Patient-reported outcomes for patients with chronic liver disease

For better responsiveness of HRQL instruments, disease-specific or condition-specific tools have been developed. These tools assess those aspects of HRQL that are related directly to the underlying disease. For patients with CLD, several tools have been developed and validated.^10-12 One of the more popular tools is the Chronic Liver Disease Questionnaire (CLDQ), which was developed and validated for patients with CLD.¹⁰ The CLDQ has 29 items and 6 domains covering fatigue, activity, emotional function, abdominal symptoms, systemic symptoms, and worry.¹⁰ More recently, HCV-specific and NASH-specific versions of the CLDQ have been developed and validated (CLDQ-HCV and CLDQ–nonalcoholic fatty liver disease [NAFLD]/NASH). The CLDQ-HCV instrument has some items from the original CLDQ with additional items specific to patients suffering from HCV. The CLDQ-HCV has 29 items that measure 4 domains: activity and energy, emotional, worry, and systemic, with high reliability and validity.¹¹ Finally, the CLDQ-NAFLD/NASH was developed in a similar fashion to the CLDQ and CLDQ-HCV. The CLDQ-NAFLD/NASH has 36 items grouped into 6 domains: abdominal symptoms, activity, emotional, fatigue, systemic symptoms, and worry.¹² All versions of the CLDQ are scored on a Likert scale of 1-7 nd domain scores are presented in the same manner. In addition, each version of the CLDQ can provide a total score, which also ranges from 1 to 7. In this context, the higher scores represent a better HRQL.^10-12In addition to generic and disease-specific instruments, some investigators may elect to include other instruments that are designed specifically to capture fatigue, a very common symptom of CLD. These include the Functional Assessment of Chronic Illness Therapy-Fatigue, Fatigue Symptom Severity, and Fatigue Assessment Inventory.^13,14

Finally, work productivity can be influenced profoundly by CLD and can be assessed by self-reports or questionnaires. One of these is the Work Productivity Activity Impairment: Specific Health Problem questionnaire, which evaluates impairment in patients’ daily activities and work productivity associated with a specific health problem, and for patients with liver disease, patients are asked to think about how their disease state impacts their life. Higher impairment scores indicate a poorer health status and range from 0 to 1.¹⁵ An important aspect of the PRO assessment that is utilized in economic analysis measures health utilities. Health utilities are measured directly (time-trade off) or indirectly (SF6D, EQ5D, Health Utility Index). These assessment are from 0 (death) to 1 (perfect health). Utility adjustments are used to combine qualty of life with quantity of life such as quality-adjusted years of life (QALY).¹⁶

Patient-reported outcome results for patients with chronic liver disease

Over the years, studies using these instruments have shown that patients with CLD suffer significant impairment in their PROs in all domains measured when compared with the population norms or with individuals without liver disease. Regardless of the cause of their CLD, patients with cirrhosis, especially with decompensated cirrhosis, have the most significant impairments.^16,17 On the other hand, there is substantial evidence that standard treatment for decompensated cirrhosis (i.e., liver transplantation) can significantly improve HRQL and other PROs in patients with advanced cirrhosis.¹⁸