Introduction 6 17 31 33 4 12 13 16 19 24 26 15 22 34 2 9 18 20 27 Mild developmental disturbances usually pose no problem for the child until greater demands have to be met at school or when more detailed evaluations are made. In addition, the cumulative effect of the failure to acquire basic skills and the resulting declining motivation may play an important role. In The Netherlands, schools are focused strongly on the early detection of children who need special assistance. After 1 year of education, at the age of 5, teachers usually have a good impression of both the cognitive and language development of their children and of their motor skills and behaviour. Standardized tests are used to assess children who are not doing well at school, and the data from these tests are used to underpin the need for special help for these children. Additionally, many neonatal intensive care units (NICUs) have follow-up programmes for premature children in which standardized assessments of different domains enable an overall evaluation of the child's development. 35 Methods Study population The study population consisted of 768 infants of less than 32 weeks of gestation and/or weighing less than 1500 g who were born between October 1992 and December 1994 and treated in three Dutch neonatal intensive care units: the Radboud University Nijmegen Medical Centre, the Academic Medical Centre, Amsterdam, and the Máxima Medical Centre, Veldhoven. Mortality before the age of 5 years was 131 (17%). Forty-six children (6%) were excluded because they had participated in another study. Thirty-three children (4%) with severe or moderate cerebral palsy, blindness, mental retardation, chromosomal abnormalities, inborn errors of metabolism, personality developmental disorders and/or attendance at special schools or institutions were excluded. Sixty children (8%) of non-Dutch parents were excluded from the analyses since school problems could be caused by language and cultural problems. As a result, 498 children (65%) qualified for the study. School performance and socio-economic situation 5 Perinatal data 32 Assessment at the age of 5 years Clinical assessments were carried out on the health and neurological functioning of the children (not reported in this article) and four developmental domains: cognition, language, motor functioning and behaviour. A paediatrician, a child psychologist and a paediatric physical therapist assessed the children. Appointments were scheduled at random. 3 This test included logical reasoning, word knowledge, visual-motor integration and word fluency. It also included visual synthesis for children younger than 5.2 years and visual analysis and memory for children aged 5.2 years or older. The norm score (IQ score) of the test is 100 with a standard deviation (SD) of 15. All scores higher or equal to 85 are classified as normal, while scores below 1 or 2 SD’s are classified as mild or severe cognitive problems, respectively. 7 11 23 1 30 Statistical analysis In order to compare the results of the follow-up assessments and school outcomes, we cross-tabulated categorical data originating from the individual developmental test results of the children with school outcomes (normal or problematic). Normal follow-up outcomes were defined as four normal developmental scores or only one mild developmental problem score. Problematic follow-up outcomes were defined as two mild developmental problem scores, one severe developmental problem score or two or more severe developmental problem scores. F Results 1 14 Table 1 Eligible and assessed children   n Percentage n Percentage Cohort 1992–1994 768 100     Died 131 17     Excluded because of participation in an other study 46 6     Excluded because of severe handicap and/or in Special Schools 33 4     Children of non-Dutch parents 60 8   Eligible 498 65 498 100   Address unknown   25 5   Moved outside the country   5 1   Treated in another hospital   6 1   Impossibility to make a convenient appointment   29 6   Refusal by the parents   38 8   Assessment not fully performed   40 8 Assessed   355 71 n n n 2 2 p Table 2 Follow-up outcomes versus school outcomes School outcomes: n n n Follow-up outcomes: n    Four normal developmental scores 124 (56%) 26 (20%)     One mild developmental problem score 51 (23%) 27 (20%)    Subtotal 175 → 49%   53 → 15% n    Two mild developmental problem scores 8 (4%) 10 (7%)     One severe developmental problem score 36 (16%) 54 (41%)     Two or more severe developmental problem scores 3 (1%) 16 (12%)    Subtotal 47 → 13%   80 → 23% 3 4 F p df F p df Table 3 Means, standard deviations (SD) and one-way analyses of variance for normal and problematic school outcomes   Follow-up outcomes School outcomes Normal Problematic F Mean SD Mean SD Gestational age Normal 30.08 1.85 30.50 1.54 2.33 Problematic 30.69 2.01 29.90 2.30 3.82* Birth weight Normal 1286.24 319.20 1314.28 307.09 .32 Problematic 1225.09 306.43 1241.22 364.36 .06 NICU stay Normal 27.20 22.33 25.07 16.53 .42 Problematic 26.91 20.82 36.94 37.17 2.89 RAKIT IQ Normal 104.82 11.77 102.39 10.64 1.83 Problematic 95.17 12.19 86.74 12.92 13.19*** Movement ABC Normal 6.11 4.31 7.81 4.23 6.44* Problematic 15.30 7.71 18.38 9.10 3.80* Language score Normal 8.29 4.68 10.78 5.74 10.48*** Problematic 11.55 7.86 15.48 8.48 6.73* CBCL Total problem score Normal 47.22 8.83 48.06 8.25 .38 Problematic 55.32 10.70 55.05 12.06 .02 p p Table 4 Comparison of child's characteristics, perinatal data and parents’ education with normal and problematic school outcomes   Follow-up outcomes School outcomes 2 Normal Problematic Percentage Percentage Male Normal 42 57 4.10* Problematic 64 63 .01 Multiple birth Normal 35 44 1.43 Problematic 32 36 .20 SGA Normal 23 37 4.29* Problematic 4 25 3.25 Apgar score Normal 15 7 2.27 Problematic 47 31 8.73* ICH Normal 5 0 2.55 Problematic 4 6 .21 PVL Normal 2 2 .04 Problematic 2 6 1.09 BPD Normal 4 6 .24 Problematic 0 16 8.40** Neonatal steroids Normal 1 0 .31 Problematic 0 11 5.62* Parents education-high Normal 42 36 .73 Problematic 39 26 2.15 Parents education-middle Normal 47 51 .11 Problematic 38 48 .90 Parents education-low Normal 11 13 .18 Problematic 23 26 .10 p p Discussion 25 36 8 10 21 The limited number of children with developmental problems who were not signalled by the school did not have special characteristics with the exception of having slightly better developmental outcomes and/or having not been born extremely premature, having not been subjected to neonatal steroids and/or having had a somewhat less complicated neonatal period. It is possible that their developmental problems did not interfere with school functioning or they were able to compensate for them, but it is also possible that their parents and/or teachers did not signal their problems adequately. Parents are sometimes very relieved that the first difficult and worrisome years are over and unconsciously cut themselves off from new problems or both parents and teachers lower their expectations and demands because of overprotection. We did not find that less well-educated parents had more difficulties in mobilizing extra help for their children than relatively well-educated parents. Children of the former displayed developmental problems more often, but they received extra help and assistance in the same ratio as children of relatively more highly educated parents. Based on this line of reasoning a possible overrepresentation of children of less well-educated parents in the unassessed group would not change the degree of concordance between the follow-up results and school outcomes. 28 29 Schools are doing quite well in identifying children with and without developmental problems, but the need for longitudinal multidisciplinary follow-up programmes in different developmental domains remains. Information that promotes the understanding of the development of these children during their school career provides schools and parents with more tools for early detection and will facilitate the design and evaluation of intervention programmes.