Medium firm mattress v firm mattress for chronic, non-specific low back pain*

Outcomes at 90 daysMedium firm mattressFirm mattressRBI (95% CI)NNT (CI)
*Abbreviations defined in glossary. RBI, NNT, and CI calculated from control event rates and unadjusted odds ratios in article. Improvement  =  a positive change in pain intensity between baseline and 90 days.
Improvement in pain while lying in bed83%78%6.1% (−6 to 15)Not significant
Improvement in pain on rising86%80%6.8% (−4 to 20)Not significant
Improvement in pain related disability82%68%20% (7 to 30)8 (5 to 23)