It has not been studied yet whether factors such as the number of subjects recruited by specialized centers for multicenter trials may influence weight loss during a low-calorie diet (LCD). This study aimed at determining whether the number of recruited subjects per center might predict relative weight loss. This is a post hoc analysis of an existing database: 701 obese subjects (77% women, 23% men, mean BMI: 38.9 kg/m(2)) were enrolled at 22 sites (4-85 subjects/site) in five countries to follow a LCD providing 800-1,000 kcal/day during 8 weeks. The main outcome measure was the percentage weight loss after the 8-week LCD. Mean weight loss differed significantly between participating centers (5.8-11.8% of the initial weight; P <0.001). There was a significant positive correlation between relative weight loss and the number of recruited subjects per center (r = 0.38; P <0.001). In a multiple stepwise regression analysis, the number of recruited subjects per center appeared to be the main predictive factor of weight loss (R(2) = 0.07; P <0.001). As the number of participants within each center is clustered, we applied a hierarchical model to model the average weight loss vs. the number of participants included at each center. This model allows to predict that for 10 extra patients in a center, the average weight loss would increase by 0.5%. This is the first study suggesting that the number of recruited subjects per center may impact weight loss, and could therefore be considered as a new predictor for weight loss that is independent from the individual.

To test the accuracy of spatial registration of real-time ultrasonography (US) fused with MRI in a phantom.

If a patient agrees to take part in a randomised trial it is reasonable to presume that the patient would prefer to be allocated into the intervention. This study's aim was to investigate how patients react after they have been randomised into control group.

Tobacco smoking is a major health and economic concern and is also known to have a significant negative effect on surgical outcomes. The benefits of a smoking cessation intervention prior to elective orthopaedic surgery have been evaluated previously. Our aim was to assess whether a smoking cessation program, initiated during the acute hospitalization period and carried out for six weeks, could reduce the number of complications following emergency surgical treatment of fractures.