The Anthroposophic Art Therapy Assessment Paint (AART-ASSESS-P): A peer-report instrument to assess patients' pictorial expression during Anthroposophic Painting Therapy.

OBJECTIVE: Anthroposophic painting therapy (APT) is a specific form of art therapy that aims to activate self-healing capacities through painting aquarelles. METHODS: The Anthroposophic Art Therapy Assessment-Paint' (AART-ASSESS-P) was developed to measure pictorial expression and validated in the framework of a comprehensive cohort design study. The validation study examined 68 breast cancer patients with fatigue. Art therapists made pre- and post-assessments of spontaneously drawn water-color paintings with a preliminary version of the AART-ASSESS-P (58 items). Inter-rater reliability (IRR) for the items was examined with Cohen's weighted Kappa (κw). Additionally, a reliability- and factor analysis (FA) were conducted. Convergence criteria were patients' self-report measures: the Satisfaction with Painting Therapy, Inner Correspondence with Painting Therapy and the Self-Regulation Questionnaire. RESULTS: IRR for the items was heterogeneous (κw= 0.09-0.89, Mean κw= 0.40, SD = 0.17). Thirty-six items were excluded due to insufficient IRR and item-total correlation (κw= < 0.30, ρitem-total< 0.30). A FA with 22 items revealed 5 subscales: Shape Development (6 items), Shape Arrangement (6 items), Order and Symmetry (5 items), Color Application (3 items), and Color Quality (2 items) explaining 61% of total variance. Psychometric properties for the AART-ASSESS-P were satisfying with Cronbach's alpha coefficients (rα = 0.60-0.81) across subscales. Due to weak inter-subscale correlations (r = 0.18-0.48, p < 0.05) and the ambiguity of face validity a sum-score was not formed. Correlations between subscales and self-reports were small (all p < 0.05). CONCLUSION: The AART-ASSESS-P is the first reliable instrument to measure pictorial expression during APT.