Supplementary Material for: Hospital and Community Validation of a Screening Instrument for Detection of Neurodisability in Indian Children Aged 6 Months to 2 Years

<i>Objective:</i> To develop and validate a screening instrument for neurological disorders in children aged 6 months to 2 years in the community. <i>Methods:</i> A comprehensive parent-administered instrument was developed to screen for hearing, vision, seizures, motor deficits and development in Indian children aged 6–24 months. This was tested for reliability and validated in the hospital setting by comparing with pre-decided gold standards. It was then used in a community survey in a two-phase design in which all screen positives and a random sample of screen negatives were validated. <i>Result:</i> The screening instrument had overall sensitivity, specificity and positive predictive values of 95.8, 68.1 and 76.1%, respectively, in the hospital setting. In the field setting, these figures changed to 95.4, 51.8 and 20.6%, respectively. The reasons for this are discussed. <i>Conclusion:</i> Community surveys must use a two-phase design to get the true prevalence. A falsely high prevalence will be computed if only a single-phase design or hospital validation is used.