 6: e1100-e1121Summary Full Text Full Text PDF PubMed Scopus (263) Google Scholar aimed to provide, for the first time ever, essential baseline data for six prominent developmental disabilities across 195 countries from 1990 to 2016, bridging a critical gap in the global developmental epidemiology. Generally, the process for estimating the prevalence of impairments entailed the use of inputs derived from rigorous systematic analyses of several data sources including population-based surveys and hospital records for countries with adequate data. These estimates were then extrapolated for countries with sparse, poor, or no primary data based on established guidelines,2Stevens GA Alkema L Black RE et al.GATHER Working GroupGuidelines for Accurate and Transparent Health Estimates Reporting: the GATHER statement.PLoS Med. 2016; 13: e1002056Crossref PubMed Scopus (165) Google Scholar as elaborated in the appendix of the paper.1Global Research on Developmental Disabilities CollaboratorsDevelopmental disabilities among children younger than 5 years in 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Glob Health. 2018; 6: e1100-e1121Summary Full Text Full Text PDF PubMed Scopus (263) Google Scholar GBD estimates for developmental disabilities, as with most other conditions for which limited data exist, are unlikely to precisely match findings solely from parental surveys for conditions such as attention deficit hyperactivity disorder and autism spectrum disorder that are more reliably diagnosed in older children. The lack of a separate estimate for cerebral palsy was duly highlighted in our paper1Global Research on Developmental Disabilities CollaboratorsDevelopmental disabilities among children younger than 5 years in 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Glob Health. 2018; 6: e1100-e1121Summary Full Text Full Text PDF PubMed Scopus (263) Google Scholar and is currently being examined by the GBD team. However, generating estimates for every known developmental disability for all countries since 1990 is an ambitious enterprise that can only be accomplished with substantial additional investment. The GBD study is committed to continuous improvement in all future estimates. But optimising available data in the interim to draw global attention to the persisting neglect and disenfranchisement of these children in various global initiatives for early childhood development is equally important.3Grantham-McGregor S Cheung YB Cueto S Glewwe P Richter L Strupp B International Child Development Steering GroupDevelopmental potential in the first 5 years for children in developing countries.Lancet. 2007; 369: 60-70Summary Full Text Full Text PDF PubMed Scopus (1953) Google Scholar, 4Black MM Walker SP Fernald LCH et al.Lancet Early Childhood Development Series Steering CommitteeEarly childhood development coming of age: science through the life course.Lancet. 2017; 389: 77-90Summary Full Text Full Text PDF PubMed Scopus (1101) Google Scholar Measuring disability is a complex endeavour. Reconciling differences between estimates or approaches across studies should not in any way distract from the moral dilemma of the unintended but inevitable consequences of the exclusive child-survival agenda, particularly in low-income and middle-income countries during the MDG era. We believe that waiting until an idealised "true" global burden is determined is not in the best interest of the affected children, whose plight Damiano and Forssberg rightly champion.5Damiano D Forssberg H We are the world: meeting the global challenge of childhood disability.Dev Med Child Neurol. 2016; 58: 649Crossref PubMed Scopus (6) Google Scholar Our study1Global Research on Developmental Disabilities CollaboratorsDevelopmental disabilities among children younger than 5 years in 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Glob Health. 2018; 6: e1100-e1121Summary Full Text Full Text PDF PubMed Scopus (263) Google Scholar is a wakeup call for better investment in both disability-specific statistics and the provision of family-oriented intervention services in early childhood globally. These are the urgent next steps. We declare no competing interests. Poor data produce poor models: children with developmental disabilities deserve betterAlthough we concur with the crucial need for baseline data for the global prevalence of developmental disabilities, we believe it is imperative that these data are accurate. The majority of children with disabilities live in low-income and middle-income countries (LMICs), but data for many regions are unavailable or inaccurate and no amount of sophisticated modelling can compensate for poor primary data sources. Therefore, we contend that the calculation of the Global Burden of Disease (GBD) for developmental disabilities (October, 2018)1 does not reflect the true global burden or its distribution. Full-Text PDF Open AccessDevelopmental disabilities among children younger than 5 years in 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016The global burden of developmental disabilities has not significantly improved since 1990, suggesting inadequate global attention on the developmental potential of children who survived childhood as a result of child survival programmes, particularly in sub-Saharan Africa and south Asia. The SDGs provide a framework for policy and action to address the needs of children with or at risk of developmental disabilities, particularly in resource-poor countries. Full-Text PDF Open Access