Impact of a national basic skills in colonoscopy course on trainee performance: An interrupted time series analysis

Table 2 Interrupted time series models of the performance indicator of colonic intubation by procedure count

	Gradient (95%CI)	P value
Pre-course lifetime procedure count: < 70
Pre-course gradient (per 10 procedures)	3.3 pp (2.6, 4.1)	< 0.001b
Step-change	5.6 pp (2.5, 8.7)	< 0.001b
Post-course gradient (per 10 procedures)	2.3 pp (1.6, 3.1)	0.0651
Pre-course lifetime procedure count: 70-140
Pre-course gradient (per 10 procedures)	3.2 pp (2.4, 4.1)	< 0.001b
Step-change	5.4 pp (1.9, 8.9)	0.003b
Post-course gradient (per 10 procedures)	0.2 pp (-0.6, 1.1)	< 0.0011b
Pre-course lifetime procedure count: > 140
Pre-course gradient (per 10 procedures)	1.3 pp (0.6, 2.1)	0.001b
Step-change	3.9 pp (0.8, 7.0)	0.014a
Post-course gradient (per 10 procedures)	0.8 pp (0.1, 1.6)	0.3341

¹Denotes comparisons of pre- and post-course gradients.

^aP < 0.05.

^bP < 0.01. Results are from interrupted time series models, using a linear regression approach, as described in the methods. Gradients are reported per 10 procedure increase in experience and are given as percentage point changes with 95% confidence intervals. CI: Confidence interval; pp: Percentage point.