Study	Reason for exclusion
Joo 2008	Tamsulosin versus no treatment for TWOC in spinal surgery patients electively catheterised perioperatively (not in acute urinary retention prior to surgery).
Kraus 2010	No catheters involved. Urodynamic assessment of daily tadalafil versus placebo on lower urinary tract symptoms.
Lim 1999	No alpha blockers used in study. Study describes outcome of TWOC in 79 untreated patients.
Liu 2009	No catheters involved as patients not in acute urinary retention. Randomised trial of amlodipine with or without terazosin for LUTS.
Lorente 2004	Use of increasing dosage of doxazosin in failed TWOC patients. 40 patients randomly assigned to doxazosin 4 mg once daily (n = 20) or no treatment (n = 20) for seven days before TWOC. Failed TWOC patients either received doxazosin 8mg (treatment group) or 4 mg (control group) once daily before a second TWOC.
Martov 2010	No catheters involved as study assessing tamsulosin for stent‐related irritative symptoms.
McNeill 2004	Long‐term follow‐up study of patient cohort who had successful TWOC following an episode of acute urinary retention (alfuzosin versus placebo).
Taube 1989b	No alpha‐blockers used in study. Study describes outcome of TWOC immediately, after 24 and 48 hours in 60 untreated patients (subdivided into three groups).
Wang 2009	No catheters involved as study assessing effect of tamsulosin in patients with indwelling double‐J ureteral stents.

LUTS = lower urinary tract symptoms
 TWOC = trial without catheter