Early Rheumatoid Arthritis in Italy: study of incidence based on a two-level strategy in a sub-area of Florence (Scandicci-Le Signe)

Abstract

The concept of Early Arthritis represents a new diagnostic-therapeutic strategy in modern rheumatology. Even if many Early Arthritis clinics are starting up, we do not yet know the frequency of this pathology in the Italian population. With the collaboration of 20 general practictioners (GPs) operating in the municipalities of Scandicci, Lastra a Signa and Signa, we assessed the incidence of rheumatoid arthritis and of new cases of Early Rheumatoid Arthritis (ERA) in the period from 1.09.2005 to 31.08.2006. The general population over 18 years old in the three municipalities according to the political electoral lists in April 2006 was as follows: Scandicci 42,474 (Males 20,290; Females 22,184), Lastra a Signa 15,368 (M 7,458; F 7,910) and Signa 13,372 (M 6,439; F 6,933). The total number of patients followed by the 20 GPs was 32,521 according to the records of ASL10 Florence. In one year 920 patients were referred by their GPs to a rheumatologist with suspected early undifferentiated arthritis according to Emery's criteria. The patients underwent a rheumatological examination and the rheumatoid factor IgM, hidden rheumatoid factors (IgG and IgA) and IgG antibodies anti-CCP (anti-cyclic citrullinate peptides) with a semiquantitative immuno-enzymatic test ELISA were investigated. In one year we observed 32 new cases of Rheumatoid Arthritis, of which 8 were males and 24 were females. The rate of incidence with respective intervals of confidence of 95% was 0.98 per thousand (0.64-1.32 per thousand). The average age was 47.7 +/- 10.5 in the females and 54.9 +/- 10.3 in the males. The patients had an average history of illness in months of 5.2 +/- 1.3 F versus 4.6 +/- 1.1 M, number of tender joints 6.2 +/- 2.3 F versus 5.3 +/- 2.2 M, number of swollen joints 4.8 +/- 1.4 F versus 4.2 +/- 1.5 M, a global assessment of 64.3 +/- 10 F versus 53 +/- 12 M, ESR (mm/h) 49.2 +/- 11.3 F versus 43.3 +/- 12.5 M, CRP (mg/dl) 2.8 +/- 1.3 F versus 2.3 +/- 1.4 M, DAS28 5.55 +/- 1.2 F versus 5.19 +/- 1.3 M, HAQ 2.5 +/- 0.4 F, 2.2 +/- 0.3 M. The rates of incidence in the Italian population affected by early rheumatoid arthritis are higher than those found in some European populations, such as those of the UK and Finland, but less than those found in the population of USA. The different data reported in the literature seem to be due to the different methods of assessing ERA and to the different types of samples studied.