Consistency of recording of chemotherapy cycles in the National Cancer Registration and Analysis Service Systemic Anti-Cancer Therapy database and the Hospital Episode Statistics Admitted Patient Care database.

We assessed the extent to which chemotherapy cycles recorded in Hospital Episode Statistics (HES) Admitted Patient Care (APC) were captured in National Cancer Registration & Analysis Service Systemic Anti-Cancer Therapy (SACT) for a cohort of lung cancer patients. All chemotherapy cycles recorded for linkage eligible lung cancer patients with a National Cancer Registration & Analysis Service diagnosis between 2012 and 2015 were identified in HES APC and SACT. Among a population of 4070 lung cancer patients, 6076 chemotherapy cycles were observed in HES APC data.