Study	Reason for exclusion
Brasel 1997	Cost‐effectiveness analysis.
Gosin 1997	Prospective interventional cohort with historical control; selected high‐risk people received filters; no data on baseline characteristics of the interventional cohort and the control group.
Khansarinia 1995	Prospective interventional cohort with historical control.
Midy 1994	Case series.
Rodriguez 1996	Prospective interventional cohort with historical control.
Rogers 1997	Prospective interventional cohort with historical control; selected high‐risk people received filters; interventional and cohort groups unmatched according to baseline characteristics.
Rosenthal 1994	Case series.
Rosner 2004	Prospective interventional cohort with historical control.
Webb 1992	Selected high‐risk patients received filters; no data on baseline characteristics of interventional and control groups; people received concurrent DVT prophylaxis.

DVT: deep vein thrombosis