Clinical and Patient Reported Outcomes In Psoriatic Arthritis: A Narrative Review of The Literature

OBJECTIVES: To appraise the literature related to the instruments used to assess clinical outcomes and patient reported outcomes (PROs) during follow-up of psoriatic arthritis (PsA) patients. METHODS: Electronic databases (MedLine/PubMed, Google Scholar, Cochrane library and ISI-WOK) were searched to identify clinical trials, observational studies, registers or systematic reviews related to the PsA patients' follow-up. English or Spanish studies published until June 1st 2017 were selected. Outcomes and Instruments used to follow-up PsA patients were identified. RESULTS: A total of 138 publications were reviewed, most of them used a combination of a clinical outcomes and a PRO to follow-up PsA patients (n=124, 89.8%), while 8.7% (n=12) and 1.4% (n=2) employed exclusively PROs and clinical outcomes. These studies described a total of 87 instruments (49.4% PROs, 36.8% clinical outcomes, 13.8% composite indices). Based on the PsA core outcomes set, established by international GRAPPA-OMERACT working group, the instruments identified were classified in musculoskeletal disease activity (n=27), skin disease activity (n=6), pain (n=5), patient global (n=25), physical function (n=4), health related quality of life (n=7), fatigue (n=5) and systemic inflammation (n=12). Some of the instruments assessed more than one domain. The most reported instruments were number of swollen/tender joint count (n=84,60.43%), C-reactive protein (n=80, 57.55%), Health Assessment Questionnaire (n=79, 56.83%), Patient Global Assessment (n=79, 56.83%), Physicians Global Assessment (n=69,49.64%), Psoriasis Area Severity Index (n=62, 44.60%), Pain (NRS n=60, 43.17%; VAS n=56, 40.29%). Most of these instruments were used in a composite index such as ACR (n=50, 35.97%) or Disease Activity Score-28 (n=50, 35.97%). CONCLUSIONS: Most of the studies used a combination of clinical outcomes and PROs to follow-up PsA patients, highlighting the importance to include a PROs in patients' monitoring. However, results of the review release the need to establish and standardize the instruments to be applied in PsA patients.