LAUSR

Key Points Question Is overall survival of patients with advanced non–small cell lung cancer (NSCLC) that is estimated from US-based clinical practice data externally valid among Canadian patients who receive the same systemic therapies? Findings In this cohort study of 17 432 patients with advanced NSCLC in the US and Alberta, Canada, among those who initiated platinum-doublet chemotherapy or pembrolizumab monotherapy as first-line systemic treatment, overall survival in the US and Canada had high concordance over 60 months of follow-up in the US and 30 months of follow-up in Canada after adjustment for differences in baseline patient characteristics. Meaning These findings suggest that patient survival estimated from US-based clinical practice data may be valid for decision-making in Canada and that transportability analyses can provide evidence of external validity.