The differences we noted between the above-noted subgroups of patients, analyzed by univariate analysis, failed to achieve the a-priori threshold for statistical significance of P ≤ 0.05, or even the delineation line for borderline significance at P ≤ 0.10.
To test this further, we created a risk-stratification score, from 0 to 4, indicating the number of poorer-outcome categories (age ≥ 46, comorbidity, malignant lesion, preoperative radiotherapy) each patient had, and there was a strong, highly significant inverse correlation between this risk-stratification score and patients’ summed final outcome score, the former explaining an impressive 57% of the variance in the latter.