POS1100 PSYCHOMETRIC PROPERTIES OF PATIENT GLOBAL ASSESSMENT IN THE EVALUATION OF PSORIATIC ARTHRITIS: A SYSTEMATIC LITERATURE REVIEW

Abstract

BackgroundRecommendations emphasize the need for the physician to work in partnership with the patient and a shared decision-making process is nowadays fundamental to manage properly Psoriatic Arthritis (PsA). Patient Global Assessment (PtGA) is a score that reflects the patient’s judgment about the disease activity and is getting more used in clinical routine and research.ObjectivesThe objective of this systematic literature review (SLR) is to analyze the role of PtGA in PsA and to describe its psychometric properties.MethodsThis SLR was conducted by two independent reviewers in accordance with the PRISMA statement, searching for articles reporting on the use of PtGA in PsA. All articles published until February 2021 in Pubmed were screened with no limitation about years of publication, language or patients’ age. Articles reporting data of PtGA of skin assessment were excluded. Psychometric properties data were analysed according to the OMERACT (Outcome Measures in Rheumatology) Filter methodology version 2.1. Measurement properties of the PtGA were analysed according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) terminology.ResultsThe literature search identified 45 studies, accounting for 8516 patients in 20 longitudinal cohort studies, 15 cross-sectional studies, 5 randomized controlled trials, 2 post-hoc analyses, 1 retrospective study and one review. Ten articles were excluded because PtGA was referred to the assessment of cutaneous psoriasis.Content validity was reported in 32 studies. Different definitions, acronyms, scales and questions to assess PtGA were retrieved through the literature (see Table 1).Table 1.Different questions, definitions, acronyms, scales and scores used to assess Patient Global Assessment retrieved. STD: studiesQUESTIONS“How would you rate the patient’s joint disease activity?”“In all the ways in which your PSORIASIS and ARTHRITIS, as a whole, affect you, how would you rate the way you felt over the past week?”“How active was your rheumatic disease on average during the last week?”“Considering all the ways PsA has affected you during the last week, circle the number that best describes how you have been doing”“How do you estimate your disease activity today?”“How active do you feel your joint disease is today?”DEFINITIONSPt visual analogue scale (VAS) for pain and global assessmentPt general disease assessmentPt global activityPt global assessmentPt global disease activityPt opinion on the level of disease activityPt global evaluationsPt perception of diseasePt disease severityACRONYMSPtGA; PGA; PaGASCALESVAS (23 std); NRS (12 std)SCORES0-100 (23 std); 0-10 (11 std); 0-5 (5 std)Face validity was reported in all the articles retrieved. PtGA was always used together with other instruments, alone or as part of composite indices: supporting its face validity, in 2 studies it was considered the instrument of reference to assess the outcome.A good correlation with PhGA, DAS28, BASDAI, ASDAS and DAPSA was found (see Figure 1). One study showed that the correlation became better (ES 1.81, 95%CI 1.42 2.19) during the follow up assessment. Three studies analyzed the discordance between patient and physician global assessment and in 25.0-49.0% found a positive discordance (PtGA higher than PhGA). Criterion validity was assessed exploring the PtGA correlation with quality of life measurements, demographic characteristics, biomarkers levels, treatment changes and damage assessments in 11 studies. The intrarater reliability was calculated only in 1 study, with an optimal correlation (ICC=0.87; 95%CI 0.83–0.90). PtGA responsiveness was used to evaluate response to treatment in 14 studies.Figure 1.Forest plot showing correlation between PtGA and other instrumentsConclusionPtGA demonstrated to be valid and feasible, but more studies are necessary to confirm its reliability and to evaluate its sensitivity to change. In addition, a clear definition of what PtGA refers to, what time and what kind of scale to adopt should be standardized.Disclosure of InterestsNone declared