... frequency-matched by gender and birthyear were randomly selected from the Danish population by means of the Civil Registration System, a national databasethat keeps track of all demographic changes ... birth year, and year or pseudo-year of RA diagnosis. bAdjusted for gender, birth year, year or pseudo-year of RA diagnosis, place of residence, educational status, history of urinary tract infection, ... non-significantly associated with RA risk. Physician-verified asthma before age 45 years and a history of urinarytract infection were both associated with significantly reducedrisk of RA. No statistically...