Leaning curve analysis using data splitting method
| Variables | 1st quarter | 2nd quarter | 3rd quarter | 4th quarter | Trend difference across quarters |
|---|---|---|---|---|---|
| Patient sequence (patient no) | 1–24 (24) | 25–48 (24) | 49–72 (24) | 73–95 (23) | |
| Age (mean±SD) | 67.46±10.484 | 62.75±11.433 | 62.13±10.999 | 66.57±9.336 | No difference across quartersp>0.085 |
| 95% CI | 63.03 to 71.89 | 57.92 to 67.58 | 57.48 to 66.77 | 62.53 to 70.6 | |
| Degree of stenosis (mean±SD) | 69.96±12.539 | 77.82±8.368 | 76.39±9.942 | 77.91±8.286 | Difference between 1st and 2nd quarter, p=0.033. No difference across other quarters |
| 95% CI | 64.53 to 75.38 | 74.29 to 81.35 | 72.19 to 80.59 | 74.24 to 81.58 | |
| Location | |||||
| MCA | 10 | 16 | 15 | 10 | Difference between 1st and 2nd quarter in frequency of location at VBA, p=0.023. No difference across other quarters |
| ICA | 6 | 7 | 5 | 8 | |
| VBA | 8 | 1 | 4 | 5 | |
| Event to stenting <30 days (rate) | 10 (41.7%) | 15 (62.5%) | 14 (58.3%) | 18 (78.3%) | Difference between 1st and 4th quarter, p=0.011. Difference between 4th quarter and the rest, p=0.05 |
| Procedural problem (rate) | 4 (16.7%) | 5 (20.8%) | 2 (8.3%) | 0 | Difference between 4th quarter and the rest, p=0.046 |
| Technical failure (rate) | 2 (8.3%) | 2 (8.3%) | 2 (8.3%) | 0 | No difference across quarters,p>0.33 |
| Guidewire- or angioplasty-related hemorrhagic complication <30 days (rate) | 1 (4.2%) | 1 (4.2%) | 1 (4.2%) | 0 | No difference across quarters,p=1 |
ICA, internal carotid artery; MCA, middle cerebral artery; VBA, vertebrobasilar artery.