Investigating disparities in smoking cessation treatment for veterans with multiple sclerosis: A national analysis.

Abstract

Smoking is a risk factor for multiple sclerosis (MS) development, symptom burden, decreased medication efficacy, and increased disease-related mortality. Veterans with MS (VwMS) smoke at critically high rates; however, treatment rates and possible disparities are unknown. To promote equitable treatment, we aim to investigate smoking cessation prescription practices for VwMS across social determinant factors. We extracted data from the national Veterans Health Administration electronic health records between October 1, 2017, and September 30, 2018. To derive marginal estimates of the association of MS with receipt of smoking-cessation pharmacotherapy, we used propensity score matching through the extreme gradient boosting machine learning model. VwMS who smoke were matched with veterans without MS who smoke on factors including age, race, depression, and healthcare visits. To assess the marginal association of MS with different cessation treatments, we used logistic regression and conducted stratified analyses by sex, race, and ethnicity. The matched sample achieved a good balance across most covariates, compared to the pre-match sample. VwMS (n=3320) had decreased odds of receiving prescriptions for nicotine patches ([Odds Ratio]OR=0.86, p<.01), non-patch nicotine replacement therapy (NRT; OR=0.81, p<.001), and standard practice dual NRT (OR=0.77, p<.01), compared to matches without MS (n=13,280). Men with MS had lower odds of receiving prescriptions for nicotine patches (OR=0.88, p=.05), non-patch NRT (OR=0.77, p<.001), and dual NRT (OR=0.72, p<.001). Similarly, Black VwMS had lower odds of receiving prescriptions for patches (OR=0.62, p<.001), non-patch NRT (OR=0.75, p<.05), and dual NRT (OR=0.52, p<.01). The odds of receiving prescriptions for bupropion or varenicline did not differ between VwMS and matches without MS. VwMS received significantly less smoking cessation treatment, compared to matched controls without MS, showing a critical gap in health services as VwMS are not receiving dual NRT as the standard of care. Prescription rates were especially lower for male and Black VwMS, suggesting that under-represented demographic groups outside of the white female category, most often considered as the "traditional MS" group, could be under-treated regarding smoking cessation support. This foundational work will help inform future work to promote equitable treatment and implementation of cessation interventions for people living with MS.