Psychometric properties of the patient dignity inventory in a longitudinal cohort of acute respiratory failure survivors

OBJECTIVES: Although greater than 50% of acute respiratory failure (ARF) survivors develop postintensive care syndrome, dignity-centered interventions—shown to improve psychosocial and existential outcomes in other longitudinally impaired populations—remain largely unexplored in ARF survivorship. We aimed to validate the Patient Dignity Inventory (PDI) among ARF survivors by evaluating internal consistency and generalizability and establishing a minimal clinically important difference (MCID).

DESIGN/SETTING/PATIENTS: Prospective cohort study (June 2022 to April 2023) of mechanically ventilated (≥24 h) adults in four University of Pennsylvania hospitals’ ICUs.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Patients completed the PDI within 1 month of ICU discharge and at 3, 6, and 12 months. We assessed internal consistency using Cronbach’s alpha (reliability of questions measuring the same construct; range 0–1) and exploratory factor analysis to identify dignity-related distress domains. We evaluated generalizability using multilevel mixed-effects modeling to estimate variance attributable to patients, questions, and timepoints, which informed phi coefficient calculation (score consistency; range 0–1). We calculated MCID by averaging anchor-based (EuroQol-5 Dimension MCID = 0.11 from baseline to 12 months) and distribution-based (average of se of the mean, 0.3 × sd, and 5% of baseline score range) estimates.

Of 967 eligible patients, 103 patients (11%) enrolled at baseline, with 70% retention at 12 months. PDI demonstrated excellent internal consistency across timepoints (Cronbach’s alpha = 0.94–0.96). Factor analysis identified 2–3 factors per timepoint, with physical, psychologic, and cognitive impairments predominating early, and existential and interpersonal concerns increasing longitudinally. Seventy-five percent of score variance was attributable to patient differences and 25% to timepoint, yielding phi = 0.93 (excellent consistency).

CONCLUSIONS: The PDI is a valid, reliable instrument for assessing dignity among ARF survivors longitudinally, demonstrating excellent internal consistency and generalizability, providing a foundation for designing and evaluating dignity-centered interventions addressing ARF survivors’ evolving needs.

National Heart, Lung, and Blood Institute

Lydia E Federico, Craig Kwiatkowski, C Jessica Dine, Yingying Lu, Taara V Prasad, Erich Dress, Stefania Scott, Michael O Harhay, Rachel A Hadler, Rachel Kohn