Sex-related and age-related differences in healthcare use before multiple sclerosis symptom onset: a matched cohort study

Background Increased healthcare use precedes classical multiple sclerosis (MS) symptom onset. Limited evidence exists on sex and age variation. We assessed physician visit patterns pre-MS onset by sex and age. Methods Using data from British Columbia, Canada, we compared annual physician visit rates (overall, by reason and specialty) in the 15 years before the neurologist-determined MS symptom onset date (index) and a matched non-MS cohort, stratified by sex and age (<30, 30–49, ≥50). Results We included 2038 MS and 10 182 non-MS persons (74% female). Mean age (years) at index was 37.6 (females) and 38.7 (males). Compared with matched non-MS persons, females with MS showed earlier and more consistent elevations in physician visits (years −14 to −1), while males had sporadic elevations (years −5, –3 and −1). Females also had longer periods of elevated rate ratios (RRs) for ill-defined signs/symptoms (years −15 to −1), mental disorders (years −14 to −1 except year −7) and musculoskeletal conditions (years −6 to −1). Females exhibited sustained elevated visits by specialty, including general practice (all years; RR ≥1.1), psychiatry (years −12 to −1 except −8 to −6; RRs ≥1.6) and ophthalmology (years −9 to −1 except −2; RRs ≥1.4). Compared with matched non-MS counterparts, those aged 30–49 years had sustained higher RRs for psychiatry visits (years −12 to −1 except −8 and −6; RRs ≥1.9) and ophthalmology (years −9 to −1; RRs ≥1.4). Other age groups had fewer elevated RRs preindex. Across comparisons, RRs were of similar magnitude across sex and age groups. Conclusions Sex-specific and age-specific differences in physician visits extended up to 15 years pre-MS onset, suggesting a durable prodromal signature, most evident in females and those aged 30–49 years.