an increasing trendP < 0.001
a positive trendP = 0.017
This was followed by a positive trend change with an IRR of 1.004 (95%CI 1.001–1.008, P = 0.017) that resulted in an increasing trend over the post-reform period: IRR of 1.002 (95%CI 1.001–1.003, P < 0.001).