An error occurred in this letter by Ebrahim and Davey-Smith (26 September). The penultimate paragraph should have read as follows.
Two responses to rigorous evaluations that showed little or no added value of health promotion programmes for cardiovascular disease have been the design and execution of potentially misleading and methodologically flawed studies,4 for which exorbitant claims are made.5 A third response has been the suggestion that rigorous evaluative methods are not appropriate in this situation.