Correction for vol. 365, p.BMJ 2019; 365 doi: https://doi.org/10.1136/bmj.l1862 (Published 25 April 2019) Cite this as: BMJ 2019;365:l1862
Preoperative physiotherapy for the prevention of respiratory complications after upper abdominal surgery: pragmatic, double blinded, multicentre randomised controlled trial
In this paper by Boden and colleagues (BMJ 2018;360, doi:10.1136/bmj.j5916, published 24 January 2018), the authors failed to update the clinical trial registry (ANZCTR-12613000664741) to reflect minor changes that were made during the trial design phase on how the primary outcome was defined. The two changes were made to better define a “doctor’s diagnosis of a PPC [postoperative pulmonary complication]” and to ensure that this reflected pragmatic clinical practice. Firstly, as doctors rarely report that the patient has a PPC but rather list “pneumonia,” “URTI,” or “chest infection,” Secondly, as a reflection of clinical practice in response to respiratory symptoms, the authors moved the criterion for prescription of antibiotics specific for a respiratory infection to the doctor diagnosis criterion.
The modified primary outcome has been used consistently for the entire trial but if readers were to use the original trial registry primary outcome measure, rather than the one specified in the published protocol and the published paper to analyse the results, an additional three patients would have a diagnosis of a PPC—two in the control group and one in the intervention group. The between group difference as reported in the paperwas 27/218 (12%) v 58/214 (27%); hazard ratio 0.48 (95% confidence interval 0.30 to 0.75), P<0.001: adjusted for age, respiratory comorbidity, and upper gastrointestinal surgery. If the trial registry primary outcome is used this adjusted outcome changes slightly and becomes 28/218 (13%) v 60/214 (28%); 0.48 (0.30 to 0.74), P<0.001. The authors have now updated the registration details to match those of the protocol.