Katrina Williams

Background The delivery of optimal medical care to children is dependent on the availability of child relevant research. Our objectives were to: i) systematically review and describe how children are handled in reviews of drug interventions published in the Cochrane Database of Systematic Reviews (CDSR); and ii) determine when effect sizes for the same drug interventions differ between children and adults. Methods We systematically identified all of the reviews relevant to child health in the CDSR 2002, Issue 4. Reviews were included if they investigated the efficacy or effectiveness of a drug intervention for a condition that occurs in both children and adults. Information was extracted on review characteristics including study methods, results, and conclusions. Results From 1496 systematic reviews, 408 (27%) were identified as relevant to both adult and child health; 52% (213) of these included data from children. No significant differences were found in effect sizes between adults and children for any of the drug interventions or conditions investigated. However, all of the comparisons lacked the power to detect a clinically significant difference and wide confidence intervals suggest important differences cannot be excluded. A large amount of data was unavailable due to inadequate reporting at the trial and systematic review level. Conclusion Overall, the findings of this study indicate there is a paucity of child-relevant and specific evidence generated from evidence syntheses of drug interventions. The results indicate a need for a higher standard of reporting for participant populations in studies of drug interventions.

Secretin is a gastro‐intestinal hormone which has been presented as an effective treatment for autism based on anecdotal evidence. To determine if intravenous secretin: 1. improves the core features of autism (social interaction, communication and behaviour problems); 2. improves the non‐core aspects of behaviour or function such as self injurious behaviour; 3. improves the quality of life of affected individuals and their carers; 4. has short term and long term effects on outcome; 5. causes harm. Results of electronic searches of CENTRAL, MEDLINE, EMBASE, PsycINFO, CINAHL, ERIC, HealthStar and Sociofile (1998 ‐ March 2005) were independently examined by two authors. Reference lists of trials and reviews were searched; experts and trialists were contacted to find unpublished studies. Randomised controlled trials of intravenous secretin comparing secretin with a placebo treatment in children or adults diagnosed with autism spectrum disorders, where at least one standardised outcome measure was reported. Fourteen studies met inclusion criteria. All outcome data were continuous. Where trials used cross‐over designs, analysis was conducted on results from first treatment phase, allowing combined analysis with parallel design trials. Where standardised assessment tools generated scores as outcome measures, comparisons were made between means of these scores. Where baseline means were reported, differences between treatment and control were determined to assess possible bias. Where mean change from baseline was reported, this was used in preference to post‐treatment scores for meta‐analyses or forest plots. As meta‐analysis was possible for only one outcome (Childhood Autism Rating Scale), it was impossible to use sensitivity or subgroup analyses to assess impact of study quality, clinical differences in the intervention, or clinically relevant differences between groups, such as age or presence of gastrointestinal symptoms. Twenty‐five established standardised outcome measures were reported to assess core features of autism, communication, behaviour, visio‐spatial skills, affect and adverse events within fourteen included studies. No more than four studies used any one outcome measure similarly. Outcomes were reported between three and six weeks. RCTs of efficacy of secretin in autism have not shown improvements for core features of autism. There is no evidence that single or multiple dose intravenous secretin is effective and as such it should not currently be recommended or administered as a treatment for autism. Further experimental assessment of secretin's effectiveness for autism can only be justified if methodological problems of existing research can be overcome.

Aim: To ascertain the incidence of autism spectrum disorders in Australian children. Setting: New South Wales (NSW) and Western Australia (WA), July 1999 to December 2000. Design: Data were obtained for WA from a prospective register and for NSW by active surveillance. Main outcome measures: Newly recognised cases of autism spectrum disorders (defined as autistic disorder, Asperger disorder and pervasive developmental disorder not otherwise specified [PDD‐NOS]) in children aged 0–14 years; incidence was estimated in 5‐year age bands (0–4 years, 5–9 years, 10–14 years). Results: In WA, 252 children aged 0–14 years were identified with autism spectrum disorder (169 with autistic disorder and 83 with Asperger disorder or PDD‐NOS). Comparable figures in NSW were 532, 400 and 132, respectively. Most children were recognised with autistic disorder before school age (median age, 4 years in WA and 3 years in NSW). Incidence of autistic disorder in the 0–4‐years age group was 5.5 per 10 000 in WA (95% CI, 4.5–6.7) and 4.3 per 10 000 in NSW (95% CI, 3.8–4.8). Incidence was lower in older age groups. The ratio of all autism spectrum disorders to autistic disorder alone was 1.5:1 in WA and 1.3:1 in NSW, and rose with age (1.8:1 and 2.9:1 in 10–14‐year‐olds in WA and NSW, respectively). Conclusions: These are the first reported incidence rates for autism for a large Australian population and are similar to rates reported from the United Kingdom. Ongoing information gathering in WA and repeat active surveillance in NSW will help to monitor any future changes.