For healthcare professionals only


Authors should have used marginal analysis

BMJ 1996; 312 doi: (Published 06 April 1996) Cite this as: BMJ 1996;312:909
  1. David J Torgerson
  1. Research fellow National Primary Care Research and Development Centre, Centre for Health Economics, University of York, York YO1 5DD

    EDITOR,—The paper by H S Cuckle and colleagues should aid purchasing decisions regarding screening for cystic fibrosis on the basis of only a single genetic marker.1 The evaluation is, however, seriously flawed with respect to screening for multimutations because the authors have fallen into the classic error of using average rather than marginal analysis.2

    In table 1 the authors show that screening for a single mutation, with uptake of 75% and a detection rate of 80%, detects 384 affected pregnancies for a total …

    View Full Text

    Log in

    Log in through your institution


    * For online subscription