Heterogeneity in health care pathways preceding the classical recognition of adult-onset multiple sclerosis: A...

Higher healthcare use before recognition of adult-onset multiple sclerosis (MS) raises the possibility of earlier disease detection.

To describe common clinical pathways before a first recorded demyelinating event or MS symptom onset.

We applied multichannel state sequence analyses to generate typologies of clinical pathways using linked clinical and population-based health administrative data in British Columbia, Canada (1991-2020). We constructed sequences of care providers and diagnostic claims in each 3-month period over the 5 years preceding the first recorded demyelinating event (N = 10,617) or MS symptom onset (N = 1761). We used the dynamic hamming distance to determine the dissimilarity between sequences. We applied hierarchical cluster analysis with Hubert's C Index to group similar pathways.

Before the first demyelinating event, 9 pathways emerged: pathways for low (25 % of cohort), moderate (25 %) and high (18 %) healthcare use; pathways representing steadily increasing (6 %) and decreasing (10 %) healthcare use over the 5 years; specialist-specific pathways for visits to neurologists/neurosurgeons (2 %), ophthalmologists (6 %) and psychiatrists (2 %), and a musculoskeletal diagnoses-related pathway (5 %). Pre-MS symptom onset, 5 pathways were identified: low (42 %), moderate (32 %) and high (20 %) healthcare use; visits to psychiatrists (2 %); and musculoskeletal diagnoses (4 %).

Adults with a pattern of recurrent visits to a neurologist/neurosurgeon or ophthalmologist could be targeted for earlier MS detection.