Chronic liver disease (CLD) and its complications such as decompensated cirrhosis and hepatocellular carcinoma are major causes of mortality and morbidity worldwide.1,2 In addition to its clinical impact, CLD causes impairment of health-related quality of life (HRQL) and other patient-reported outcomes (PROs).1 Furthermore, patients with CLD use a substantial amount of health care resources, making CLD responsible for tremendous economic burden to the society.1,2
Although CLD encompasses a number of liver diseases, globally, hepatitis B virus (HBV) and hepatitis C virus (HCV), as well as alcoholic and nonalcoholic steatohepatitis (NASH), are the most important causes of liver disease.1,2 In this context, recently developed treatment of HBV and HCV are highly effective. In contrast, there is no effective treatment for NASH and treatment of alcoholic steatohepatitis remains suboptimal.3 In the context of the growing burden of obesity and diabetes, the prevalence of NASH and its related complications are expected to grow.4
In recent years, a comprehensive approach to assessing the full burden of chronic diseases such as CLD has become increasingly recognized. In this context, it is important to evaluate not only the clinical burden of CLD (survival and mortality) but also its economic burden and its impact on PROs. PROs are defined as reports that come directly from the patient about their health without amendment or interpretation by a clinician or anyone else.5,6 Therefore, this commentary focuses on reviewing the assessment and interpretation of PROs in CLD and why they are important in clinical practice.
Assessment of patient-reported outcomes
Although a number of PRO instruments are available, three different categories are most relevant for patients with CLD. In this context, PRO instruments can be divided into generic tools, disease-/condition-specific tools, or other instruments that specifically measure outcomes such as work or activity impairment (Table 1).
Generic HRQL tools measure overall health and its impact on patients’ quality of life. One of the most commonly used generic HRQL tools in liver disease is the Short Form-36 (SF-36) version 2. The SF-36 version 2 tool measures eight domains (scores, 0–100; with a higher score indicating less impairment) and provides two summary scores: one for physical functioning and one for mental health functioning. The SF-36 has been translated into multiple languages and provides age group– and disease-specific norms to use in comparison analysis.7 In addition to the SF-36, the Sickness Impact Profile also has been used to assess a change in behavior as a consequence of illness. The Sickness Impact Profile consists of 136 items/12 categories covering activities of daily living (sleep and rest, eating, work, home management, recreation and pastimes, ambulation, mobility, body care and movement, social interaction, alertness behavior, emotional behavior, and communication). Items are scored on a numeric scale, with higher scores reflecting greater dysfunction as well as providing two aggregate scores: the psychosocial score, which is derived from four categories, and an aggregate physical score, which is calculated from three categories.8 Although generic instruments capture patients’ HRQL with different disease states (e.g., CLD vs. congestive heart failure), they may not have sufficient responsiveness to detect clinically important changes that can occur as a result of the natural history of disease or its treatment.9