Table 2

 Clinical and laboratory features of the present groups

Polyarticular PsA, n = 388Polyarticular RA, n = 363Non-polyarticular PsA, n = 200Test statistic for all three groupsp ValueTest statistic for polyarticular PsAv non-polyarticular PsAp Value
CCP, cyclic citrullinated peptide; f, female; F, F ratio of one-way analysis of variance; HAQ, Health Assessment Questionnaire; KW, Kruskall–Wallis; m, male; NA, not applicable; NS, not significant; PsA, psoriatic arthritis; RA, rheumatoid arthritis; RF, rheumatoid factor; T, independent samples t test statistic; U, Mann–Whitney U statistic.
*Tukey’s retrospective analysis.
†14 patients with rheumatoid arthritis also had psoriasis.
‡Ratio of number of matched joint pairs to total number of joints (range 0–1).
§CCP available for only 222 patients with polyarticular PsA, 229 with polyarticular RA and 112 patients with non-polyarticular PsA.
Age (years)51.558.347.9F = 48.3<0.001NA0.005*
Sexm = 183;f = 205m = 103;f = 260m = 123;f = 77χ2 = 62.4<0.001χ2 = 10.90.001
Duration of arthritis (years)13.012.511.5F = 1.61NSNANA
Duration of psoriasis (years)†20.017.818.4F = 1.19NSNANA
Total number of involved joints (median, range)21234KW χ2 = 180.2<0.001U = 15 714<0.001
HAQ0.900.890.68F = 0.83NSNANA
Symmetry number‡0.670.860.50KW χ2 = 152.3<0.001U = 23 710<0.001
RF positive, n (%)22 (6)274 (76)5 (3)χ2 = 522.3<0.001χ2 = 3.0NS
CCP positive, n (%)§15 (7)163 (71)11 (10)χ2 = 245.1<0.001χ2 = 0.9NS
Dactylitis, n (%)220 (57)17 (5)89 (45)χ2 = 246.9<0.001χ2 = 11.80.008
Enthesitis, n (%)209 (54)53 (15)103 (52)χ2 = 145.1<0.001χ2 = 0.5NS
Spinal pain and stiffness, n (%)148 (38)83 (23)81 (41)χ2 = 32.4<0.001χ2 = 2.4NS