Reddell 1992.
| Methods | RCT | |
| Participants | Subjects: 642 fleet service clerks; 70 women, 572 men. Age range: 19‐67 years. 26% of 642 subjects had suffered a previous back injury and 56% a previous back pain. No data available regarding subjects with current LBP. | |
| Interventions | Preventive intervention: 
1) Weightlifting belt (n=145), belt use at work, 8 months. 
2) Belt plus training class (n=127), belt use at work and 1 hour training class on spine anatomy and body mechanics. Control intervention: 3) Training class (n=122), 1 hour training class. 4) No intervention (n=248). | |
| Outcomes | Lumbar injuries, lost work days case lumbar injury, restricted work days, case lumbar injury, compensation cost. No significant differences after 8 months. | |
| Notes | Of the 896 clerks selected to participate in this study 642 were located and interviewed at the end of 8 months. Only data of these subjects is presented in the article. Compliance: 58% stopped using it before the end of 8 months. Complaints: heat production around the waist, the belt rides up and pinches ribs. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement | 
| Adequate sequence generation? | Unclear risk | Unclear from text | 
| Allocation concealment? | High risk | C ‐ Inadequate | 
| Blinding? All outcomes ‐ patients? | High risk | |
| Blinding? All outcomes ‐ outcome assessor? | High risk | |
| Incomplete outcome data addressed? All outcomes ‐ drop‐outs? | Unclear risk | Unclear from text | 
| Incomplete outcome data addressed? All outcomes ‐ ITT analysis? | High risk | |
| Similarity of baseline characteristics? | Low risk | |
| Co‐interventions avoided or similar? | High risk | |
| Compliance acceptable? | High risk | Compliance: 58% stopped using it before the end of 8 months. | 
| Timing outcome assessments similar? | Low risk | |