Joinpoint software was used to quantify the average annual change in calls, and whether there was a significant change in trend at any time, including following rescheduling.


 Joinpoint analysis showed that the frequency of cases increased significantly from 2004 to 2015, with an average annual percentage change (AAPC) of 19.5% [95% confidence interval (CI) = 13.8-25.5% P < 0.0001] for paracetamol/codeine and 17.9% (95% CI = 7.9-28.9%, P < 0.01) for ibuprofen/codeine. 
Joinpoint