OBJECTIVE: To apply and compare different classification criteria on a representative nationwide sample of psoriatic arthritis (PsA) twins and to estimate the prevalence and incidence of PsA. METHODS: The study comprised three Danish nationwide twin cohorts. In 1994 37 388 Danish twin individuals and in 2002 46 418 twin individuals received a questionnaire, including questions on rheumatic diseases. Twins reporting PsA and their co-twins were classified according to the Moll and Wright and CASPAR (ClASsification criteria for Psoriatic ARthritis) criteria based on interview, clinical examination and scrutiny of medical records. RESULTS: 228 twin individuals reported PsA and 164 (72%) participated in clinical validation. By using the Moll and Wright and CASPAR criteria, 54 and 50 cases were diagnosed with PsA respectively. The positive predictive value of self-reported PsA was 31%. According to the Moll and Wright and CASPAR criteria the prevalence was 0.15% (95% CI: 0.13%, 0.22%) and 0.14% (95% CI: 0.11%, 0.19%) respectively. The annual incidence rate based on new self-reported cases in 2002 was 6/100 000 person-years (95% CI: 3/100 000 person-years, 11/100 000 person-years). CONCLUSIONS: The positive predictive value of self-reported PsA was 31%. The prevalence and incidence figures of PsA were equivalent to the previously reported occurrence in population- and hospital-based studies.
OBJECTIVE: To apply and compare different classification criteria on a representative nationwide sample of psoriatic arthritis (PsA) twins and to estimate the prevalence and incidence of PsA. METHODS: The study comprised three Danish nationwide twin cohorts. In 1994 37 388 Danish twin individuals and in 2002 46 418 twin individuals received a questionnaire, including questions on rheumatic diseases. Twins reporting PsA and their co-twins were classified according to the Moll and Wright and CASPAR (ClASsification criteria for Psoriatic ARthritis) criteria based on interview, clinical examination and scrutiny of medical records. RESULTS: 228 twin individuals reported PsA and 164 (72%) participated in clinical validation. By using the Moll and Wright and CASPAR criteria, 54 and 50 cases were diagnosed with PsA respectively. The positive predictive value of self-reported PsA was 31%. According to the Moll and Wright and CASPAR criteria the prevalence was 0.15% (95% CI: 0.13%, 0.22%) and 0.14% (95% CI: 0.11%, 0.19%) respectively. The annual incidence rate based on new self-reported cases in 2002 was 6/100 000 person-years (95% CI: 3/100 000 person-years, 11/100 000 person-years). CONCLUSIONS: The positive predictive value of self-reported PsA was 31%. The prevalence and incidence figures of PsA were equivalent to the previously reported occurrence in population- and hospital-based studies.
Authors: P Härle; W Hartung; P Lehmann; B Ehrenstein; N Schneider; H Müller; U Müller-Ladner; I Tarner; T Vogt; M Fleck; T Bongartz Journal: Z Rheumatol Date: 2010-03 Impact factor: 1.372
Authors: Maryam M Asgari; Jashin J Wu; Joel M Gelfand; Craig Salman; Jeffrey R Curtis; Leslie R Harrold; Lisa J Herrinton Journal: Pharmacoepidemiol Drug Saf Date: 2013-05-02 Impact factor: 2.890
Authors: Sofia Löfvendahl; Elke Theander; Åke Svensson; Katarina Steen Carlsson; Martin Englund; Ingemar F Petersson Journal: PLoS One Date: 2014-05-29 Impact factor: 3.240