| Study characteristics |
| Methods |
RCT |
| Participants |
Setting: Basel, Switzerland
N = 378.
Sample: volunteers recruited from long‐term cohort study, and newspaper advertisements (52% women)
Age (years): mean 75 (SD 4.2)
Inclusion criteria: aged over 70; mobile; independent lifestyle
Exclusion criteria: primary hyperparathyroidism; polyarthritis or inability to walk; calcium supplementation > 500 mg/day; vitamin D intake > 200 IU/day, active kidney stone disease; history of hypercalcuria, cancer or other incurable diseases; dementia, elective surgery planned within next 3 months; severe renal insufficiency; fracture or stroke within last 3 months |
| Interventions |
1. Alfacalcidol (Alpha D3 TEVA) 1 µg/day for 36 wks
2. Placebo daily for 36 wks |
| Outcomes |
1. Number of people falling
2. Adverse effects
Other outcomes reported but not included in this review |
| Duration of the study |
9 months |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Randomised using "numbered containers"; numbered and blinded by independent statistical group |
| Allocation concealment (selection bias) |
Low risk |
Numbered and blinded by independent statistical group |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
Double‐blind, placebo‐controlled study |
| Blinding of outcome assessment (detection bias)
Falls and fallers |
Low risk |
Subjects (blind to intervention group) asked to record falls in a diary and to telephone within 48 hours of a fall. Questionnaire about incidence of falls at clinic visits (4 wks, 12 wks, and every 12 wks subsequently to 36 wks) and "All investigators and staff conducting the study remained blinded throughout the treatment period." |
| Incomplete outcome data (attrition bias)
Fallers |
Low risk |
SeeAppendix 3 for method of assessment |
| Risk of bias in recall of falls |
Unclear risk |
Subjects asked to record falls in a diary and to telephone within 48 hours of a fall. Also questionnaire about incidence of falls at clinic visits (4 wks, 12 wks, and every 12 wks subsequently to 36 wks). |
