Studer 1996.

Methods	Randomised prospective study, with 1 subsequent paper published with longer follow‐up data: Studer 1996 (primary reference) Studer 1991 Median follow‐up: Anti‐reflux nipple 36 months, afferent tubular segment 30 months Drop‐outs: Total 60 patients operated on, but data on 40 presented as follow‐up was more than a year in this subgroup. Total 20 drop‐outs. Studer 1996 (primary reference) Median follow‐up: Anti‐reflux nipples 57 months, afferent tubular segment 45 months Drop‐outs: None
Participants	Incl: radical cystectomy, bladder substitution with ileal segment and male patients only Excl: Patient follow‐up less than a year, female patients Studer 1991 n (anti‐reflux nipple) = 20 n (afferent tubular segment) = 20 Sex: All males Mean age: 63.7 years Studer 1996 (primary reference) n (anti‐reflux nipple) = 35 n (afferent tubular segment) = 35 Sex: All males Median age: anti‐reflux nipple 66.6 years and afferent tubular segment 63.8 years
Interventions	I: Anti‐reflux nipple II: Afferent ileal tubular segment
Outcomes	Studer 1991 I: Reflux vs No reflux II: Urinary continence (day and night) III: Bacteriuria presence IV: Serum acidosis V: Serum B12 VI: Kidney size Studer 1996 (primary reference) I: Urinary continence (day and night) II: Bacteriuria presence III: Pyelonephritis IV: Uretero‐intestinal strictures requiring re‐operation V: Upper tract dilatation VI: Functional reserve VII: Renal function VIII: Voiding habits IX: Urinary stones
Notes	No mention of disease type in the inclusion criteria of the study. Studer 1996 was used as the primary study as this had the longest follow‐up. Studer 1991 Unclear causes of deaths. 18 deaths from "progressive" disease and 3 deaths from "other" causes. In 3 patients with metabolic acidosis requiring correction, no mention was made of which treatment group these patients originated from. Studer 1996 (primary reference) Note 22 deaths from progressive bladder cancer. Conflicting numbers of pyelonephritis in patients compared to Studer 1991. For the purposes of analysis, the numbers from the later report; Studer 1996 were included in the tables. It was not possible to extract data from Fig. 2 of Studer 1996 paper for the purposes of analysing the incidence of bacteriuria / positive culture. In upper tract dilatation, the numbers used in the final analysis were from Studer 1996. It should be noted that renal units were used rather than patient numbers. It was not possible to analyse the outcomes of metabolic acidosis, functional reserve, renal function and voiding habits in both reports as no actual figures were presented.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	not stated
Allocation concealment (selection bias)	Unclear risk	not stated
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	not stated
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	not stated
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Total 60 patients operated on, but data on 40 presented as follow‐up more than a year in this subgroup. Total 20 drop‐outs.

Incl. = inclusion criteria 
 Excl. = exclusion criteria 
 GFR = Glomerular filtration rate (mls/min)