Sun exposure and interaction with family history in risk of melanoma, Queensland, Australia

Sun exposure is the main environmental risk factor for melanoma, but the timing of exposure during life that confers increased risk is controversial. Here we provide the first report of the association between lifetime and age-specific cumulative ultraviolet exposure and cutaneous melanoma in Queensland, Australia, an area of high solar radiation, and examine the association separately for families at high, intermediate and low familial melanoma risk. Subjects were a population-based sample of melanoma cases diagnosed and registered in Queensland between 1982 and 1990 and their relatives. The analysis included 1,263 cases and relatives with confirmed cutaneous melanoma and 3,111 first-degree relatives without melanoma as controls. Data an lifetime residence and sun exposure, family history and other melanoma risk factors were collected by a mailed questionnaire. Using conditional multiple logistic regression with stratification by family, cumulative sun exposure in childhood and in adulthood after age 20 was significantly associated with melanoma, with estimated relative risks of 1.15 per 5,000 minimal erythemal doses (MEDs) from age 5 to 12 years, and 1.52 per 5 MEDs/day from age 20. There was no association with sun exposure in families at high familial melanoma risk. History of nonmelanoma skin cancer (relative risk [RR] = 1.26) and multiple sunburns (RR = 1.31) were significant risk factors. These findings indicate that sun exposure in childhood and in adulthood are important determinants of melanoma but not in those rare families with high melanoma susceptibility, in which genetic factors are likely to be more important. (C) 2002 Wiley-Liss, Inc

A comparison of multiple imputation and doubly robust estimation for analyses with missing data

Multiple imputation is now a well-established technique for analysing data sets where some units have incomplete observations. Provided that the imputation model is correct, the resulting estimates are consistent. An alternative, weighting by the inverse probability of observing complete data on a unit, is conceptually simple and involves fewer modelling assumptions, but it is known to be both inefficient (relative to a fully parametric approach) and sensitive to the choice of weighting model. Over the last decade, there has been a considerable body of theoretical work to improve the performance of inverse probability weighting, leading to the development of 'doubly robust' or 'doubly protected' estimators. We present an intuitive review of these developments and contrast these estimators with multiple imputation from both a theoretical and a practical viewpoint. Copyright 2006 Royal Statistical Society.

Inpatient treatment in child and adolescent psychiatry - an exploratory prospective study of health gain and costs

Background: Inpatient treatment is a complex intervention for the most serious mental health disorders in child and adolescent psychiatry. This is the first large-scale study into its effectiveness and costs. Previous studies have been criticised for methodological weaknesses. Methods: A prospective cohort study, including economic evaluation, conducted in 8 UK units (total n ¼ 150) with one year follow-up after discharge. Patients acted as their own controls. Outcome measurement was the clinician-rated Childhood Global Assessment Scale (CGAS); researcher-rated health needs assessment; parent- and teacher-rated symptomatology. Results: We found a significant (p < .001) and clinically meaningful 12-point improvement in CGAS following mean 16.6 week admission (effect size .92); this improvement was sustained at 1 year follow-up. Comparatively, during the mean 16.4 week pre-admission period there was a 3.7-point improvement (effect size .27). Health needs assessment showed similar gain (p < .001, effect size 1.25), as did teacher- and parent-rated symptoms. Improvement was found across all diagnoses. Longer stays, positive therapeutic alliance and better premorbid family functioning independently predicted better outcome. Mean cost of admission was £24,100; pre-admission and postdischarge support costs were similar. Conclusions: Inpatient treatment is associated with substantive sustained health gain across a range of diagnoses. Lack of intensive outpatient-treatment alternatives limits any unqualified inference about causal effects, but the rigour of measurement here gives the strongest indication to date of the positive impact of admission for complex mental health problems in young people. Keywords: Child, adolescent, psychiatry, inpatient, outcomes, costs