A long-term nationwide study on mortality associated to rheumatoid arthritis in Italy.

Objectives: We aimed to evaluate trends of rheumatoid arthritis (RA) mortality reported as the underlying cause of death (UCD) and as multiple causes of death (MCD) in Italy between 2003 and 2015.

Methods: Analyses were carried out on the Italian National Cause of Death Register, managed by the Italian National Institute of Statistics (ISTAT). Deaths from January 1, 2003 to December 31, 2015 with any mention of RA were included. Diseases are coded according to the International Classification of Diseases, 10th Edition (ICD- 10, 2009 version). Time trends of age-standardised rates were analysed for RA both as UCD and MCD, and the annual percent change (APC) was estimated.

Results: Overall, 26,564 deaths with a mention of RA were retrieved out of 7,595,214 deaths (0.35% of all certificates). The mention of RA as MCD increased throughout the study period, meanwhile the selection as the UCD decreased. RA mortality rates based on the UCD declined (males APC -3.1%, CI -3.9, -2.3; females APC -3.3%, CI -4.1, -2.4); while rates based on the MCD were stable. Specifically, rates were stable or declined among younger subjects and increased in subjects aged ≥80 years.

Conclusions: RA was found to be increasingly reported in death certificates in the last two decades in Italy, although it is less frequently reported as the UCD. Due to the increased survival of patients, we observed a shift of RA-related mortality towards the elderly, making RA a comorbidity contributing to death in these patients.