Ness 2007

Methods	RCT.
Participants	Singleton (and 3 twin) gestations; uterine contractions or symptoms suggestive of PTL at 24 to 33 6/7 weeks. N = 100.
Interventions	TVU CL knowledge or not (the control group did receive TVU CL, but results were blinded to managing physicians). Time TVU CL results available: not specified. Protocol for TVU knowledge group: yes.
Outcomes	Primary: time from initial evaluation to discharge.
Notes	Intention to treat; 97% singletons; protocol for management of TVU CL group, which included management based on FFN for women with CL 20 to 29 mm. Short TVU CL (< 20 mm): 11/51 (22%) in knowledge group; 7/49 (15%) in the control group.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random numbers.
Allocation concealment (selection bias)	Low risk	Numbered, sealed opaque envelopes.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Women and physicians knew which group was randomized to 'knowledge' or 'no knowledge'.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Intention‐to‐treat analyses.
Selective reporting (reporting bias)	Low risk	Primary outcome time from evaluation to discharge. All other outcomes reported.
Other bias	Low risk	Baseline characteristics similar.