Gold 2004.

Methods	Cluster‐randomized controlled trial (unit of randomization was retirement facility)
Participants	# Randomized: 185 (94 intervention, 91 control) Lost to follow‐up: 9 intervention, 5 control Age: 81 Country: USA Inclusion criteria: women, at least one vertebral fracture (reduction in vertebral height compared to adjacent vertebrae of 20% or greater) Exclusion criteria: vertebral fracture in the last 6 months, hip fracture in the last 12 months, more than 2 errors on the short portable mental status questionnaire, corrected vision worse than 20/40, active cardiac, pulmonary, neurological disease or rheumatoid arthritis, injurious fall in the last 6 months, not an independent ambulator
Interventions	Experimental Frequency: 3 times/week for exercise, 2 times/week for coping class Intensity: not specified Time: 45 minutes each for exercise class and coping class Type: stretching, strengthening with weights and resistance bands, instruction on optimal alignment and body mechanics, coping class Duration of intervention: 6 months Supervisor: physical therapist Supervision/Setting: group class in retirement facility Progression of intensity: yes Control: weekly class on general health information Duration of follow‐up after baseline assessment: 6 months
Outcomes	Trunk extension strength: peak isometric strength in foot pounds‐ mean of 3 maximal trials using B‐200 isostation Pain ‐ subscale of Functional Status Index Psychological symptoms ‐ Global Severity Index of the Hopkins Symptom Checklist 90 ‐ Revised
Notes	Adherence: 58% Adverse events Due to intervention: ‐ fracture of costal cartilage while rolling from supine to prone ‐ pain Unclear if due to intervention: ‐ hip fracture when lifting leg into measurement device (6‐month assessment) ‐ metatarsal fracture when weight dropped on foot Not due to intervention: ‐ none Between‐group comparison as actual difference or change scores: change scores
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization was performed using a random number generator with equal allocation to the two arms." Comment: probably done.
Allocation concealment (selection bias)	Low risk	Quote: "All researchers except the biostatistician were masked to allocation status until a site was enrolled." Comment: probably done.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Participants were unaware of the content of the intervention that they did not receive initially." Comment: probably done.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "All personnel involved with subject contacts, data collection, and intervention administration were masked to the intervention status of the sites and to the study hypotheses throughout the trial." Comment: probably done.
Blinding of subjective outcome assessment (detection bias)	Unclear risk	Comment: Pain and Global Severity Index were reported by participants who were unaware of group allocation.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: data were excluded from 63 of a total of 185 participants for the muscle strength outcome because of equipment problems; analyses for this outcome used a sample size of 122.
Selective reporting (reporting bias)	Unclear risk	Comment: Gold 2004 reported on data from three primary outcomes. However, the data belong to a much larger database that includes data from a number of studies, and a number of other outcomes were collected but were not reported in the paper. Data on walking endurance (six‐minute walk distance) was presented at the American Society for Bone and Mineral Research Annual Meeting in 2004, and data on trunk endurance (Timed Loaded Standing) were presented at the American Society for Bone and Mineral Research Annual Meeting in 2007. We have been in contact with the authors to get access to these data and other unreported outcomes, but they were not available in time for this review. We were informed that the three primary outcomes were chosen a priori.