An article appeared recently in a journal for general practitioners, in which the author (a general practitioner) told the story of his own shoulder pain.1 He had had some physiotherapy that made it feel better, and then had read a meta-analysis that said that physiotherapy was of no proven benefit for shoulder pain. His shoulder pain had recurred and he had had an injection that made it feel a lot better, and then had read a meta-analysis that concluded that there was little scientific basis for injecting the shoulder. “Are we using the right sort of evidence?” he pleaded in desperation.

Musculoskeletal doctors will recognise that plea. The GP had admittedly overinterpreted the meta-analyses because each one would have ended with the observation that “there have been too few randomised controlled trials of sufficient quality on which to base a judgement of effectiveness”. This does not mean that physiotherapy or shoulder injections are useless. The absence of evidence is a very different affair to having clear evidence that an intervention does not work. Why then will so many clinicians feel sympathy with the perplexed GP?