Letter to the editor: Expert evidence vs. expert opinion

Abstract

Congratulations on your editorial and the two articles relating to the area of screening [1Knottnerus J.A. Tugwell P. Editorial: primum non nocere: appropriate evidence assessment and fair judgment over time.J Clin Epidemiol. 2020; 122: A6-A7Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar, 2Raffle A.E. Gray J.A.M. The 1960s cervical screening incident at National Women’s Hospital, Auckland, New Zealand; insights for screening research, policy making and practice.J Clin Epidemiol. 2020; 122: A8-A13Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar, 3Chalmers I. The ‘unfortunate experiment’ that was not, and the indebtedness of women and children to Herbert (‘Herb’) Green (1916-2001).J Clin Epidemiol. 2020; 122: A14-A20Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar]. Screening is fraught with difficulties, given that it assesses people with no symptoms and may result in invasive procedures and even harm. This was not recognized for many years. As the two articles allude to, it takes time and perseverance to ‘set the records straight'. Too often history has been written by the victors, as was the case following New Zealand's 1987–88 Cartwright Inquiry [[4]The Report of the Committee of Inquiry into Allegations Concerning the Treatment of Cervical Cancer at National Women’s Hospital and into Other Related Matters. Government Printing Office, Auckland1988Google Scholar]. The first anniversary of the Cartwright Inquiry declared four women had taken on the ‘might of the medical profession’ and had won [[5]Sunday Star. 1989Google Scholar]. The reputations of leading obstetricians and gynecologists were irreparably damaged. My late father Dr Graeme Overton, an obstetrician–gynecologist who worked at National Women's Hospital, realized as early as 1989 that the serious charges against Professor Green of mismanagement of carcinoma in situ (CIS) were false [[6]Corbett J. Second Thoughts on the ‘Unfortunate Experiment at National Women’s’.Metro. July. 1990; : 54-71Google Scholar]. His attempts to bring about scientific discussion using evidence resulted in personal attacks from media and Cartwright Inquiry supporters, with statements such as the following in the local press [[7]Editorial. Auckland Star. 1989Google Scholar]: ‘The intransigence and arrogance of some sections of the medical profession is sadly evident in the bid by Dr Graeme Overton to revive examination of major findings of the cervical cancer inquiry... [which] indicates a dangerous inability to accept the serious deficiencies in patient care and medical controls exposed.’ The use of emotive headlines by media inhibited relevant discussion in the immediate aftermath of the Inquiry, and beyond [[8]Auckland Star. 1988Google Scholar]. In 1990, Jan Corbett, a journalist who interviewed Dr Overton and wrote an article questioning the Inquiry's findings, subsequently outlined the personal attacks she experienced after publication of her article [[6]Corbett J. Second Thoughts on the ‘Unfortunate Experiment at National Women’s’.Metro. July. 1990; : 54-71Google Scholar,[9]Corbett J. Have you been burned at the stake yet?.Metro. October. 1990; : 156-165Google Scholar]. Nearly 2 decades later, when medical historian Professor Linda Bryder presented an independent, thorough evaluation of this so-called ‘unfortunate experiment’ [[10]Bryder L. A History of the ‘Unfortunate Experiment’ at National Women’s Hospital. Auckland University Press, Auckland, New Zealand2009Google Scholar], she too faced a barrage of attacks, including attempts to prevent publication of her book (documentation shared with the JCE editors). Judge Cartwright who presided over the Inquiry had claimed to have consulted ‘expert opinion’, but she confused ‘expert opinion’ with ‘expert evidence’. And therein lies the problem, as the Cochrane Collaboration has been trying to get across for years. As Cochrane's UK Director, Professor Martin Burton stated the following in January 2020 [[11]Burton M. Expert opinion is not always right.2020https://www.evidentlycochrane.net/expert-opinion-not-always-right/Date accessed: January 27, 2020Google Scholar]: ‘Beware of putting too much weight on a person's so-called expertise. Instead consider challenging them to provide the evidence for their recommendations.’ ‘Expert evidence’ is the bedrock of the recent book on screening by Raffle et al. [[12]Raffle A.E. Mackie A. Gray J.M. Screening evidence and practice.2nd ed. Oxford University Press, Oxford, England2019Crossref Google Scholar]. It also reveals the value of being distanced, in location and in time, from the very emotive climate that existed in 1980s New Zealand, as explained in Bryder's book. This fully independent assessment should allow this major injustice in New Zealand's history to be corrected. Professor Green recognized that not all CIS leads to cancer and was a leader in reducing harm from overtreatment in cases of CIS. Raffle et al. show that the ‘victors' framed their discussions to prove otherwise. Finally we have some evidence-based medicine.