||Shah, V., Rezaeishahreza, A., Lui, E., Aser, R., Bartlett, S., Li, M., Howell, D., Peipert, J., Novak, M., Mucsi, I.
||Purpose: To evaluate the reliability and validity of the PROMIS Depression computerized adaptive test (PROMIS-D CAT) in relation to a legacy measure in adult Kidney Transplant Recipients (KTR).
Methods: A cross-sectional sample of adult outpatient KTR completed the PROMIS-D CAT and Patient Health Questionnaire (PHQ-9) on an electronic data capture platform. Socio–demographic and relevant clinical data was collected from medical records. Construct validity was assessed using Spearman’s Rho and known groups comparisons; test-retest reliability using intra-class correlation (ICC). Receiver operating characteristics (ROC) analysis was used to assess discrimination of PROMIS-D CAT using an established cut-off on the PHQ-9 (≥10) for moderate/severe depression. The PROMIS-D CAT cut-off for moderate/severe depression was identified using the Youden Index.
Results: Mean (SD) age of the 156 participants was 50(16) years, mean (SD) CKD-EPI eGFR was 54(22), 67% was male and 64% Caucasian. Median (IQR) time since transplant was 8.5(3.4-13.8) years. Based on the PHQ-9, 17% reported moderate/severe depression. The PROMIS-D CAT and the PHQ-9 (r=0.59) were moderately correlated. Test-retest reliability was good (ICC=0.73). Mean (SD) PROMIS-D CAT scores were higher for patients with a Charlson Comorbidity Index ≥ 4 compared to <3 (51(7) vs 48(8); p=0.07) and patients with eGFR <30 compared to >60 (52(8) vs 49(9), p=0.07). Patients from minority groups had higher PROMIS-D CAT scores compared to Caucasians (51(8) vs 48(8); p<0.05). ROC analysis suggested excellent discrimination with an area under the curve of 0.91 (95% CI: 0.85-0.97). The Youden Index identified cut-off for moderate/severe depression for the PROMIS-D CAT was 54 (Sensitivity: 88%, specificity: 82%, positive predictive value: 0.5, negative predictive value: 0.97).
Conclusion: These results provide new evidence of the validity and reliability of PROMIS-D CAT in KTR and support its use in research and care. In addition, a previously-calculated crosswalk between the PHQ-9 and PROMIS-D CAT allows for easy conversion among centers using the PHQ-9.