Current Marijuana Usage By MS Status and Disability in the Narcoms Registry
Objectives: To assess current marijuana usage by current MS type and disability level as measured by the Patient Determined Disease Steps (PDDS).
Methods: In August 2014, all active participants (12,260) in the North American Research Committee on Multiple Sclerosis (NARCOMS) were invited to complete an online, anonymous questionnaire with socio-demographic and clinical characteristics including current PDDS and type of MS: relapsing remitting MS, active with a relapse in prior 2 years (RRMS-A), relapsing but stable (RRMS-S), progressive but used to have relapses (SPMS), and progressive from onset with no prior relapses (PPMS). Marijuana referred to smoking, ingesting, or any controlled substance derived from marijuana or synthetic marijuana. Results are summarized as mean(SD), median(IQR) or %, as applicable.
Results: Of 5665 respondents 78.3% were women, current mean(SD) age 55.5(10.2) years with median(IQR) age at diagnosis 37(29,45) years. MS was relapsing from onset in 90.2% of respondents: 26.5% RRMS-A, 42.8% RRMS-S, 20.9% SPMS, and 9.8% PPMS. Participants with PPMS onset were older at diagnosis [44(35,51) vs SPMS 35(28,42), RRMS-S 37(29,44), RRMS-A 36(29,43); all p<0.0001] and time of survey [62(57,67) vs SPMS 59(54,64), RRMS-S 55(48,62), RRMS-A 54(45,60); all p<0.0001] and more likely to be male (35.8% vs SPMS 28.4, p=0.0021; RRMS-S 17.5, RRMS-A 18.2, both p<0.0001). PPMS had worse current disability [PDDS 5(4,7) compared to RRMS-A 3(2,4) and RRMS-S 2(0,4), both p<0.0001]. 906 (16.0%) participants reported current marijuana usage. When adjusted for current age and gender, those with RRMS-S were least likely to currently be using marijuana compared to all other types: PPMS vs RRMS-S (OR 1.4, p=0.0232), SPMS (OR 1.7, p<0.0001), RRMS-A (1.5, p<0.0001) and those with PDDS 0 (Normal) were less likely to currently use marijuana compared to all levels except PDDS 8 (Bedridden, all p<0.005), while PPDS 1 (Mild Disability) were less likely to currently use compared to PDDS 2(Moderate)-5(Late Cane) (all p<0.05). There was no difference in the median days/month for those reporting use by type of MS: 20(IQR 5, 20; p=0.22).
Conclusions: Those with higher current disability and those reporting active relapsing or progressive disease were more likely to report current marijuana usuage.