Ralston 2011.

Study characteristics
Methods	RCT (international multicentre)
Participants	Setting: 24 countries N = 515 Sample: women with postmenopausal osteoporosis recruited from 77 centres Age (years): mean 73 Inclusion criteria: aged ≥ 65; osteoporotic (low BMD T scores or previous fragility fracture); vitamin D insufficiency (serum 25[OH]D 8 to 20 ng/ml); increased risk of falls (≥ 1 fall in previous 12 months + reduced lower extremity physical function) Exclusion criteria: using specified drugs affecting bone metabolism; receiving chemotherapy or heparin; unable to stand or walk independently; abnormal electrocardiogram or laboratory safety screening tests; malignancy within previous 5 years; malabsorption syndrome; uncontrolled upper gastrointestinal or cardiovascular disorders; hyperparathyroidism; renal disease
Interventions	1. Intervention: weekly alendronate 70 mg + vitamin D3 5600 IU in 1 tablet 2. Control: referred for standard care for osteoporosis from personal physician
Outcomes	1. Risk of falling (based on time to first fall)
Duration of the study	1 year
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Participants were randomized—using a computer‐generated allocation schedule generated by the study sponsor"
Allocation concealment (selection bias)	Unclear risk	Allocation is not clearly reported. Quote: "Participants were randomized—using a computer‐generated allocation schedule generated by the study sponsor" "Due to the referred‐care nature of the trial, it was an open‐label design. However, participants, investigators, site staff, and the sponsor's clinical team were blinded to postbaseline concentrations of serum 25(OH)D and BTMs…"
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open label study. Quote: "Due to the referred‐care nature of the trial, it was an open‐label design. However, participants, investigators, site staff, and the sponsor's clinical team were blinded to postbaseline concentrations of serum 25(OH)D and BTMs…".
Blinding of outcome assessment (detection bias) Falls and fallers	High risk	Self reported falls and likely the study personnel ascertaining falls were aware of allocated group as only blinding to "postbaseline concentrations of serum 25(OH)D and BTMs…" is mentioned. Fall events were also reviewed at office visits where staff were not blind to allocated groups.
Incomplete outcome data (attrition bias) Fallers	Low risk	SeeAppendix 3 for method of assessment
Risk of bias in recall of falls	Low risk	Quote: "Participants were asked to record falls on a study calendar and to notify the study site of falls by telephone or prestamped postcard. After notification, study‐site personnel telephoned women reporting falls to obtain details about the event, including a description of the fall, the location, contributing factors (e.g., tripping, poor vision), the immediate aftermath, longer‐term consequences, and the medical attention that was required. All participants were also routinely contacted on a monthly basis to survey fall incidences (except when an office visit was scheduled in the same month, where fall events were reviewed). Falls were adjudicated by an independent committee".