Although smoking is associated with a more severe disease course in people with multiple sclerosis (MS), the magnitude of effect of smoking cessation on MS progression is unknown. Tanasescu et al. quantify the impact of smoking cessation on reaching MS disability milestones by the means of data from a cross-sectional study with retrospective reports on 1270 patients with MS. They show the reduction in the risk of disability progression after smoking cessation is significant and time-dependent. Patients with MS who quit smoking have a lower risk of reaching disability milestones (4% lower risk of reaching EDSS 4.0 and 3% lower risk of reaching EDSS 6.0 for each ‘smoke-free year’), and report a significantly lower level of disability in the self-reported outcomes (MSIS-29 and PDDS) compared with current smokers. Non-smoker people with MS in this study report a significantly lower level of disability in all the patient self-reported outcomes compared with current MS smokers. These data suggest the earlier the patients with MS quit smoking, the stronger the reduction in the risk of reaching disability milestones.
key points
-this study provides for the first time quantitative estimates of the effects of smoking cessation in MS, essential for informing smoking cessation trials.
-when assessing for treatment effects in clinical trials of treatments for MS, adjusting for smoking cessation should be considered.
-smoking cessation should be an early intervention in people with MS.
Tanasescu R, Constantinescu CS, Tench CR, Manouchehrinia A. Smoking cessation and the reduction of disability progression in Multiple Sclerosis: a cohort study. Nicotine Tob Res. 2017 Apr 10.