Hayashi 1992.

Study characteristics
Methods	Multicentre open quasi‐randomised trial Blinding of outcome assessors unclear Completion rate unclear
Participants	228 medical institutions in Japan 740 men and women with osteoporosis, based on Savile criteria of vertebral trabecular pattern, mean age 74.2 years (SD 8.2) Inclusion criteria: no further details Exclusion criteria: not given
Interventions	1. 1 μg alfacalcidol daily 2. No treatment Randomised 740, completed unclear Duration of treatment 1 year
Outcomes	Number of persons with vertebral fracture on X‐ray
Notes	Author provided fracture data 15 January 2013
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	States randomisation "alternatively based upon the chronological order of consultation"
Allocation concealment (selection bias)	High risk	States randomisation "alternatively based upon the chronological order of consultation"