Fullen 1973.

Methods	Study design: A single centre study. Country: United States. Follow up was adequate.
Participants	Number: 129 participants with proximal femoral fractures. Age: Average age 69 and 67 years (filter and control group respectively). Sex: Gender distribution not stated. Inclusion criteria: Proximal femoral fractures were invited to participate in the study. Exclusion criteria: Refusal to participate in the trial.
Interventions	Treatment: Permanent caval filter. Control: No filter.
Outcomes	Primary outcomes. 1. Mortality. 2. Pulmonary embolism. Secondary outcomes. 1. Complications from filter insertion. Outcomes assessed when clinically indicated and at discharge.
Notes	Jadad score 2/5. Anticoagulation was not used in either the intervention (filter) or control arm. Not an intention to treat analysis.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	High risk	Randomisation based on odd or even hospital number.
Allocation concealment?	High risk	Open study design; participation in filter group based on consent.
Blinding? Mortality	High risk	Open study design; blinding of outcome assessors not stated.
Blinding? Pulmonary embolism	High risk	Open study design; blinding of outcome assessors not stated.
Incomplete outcome data addressed? Mortality	Low risk	Cause of death and numbers reported. Follow‐up complete as in‐hospital population.
Incomplete outcome data addressed? Pulmonary embolism	Low risk	Definite, probable and possible pulmonary embolism rates reported. Blinding of outcome assessors not stated. Use of chest radiography in diagnosis of PE is inaccurate. Not stated whether all patients had routine imaging, or only when clinically indicated.
Free of selective reporting?	Unclear risk	Protocol brief. Mortality, PE and filter complication outcomes documented. Rates of DVT not reported.