Joinpoint analysis of the use of surgery
| Segment | Lower end point | Upper end point | Annual percentage change | Lower 95th CI | Upper 95thCI | Test statistic (t) | Prob > |t| |
| 1 | 1993 | 2007 | 2.6* | 1.9 | 3.2 | 8.2 | 0.0 |
| 2 | 2007 | 2013 | −1.7* | −3.1 | −0.3 | −2.6 | 0.0 |
*Reflects significance at the 0.05 level.