Dear Editor, We welcome the efforts of El-Yahchouchi et al. [1] on undertaking a retrospective study of a large patient cohort to address the important issue of comparison of efficacy of particulate (triamcinolone and betamethasone) and nonparticulate (dexamethasone) lumbar transforaminal epidural steroid injections (TFESI). The authors conclude that lumbar TFESI of dexamethasone is noninferior to betamethasone and triamcinolone for treatment of radicular pain and that dexamethasone is superior to triamcinolone and betamethasone with regard to pain and functional outcome at 2 months. However, we have several questions regarding their methodology and conclusions of this article. First, particulate steroids were used in 87% (N = 3,162) of their TFESIs, whereas dexamethasone was used in only 13% (N = 481). This is a considerable difference in sample size between the particulate and nonparticulate groups, and it is reflected in the wider …