Meta-analysis of randomized, controlled clinical trials of antibiotic prophylaxis in biliary tract surgery

In this study all available clinical trials of antibiotic prophylaxis in biliary tract surgery, published from 1965 to 1988, were examined. Results of 42 randomized, controlled trials (4129 patients), in which a group of patients treated with antibiotics was compared with a group of patients not treated with antibiotics, were pooled. Wound infection rates in the control groups range from 3 to 47 per cent and are 15 per cent overall. The overall difference in infection rates is 9 per cent in favour of antibiotic treatment (95 per cent confidence interval 7-11 per cent), while the common odds ratio is 0.30 (95 per cent confidence interval 0.23-0.38). Subgroup meta-analysis showed a significant stronger protective effect in high risk patients, while the timing of wound inspection (i.e. early in hospital or late at follow-up) markedly influenced the treatment effect reported. Comparison of wound infection rates in patients treated with first generation versus second or third generation cephalosporins (11 trials, 1128 patients), as well as single-dose versus multiple-dose regimens (15 trials, 1226 patients) did not reveal any significant effect (P greater than 0.05) in each trial separately as well as in the overall comparison. The results indicate that there is evidence against further use of no-treatment controls and that the choice of treatment regimen can largely be made on the basis of cost.