Table 3. Impact of center volume on the clinical outcomes of PTAS.

Case volume (case per year)	30 days after PTAS				During clinical follow-up
	Studies (patients), n	I2	Incidence (%)	p for subgroup	Studies (patients), n	I2	Incidence (per 100 peson-year)	p for subgroup
First Quartile
< 4	4 (64)	0%	15 (6–23)		4 (64)	0%	16 (8–24)
≥ 4	11 (490)	46%	7 (3–11)	0.10	10 (393)	39%	7 (4–9)	0.02
Median
< 7	8 (123)	0%	14 (8–20)		8 (123)	0%	16 (10–22)
≥ 7	7 (431)	60%	6 (3–10)	0.04	6 (334)	14%	6 (4–8)	<0.01
Third Quartile
< 10	10 (188)	16%	14 (9–19)		10 (188)	0%	13 (9–16)
≥ 10	5 (366)	0%	4 (2–7)		4 (269)	0%	5 (3–7)	<0.01