Evans 2015.

Methods	Design: multicentre (nine sites) parallel group, two‐arm randomised controlled trial Setting: USA Timing: unclear Interventions: percutaneous vertebroplasty versus kyphoplasty Sample size: total sample size of 96 participants would provide 80% power to detect a ‘medium’ effect size of 0.58; planned to recruit a total of 120 participants assuming up to 20% loss to follow‐up at 12 months Analysis: intention‐to‐treat analysis
Participants	Number of participants Numbers screened for eligibility and number excluded or declined to participate is not stated. 115 patients randomised (56 to vertebroplasty, 59 to kyphoplasty) Data for 88 (70.7% of vertebroplasty group, 78.2% of kyphoplasty group) available at 12‐month assessment Inclusion criteria Older than 50 years of age Pain that had occurred in the previous 12 months attributable to one or more compression fracture of the vertebrae in the areas T4‐L5 confirmed with a physical examination and imaging Fractures detected on plain radiography Pain of at least 5 (on a scale of 0 to 10) Candidates for minimally invasive surgery Able to successfully complete a battery of health questionnaires Available and willing to participate in follow‐up Exclusion criteria Neurological deficits related to the compression fracture or other contraindications to vertebral augmentation History of surgery within last 60 days History of open back surgery Concomitant hip fracture, rib fracture, or sacral insufficiency fracture Malignant tumour deposit (multiple myeloma), tumour mass, or tumour extension into the epidural space at the level of the fracture to be treated Baseline characteristics Vertebroplasty group: Mean (SD) age: 76.1 (10.0) years; 77.6% female: 22.4% male Mean (SD) Charlson score: 0.43 (0.90) Comorbidities: 57.9% Neurological deficit: 4.7% Prior fracture history · Vertebral: 17.9% · Non‐vertebral: 3.6% · None listed: 78.6% Prior back surgery: 3.6% Osteoporosis: 45.0% Mean (SD) current fracture %: 25.2 (18.8) Current fracture level · L1 only: 12.5% · T11 only: 7.1% · T12 only 8.9% · Other locations: 50.0% · Not listed: 21.4% Narcotic medication at entry: 64.1% NSAID at entry: 22.2% Mean (SD) average pain (0 to 10): 7.9 (2.0) Mean (SD) SOF‐6 ADL score: 17.4 (3.1) Mean (SD) Roland‐Morris disability score: 16.3 (7.4) Mean (SD) EuroQOL score: 10.1 (1.6) Mean (SD) SF‐36 aggregate physical health: 26.6 (7.6) Mean (SD) SF‐36 aggregate mental health: 42.4 (12.7) Mean (SD) OPAQ body image score (1 to 5): 3.5 (1.4) Kyphoplasty group: Mean (SD) age: 75.1 (10.1) years; 64.8% female: 35.2% male Mean (SD) Charlson score: 0.49 (0.99) Comorbidities: 60.5% Neurological deficit: 8.7% Prior fracture history · Vertebral: 10.2% · Non‐vertebral: 11.9% · None listed: 78.0% Prior back surgery: 10.2% Osteoporosis: 37.2% Mean (SD) current fracture %: 23.1 (17.5) Current fracture level · L1 only: 17.0% · T11 only: 10.2% · T12 only 15.2% · Other locations: 35.6% · Not listed: 22.0% Narcotic medication at entry: 57.1% NSAID at entry: 26.2% Mean (SD) average pain (0 to 10): 7.4 (1.9) Mean (SD) SOF‐6 ADL score: 17.7 (4.0) Mean (SD) Roland‐Morris disability score: 17.3 (6.6) Mean (SD) EuroQOL score: 10.4 (1.9) Mean (SD) SF‐36 aggregate physical health: 26.1 (6.9) Mean (SD) SF‐36 aggregate mental health: 45.4 (14.2) Mean (SD) OPAQ body image score (1 to 5): 3.5 (1.4)
Interventions	Vertebroplasty Vertebral augmentation was performed according to standard practice according to each practitioner’s preference. The approach, device, and cement used for the procedure were at the operators’ discretion. Kyphoplasty Also performed according to standard practice according to each practitioner’s preference. The approach, device, and cement used for the procedure were at the operators’ discretion.
Outcomes	Outcomes were measured at baseline, 3 days, 1 month, 6 months, and 12 months after treatment (telephone follow up at day 3, 1 month and 6 months and in person at 1 year). Primary outcome Mean pain on a 0 to 10 numerical verbal scale Secondary outcomes Use of pain medications Roland‐Morris Low Back Pain and Disability Questionnaire (RMDQ) Short‐Form Health Survey Instrument (SF‐36) EuroQOL EQ‐5 Health States Instrument Study of Osteoporotic Fractures‐Activities of Daily Living (SOF‐ADL6) Modified Deyo Patrick Pain Frequency and Bothersomeness Scale Osteoporotic Assessment Questionnaire (OPAQ) Body Image Scale Adverse events Outcomes included in this review Mean pain Roland‐Morris Disability Questionnaire (RMDQ) European Quality of Life – 5 Dimensions (EQ‐5D) Adverse events
Source of funding	Supported by Carefusion, Johnson and Johnson/DePuy Synthes Spine, Cardinal Health and Stryker.
Notes	Clinicaltrials.gov trial identifier: NCT00279877 SD for EuroQOL EQ‐5 Health States Instrument imputed from baseline for both treatment groups.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Trial participants were randomly assigned to either the kyphoplasty intervention or the vertebroplasty intervention using a variable block randomisation scheme to ensure balance of assignment to both groups over time. The block sizes were randomly varied and of sufficient size to minimise the ability of any investigator or co‐ordinator to guess the next assigned treatment.
Allocation concealment (selection bias)	Low risk	The random treatment assignments were placed in sequentially numbered envelopes and distributed to the clinical sites.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	The study is reported as 'single‐blind' in the clinical trial registry, but reports of who was blinded are contradictory: the site co‐ordinators and other personnel who collected trial participant data and administered the study questionnaires were blinded to the assigned treatment, according to the results report but participant blinding was reported in the trial registry.
Blinding of outcome assessment (detection bias) Self‐reported outcomes (e.g., pain, disability)	Unclear risk	Unclear if the 'single‐blinded' study refers to blinding of participants or not.
Blinding of outcome assessment (detection bias) Objective outcomes (e.g., radiographic outcomes)	Low risk	No objective outcomes were measured.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	A quarter of the participants did not complete follow‐up (21.8% of vertebroplasty group, 29.3% of kyphoplasty group). The authors report that the pattern of loss to follow‐up appeared to be missing at random.
Selective reporting (reporting bias)	High risk	Adverse events were to be measured but were not reported.
Other bias	Unclear risk	Quote: “Another limitation of our study is the lack of standardisation of the procedures. The approach, device, and cement used for the procedures were at the operators’ discretion.”