Overall survival was not significantly different between patients with cN0-pN2a1 non-small cell lung cancer who underwent NS and patients who underwent SF for cN2-pN2a1 before (A) and after (B) applying the matching-weights procedure. Cox model after the matching-weights procedure: (NS vs reference of SF) HR, 1.24 (95% CI, 0.67-2.28). For the matching-weights analyses, each patient contributes a fraction reflecting the matching-weights; therefore, the effective sample size (numbers at risk) may not be an integer. The number of patients at risk and 95% CI estimates corresponding to each time point are presented below the figure for each group. CI, confidence interval; HR, hazard ratio; NS, neoadjuvant therapy followed by surgery; SF, surgery first.