Predictive value of preschool surveillance in detecting learning difficulties

Objectives-The Hall report specified the early detection of mild to moderate learning difficulties as one aim of child health surveillance (CHS). This study examines the efficacy of preschool CHS in the early recognition of children with these disorders. Design-A retrospective case-control study. Subjects-All children (n=408) with mild to moderate learning difficulties born between 1 July 1983 and 30 June 1984 and resident in North and West Belfast. Controls-2406 birth records and 150 full child health records controlled for age and geographical area. Results-The prevalence of mild to moderate learning difficulties in North and West Belfast was 16%. Only 6% of children with learning difficulties were identified by the CHS in the preschool period, although the detection rate for children eventually requiring placement in schools for moderate learning difficulties was better. Coverage of the CHS ranged from 90% at the 2 year examination to 98% at the 4 year examination. Perinatal variables associated with learning difficulties after multiple logistic regression analysis were lower social class (odds ratio (OR) 3.9), prematurity <35 weeks (OR 3.0), male sex (OR 1.6), and birth to an unmarried mother (OR 0.6). Independent preschool variables identified by the CHS were speech delay (OR 3.3), poor parenting skills (OR 4.0), behaviour problems (OR 2.8), enuresis (OR 2.4), poor visual acuity (OR 1.8), and otitis media with effusion (OR 1.4). A statistical model for the early detection of learning difficulties using these risk factors is unable to predict accurately the children who will develop mild to moderate learning difficulties. Conclusions The CHS as it existed from 1983 to 1989 in North and West Belfast was poorly sensitive to the detection of mild to moderate learning difficulties despite excellent coverage. An accurate predictive model for learning difficulties could not be developed from the risk factors documented by the CHS.