Letter 1: Randomized clinical trial of antibiotic therapy versus appendicectomy as primary treatment of acute appendicitis in unselected patients (Br J Surg 2009; 96: 473–481)

Sir I dispute the conclusion of Hansson et al. that ‘comparison of antibiotics and surgery to treat acute appendicitis found comparable treatment efficacy’. The design of the study allowed patients, once randomized to a particular treatment, to receive the alternative treatment based on patient preference or medical judgement. Almost 50 per cent of the group allocated to receive antibiotic therapy instead received surgery. Consequently, the authors have chosen to evaluate the data on a per protocol basis (i.e. based on the treatment received rather than on their original allocation). This cannot therefore be considered to be a randomized trial. In 67 per cent of cases where patients allocated to the antibiotic treatment actually received surgery, this occurred because the surgeon deemed surgery to be necessary. Although it is not clear that this decision was made for sound medical reasons in every case, this has led to a highly selected group of patients undergoing surgery, and has introduced significant bias. Analysis of the patient characteristics of the two groups shows that those undergoing surgery had higher rates of local and general peritonitis and higher mean white cell count pre-operatively. This may in part account for the higher rates of complications in the surgery group.