Assessment of a neuro-developmental screening tool in children in Bhutan

Background: Developmental screening tools are designed to fit the cultural context in which they are utilized, yet often find a wider international audience. This study evaluates the efficacy of one such tool, the Parental Evaluation of Developmental Status: Developmental Milestones (PEDS:DM), developed in the United States and tested in the lower income Asian country of Bhutan. We aimed to test the PEDS:DM instrument to measure neurodevelopmental delay in children in Bhutan. Methods: In total, 96 community-dwelling Bhutanese children (3-7 years old) without diagnosed neurocognitive conditions were recruited from ambulatory clinics in urban Bhutan in 2016 as part of a larger study on retinal imaging and cognitive and growth parameters. Scoring was based on neurocognitive domains (gross and fine motor, receptive and expressive speech, self-help, social-emotional). Rates of failure (meant to indicate delay) within domains were calculated. Results: Modifications of some standard questions were deemed necessary by the study staff to suit the cultural context, such as replacing kickball with football in a question regarding games played with rules to maintain local relevance. In a modified PEDS:DM test with these improvised modifications, the mean percentage of age-appropriate domains failed was 58.8% and the mean percent delay was 12.3% (range 0-41.4%, available in n=83). The highest prevalence of failures was 59.4% for receptive language and 76.3% for expressive language, much higher than the lowest rate of failure seen in self-help (5.4%).  Conclusions: The PEDS:DM requires further modifications and validation studies before it can be reliably implemented to assess developmental delay in children in Bhutan. In this pilot study, the rate of delay as reported by the PEDS:DM would be scored as markedly elevated, especially when compared to available epidemiologic studies in the region.