Health care use preceding pediatric multiple sclerosis: A population-based study from Ontario, Canada
Bibliographic record
Abstract
BACKGROUND: Investigations of a prodrome in multiple sclerosis (MS) usually have included adults. OBJECTIVE: To compare rates and reasons for health care use in youth with and without MS, considering time relative to the MS index date and to birth. METHODS: This retrospective cohort study used population-based administrative data (1991-2020) from Ontario, Canada. We matched youth (<18 years) with MS up to 5:1 to youth without MS by sex, birth year, region, and duration of observation (full cohorts). Subcohorts had data from birth to MS index date (first demyelinating disease claim). We compared health services use, adjusting for age, sex, area-level income, region, and year. RESULTS: We included 451 individuals with pediatric-onset MS and 1422 without MS. As of 6 years pre-index, the full MS cohort had higher physician services use (year 6: rate ratio (RR) = 1.45; 95% confidence interval (95% CI) = 1.25-1.67) and hospitalizations (RR = 2.79; 95% CI = 1.31-5.94). Findings were similar in subcohorts. The MS subcohort had elevated physician visit rates in early life that rose as the MS index date approached. DISCUSSION: Youth with pediatric-onset MS exhibit increased health care use from birth. Early life may be a risk period for MS. A prodromal phase may emerge 6 years before the onset of typical MS symptoms.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.004 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".