Public disclosure of clinical trials in children

Guanfacine for attention deficit and hyperactivity disorder in pediatrics: a systematic review and meta-analysis

To review the evidence from randomized controlled trials (RCTs) on the safety and efficacy of guanfacine in pediatric attention deficit hyperactivity disorder (ADHD), a bibliographic search up to May 2014 was performed using the Cochrane Library׳s Central Register of Controlled Trials, the Embase, PsycINFO, and Medline databases, and clinical trials registers. The search terms used were: ["guanfacine"] and ["child" or "adolescent" or "pediatrics"] and ["randomized controlled trial"] and ["Attention Deficit Disorder with Hyperactivity" or "Attention Deficit Disorder" or "Attention Hyperactivity Disorder" or "Hyperactivity" or "ADHD"]. A meta-analysis was performed using response, defined as a score ≤ 2 on the Clinical Global Impression Improvement score, as the outcome measure. In all, 7 out of 48 studies were included, for a total of 1752 participants. All studies compared guanfacine versus placebo, with a duration ranging from 6 to 16 weeks. In all, the Clinical Global Impression Improvement score was reported as a secondary measure. Overall, 694/1177 (59.0%) participants in the guanfacine group benefited from the treatment compared to 192/575 (33.3%) in the placebo group (pooled OR 3.2; 95%CI 2.4-4.1). The participants with at least one adverse event were 948 (82.4%) in the guanfacine and 376 (67.9%) in the placebo group (OR 2.6; 95%CI 1.6-4.4). Somnolence (OR 4.9), sedation (OR 2.8), and fatigue (OR 2.2), were the adverse events with the greatest risk of occurrence in the guanfacine versus the placebo group. On the basis of seven randomized, placebo controlled trials guanfacine resulted safe and effective in treating children and adolescents with ADHD.

Children's presence in research. A review of online registers

OBJECTIVES

To determine how many online clinical trial registers include paediatric trial data, how much information is provided, ease of searching for paediatric trials and the accessibility of paediatric trial data in general.

METHODS

Medline and Google were searched for mention of clinical trial registers in July 2008. All registers considered to be eligible were evaluated for trial information provided, search options available, and number of trials, both total and paediatric. A meta-analytic weighted average of the presence of paediatric trials was calculated and compared to the percentage of published paediatric trial articles in Medline. The paediatric trials in the registers were searched for in the World Health Organization's International Clinical Trials Registry Platform (ICTRP). All online, freely accessible registers including ongoing trials on different drugs or therapeutic areas, were eligible for review.

RESULTS

Twelve registers were included in the review. All except one provided detailed trial data, while search options varied between registers: seven provided free-text searching, two listed their trials by condition, two provided elaborate search options (age group, condition, study purpose, etc) and one simply listed its trials. Nine of the 12 registers' search facilities made it possible to search for paediatric trials, and these were analysed further: the percentage of paediatric trials in the single registers ranged from 4.8 to 33.3%, and the weighted average was 15% (95% confidence interval 8.2-21.8). The percentage of published, paediatric trial articles was 25%. Of the paediatric trials also searched for in the ICTRP, 66% were found.

CONCLUSIONS

Great difficulty was found in retrieving paediatric trials due to the limited and inadequate search functions of the registers reviewed but, in general, the registers seem to represent fewer paediatric trials than those reported in the literature. The ICTRP portal is important for trial accessibility, but it is still in an initial phase and far from representative of the global research situation, especially in the field of paediatrics.

The DEC-net European register of paediatric drug therapy trials: contents and context

OBJECTIVE

To describe the results and conclusions of DEC-net, an international, publicly available register of paediatric drug therapy clinical trials, and to assess which paediatric health areas are covered by research and by which trial types.

METHODS

The contents of the register, which was set up by four groups (Italy, UK, France, Spain) who searched for paediatric trials and collected data between 2004-2006, were analysed. The disease areas reflected were compared with those covered by published trials and Burden of Disease (BD) data.

RESULTS

In all, 257 trial records were analysed, 86 of which were entered by the Italian partner, 84 by the UK partner, 56 by the French partner and 31 by the Spanish partner. Spain entered the majority of multinational trials, while the UK had the majority of single-centre national trials. Most trials were experimental (79%), and the most commonly represented diseases were neoplasms (14% trials). In all, 28% were double-blind randomised controlled trials (RCTs). The most common disease areas addressed in the 257 trials were similar to the published trials' areas. In contrast, the primary research area was low on the BD list.

CONCLUSIONS

DEC-net has demonstrated that international research efforts exist, even for paediatrics, although there may be an imbalance between national and multinational studies and a limited approach to double-blind RCTs. Recent initiatives will increase the number of children participating in research, and European legislation will require prospective registration. Paediatric research priorities must be better defined, however, and this can be done by registering research and making the information available to all relevant actors.