Abstract / Summary
Abstract Background Cross-national differences in healthcare systems may influence diagnostic pathways and patient-reported outcomes in myasthenia gravis (MG); however, comparative data remain limited. This study aimed to observe differences in diagnostic timelines and quality of life between Canada and the United States using real-world data from the MyRealWorld MG registry; findings are meant to be hypothesis-generating. Methods We conducted a retrospective analysis of registry data, including 32 Canadian and 679 US participants. Diagnostic intervals were measured using three intervals: (1) symptom onset to first medical contact, (2) first medical contact to confirmed diagnosis, and (3) symptom onset to diagnosis. Between-country comparisons were performed using Mann–Whitney U tests, and multivariable linear regression models adjusted for age, sex, and MGFA class were used to assess quality-of-life outcomes (MG-QOL-15r and EQ-5D-5 L). The diagnosing physician’s specialty and diagnostic test were compared using Fisher’s exact probability test. All analyses were performed within RStudio. Given the small Canadian sample, diagnostic comparisons were primarily powered to detect moderate to large between-country differences. Results No statistically significant differences were observed in diagnostic timelines, specialist visits, or diagnostic testing patterns between countries. However, Canadian participants demonstrated significantly better quality of life, with lower MG-QOL-15r scores (β = 5.241, p = 0.002) and higher EQ-5D-5 L index values (β=-0.134, p = 0.021) after adjustment. Conclusion While diagnostic processes were similar, meaningful differences in quality of life were observed. These findings raise the possibility that broader clinical, social, and system-level factors may influence patient outcomes beyond diagnostic timing alone.