Randomised controlled trials of homeopathy in hyperactive children: treatment procedure leads to an unconventional study design. Experience with open-label homeopathic treatment preceding the Swiss ADHD placebo controlled, randomised, double-blind, cross-over trial

BACKGROUND: Treatment of patients with attention deficit hyperactivity disorder (ADHD) with homeopathy is difficult. The Swiss randomised, placebo controlled, cross-over trial in ADHD patients (Swiss ADHD trial) was designed with an open-label screening phase prior to the randomised controlled phase. During the screening phase, the response of each child to successive homeopathic medications was observed until the optimal medication was identified. Only children who reached a predefined level of improvement participated in the randomised, cross-over phase. Although the randomised phase revealed a significant beneficial effect of homeopathy, the cross-over caused a strong carryover effect diminishing the apparent difference between placebo and verum treatment. METHODS: This retrospective analysis explores the screening phase data with respect to the risk of failure to demonstrate a specific effect of a randomised controlled trial (RCT) with randomisation at the start of the treatment. RESULTS: During the screening phase, 84% (70/83) of the children responded to treatment and reached eligibility for the randomised trial after a median time of 5 months (range 1-18), with a median of 3 different medications (range 1-9). Thirteen children (16%) did not reach eligibility. Five months after treatment start, the difference in Conners Global Index (CGI) rating between responders and non-responders became highly significant (p = 0.0006). Improvement in CGI was much greater following the identification of the optimal medication than in the preceding suboptimal treatment period (p < 0.0001). CONCLUSIONS: Because of the necessity of identifying an optimal medication before response to treatment can be expected, randomisation at the start of treatment in an RCT of homeopathy in ADHD children has a high risk of failure to demonstrate a specific treatment effect, if the observation time is shorter than 12 months.

Learning to drive: learners' self-reported cognitive failure level predicts driving instructor's observation rating of driving performance

OBJECTIVES Evidence increases that cognitive failure may be used to screen for drivers at risk. Until now, most studies have relied on driving learners. This exploratory pilot study examines self-report of cognitive failure in driving beginners and error during real driving as observed by driving instructors. METHODS Forty-two driving learners of 14 driving instructors filled out a work-related cognitive failure questionnaire. Driving instructors observed driving errors during the next driving lesson. In multiple linear regression analysis, driving errors were regressed on cognitive failure with the number of driving lessons as an estimator of driving experience controlled. RESULTS Higher cognitive failure predicted more driving errors (p < .01) when age, gender and driving experience were controlled in analysis. CONCLUSIONS Cognitive failure was significantly associated with observed driving errors. Systematic research on cognitive failure in driving beginners is recommended.