Design: Longitudinal non-intervention study of the physical and psychological development of children recruited from the community in 1986-7 after entry into primary school at age 5-6 years; this is the second psychometric assessment made in 1994-5 after entry into secondary school at age 11-13 years.

Setting: Southampton and Winchester health districts.

Subjects: 106 short normal children (<3rd centile for height when recruited) and 119 controls of average stature (10th-90th centile).

Main outcome measures: Psychometric measures of cognitive development, self concept development, behaviour, and locus of control.

Results: The short children did not differ significantly from the control children on measures of self esteem (19.4 v 20.2), self perception (104.2 v 102.4), parents' perception (46.9 v 47.0), or behaviour (6.8 v 5.3). The short children achieved significantly lower scores on measures of intelligence quotient (IQ) (102.6 v 108.6; P<0.005), reading attainment (44.3 v 47.9; P<0.002), and basic number skills (40.2 v 43.5; P<0.003) and displayed less internalisation of control (16.6 v 14.3; P<0.001) and less satisfaction with their height (P<0.0001). More short than control children, however, came from working class homes (P<0.05). Social class was a better predictor than height of all measures except that of body satisfaction. Attainment scores were predicted by class and IQ together rather than by height. Height accounted for some of the variance in IQ and locus of control scores.

Conclusions: These results provide only limited support for the hypothesis that short children are disadvantaged, at least up until 11-13 years old. Social class seems to have more influence than height on children's psychological development.

Department of Child Health,
Southampton University Hospitals Trust,
Southampton General Hospital,
SO16 6YD
A Bruce Downie, research assistant (psychology)
Jean Mulligan, data manager
Linda D Voss, senior research fellow

Department of Psychology,
University of Southampton,
Southampton SO17 1BJ
Robert J Stratford, senior lecturer in psychology

Department of Paediatrics,
Southampton University Hospitals Trust,
SO16 6YD
Peter R Betts, consultant paediatrician

Correspondence to: Dr Voss.

Design: A prospective, collaborative, population based survey.

Setting: The former Northern Regional Health Authority.

Subjects: All the births between 1983 and 1994 at 22 to 27 completed weeks' gestation to women normally resident in the region.

Main outcome measures: Miscarriage, stillbirth, death in the first year of life, and disability in survivors.

Results: There were 479,070 registered births in the study period. No baby of 22 weeks' gestation survived; only eight (4%) of the 197 babies of 23 weeks who were alive at the onset of labour survived for a year - a proportion that did not change during the study period. Survival among other babies of less than 28 weeks improved progressively between 1983-6 and 1991-4, but administration of artificial surfactant to babies requiring ventilation from mid-1990 was associated with further improvement in survival only in those over 25 weeks' gestation. Babies of 24 weeks required three times as much high dependency care per survivor as babies of 27 weeks (76 v 26 days). The rate of severe disability in the one year survivors of less than 26 weeks' gestation (30/123; 24%) was similar to that seen in the sampled survivors of 26 and 27 weeks (29/108; 27%); the proportion disabled did not change significantly during the study period. All the children born in 1983, 1987, and 1991 were later reassessed in greater detail: 10% (13/136) seemed destined for a continuing life of total dependency.

Conclusions: Gestation, if accurately assessed, can give a woman facing very preterm delivery a clear indication of the prognosis for her baby and help her judge the appropriateness of accepting obstetric intervention and sustained perinatal support.

South Cleveland Hospital,
Middlesbrough,
Cleveland TS4 3BW
Win Tin, consultant paediatrician

Royal Victoria Infirmary,
Newcastle upon Tyne NEW 4LP
Unni Wariyar, consultant paediatrician
Edmund Hey, consultant paediatrician

Correspondence to: Dr Tin.

Design: Meta-analysis of metabolic ward studies of solid food diets in healthy volunteers.

Subjects: 395 dietary experiments (median duration 1 month) among 129 groups of individuals.

Results: Isocaloric replacement of saturated fats by complex carbohydrates for 10% of dietary calories resulted in blood total cholesterol falling by 0.52 (SE 0.03) mmol/l and low density lipoprotein cholesterol falling by 0.36 (0.05) mmol/l. Isocaloric replacement of complex carbohydrates by polyunsaturated fats for 5% of dietary calories resulted in total cholesterol falling by a further 0.13 (0.02) mmol/l and low density lipoprotein cholesterol falling by 0.11 (0.02) mmol/l. Similar replacement of carbohydrates by monounsaturated fats produced no significant effect on total or low density lipoprotein cholesterol. Avoiding 200 mg/day dietary cholesterol further decreased blood total cholesterol by 0.13 (0.02) mmol/l and low density lipoprotein cholesterol by 0.10 (0.02) mmol/l.

Conclusions: In typical British diets replacing 60% of saturated fats by other fats and avoiding 60% of dietary cholesterol would reduce blood total cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol.

Clinical Trial Service Unit and Epidemiological Studies Unit,
Nuffield Department of Clinical Medicine,
Radcliffe Infirmary,
Oxford OX2 6HE
Robert Clarke, research fellow
Rory Collins, professor of medicine and epidemiology
Paul Appleby, research officer
Richard Peto, professor of medical statistics and epidemiology

Department of Statistics,
London School of Hygiene and Tropical Medicine,
London WC1E 7HT
Chris Frost, lecturer

Correspondence to: Dr Clarke.