Physician Visits Increased Up to 15 Years Before MS Symptom Onset

Results from a large, matched cohort study published in JAMA Network Open reveal that health care use begins to rise 14 to 15 years before the onset of the first recognized symptoms of multiple sclerosis (MS). The findings suggest a longer prodromal phase than previously understood, with mental health visits and nonspecific symptoms appearing years before nervous system manifestations.

In this matched cohort study, researchers reviewed linked clinical and administrative data from 1991 to 2018 in British Columbia, Canada. The study included 2038 people with MS identified through MS clinic records, and 10,182 individuals in a matched control group. Matches were based on sex, birth year, socioeconomic status, and location, and MS symptom onset was determined retrospectively by a neurologist based on medical history. Findings were reported as adjusted rate ratios (ARRs) for all-cause physician visits, accounting for baseline participant characteristics, with crude rate ratios (RR) reported for specialties and other specific symptom types.

In terms of key findings from the study:

• All-cause physician visit RRs were increased 14 years before MS symptom onset (ARR, 1.19; 95% CI, 1.07 to 1.33) and peaked in the year before onset (ARR, 1.28; 95% CI, 1.21 to 1.35).
• Mental health–related visit RRs increased 14 years before onset, which, in the 3-years before onset, ranged from 1.30 (95% CI, 1.05 to 1.58) to 1.38 (95% CI, 1.12 to 1.68).
• Ill-defined symptoms and signs were higher 15 years prior to symptom onset, peaking in the year before onset (RR, 1.37; 95% CI, 1.19 to 1.56).
• Sensory organ visit RRs were elevated from 8 years before MS symptom onset.
• Musculoskeletal visit RRs were elevated from 5 years before MS symptom onset.
• Nervous system visit RRs were elevated 4 years before MS symptom onset, with a peak of 2.42 in the year before onset (95% CI, 1.17 to 1.30).
• Neurology visits rose sharply from 8 years before onset, reaching a peak RR of 5.46 (95% CI, 4.30 to 6.93) in the year before onset.
• Ophthalmology visit rose significantly from 9 years pre-onset, reaching a peak RR of 1.64 (95% CI, 1.30 to 2.08) in the year before onset.

Source: Ruiz-Algueró M, Zhu F, Chertcoff A, Zhao Y, Marrie RA, Tremlett H. Health Care Use Before Multiple Sclerosis Symptom Onset. JAMA Netw Open. 2025;8(8):e2524635. doi:10.1001/jamanetworkopen.2025.24635