Pre-pandemic care-seeking patterns and subsequent diagnoses of post-COVID condition, post viral fatigue syndrome, and exhaustion disorder: a registry-based cohort study of 208,050 Swedish women.

BACKGROUND: Women are disproportionately diagnosed with symptom-based conditions, notably post-COVID condition (PCC). In Sweden, as of February 2022, 2.3% of PCR-verified female COVID-19 cases versus 1.6% of male cases had a PCC diagnosis. Post-viral fatigue syndrome (PVFS) and exhaustion disorder (ED), a common and relevant diagnosis in Sweden, share substantial symptom overlap with PCC. AIMS: To quantify the association between pre-pandemic, symptom-based primary-care visits and subsequent PCC, PVFS, and ED among adult women, adjusting for risk factors for severe COVID-19. METHODS: We conducted a registry-based prospective cohort study of 208,050 women from the Swedish Medical Birth Register, linked to primary-care data and national sociodemographic registers. The exposure was the frequency of visits for predefined symptom-based conditions during 2015-2019. Adjusted odds ratios (ORs) for diagnoses in 2020-2024 were estimated using logistic regression controlling for BMI, education, age, and region of birth. RESULTS: Across 2,431,182 primary-care physician visits, 19% were symptom-based. Women with >8 such visits had higher odds of all three outcomes: PCC (OR 5.45, 95% CI 4.43-6.71), PVFS (OR 7.71, 95% CI 5.97-9.96), and ED (OR 5.32, 95% CI 4.84-5.85). Pre-pandemic BMI and education were not associated with PCC or PVFS but showed some association with ED. Still, 17% of women with PCC had no recorded symptom-based visits before the pandemic. CONCLUSIONS: Pre-pandemic symptom-based primary-care visits were strongly associated with higher risk of PCC, PVFS, and ED in a dose-dependent way, but modest discrimination underscores heterogeneous individual risk. Patterns suggest other influences alongside biological susceptibility.