A follow-up study of children hospitalised with community-acquired pneumonia.

OBJECTIVE: To investigate the outcome for children hospitalised with radiologically confirmed community-acquired pneumonia (CAP) DESIGN: Controlled follow-up study. SETTING: Community based in Newcastle upon Tyne, North Tyneside and Northumberland schools. PATIENTS: 103 cases of radiologically confirmed CAP a median of 5.6 years (range 4.4-7.4) after admission to Newcastle General Hospital, matched for sex and school class to a mean of two controls (n = 248). INTERVENTIONS: A respiratory questionnaire, clinical examination and spirometry measurements. MAIN OUTCOME MEASURES: Multiple regression was used to describe associations between explanatory variables, including CAP, and outcome variables: forced expiratory volume in 1 s percent predicted (FEV(1) %), forced vital capacity percent predicted (FVC %), persistent cough, doctor diagnosis of asthma and abnormal chest shape. RESULTS: Cases were 2.9 times more likely (95% CI 1.45 to 5.71, p = 0.020) than controls to have persistent cough and 5.5 times more likely to have an abnormal chest shape (95% CI 1.65 to 18.28, p = 0.005). Cases of an atopic parent had a 7.0% deficit in FEV(1) % predicted (95% CI -10.5 to -3.2, p<0.001) and a 4.4% deficit in FVC % predicted (95% CI -8.0 to -0.78, p = 0.017), but were not at increased risk of subsequent asthma. Cases of a non-atopic parent were at increased risk of subsequent asthma (OR 4.8, 95% CI 1.43 to 16.34, p = 0.011) but not of deficit in lung function. CONCLUSIONS: CAP requiring admission to hospital is associated with deficits in lung function and persistent respiratory symptoms. This has implications for follow-up for which recommendations are currently lacking. Parental atopy may be a determinant of outcome.

Childhood solid tumours in relation to population mixing around the time of birth.

In a retrospective cohort study of 673 787 live births in the Northern Region of England, 1975-1994, we investigated whether a higher level of population mixing around birth was a risk factor for solid tumours, by diagnostic group (Hodgkin's disease, brain and spinal tumours, neuroblastoma, other solid tumours), diagnosed during 1975-2001 under age 15 years. Logistic regression was used to relate risk to population mixing, based on (i) all movers and (ii) incomers from outside the region. Both ward and county district level analyses were performed. There was a decreased risk of brain and spinal tumours with increasing population mixing based on incomers from outside the region (OR for trend across three categories=0.79, 95% CI: 0.66-0.95, P=0.01 in the ward level analysis). Although this may be because of chance, it is consistent with a role of exposure to infection and immunological response in the aetiology of these tumours. For other tumour groups, there was no consistent evidence of an association between risk and population mixing.

Childhood leukaemia and non-Hodgkin's lymphoma in relation to proximity to railways.

We investigated whether living close to railway lines is a risk factor for childhood leukaemia and non-Hodgkin's lymphoma in electoral wards in England and Wales, 1966-1987. The national rail network, 1966-1987, was digitised and the numbers of cases in each ward were related to two measures of environmental exposure to railways: a proximity and a density function, contributions to these functions being weighted by the frequency of use and time in use of each stretch of railway. Poisson regression was used to derive rate ratios in relation to these measures of exposure to railways, both unadjusted and adjusted for population mixing. We found no association between risk of leukaemia and railway proximity (unadjusted rate ratio for trend from the lowest to the median value=1.006, 95% CI: 0.998 - 1.013, P=0.14) and a very small association with railway density, of marginal statistical significance (rate ratio for trend=1.001, 95% CI: 1.000 - 1.003, P=0.05). This effect depended on two deprived, urban wards with high railway density and high population mixing and became nonsignificant (P=0.09) after allowing for population mixing. The very weak association between railway density and risk of childhood leukaemia is likely to be a consequence of the association between population mixing and proximity to railways in very deprived, urban wards.

Population mixing and childhood leukaemia and non-Hodgkin's lymphoma in census wards in England and Wales, 1966-87.

We found an increased risk of childhood leukaemia with higher levels of inward migration, particularly from outside the region (rate ratio=1.9, 95%CI: 1.2-2.9, P<0.01). This significant effect was observed only in urban areas, although a marked but non-significant effect was seen in affluent, rural areas.

Placental angioarchitecture in monochorionic twin pregnancies: relationship to fetal growth, fetofetal transfusion syndrome, and pregnancy outcome.

OBJECTIVE: We sought to correlate placental vasculature with fetal growth and outcome in monochorionic twins. STUDY DESIGN: Eighty-two patients with consecutive monochorionic pregnancies underwent biweekly ultrasonography for determination of fetal growth and well-being. After delivery, blinded placental injection studies delineated vascular anastomoses and territory share. Degree of balance in arteriovenous anastomoses equaled the number of arteriovenous anastomoses in one direction minus the number in the other. RESULTS: Pregnancies affected by fetofetal transfusion syndrome (n = 21) had numbers of arteriovenous and venovenous anastomoses that were similar to those in pregnancies without fetofetal transfusion syndrome but fewer arterioarterial anastomoses (P <.0001). Fetofetal transfusion syndrome occurred in 78% of pregnancies with >/=1 arteriovenous and no arterioarterial anastomoses. Birth weight discordancy correlated with placental territory discordancy (P <.0001) and the degree of balance in arteriovenous anastomoses (P =.004). The larger placental share twin had a greater growth velocity than its smaller placental share co-twin (P =.008) for all but one anastomotic pattern. Where arteriovenous anastomoses were aligned with the net venous outflow to the fetus with the smaller territory, co-twins had similar birth weights and growth velocities irrespective of placental share. Fetal survival was higher in pregnancies with an arterioarterial anastomosis (P =.01) but lower with a venovenous anastomosis (P =. 01). Survival of both fetuses was inversely associated with birth weight discordancy (P <.0001). CONCLUSION: Although interrelationships among the various types of anastomoses are complex, our data suggest that the placental territory share and the pattern of arteriovenous anastomoses influence fetal growth, that arterioarterial anastomoses protect against fetofetal transfusion syndrome, and that venovenous anastomoses reduce perinatal survival.