EDITOR,--J Fletcher and colleagues' paper on using decision analysis to evaluate screening for Down's syndrome is valuable, but several extra factors need to be considered.1 The authors state that screening causes anxiety but fail to mention the reassurance that it gives to many women. In addition, they based their study on use of the triple test despite the considerable body of evidence showing that a double test is as effective.2 3 Indeed, the national external quality assurance scheme's reports on Down's …