Logghe 2009.

Methods	Study design: RCT Number of study arms: 2 Length of follow‐up: 12 months
Participants	Setting: 2 industrial towns in the western Netherlands Number of participants: 269 Number analysed: 269 Number lost to follow‐up: 0 Sample: registered with participating 23 general practices Age (years): mean 77 (SD 4.6) Sex: 71% female Inclusion criteria: aged ≥ 70; community‐dwelling; high falls risk (1 or more falls in previous year or 2 or more risk factors for falling (disturbed balance, mobility problems, dizziness, using benzodiazepines or diuretics)) Exclusion criteria: none described
Interventions	1. Group‐based Tai Chi: 1 hour, 2 a week for 13 weeks + fall‐prevention brochure 2. Control: fall‐prevention brochure
Outcomes	1. Rate of falls 2. Number of people who experienced 1 or more falls (risk of falling) 3. Number of people who died
Duration of the study	52 weeks
Adherence	Adherence measured by lesson attendance 1. Group‐based Tai Chi: 47% attended 80% of lessons
Notes	Source of funding: Netherlands Organization for Health Research and Development (ZonMw) Economic information: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "An independent research assistant performed a prestratified block randomization using a computer‐generated randomization list"
Allocation concealment (selection bias)	Low risk	Quote: "An independent research assistant performed ... randomization"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Participants and personnel not blinded to allocated group but impact of non‐blinding unclear
Blinding of outcome assessment (detection bias) Falls	Low risk	Falls self‐reported but Quote: "The blinded research assistant contacted the participant when forms were missing or incomplete, and they then completed the forms together over the telephone". Falls were recorded and confrimed using the same method in both groups
Blinding of outcome assessment (detection bias) Fractures	Unclear risk	Not applicable
Blinding of outcome assessment (detection bias) Hospital admission, medical attention and adverse events	Unclear risk	Not applicable
Blinding of outcome assessment (detection bias) Health related quality of life (self report)	Unclear risk	Not applicable
Incomplete outcome data (attrition bias) Falls and fallers	Low risk	No missing fall data
Selective reporting (reporting bias)	Unclear risk	Minimum set of expected outcomes not reported (adverse events not reported)
Method of ascertaining falls (recall bias)	Low risk	Quote: "At baseline, the participants received a falls calendar and the instruction to fill it out on a daily basis for 1 year ... The fall calendars were collected monthly by mail. The blinded research assistant contacted the participant when forms were missing or incomplete, and they then completed the forms together over the telephone"