Table 2 Variables, research hypothesis, outcome measures and methods of statistical analysis
Measures | Research hypothesis | Variables and outcome measures | Population | Statistical test | |
|---|---|---|---|---|---|
Descriptive analysis | Homogeneity of groups | Quantitative variables | Scores (/100), SC (μg/dl), HR (/mn), BP (mmHg), PNN50 (%), HF/LF | Total population | mean, standard deviation and / or median and interquartile range |
Qualitative variables | age, sex, status, years of experience | Total population | Number and percentage | ||
Evaluation of the effect of stress on performance | Impact of stress on performance with capabilities(stress adapted) or decreased (unsuitable stress) | Markers of biological stress (SC) | Total population | Pearson correlation coefficient (or Spearman correlation coefficient, if necessary) | |
Markers of electrophysiological stress (HR, BP, PNN50, HF/LF) | Groups 1 and 2 | ||||
Markers of psychological stress (STAI, PCLS, IES-R) | Research of heterogeneity related to status | ||||
Performance: overall performance scores, IO access score and scales assessing teamwork | |||||
Evaluation of changes in performance scores over time | Performance scores improved over time | Overall team performance, IO access performance score and scales assessing teamwork | Groups 1 et 2 | ANOVA for repeated measures (or a non-parametric test like Kruskal-Wallis if necessary). Scheffe tests to test the difference by pair in case of significance with the ANOVA test | |
For the whole population, linear models with mixed effects may be considered in order to take into account in the same analysis all data collected in the simulation sessions, including the development of stress management strategies in parallel to stress and repeated simulations. | |||||
Evaluation of repeated simulations on performance | Improvement of performance during repeated simulations with higher scores in group 1 | Score of overall performance, IO access score and score of scales assessing teamwork: | Comparison between group 1 and 2 | Student t-test and research of status and group effect by ANVOA | |
Relative variation of the different scores = (final score—T0 score)/T0 score | |||||
Evaluation of repeated simulations on stress level | Repetitive simulation-based training-related improvement in performance is not associated with a blunting of stress response in MDT members | Markers of biological stress (SC) | Comparison between group 1 and group 2 | Student t-test or non-parametric test U of Mann-Whitney if necessary | |
Markers of electrophysiological stress (HR, BP, PNN50, HF/LF) | |||||
Markers of psychological stress (STAI, PCLS, IES-R) | |||||
Inter-observer reproducibility | Very good reproducibility due to the use of validated scales | Scales of assessment: | Observers | Intra-class coefficient correlation | |
Overall performance, IO access, BAT, CTS | |||||