Linking the GAD-7 and PHQ-9 to the TBI-QOL Anxiety and Depression Item Banks

• Published in: The journal of head trauma rehabilitation Vol. 34; no. 5; p. 353
• Main Authors: Boulton, Aaron J, Tyner, Callie E, Choi, Seung W, Sander, Angelle M, Heinemann, Allen W, Bushnik, Tamara, Chiaravalloti, Nancy, Sherer, Mark, Kisala, Pamela A, Tulsky, David S
• Format: Journal Article
• Language: English
• Published: United States 01.09.2019
• ISSN: 1550-509X
• DOI: 10.1097/HTR.0000000000000529

To link scores on commonly used measures of anxiety (7-item Generalized Anxiety Disorder Scale; GAD-7) and depression (9-item Patient Health Questionnaire; PHQ-9) to the Traumatic Brain Injury Quality of Life (TBI-QOL) measurement system. 5 Traumatic Brain Injury Model Systems. A total of 385 individuals with traumatic brain injury (TBI) (31% complicated mild; 14% moderate; and 54% severe). Observational cohort. GAD-7, PHQ-9, TBI-QOL Anxiety v1.0 and TBI-QOL Depression v1.0. Item response theory-based linking methods were used to create crosswalk tables that convert scores on the GAD-7 to the TBI-QOL Anxiety metric and scores on the PHQ-9 to the TBI-QOL Depression metric. Comparisons between actual and crosswalked scores suggest that the linkages were successful and are appropriate for group-level analysis. Linking functions closely mirror crosswalks between the GAD-7/PHQ-9 and the Patient-Reported Outcomes Measurement Information System (PROMIS), suggesting that general population linkages are similar to those from a TBI sample. Researchers and clinicians can use the crosswalk tables to transform scores on the GAD-7 and the PHQ-9 to the TBI-QOL metric for group-level analyses.