Sideras 2006.

Study characteristics
Methods	Trial acronym: none reported, trial of the North Central Cancer Treatment Group and Mayo Clinic Design: multicentre, placebo‐controlled 2‐arm randomised study; type of analyses not reported After 52 accrued participants, the study was modified because of concerns that the low accrual rate was related to the requirements for placebo injections. The saline placebo injections were eliminated, then, unblinded LMWH was compared with standard clinical care (with 89 more participants accrued after that point). Median duration of follow‐up: not reported, planned minimum follow‐up of 18 months
Participants	Patients with advanced breast cancer who had failed first‐line chemotherapy; advanced prostate cancer who had failed primary hormonal therapy; advanced lung cancer; or advanced colorectal cancer. Median age: 64.5 years in for blinded LMWH group; 63.5 years in placebo group; 68.5 years in unblinded LMWH group; 70.5 years in standard care group. SDs not reported Gender, n (%) males: 12 (50%) in blinded LMWH group; 11 (42%) in placebo group; 28 (64%) in unblinded LMWH group; 31 (70%) in standard care group Metastatic disease, n (%): not reported, but all had advanced incurable cancer Previous VTE, n (%): 1 (4%) in blinded LMWH group; 1 (4%) in placebo group; 2 (5%) in unblinded LMWH group; 0 (0%) in standard care group
Interventions	First part of the study, double‐blind (52 participants): LMWH, dalteparin (5000 IU SC, once daily) plus standard care Control: placebo (saline injections) plus standard care Second part of the study, open (86 participants): LMWH, dalteparin (5000 IU SC, once daily) plus standard care Control: standard care alone Duration: 18 weeks or until disease progression
Outcomes	Primary outcome: overall survival Secondary outcomes: toxic effects, incidence of thromboembolic events, changes in quality of life
Notes	Funding: Public Health Services grants from the National Cancer Institute, Department of Health and Human Services Disclosure of potential conflicts of interest: not reported and no COI forms available Publication format: full‐text publication
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: method of random sequence generation not reported.
Allocation concealment (selection bias)	Low risk	Quote: "The randomization processes applied were handled through the North Central Cancer Treatment Group (NCCTG) Randomization Office." Comment: adequate method of allocation concealment.
Blinding (performance bias and detection bias) All outcomes	High risk	Comment: the study used a double‐blind design in the first part of the trial, and an open‐label design in the second part. It is not reported if outcome assessors were blinded.
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: for effectiveness and safety, 68/69 (98.6%) participants were analysed in the LMWH group, and 70/72 (97.2%) were analysed in the placebo group.
Selective reporting (reporting bias)	Low risk	Comment: all outcomes reported in the methods section were addressed in the results or discussion sections.