What doesn't work and how to show it

Ineffectiveness is hard to prove and accept

Archie Cochrane, the British epidemiologist, posed three key questions to ask about a healthcare intervention: “Can it work?” “Does it work in practice?” and “Is it worth it?”1 It would be great if the answers to these were always positive, but life isn't like that. The possible answers might be classed as “yes,” “not sure,” and “no.” The rules for deciding “yes” are relatively clear and well known, but less has been written about deciding that something doesn't work. This theme issue looks at examples of interventions that don't appear to work, the dilemmas of trying to decide between an answer of “not sure” and “no,” and what to do when we are not sure.

Doust and …