Statistical analysis
cataract
CATARACT, REGRESSION
For continuous measurements, descriptive statistics were presented in terms of minimum, maximum, mean, and standard deviation. For categorical measurements, proportions were used. To test for group difference in continuous baseline measures, the t-test or the Mann–Whitney U test was used depending on the normal distribution of measures within each group and assumptions of equal variances; when the t-test was used, the effect size was reported in Cohen’s d, where 0.2, 0.5, and 0.8 represent small, medium, and large differences in effect sizes, respectively. For the Mann–Whitney U tests, effect sizes are given by biserial correlation classification. The chi-square test was used to test for the differences in proportion among sex, laterality, and type of cataract.The effect of the quasi-experiment design was assessed using the treatment effect via regression adjustment estimator. Two indicators of the effect were calculated: average treatment effect (ATE) and the potential-outcome means for each treatment level.All the models were run using STATA (version 14). The adopted statistical significance threshold was 0.05.For all specular microscope variables we used the Mann-Whitney test for analysis. This comparison was made both in the pre and post. But we also compared the groups for gain, which is the simple mathematical difference of post-pre (when positive, it means an increase, but when negative, it means a reduction).