The association between gastro-oesophageal reflux disease and subsequent rheumatoid arthritis occurrence: a nested case–control study from Taiwan

OBJECTIVE: Gastro-oesophageal reflux disease (GORD) is a common comorbidity among patients with rheumatoid arthritis (RA). While GORD has been attributed to the antirheumatic medications, no studies of human cohorts have investigated a link between GORD and RA. This study investigates whether GORD is associated with a subsequent RA diagnosis over a 5-year follow-up using a population-based dataset. SETTING: Taiwan PARTICIPANTS: We used data from the Taiwan Longitudinal Health Insurance Database. The study group consisted of 13 645 patients with an ambulatory claim showing a GORD diagnosis. We used propensity score matching to select 13 645 comparison patients (one per study patient with GORD). INTERVENTION: We tracked each patient’s claims over a 5-year period to identify those who subsequently received a diagnosis of RA. Cox proportional hazard (PH) regression modelling was used for analysis. RESULTS: Over 5-year follow-up, RA incidence rate per 1000 person-years was 2.81 among patients with GORD and 0.84 among the comparison group. Cox PH modelling showed that GORD was independently associated with a 2.84-fold increased risk of RA (95% CI 2.09 to 3.85) over 5-year follow-up, after adjusting for the number of ambulatory care visits within the year following the index date (to mitigate surveillance bias). CONCLUSIONS: We observed that GORD might associate with subsequent RA occurrence. Because current treatment guidelines for RA emphasise early diagnosis and prompt treatment, the observed association between GORD and RA may help acquaint clinicians to patients with GORD with higher RA risk and facilitate early diagnosis and treatment.