Long-term backache after childbirth. Study should have been randomised.

EDITOR,—We wish to make several comments about Robin Russell and colleagues' study looking at possible factors in long term backache after childbirth.1 Firstly, the study was not randomised with respect to controls, and the authors justify this by stating that randomisation would have been unethical. We would argue that a randomised controlled trial is the only way to validate the use of …