Perceived Dignity is an Unrecognized Source of Emotional Distress in Patients with Rheumatic Diseases: Results from the Validation of the Mexican Version of the Patient Dignity Inventory

Introduction: Dignity has rarely been explored in patients with rheumatic diseases (RMDs), which contrasts with patients´ observations that dignity is a relevant area for research focus. The study's primary objective was to adapt and validate the Mexican version of the Patient Dignity Inventory (PDI-Mx) in patients with RMDs, and to estimate the proportion of patients with distress related to perceived dignity (DPD) assessed with the PDI-Mx.

Methods: This cross-sectional study was developed in 2 phases. Phase 1 consisted of pilot testing and questionnaire feasibility (n = 50 patients), PDI-Mx content validity (experts' agreement), construct validity (exploratory factor analysis), discriminant validity (Heterotrait-Monotrait correlations' rate [HTMT]), criterion validity (Spearman correlations) and PDI-Mx reliability with internal consistency (Cronbach's alpha) and test-retest (intra-class correlation coefficients [ICC]) in 220 additional outpatients (among whom 30 underwent test-retest). Phase 2 consisted of quantifying DPD (PDI-Mx cut-off ≥54.4) in 290 outpatients with RMDs.

Results: Overall, patients were representative of typical outpatients with RMDs from a National tertiary care level center. The 25-item PDI-Mx was found feasible, valid (experts' agreement ≥82%; a 4-factor structure accounted for 68.7% of the total variance; HTMT = 0.608; the strength of the correlations was moderate to high between the PDI-Mx, the Depression, Anxiety, and Stress scale dimensions scores, and the Health Assessment Questionnaire Disability Index score) and reliable (Cronbach's ɑ = 0.962, ICC = 0.939 [95%CI = 0.913-0.961]). DPD was present in 78 patients (26.9%).

Conclusions: The PDI-Mx questionnaire showed good psychometric properties for assessing DPD in our population. Perceived dignity in patients with RMDs might be an unrecognized source of emotional distress.