The High Court has allowed Clinical Pathology Laboratories Incorporated (CPL) to remove markings from a 2010 cervical smear slide so it can carry out a blind review. The order is limited to that purpose and follows an earlier refusal that was set aside on appeal.
Vivienne Wallace is among the plaintiffs who have brought proceedings arising from the CervicalCheck Screening Programme. Her smear tests in September 2010 and July 2013 were reported as normal. She was diagnosed with cervical cancer in October 2014. In these proceedings, she alleges, among other matters, that CPL misread the 2010 slide, allowing the cancer to develop or spread before diagnosis. The allegation has not been determined in this application.
CPL sought permission to remove all markings from the slide, numbered ZA322603, to allow cytoscreeners to review it without seeing marks made during the original screening and a later Cancer Audit Review. The plaintiff’s expert had already reviewed and digitally imaged the marked slide, and held it for 13 months.
A High Court refusal in January 2021 was set aside by the Court of Appeal, which remitted the application for reconsideration after further evidence. The Court of Appeal said CPL had to provide appropriate, admissible evidence of a real risk that refusing the order would prejudice its defence. The court also had to consider countervailing circumstances, including any demonstrable prejudice to Ms Wallace, and balance the parties’ interests.
CPL relied on cytologist Alison Cropper’s evidence that a reviewer who knows of the later cancer diagnosis may be affected by hindsight bias. She proposed a review by three cytoscreeners who would not be told why it was being conducted. Ms Wallace’s solicitor argued that removing the marks would destroy critical evidence. No expert evidence was submitted for her in opposition.
Ms Justice Reynolds found that CPL had established a real risk of litigious disadvantage if it could not conduct the blind review. She said reviewing the marked slide compromised the integrity of that exercise. She was not satisfied that compelling countervailing circumstances, including demonstrable prejudice to the plaintiff, justified refusing the order.
The court therefore granted CPL liberty to remove the markings for the purpose of the blind review in the process outlined by Ms Cropper. The ruling concerns this evidence-handling application; it does not decide whether the original screening was negligent or determine the underlying claim.