| Variable | Inclusion | Exclusion |
|---|---|---|
| Population | Children aged 1-4 yr who were not at high risk of developmental delay or suspected of having developmental delay | Children born preterm (gestational age < 37 completed wk at birth) or with low birth weight (< 2500 g); children with other known disorders that may be associated with or affect development |
| Interventions | Screening with any test, tool or questionnaire used to screen for developmental delay, including tools for specific domains, tools for general developmental delay and tools for autistic disorder and autism spectrum disorders | Denver Developmental Screening Test7 |
| Comparators | Effectiveness of screening: No screening comparison Harms of screening: No comparison group necessary | |
| Outcomes | Effectiveness of screening: Clinically relevant changes in referral rates for early intervention; time to referral to early intervention; cognitive function; academic performance; incidence of mental health conditions (diagnosis or symptoms) as defined by DSM-IV, including anxiety, depression, oppositional defiant disorder and obsessive-compulsive disorder; overall quality of life; survival; and functionality as an adult (including employment, criminality and independence) Harms of screening: Parental anxiety and stigma (labelling) | |
| Study designs | Effectiveness of screening: RCTs and controlled cohort studies Harms of screening: Any study design | |
| Settings | Primary care settings and public health clinics | School settings |
| Language | English or French |
Note: DSM-IV = Diagnostic and Statistical Manual of Mental Disorders, 4th edition,17 RCT = randomized controlled trial.