Characteristics of the psoriatic arthritis (PsA) study population.

Data obtained from self-reports.A = responders 1st series of questionnaires;B = 1st series PsAQoL complete; used for internal con- sistency assessment;C = 1st and 2nd series PsAQoL complete; used for calculating test-retest reliability;D = 1st series PsAQoL, HAQ and Skindex complete; used for convergent validity analyses.PsA, psoriatic arthritis; n, number; y, years; SD, standard deviation; DMARD, disease-modifying antirheumatic drugs; anti-TNFα, anti-tumor necrosis factor α; NSAID, non-steroidal anti- inflammatory drug; PsAQoL, psoriatic arthrtitis quality of life; HAQ, health assessement questionnaire.