Increased healthcare utilisation in the 5 years preceding systemic lupus erythematosus diagnosis: a Danish nationwide cohort study

This study aimed to analyse healthcare utilisation patterns in the 5 years preceding a diagnosis of systemic lupus erythematosus (SLE) in Denmark compared to matched healthy individuals. Understanding these patterns could support earlier diagnosis and reduce diagnostic delay. A nationwide, registry-based cohort study was conducted using data from the Danish national healthcare registries between 2006 and 2021. Healthcare utilisation, including general practitioner (GP) visits, specialist consultations, prescriptions, blood tests, diagnostic imaging, and hospital admissions, was examined. Incidence rate ratios were calculated using negative binomial regression models adjusted for demographic and clinical covariates. We included 2022 individuals diagnosed with SLE and 20,019 matched reference individuals. 83.8% of patients were female, with an average age of 47.1 years. Even at baseline, patients with SLE exhibited significantly higher healthcare utilisation compared to references for all outcomes which continued throughout the 5-year follow-up. Patients with SLE had approximately 12 annual GP contacts until 1.5 year before diagnosis, where the contact rate increased substantially. Reference individuals consistently had about 4 contacts per year. The incidence rate ratio was approximately 3 during the 5 to 1.5 years preceding diagnosis, increasing to 5.20 (95% confidence interval 4.95-5.46) in the last 6 months before diagnosis. Increased healthcare utilisation years before SLE diagnosis suggests that early symptoms are present and prompt medical attention long before formal diagnosis. These findings highlight the potential for earlier identification of SLE, underscoring the need for improved diagnostic strategies to reduce delays and enhance patient outcomes.