BACKGROUND AND AIMS: NASH-CHECK is a newly developed patientreported outcome measure (PROM) assessing symptoms and healthrelated quality of life (HRQOL) in nonalcoholic steatohepatitis (NASH). The aim of the study was to conduct an evaluation of the preliminary dimensional structure of this PROM. The evaluation was guided by a conceptual model prepared during the initial development of NASHCHECK, from which items were categorised into logical groupings comprising 10 symptoms items and 21 HRQOL items (activity limitations = 8 items; emotions and lifestyle issues = 13 items).
METHOD: Data from a randomised, double-blind, placebo-controlled phase 2 trial of tropifexor in adult patients with NASH were used for the evaluation. Analyses included item correlations, exploratory factor analysis and Rasch analysis.
RESULTS: The analysis sample included 104 patients with NASH fibrosis grades 1 to 3 (54.8% female; mean [standard deviation] age = 51.2 [12.7] years; mean [standard deviation] body mass index = 32.5 [6.1]). Type 2 diabetes was present for 60 (65.4%) patients. Figure 1 shows a summary of the preliminary structure of NASH-CHECK resulting from the analyses. The results supported a 4-item cognitive symptoms subscale with the remaining symptoms items (e.g. pain, bloating, fatigue, itch) as individual items. For HRQOL, analysis supported the distinction between activity limitations and emotions & lifestyle. Analysis supported an overall activity limitations summary score which can be further divided into two activity limitations subscales (daily activities; ambulation). For emotions & lifestyle, production of an overall psychosocial summary was supported along with two subscales (emotions and social). Some items were highly correlated with each other (>0.80) suggesting potential content overlap (e.g. single symptoms items fatigue and need to rest, ambulatory items within the activity limitations subscales). In addition, one item (food restriction) showed a lack of association with other HRQOL items.
CONCLUSION: The results provide evidence for a preliminary dimensional structure for NASH-CHECK that is in line with the proposed logical groupings in the conceptual model. Further analyses using new trial data are planned to confirm the dimensional structure of NASH-CHECK.
