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I have performed comparison of repeated measures for a group using Friedman’s test (K-related-samples test) and additional post-hoc analysis with Wilcoxon signed-rank test and Bonferroni correction. I have been told that this would be correct to do when looking for a change between the measurements and your measures are not normally distributed.

Now I'm not sure how to report my results correctly. Is it correct to a report mean with standard deviation or median with 25th to 75th percentile?

Example with mean:

Comparison of the repeated measures was performed using Friedman’s test showing a statistically significant decrease in concentration, χ2(3) = 24.877, p < 0.001. Post-hoc analysis with Wilcoxon signed-rank test was conducted with a Bonferroni correction applied, resulting in a significance level set at p < 0.0083. The mean concentration (±SD) was 0.045 (0.012) at baseline, 0.032 (0.012) at time2, 0.027 (0.007) at time 3 and 0.024 (0.006) at time4. A significant decrease was seen between time2 and baseline (Z = 2.900, p = 0.004), between time3 and baseline (Z = 3.180, p = 0.001) and between time4 and baseline (Z = 3.180, p = 0.001).

Could that work?

Thanks for helping!

Best, Rebecka.

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