Socioeconomic determinants of quality of care and outcomes in multiple sclerosis

Abstract

Background: Multiple sclerosis (MS) is a chronic, inflammatory disease affecting the central nervous system (CNS), leading to varying degrees of neurological disability. While disease-modifying treatment (DMT) can ameliorate the severity of certain subtypes of this heterogenous disease, recent research has increasingly focused on understanding other factors influencing MS outcomes. Two such factors are explored in this thesis: quality of MS care, and sociodemographic status.

Aims and Hypotheses: This thesis aims to explore the relationship between social determinants of health, quality of care (QoC) and MS outcomes in a universal healthcare context. It hypothesises that: 1. Higher quality of clinical care, including earlier initiation of DMT, is associated with more favourable clinical and patient-reported outcomes; 2. Socioeconomic status influences the quality of MS care received, as well as MS outcomes; 3. Race is associated with disparities in treatment and disability severity among people living with MS.

Materials and Methods: This research comprises a series of observational studies using data from the Swedish MS Registry, linked with national administrative and healthcare databases, and a cross-sectional observational study conducted in a tertiary hospital in the United Kingdom (UK).

Study 1 and Study 2 used longitudinal data from the Swedish MS Registry to explore the relationship between QoC indicators and patient outcomes. Study 1 assessed the effectiveness of early treatment – a QoC indicator - in improving symptoms and quality of life of people living with relapsing-remitting MS, while study 2 explored whether clinics’ performance on quality indicators set by the Swedish MS society guidelines – including treatment timeliness, outpatient visit frequency, Magnetic Resonance Imaging (MRI) frequency, and completeness of data entry - correlated with clinical and patient-reported outcomes in people with relapsing and progressive subtypes of disease.

Study 3 used data from the Swedish MS Registry linked to national administrative databases to explore whether sociodemographic factors prior to disease onset - such as educational attainment, income, and marital status – are associated with future severity of disability and symptoms of MS.

Study 4 compared the quality of MS care received by individuals of differing socioeconomic statuses within Sweden's universal healthcare system. We measured patients’ time from disease onset to diagnosis, time from diagnosis to treatment initiation, frequency of neurology clinic visits, and the number of MRI scans conducted within the first four years post-diagnosis. These indicators were analysed in relation to premorbid educational attainment and income levels.

Study 5 utilised cross-sectional data from a major tertiary hospital in London. It explored the relationship between race, disease severity and treatment intensity within a nominally equitable healthcare system. All studies included both descriptive and multivariable analyses, as well as causal methodologies when comparing binary treatment exposures.

Results: Studies 1 and 2 revealed that QoC was associated with clinical and patientreported outcomes in relapse-onset but not progressive-onset MS. Early DMT initiation was significantly associated with lower clinical disability as well as lower physical and psychological symptom burden, though overall quality of life was unaffected. More frequent clinic visits and MRI scans also appeared to correlate to physical health outcomes in people with relapse-onset MS.

Study 3 found that higher premorbid educational attainment and income were both associated with significantly more favourable disability scores and symptoms. Single people and married/partnered people experienced comparable disease severity, while people who underwent marital separation prior to disease onset experienced significantly worse outcomes.

Study 4 found that people with higher premorbid income had a faster time from diagnosis to DMT start, while those with higher educational attainment had a higher visit and MRI frequency in the first four years from diagnosis.

Study 5 found significant racial disparities in a contemporary cohort of people with MS in the UK, with Black and Asian people experiencing worse disability outcomes compared to White people. Black people faced longer delays in receiving their first DMT and spent a smaller proportion of their disease duration on treatment compared to White people.

Conclusions: The findings from these studies collectively indicate that both healthcare and sociodemographic factors significantly influence outcomes of MS patients. Early intervention and sustained, high-quality healthcare are crucial for improving patient outcomes. However, MS outcomes are not only influenced by healthcare factors, but also by socioeconomic status, marital status and race. This highlights the need for strategies beyond affordable healthcare in order to achieve health equity, such as cultural competency, enhanced support and outreach for vulnerable patients, and future research to understand the mechanisms through which these disparities occur. Holistic MS management must consider not just clinical, but also social determinants of health.