Background: Regulatory and Health Technology Assessment (HTA) agencies are increasingly using real world data (RWD) to support real world evidence (RWE), but the readiness of healthcare systems to reliably generate RWE is unknown. As a quality assurance measure we examined the preparedness of a single payer system to provide RWE by evaluating the frequency of CT imaging during standard first line metastatic systemic treatment of breast, colorectal (CRC) and lung cancer. Methods: A 1-year cohort of de novo metastatic breast, CRC, lung cancer patients treated with first line systemic therapy (excluding hormone therapy) referred to BC Cancer in 2016 was retrospectively reviewed. Duration of first line treatment was calculated from first to last dose of therapy. Baseline CT included imaging within 8 weeks prior to and 3 weeks after treatment initiation (first cycle). Last CT included imaging up to 8 weeks after the last dose of therapy. Results: A cohort of 675 patients was identified from the BC Cancer Registry. The distribution of de novo metastatic disease at diagnosis was lung (n = 379), CRC (n = 214) followed by breast cancer (n = 82). Conclusions: In our publicly funded health care system, baseline CT scans within 4 weeks prior to treatment ranged from 57-72%. The median CT imaging interval during first line metastatic treatment was ranged from 7.9-11.3 weeks. RWD from routine clinical practice differs significantly from clinical trials, the gold standard for regulatory and HTA assessments. Population-based data may contribute to RWE with caution due to limitations imposed by clinical practice.