Table 1 Characteristics of included studies

Trials comparing VT methods

 Mowat, 2018 [15]

Australia

RCT

POD0

Backfill vs. autofill

200 mL backfill (20)

Autofill (20)

PVR < 150 mL with voided volume ≥ 68%

Successful VT rate (95% vs. 90%; P = 1); time to discharge (16 h vs. 18.5 h; P = 0.43)

 Foster, 2007 [14]

USA

RCT

POD0

Backfill vs. autofill

300 mL backfill (27)

Autofill (28)

Voided volume ≥ 200 mL with PVR < voided volume

Successful VT rate (61.5% vs. 32.1%; P = 0.02); patient satisfaction (91.7% vs. 96.3%; P = 0.22); time to discharge (199.5 min vs. 226.6 min; P = 0.08)

Trials comparing VT methods

 Tunitsky-Bitton, 2015 [18]

USA

RCT

POD0

300 mL backfill

FOS (50)

SVT (52)

Int: FOS ≥ 50%; control: voided volume ≥ 200 mL or PVR ≤ 1/3 total volume

Discharge with catheter rate (26.0% vs. 25.5%; P = 0.95); void volume (200 vs. 275; P = 0.16); PVR (107.5 vs. 66; P = 0.4); patient satisfaction (P > 0.05); correct passing rate (0/76; 95% CI, 0–5.8%); UTI (6% vs. 5.7%)

 Williams, 2019 [16]

USA

RCT

POD0

Backfill

FOS (49)

SVT (53)

Int: FOS ≥ 50% or PVR < 500 mL; control: voided volume ≥ 2/3 total instilled

Discharge without catheter rate (8.2% vs. 9.4%; difference—− 1.3%; 95% CI, − 11.1 to 8.5%; P = 1); unexpected postoperative visits rate (10.2% vs. 3.8%; difference 6.0%; 95% CI, − 5.2 to 17.2%); correct passing rate (6.1% vs. 0; difference 6.1% (− 4.0, 16.2)); UTI (4.1% vs. 3.8%; difference 0.3%; 95% CI, − 9.4% to 10.1%); time to discharge (2.1 h vs. 3.2 h; P = 0.0002)

 Pilkinton, 2019 [17]

USA

RCT

POD0

300 mL backfill

FOS (86)

SVT (87)

Int: FOS ≥ 50%; control: voided volume ≥ 200 mL or 2/3 instilled

Discharge without catheter rate (17.4% vs. 26.4; RR 0.65, 95% CI 0.37–1.18, P > 0.05); correct passing rate (2.8% vs. 3.1%; difference 20.31% 95% CI 28.69 to 8.08%); UTI (9% vs. 7%; P > 0.05)