Incidence of psoriasis and association with comorbidities in Italy: a 5-year observational study from a national primary care database.

An observational study was conducted to estimate the incidence of psoriasis in Italy, as well as the utilization of healthcare resources and the association with selected comorbidities in psoriasis patients. The data source was the Health Search/Thales Database, containing computer-based patient records from over 900 primary care physicians (PCPs) throughout Italy. The study cohort comprised all adults receiving a first-ever diagnosis of psoriasis during the years 2001-2005. From a total sample of 511,532 individuals, the incidence of psoriasis was 2.30-3.21 cases per 1,000 person-years. Psoriatic arthritis was present in 8% of psoriasis patients. The comparison with matched controls showed that psoriasis patients were more likely to have comorbidities (e.g., chronic bronchitis, chronic ischemic heart disease, obesity and diabetes mellitus) and to undergo PCP visits and hospitalizations, and to refer for specialist visits. The use of non-steroidal anti-inflammatory drugs appeared to be significantly more prevalent in patients as compared to controls. Topical therapy with corticosteroids and non-steroidal preparations accounted for 45.3% and 47.2% of all cases, respectively. Only a minority of cases used systemic immunosuppressive drugs or acitretin. The incidence rate of psoriasis in our study was particularly high and might reflect an overestimation by PCPs. Our results show the association between psoriasis and multiple comorbidities.