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

Abstract

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. 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). 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. 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.