Bristow 2011.

Study characteristics
Methods	Retrospective chart review at Johns Hopkins Hospital, USA Women enrolment was between January 1995 and December 2008
Participants	405 women with FIGO stage IIIC epithelial ovarian cancer based on intraoperative findings or radiographic imaging coupled with fine‐needle biopsy diagnosis. All epithelial histological subtypes were included. Borderline ovarian tumours of low malignant potential were excluded. Women characteristics reported as Whites (n = 366) vs African‐Americans (n = 39) Median age: 59 vs 59 years ASA class, I/II/III/IV: 5/124/232/5 vs 0/4/31/4 Histology, serous/non‐serous: 314/52 vs 31/8 Tumour grade, 1/2/3: 39/33/294 vs 2/4/33 Optimal RD (defined as ≤ 1 cm)/no gross RD: 267/188 vs 18/21
Residual disease details	All women underwent attempted surgical cytoreduction either primarily Residual disease was defined as: SVRD (RD 0.1 cm to 1.0 cm) NMRD (no gross RD) Residual disease was noted as follows: Optimal (≤ 1 cm): White, n (%): 178 (44%); African‐American; n (%): 18 (4.5%) NMRD: White, n (%): 188 (46.5%); African‐American; n (%):21 (5%)
Outcomes	SVRD vs NMRD: HR for OS 2.74 (95% CI 1.98 to 3.71) (HR adjusted for age, race, tumour grade, histology, ASA score, surgical complexity score, serum albumin, administration of platinum‐based chemotherapy and significant peri‐operative morbidity) OS was calculated from the date of diagnosis using Kaplan–Meier curves and compared using the log‐rank test and Cox proportional hazards model
Risk of bias (QUIPS)	1. Study participation (a‐f): low risk Adequate number of participants and description of target population. Baseline characteristics, eligibility criteria, sampling frame and period/place study took place presented clearly. 2. Study attrition (a‐e): unclear risk Unclear if patients with incomplete follow‐up were excluded before arriving at the stated sample size. Insufficient information to permit judgement. 3. Prognostic factor measurement (a‐f): low risk Valid and reliable measurement of RD Outcome level assessment: Outcome: overall survival 4. Outcome measurement (a‐c): low risk Valid and reliable measurement of outcome 5. Adjustment for other prognostic factors (a‐g): high risk HR for OS was adjusted for race, tumour grade 3, non‐serous histology, ASA score >3, surgical complexity score, serum albumin < 3.0 g/dL, platinum‐based therapy, residual disease and perioperative morbidity in multivariable Cox model 6. Statistical analysis and reporting (a‐d): high risk No conceptual framework; unclear of variable selection criteria in multivariate model Outcome: progression‐free survival Not reported
Notes	A total of 433 ovarian cancer women were identified with stage IIIC disease. Of these, 28 women were variously classified as either Asian‐Pacific Islander, Hispanic, unknown or other and were excluded from further study. Source of funding: the Queen of Hearts Foundation for Ovarian Cancer Research Declaration of interest: none declared Median follow‐up: 33.0 months The 30‐day mortality rate for all 405 women was 1.5% Retrospective non‐randomised study. Blinding not reported (but not applicable). Adjusted HRs are derived from a prognostic model. No details on how modelling was performed, but this seems to have been done based on significance testing (and not on including putative confounders in the analysis, irrespective of statistical significance). Women and disease characteristics not reported according to debulking status. NB: study only included women with stage IIIC ovarian cancer/possible overlap with Peiretti 2012.