A total of six RCTs (n=603) were included in the review. Four of these compared antibiotics against control (n=483) and two compared different antibiotic regimens (n=120). Only two RCTs reported blinding of the patients and/or outcome assessors.
The included studies met between one and five of the six quality assessment criteria. All stated that they were randomised, but five of the six did not state a method of randomisation. None of the studies accounted for withdrawals.
Of the four studies categorised as RCTs, three reported statistically significant reductions in infections associated with antibiotic prophylaxis when compared with no antibiotics: 53% versus 6% (p=0.001), 43% versus 14% (p=0.01), and 22% versus 2%, 6% or 8% (for 1-day treatment, '1-shot' prophylaxis and 3-day treatment, respectively; p=0.001). One RCT reported a benefit of antibiotic prophylaxis of borderline statistical significance (20% versus 5%, p=0.06; for up to 48 hours coverage).
One RCT found no difference between infection rates for two different antibiotic regimens, while a second reported no significant difference between 1- and 5-day treatment with penicillin (although the data were based only on the results from 30 patients).