Figure Relative efficacy of doxycycline vs parenteral treatment

Relative efficacy of doxycycline vs parenteral treatment (ratio of response rate to doxycycline to response rate to parenteral penicillin or ceftriaxone; RR of 1.0 indicating identical response rates with the agents being compared) in eight studies, and in aggregate. Responses in most studies were judged clinically; in study 6, CSF criteria were used as well. For summed data, RR is 0.986 (95% CIs 0.948 to 1.025). Additional analyses of doxycycline vs parenteral penicillin or ceftriaxone individually and of parenteral penicillin vs ceftriaxone similarly showed no significant differences. Key to studies: #1²⁷; #2¹⁹; #3¹⁵; #4³⁴; #5¹⁴; #6²⁰; #7³³; #8³⁵.