Efficacy of a Web Tutorial Based on Case Vignettes for Teaching Literature Critical Assessment to Nursing Students: a Randomized Controlled Trial

Statistical analysis : Qualitatives variables will be presented with the number and percentage of participants and of missing data for each outcome. Quantitative variables will be presented with the number and percentage of participants, mean, standard deviation and range. Assymetrical variables will be presented with the median and the interquartile range. Quantitative outcomes will be compared between groups with a Fisher test in a linear mixed model. (the fixed effect will be the allocation group and the random effect will be the nursing institute so as to take into account the similarity of the students for each institute). Qualitative outcomes will be compared using a mixed effect logistic regression model (the fixed effect will be the allocation group and the random effect will be the nursing institute so as to take into account the similarity of the students for each institute). The data analysis will be carried out as an 'intention-to treat analysis' in all randomized participants. For the primary outcome, missing data will be dealt with the multiple imputation method. Sensibility analysis will be used to confirm the results for the primary outcome. Two-tailed tests will be applied at a standard level of 5%. The statistical analysis will be performed with SAS 9.3 statistical software.