%0 Journal Article
%T Health professionals prefer to communicate risk-related numerical information using "1-in-x" ratios
%J Medical decision making
%D 2018
%A Sirota, Miroslav
%A Juanchich, Marie
%A Petrova, Dafina
%A Garcia-Retamero, Rocio
%A Walasek, Lukasz
%A Bhatia, Sudeep
%V 38
%N 3
%P 366-376
%X BACKGROUND: Previous research has shown that format effects, such as the "1-in-X" effect-whereby "1-in-X" ratios lead to a higher perceived probability than "N-in-N*X" ratios-alter perceptions of medical probabilities. We do not know, however, how prevalent this effect is in practice; i.e., how often health professionals use the "1-in-X" ratio. <br><br>METHODS: We assembled 4 different sources of evidence, involving experimental work and corpus studies, to examine the use of "1-in-X" and other numerical formats quantifying probability. <br><br>RESULTS: Our results revealed that the use of the "1-in-X" ratio is prevalent and that health professionals prefer this format compared with other numerical formats (i.e., the "N-in-N*X", %, and decimal formats). In Study 1, UK family physicians preferred to communicate prenatal risk using a "1-in-X" ratio (80.4%, n = 131) across different risk levels and regardless of patients' numeracy levels. In Study 2, a sample from the UK adult population ( n = 203) reported that most GPs (60.6%) preferred to use "1-in-X" ratios compared with other formats. In Study 3, "1-in-X" ratios were the most commonly used format in a set of randomly sampled drug leaflets describing the risk of side effects (100%, n = 94). In Study 4, the "1-in-X" format was the most commonly used numerical expression of medical probabilities or frequencies on the UK's NHS website (45.7%, n = 2,469 sentences). <br><br>CONCLUSIONS: The prevalent use of "1-in-X" ratios magnifies the chances of increased subjective probability. Further research should establish clinical significance of the "1-in-X" effect.<p /> <p>Language: en</p>
%G en
%I SAGE Publishing
%@ 0272-989X
%U http://dx.doi.org/10.1177/0272989X17734203