Figure 4

Diffusion pattern of two COX-2 inhibitors (market share; cost (NT dollars)), quarterly, 2001-2004. The market share (cost) of celecoxib in the NSAIDs market rapidly increased to 19.32% in only six months (2001 S4) after its listing into the NHI's benefit coverage and continued to increase thereafter. Its competitor, the follower COX-2 inhibitor (rofecoxib), however, took about two years to reach its market share (cost) to 20.22% (2003 S4) after its listing and sustained a 5% market share gap to celecoxib thereafter.