Distribution of exposure characteristics of conventional NSAIDs and coxibs and RRs of upper GI events during current exposure (compared to past exposure).

Each NSAID prescription was classified according to first-ever use, long gap (previous prescription at least 6 mo before), and short gap (previous prescription within the last 6 mo). The medication possession ratio was estimated for the prescriptions issued after a short gap and divided into very low (

每一条非甾体抗炎药（Non-Steroidal Anti-Inflammatory Drugs, NSAID）处方均按照首次使用、长间隔（即上次处方开具时间至少早于本次6个月）以及短间隔（即上次处方开具时间在本次6个月以内）进行分类。针对短间隔后开具的处方，估算其药物持有率，并将其划分为极低（