Table 2.

Quality of the evidence, in aggregate, supporting single-dose doxycycline for Lyme disease prophylaxis.

No. of studies	Limitations	Imprecision	Inconsistency	Indirectness	Quality
1	Inappropriate surrogate (EM) Insufficient duration of observation Insufficient reporting of negative treatment-associated outcomes	Few events Wide CI Unsupported assumption regarding outcomes in dropouts	Non-replicated in humans Inconsistent with animal model	Not applicable to patients bitten by species other than Ixodes scapularis Not applicable to patients exposed to multiple tick-borne diseases Efficacy not applicable to other antibiotics Effectiveness findings applicable to prevention of EM only and not other, non-EM presentations	Very low

EM: Erythema migrans.