‘Testing the validity of the “value of a prevented fatality” (VPF) used to assess UK safety measures’: Reply to the comments of Chilton, Covey, Jones-Lee, Loomes, Pidgeon and Spencer

Thomas and Vaughan (2014) (hereafter “the Article”) drew ttention to the weaknesses in the approach underpinning he “value of a prevented fatality” (VPF) used as a refernce for health and safety decisions across the UK’s process, uclear and other industries, as well as the NHS (Glover and enderson, 2010). It is important for the UK’s future health and afety strategy that the lack of evidence for the VPF should be ebated openly in the pages of a learned journal. Hence we are leased that Chilton, Covey, Jones-Lee, Loomes, Pidgeon and pencer, authors from the Carthy study (Carthy et al., 1999), ave attempted to answer our criticisms and that we have een given the opportunity to respond. Having studied the comments provided by Chilton et al., we elieve that our significant reservations concerning the Carthy tudy and its methods remain entirely valid. We find encourgement in the several admissions by Chilton et al. that our riticisms are justified. A major problem for the Carthy chained approach is the ignificant deviation between direct and indirect measureents of the same quantity, which common sense suggests hould not occur. Two “values of a prevented injury” (VPI) per ndividual can be calculated for one specified serious but nonatal injury cited in the Carthy study, with one personal VPI, (1) Xi , calculated directly and the other, m Xi through two-injury haining. The two figures should be the same or similar, but hey turn out to be completely different. Moreover, there is arely any correlation between the two in the 167-strong samle. We are pleased that Chilton et al. acknowledge this in their Concluding comments”: