Use of primary health care and radiological imaging preceding a diagnosis of rheumatoid arthritis: a nationwide cohort study in Denmark

Objective To explore health-care use in the 12 months preceding a diagnosis of RA in Denmark. Methods We conducted a population-based cohort study using data from national registries. Every patient diagnosed with RA in 2014-18 was matched to 10 reference individuals without RA from the Danish background population. Health-care use was defined as contacts to general practitioners, contacts to private practicing physiotherapists, and X-rays of hands and/or feet performed in primary or secondary care. We estimated the monthly contact rates for patients and references in the 12 months preceding the diagnosis, and we compared incidence rates for health-care use in each month between the two groups while adjusting for sociodemographic characteristics and comorbidity. Results We included 7427 patients with RA and 74 270 references. Patients with RA had increasing contact rates with general practitioners and physiotherapists from 6 to 8 months before the diagnosis. Compared with references, women with RA had statistically significantly more contacts to general practitioners and physiotherapists during all 12 months. A similar contact pattern was seen in men, albeit less distinct. The number of X-rays increased slightly from 8 months before the diagnosis, with a steep increase in the last 3 months. Conclusion Increased contacts to general practitioners and physiotherapists were seen in all 12 months preceding the RA diagnosis, intensifying in the last 6 to 8 months. Imaging increased from 3 months before the diagnosis. This indicates an opportunity to expedite referral to specialist care and ensure earlier diagnosis of RA.