Ciprofloxacin used at study entry independently predicted invasive Candida infection ( adjusted hazard ratio = @ -LSB- @-@ @ -RSB- ) ; the risk gradually increased with duration of ciprofloxacin therapy : six of @ in patients not exposed ( @ % ) , eight of @ ( @ % ) when used for @-@ days ( hazard ratio = @ ; @ % CI , @-@ @ ) , and @ of @ ( @ % ) when used for @ days ( hazard ratio = @ ; @ % CI , @-@ @ ; p = @ ) .