Table 3

Leaning curve analysis using data splitting method

Variables1st quarter2nd quarter3rd quarter4th quarterTrend difference across quarters
Patient sequence (patient no)1–24 (24)25–48 (24)49–72 (24)73–95 (23)
Age (mean±SD)67.46±10.48462.75±11.43362.13±10.99966.57±9.336No difference across quartersp>0.085
95% CI63.03 to 71.8957.92 to 67.5857.48 to 66.7762.53 to 70.6
Degree of stenosis (mean±SD)69.96±12.53977.82±8.36876.39±9.94277.91±8.286Difference between 1st and 2nd quarter, p=0.033. No difference across other quarters
95% CI64.53 to 75.3874.29 to 81.3572.19 to 80.5974.24 to 81.58
 MCA10161510Difference between 1st and 2nd quarter in frequency of location at VBA, p=0.023. No difference across other quarters
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%)0Difference between 4th quarter and the rest, p=0.046
Technical failure (rate)2 (8.3%)2 (8.3%)2 (8.3%)0No difference across quarters,p>0.33
Guidewire- or angioplasty-related hemorrhagic complication <30 days (rate)1 (4.2%)1 (4.2%)1 (4.2%)0No difference across quarters,p=1
  • ICA, internal carotid artery; MCA, middle cerebral artery; VBA, vertebrobasilar artery.