Prevalence of developmental delay among children: A national study based on administrative database of the single‐payer National Health Insurance System in Taiwan

Abstract Background Developmental delay (DD) indicates a failure to meet the developmental milestones of most children of the same age. Studies based solely on the ICD coding manual may underestimate the prevalence of DD. Real‐world use of rehabilitation data may be useful in the identification of more DD children previously undiagnosed with DD. Aim The aim of this study is to estimate the prevalence of DD among children aged 0–6 by age and sex in Taiwan based on modified ICD codes. Methods A list of ICD codes specific to DD (including delays and disabilities requiring early intervention) was generated from the existing ICD codebook and modified based on National Health Insurance (NHI) claims data pertaining to developmental rehabilitation of children aged 0–6. The validity of the codes was subsequently assessed by DD experts in various fields using the consensus development technique. The resulting list was used to estimate the prevalence of DD among children in Taiwan from 2000 to 2015 based on analysis of longitudinal NHI data. Result Between 2000 and 2015, the prevalence of DD among children aged 0 to 6 years increased from 2.0% to 5.7%, and the sex ratio was 181–197 males per 100 females. The prevalence estimate obtained in this study (5.6%) was 229% higher than existing government statistics (1.6%) published in 2014. Conclusions The codes developed using claims data in this study can be used to estimate the prevalence of DD among children and evaluate the effectiveness of intervention programmes. Consistent increases in the prevalence of DD indicate that efforts to promote early intervention have been effective. Nonetheless, the low prevalence rate among 0–2 years children with developmental delay and low prevalence rate of female CWDD means that the policy should notice the lack of access to healthcare services for infants and female children and produce a more equitable or fair distribution of healthcare resources.