Wong 2013.

Methods	Randomised controlled trial
Data	Setting: primary care, Canada. Participants were 952 people aged 50‐70 years who had not responded to initial invitation by 4 weeks. People were being recruited to a colorectal cancer screening trial not had recent colorectal cancer screening
Comparisons	Investigated use of telephone reminders to non‐responders Intervention: up to 3 telephone reminders to those not responding to initial posted invitation Comparison: no telephone reminders (but did get a 2nd invitation)
Outcomes	Proportion recruited to trial
Notes
Risk of bias
Item	Authors' judgement	Description
Random Sequence generation ok?	Yes	Adequate
Allocation concealment?	Yes	Adequate
Blinding of participants and personnel ok?	Yes	Participants blinded, study nurse making calls clearly not but outcome objective
Blinding of outcome assessment ok?	Yes	Recruitment objective (this was study's secondary outcome, primary was attendance at eligibility screening)
Incomplete outcome data handled ok?	Yes	Adequate
Free of selective reporting?	Yes	Recruitment reported and this is only outcome needed for review
Was the study free of other bias?	Yes	No other biases apparent
Overall bias?	No	Low risk of bias

CBT: cognitive behavioural therapy; CME: continuing medical education; CVD: cardiovascular disease; DSM‐IV: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; GP: general practitioner; HRT: hormone replacement therapy; NICU: neonatal intensive care unit; NSAIDs: non‐steroidal anti‐inflammatory drugs; PIL: participant information leaflet; PL/SQL: procedural language extension to Structured Query Language; RCT: randomised controlled trial; SMS: short message service; SOP: standard operating protocol.