A pragmatic cluster randomized controlled trial of an educational intervention for GPs in the assessment and management of depression

Background. General practitioners (GPs) can be provided with effective training in the skills to manage depression. However, it remains uncertain whether such training achieves health gain for their patients. Method. The study aimed to measure the health gain from training GPs in skills for the assessment and management of depression. The study design was a cluster randomized controlled trial. GP participants were assessed for recognition of psychological disorders, attitudes to depression, prescribing patterns and experience of psychiatry and communication skills training. They were then randomized to receive training at baseline or the end of the study. Patients selected by GPs were assessed at baseline, 3 and 12 months. The primary outcome was depression status, measured by HAM-D. Secondary outcomes were psychiatric symptoms (GHQ-12) quality of life (SF-36), satisfaction with consultations, and health service use and costs. Results. Thirty-eight GPs were recruited and 36 (95%) completed the study. They selected 318 patients, of whom 189 (59%) were successfully recruited. At 3 months there were no significant differences between intervention and control patients on HAM-D, GHQ-12 or SF-36. At 12 months there was a positive training effect in two domains of the SF-36, but no differences in HAM-D, GHQ-12 or health care costs. Patients reported trained GPs as somewhat better at listening and understanding but not in the other aspects of satisfaction. Conclusions. Although training programmes may improve GPs' skills in managing depression, this does not appear to translate into health gain for depressed patients or the health service

Sources of bias in outcome assessment in randomised controlled trials: a case study

Randomised controlled trials (RCTs) can be at risk of bias. Using data from a RCT we considered the impact of post-randomisation bias. We compared the trial primary outcome, which was administered blindly, with the secondary outcome which was not administered blindly. 522 children from 44 schools were randomised to receive a one-to-one maths tuition programme that was assessed using two outcome measures. The primary outcome measure was assessed blindly whilst the secondary outcome was delivered by the classroom teacher and therefore this was un-blinded. The effect sizes for primary and secondary outcomes were substantially different (0.33 and 1.11 respectively). Test questions that were similar between the two tests this did not explain the difference. There was greater heterogeneity between schools for the primary outcome, compared with the secondary outcome. We conclude that, in this trial, the difference between the primary and secondary outcomes was likely to have been due to lack of blinding of testers

State-of-the-art survey of dissimilar metal joining by solid state welding

State-of-the-art of dissimilar metal joining by solid state diffusion bonding and roll and press welding, emphasizing stainless steel and aluminum allo