SIMS is a multi-centre randomised controlled trial, funded by the NIHR HTA Programme, of surgical options for the management of female stress urinary incontinence (SUI).  The aim of this trial is to evaluate the clinical and cost effectiveness of adjustable anchored Single Incision Mini-Slings (SIMS) compared to tension-free Standard Mid-urethral Slings (SMUS). 

SIMS recruited 600 women.  Trial participants will be followed-up for 36 months.

The primary outcome measure is patient-reported success rate measured by the validated PGI-I (a 1-item questionnaire designed to assess the patient’s impression of changes in her urinary symptoms) at 12-months.

SIMS closed to recruitment in September 2017 with 600 participants recruited.  The SIMS follow-up period has been extended to 10 years post-randomisation.

SIMS is led by Professor Mohamed Abdel-Fattah based at the University of Aberdeen.

For more information please see the SIMS Study Website



Ongoing - Data Collection/Follow Up


Abdel-Fattah M, Cooper D, Davidson T, Kilonzo M, Hossain M, Boyers D, Bhal K, Wardle J, N'Dow J, MacLennan G, Norrie J. Single-Incision Mini-Slings for Stress Urinary Incontinence in Women.  N Engl J Med. 2022 Mar 31;386(13):1230-1243. doi: 10.1056/NEJMoa2111815.


Abdel-Fattah M, Cooper D, Davidson T, Kilonzo M, Boyers D, Bhal K, McDonald A, Wardle J, N'Dow J, MacLennan G, Norrie J.  Single-incision mini-slings versus standard synthetic mid-urethral slings for surgical treatment of stress urinary incontinence in women: The SIMS RCT. Health Technol Assess. 2022 Dec;26(47):1-190. doi: 10.3310/BTSA6148. 


Kilonzo M, Boyers D, Cooper D, Davidson T, Bhal K, N'Dow J, MacLennan G, Norrie J, Abdel-Fattah M. Three-year cost utility analysis of mini versus standard slings: A trial based economic evaluation. BJUI Compass. 2023 Nov 13;5(2):230-239. doi: 10.1002/bco2.303. PMID: 38371196; PMCID: PMC10869650.


Boyers D, Kilonzo M, Davidson T, Cooper D, Wardle J, Bhal K, N'Dow J, MacLennan G, Norrie J, Abdel-Fattah M. Patient preferences for stress urinary incontinence treatments: a discrete choice experiment. BMJ Open. 2023 Aug 29;13(8):e066157. doi: 10.1136/bmjopen-2022-066157.


Young, C., Cooper, D., Mostafa, A., Abdel-Fattah, M. The “Aberdeen Home Continence Stress Test”: a novel objective assessment tool for female stress urinary incontinence. International Urogynecology Journal, vol. 34, no. 8, pp. 1961–1969


Nipa, S. I., Cooper, D., Mostafa, A., Hagen, S., Abdel-Fattah, M.  Novel clinically meaningful scores for the ICIQ-UI-SF and ICIQ-FLUTS questionnaires in women with stress incontinence.  International Urogynecology Journal.