Lower respiratory tract infection ( LRTI ) by @ year ( relative risk -LSB- RR -RSB- , @ ; @ % CI , @-@ @ ) , childcare by @ year ( RR , @ ; @ % CI , @-@ @ ) , and higher body mass index ( RR , @ ; @ % CI , @-@ @ ) were associated with increased risk of early transient wheeze , whereas breastfeeding was protective ( RR , @ ; @ % CI , @-@ @ ) .