We aimed to evaluate the impact of using CR and non-CR data sources on the diagnostic accuracy of the Ovatools ovarian cancer (OC) risk prediction model.<h4>Methods</h4>Retrospective cohort study using linked Clinical Practice Research Datalink (CPRD), hospital episodic statistics (HES) and CR data from women tested for cancer antigen 125 (CA125) in England (1 May 2011-31 December 2017). This evidence concerns the gene MUC16 and ovarian cancer.