Titlestad 2001.

Methods	Design: Parallel group RCT Country: Denmark Multicentre study: No Setting: Hospital Follow‐up: 30 days Unit of allocation: Patients Unit of analysis: Patients
Participants	Inclusion criteria: Patients admitted —acute and elective— to the Department of Colorectal surgery, undergoing open colorectal surgery Exclusion criteria: Those receiving blood transfusions within the final 3 months prior to surgery and those below 18 years Patients enrolled: 279 Patients randomised: 279 Leukocyte‐depleted erythrocyte suspensions group (LD‐SAGM): 139 patients Buffycoat‐depleted group: 140 patients Patients transfused: 125 (112 to the allocated group) Patients considered for the analysis: 279 Main characteristics of patients: Age: Median/range: Leukocyte‐depleted erythrocyte group = 71 (66 to 77) years; Leukocyte‐depleted erythrocyte = 73 (62 to 79) years Percentage of men: LD‐SAGM group = 51%; Non‐leukocyte‐depleted erythrocyte suspensions (SAGM) group = 60% Number of malignant colorectal disease: LD‐SAGM group = 37; SAGM group = 56 Hemoglobin: Median/range: LD‐SAGM group = 12.6 (10.6 to 14.2) g/dL; SAGM group = 12.4 (11.1 to 13.9) g/dL
Interventions	Experimental: LD‐SAGM (pre‐storage leukoreduction). Control: SAGM. Cointervention: "all patients received perioperative prophylactic antibiotics intravenously (3 g ampicillin or 3 g cefuroxim and 1.5 g metronidazol)" (Page 149). Platelet transfusion as co‐intervention was not reported
Outcomes	This RCT did not specify by primary or secondary outcomes. Posooerative infectious complications: Abdominal wound infection, intra‐abdominal abscess, septicaemia, pneumonia. Non‐infectious surgical complications: Anastomosis leakage, wound rupture, intra‐abdominal bleeding, acute myocardial infarction, deep vein thrombosis, pulmonary embolism, cerebral ischaemic stroke, death.
Notes	Trial registration: Not reported Funding: Not reported Role of sponsor: Not reported A priori sample size estimation: Yes (but not fulfilled) Conducted: Between May 1997 and November 1999 Declared conflicts of interest: Not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Patients were allocated in the blood bank to receive either..." Page 148. Comment: Insufficient information to permit judgement of ‘low risk’ or ‘high risk’.
Allocation concealment (selection bias)	Unclear risk	Comment: Insufficient information to permit judgement of ‘low risk’ or ‘high risk’.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "The blood units were supplied by the blood bank, and all units were blinded. White labels were placed on the unit product code numbers, but bar code labels were intact, ensuring safe handling" (Page 149).
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Surgeons who were blinded to the transfusion protocol performed the follow‐up examinations" (Page 149).
Incomplete outcome data (attrition bias) All outcomes	Low risk	Loss after transfusion: 10.4% (13/125). Loss after transfusion LR group: 12.7 % (7/55). Loss after transfusion Control group: 8.5% (6/70). Imbalance between comparison groups: 4.2%.
Selective reporting (reporting bias)	Low risk	The study protocol is not available but it is clear that the published reports include all expected outcomes, including those that were pre‐specified.
Other bias	High risk	Sample size bias. "Discontinued study due to large exclusions than expected, as well as higher rates of infection, insufficient sample size" (Page 149). The estimation of sample size bias considered 10% of random error and did not reported it. Design bias. Industry bias: Unclear.