Arrillaga 1999.

Methods	Quasi‐RCT (algorithm used was based on the daytime and weekday availability of ultrasound). Location: Community Hospital, Level‐I‐Trauma Center, South Carolina, USA. Recruitment period: 9 months Risk of bias assessment: A. Adequacy of concealment: 0 B. Intention‐to‐treat: 0 C. Blinding: 0 D. Comparability of treatment groups at entry: 1 E. Comparability of care programmes: 0 F. Definition of inclusion and exclusion criteria: 1 G. Description of interventions: 1 H. Definition of outcomes: 2 I. Duration of surveillance: 0 (not defined)
Participants	Inclusion criteria: consecutive patients with suspected blunt abdominal trauma. 331 enrolled (US 105, no US 226). US group: mean age 38.1 (SD 22.7) years, mean ISS 13.0 (SD 11.6), 62% males. No US group: mean age 33.6 (SD 18.6) years, mean ISS 13.4 (SD 9.7), 69% males
Interventions	a. Clinical examination, focused ultrasound for free fluid, further management depended on sonograms and hemodynamic stability b. Clinical examination, CT in stable and DPL in unstable patients
Outcomes	1. Number of diagnostic tests (CT, DPL) 2. Mortality 3. Morbidity (not specified) 4. Length of stay 5. Total costs
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Allocation according to admission date and time
Allocation concealment (selection bias)	High risk	Allocation according to admission date and time
Blinding (performance bias and detection bias) All outcomes	High risk	No blinding attempted
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding attempted
Blinding of outcome assessment (detection bias) All outcomes	High risk	No blinding attempted
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear
Selective reporting (reporting bias)	Unclear risk	Unclear
Other bias	Unclear risk	Unclear