Compared with placebo , unscheduled medical attendances for wheezing episodes were reduced in children given montelukast in the @/@ stratum ( @ -LSB- @ -RSB- vs @ -LSB- @ -RSB- ; IRR @ , @ % CI @-@ ; p = @ ) , but not in those in the @/x + x/x stratum ( @ -LSB- @ -RSB- vs @ -LSB- @ -RSB- ; @ , @-@ ; p = @ , pinteraction = @ ) .