2.5. Statistical Analysis

This work’s statistical evaluation was carried out using the software SPSS Statistics Version 28 for Macintosh (IBM, Armonk, NY, USA). The demographic data were checked using Student’s t test for independent samples, and the normal distribution of the data was assessed in advance using the Kolmogorov-Smirnov test. Categorical data were evaluated using Fisher’s exact test, and continuous data were evaluated using Student’s t test. Separate linear mixed models were built to estimate the effect of anxiety or depression on repeatedly measured PROs (NRS-BP, NRS-LP, ODI, SF-36) following PRI. The effects were adjusted for the respective baseline PRO and the timepoints of assessment. The two-sided level of significance was 0.05 for all statistical tests.