Genetic risk estimation by healthcare professionals

• Published in: Medical journal of Australia 2005-02, Vol.182 (3), p.116-118
• Main Authors: Bonke, Benno, Stijnen, Theo, Tibben, Aad, Lindhout, Dick, Clarke, Angus J
• Format: Article
• Language: English
• Subjects: Australia; Bayes Theorem; Biological and medical sciences; Cancer; Clinical Competence; Counseling; Estimates; Fetuses; General aspects; Genetic Services - statistics & numerical data; Genetic testing; Genetic Testing - statistics & numerical data; Genetics; Health risk assessment; Humans; Huntington Disease - diagnosis; Huntington Disease - genetics; Huntingtons disease; Italy; Medical genetics; Medical personnel; Medical sciences; Mutation; Netherlands; Pedigree; Probability Theory; Risk Assessment - methods; Risk Assessment - statistics & numerical data; United Kingdom
• ISSN: 0025-729X; 1326-5377
• DOI: 10.5694/j.1326-5377.2005.tb06610.x

Objectives: To assess whether healthcare professionals correctly incorporate the relevance of a favourable test outcome in a close relative when determining the level of risk for individuals at risk for Huntington's disease. Design and setting: Survey of clinical geneticists and genetic counsellors from 12 centres of clinical genetics (United Kingdom, 6; The Netherlands, 4; Italy, 1; Australia, 1) in May–June 2002. Participants were asked to assess risk of specific individuals in 10 pedigrees, three of which required use of Bayes’ theorem. Participants: 71 clinical geneticists and 41 other healthcare professionals involved in genetic counselling. Main outcome measures: Proportion of respondents correctly assessing risk in the three target pedigrees; proportion of respondents who were confident of their estimate. Results: 50%–64% of respondents (for the three targets separately) did not include the favourable test information and incorrectly estimated the risks as being about equal to the prior risks; 77%–91% of these respondents were “sure” or “completely sure” that their estimations were correct. Twenty of the 112 respondents correctly estimated the risks for all three target pedigrees. Conclusions: Clinical geneticists and genetic counsellors frequently use prior risks in situations where Bayes’ theorem should be applied, leading to overestimations of the risk for an individual.