Table 3

 Evidence of efficacy—pooled effect size (ES) and number needed to treat (NNT)

InterventionStudiesESpain (95% CI)ESfunction (95% CI)
Category*NoDurationNNT (95% CI)
*See table 1 for definitions.
No, number of studies; ES, effect size of treatment compared with placebo unless otherwise stated; NNT, number needed to treat to obtain moderate to excellent (>50%) pain relief or symptomatic improvement; –, not available; NS, not significant.
EducationIb124 months
Weight lossIII12
NSAIDsIa141–20 weeks0.69 (0.12 to 1.26)4 (3 to 6)
OpioidsIb14 weeks0.78 (0.38 to 1.18)0.78 (0.26 to 1.30)NS
Chondroitin sulphateIb16 months
Avocado soybean unsaponifiableIb26–12 months0.31 (−0.64 to 1.26)0.52 (−0.36 to 1.40)
DiacerheinIb13 years0.00 (−0.17 to 0.17)0.00 (−0.17 to 0.17)
Hyaluronic acidIII33–12 months
Intra-articular steroidIb13 monthsNS
OsteotomyIII92–20 years
THRIII1182–20 years