An estimated 900,000 individuals in the United States are currently living with Multiple Sclerosis (MS) (Wallin, Culpepper, and Campbell, 2019). MS is a disabling condition impacting the central nervous system and resulting in a myriad of symptoms including fatigue, muscle spasms and/or numbness in the limbs (Wallin, Culpepper, and Campbell, 2019, Thompson, Banwell, and Barkhof, 2018). Individuals with MS have complex health care needs and often face inequities in health and healthcare access. Mental and physical co-morbidities such as depression, anxiety, osteoporosis, fractures, hyperlipidemia, and hypertension are commonly reported in this population (Marrie and Hanwell, 2013). Research shows that the incidence and prevalence of secondary conditions are higher among people with MS compared with the general population (Peterson et al., 2022).

One marker of poor access to appropriate primary care and receipt of less effective healthcare, are higher rates of potentially preventable hospitalizations (PPHs). The Agency for Healthcare Research and Quality (AHRQ) defines PPHs as hospitalizations for chronic and acute conditions that should be avoided in the presence of timely and effective access to ambulatory care (Published Agency for Healthcare Reseach and Quality (AHRQ) 2021, Published Agency for Healthcare Research and Quality (AHRQ) 2021). Despite efforts to address disparities in access to care, research reveals that individuals with MS, compared to the general population, face higher out-of-pocket healthcare costs; have more financial difficulty paying for prescription medications; and do not receive recommended preventive services such as bone density and cancer screenings (Peterson et al., 2022, Shabas and Weinreb, 2000, Mayo et al., 2021, Minden et al., 2007, Mikula, Nagyova, and Krokavcova, 2015, Mahmoudi, Sadaghiyani, and Lin, 2022, Rodriguez et al., 2021). Furthermore, persons with MS report barriers to accessing health services that include a lack of interactions with health care providers, difficulty navigating the health care system and challenges in accessing facilities (Shabas and Weinreb, 2000, Mayo et al., 2021, Minden et al., 2007). Additionally, a study from Manitoba, Canada noted individuals with MS were more likely to have hospital admissions for bacterial pneumonia, influenza, urinary tract infections (UTI) and pressure ulcers compared to the general population (Marrie, Elliott, and Marriott, 2014). Particularly, over the last decade, hospitalizations due to UTI have remained high in this population, which may reflect continued inadequate access to care (Nusrat, Levinthal, and Bielefeldt, 2013).

Despite inequities in health and health care among people with MS (Mayo et al., 2021), little is known about their risk of PPHs compared with the general population. Additionally, based on our knowledge, no study examined PPH risk in individuals with MS using a national cohort of privately insured individuals with MS. This void in literature makes it difficult to identify priority areas of health policy focus for this patient population.

To address this important gap, we conducted a retrospective cohort study using data from a large, national private health insurance database in the United States to examine disparities in PPHs among individuals with MS compared with their counterparts without MS. Furthermore, we aimed to elucidate the role that receipt of preventive services can have in explaining PPH risk. Findings from this study have the potential to inform policies and clinical care aimed at mitigating health inequities in this vulnerable population and inform the role of preventive care for individuals with MS.