Systematic Literature Review and Critical Appraisal of Health Economic Models Used in Cost-Effectiveness Analyses in Non-Alcoholic Steatohepatitis: Potential for Improvements.

BACKGROUND: Non-alcoholic steatohepatitis (NASH) is a severe, typically progressive form of non-alcoholic fatty liver disease (NAFLD). The global prevalence of NASH is increasing, driven partly by the global increase in obesity and type 2 diabetes mellitus (T2DM), such that NASH is now a leading cause of cirrhosis. There is currently an unmet clinical need for efficacious and cost-effective treatments for NASH; no pharmacologic agents have an approved indication for NASH. OBJECTIVE: Our objective was to summarise and critically appraise published health economic models of NASH, to evaluate their quality and suitability for use in the assessment of novel treatments for NASH, and to identify knowledge gaps, challenges and opportunities for future modelling. METHODS: A systematic literature review was performed using the MEDLINE, Embase, Cochrane Library and EconLit databases to identify published health economic analyses in patients with NAFLD or NASH. Supplementary hand searches of grey literature were also performed. Articles published up to November 2019 were included in the review. Quality assessment of identified studies was also performed. RESULTS: A total of 19 articles comprising 16 unique models including either NAFLD as a whole or NASH alone were included in the review. Structurally, most models had a state-transition component; in terms of health states, two different approaches to early disease states were used, modelling either progression through fibrosis stages or NAFLD/NASH-specific health states. Conditions that frequently co-exist with NASH, such as obesity, T2DM and cardiovascular disease were not captured in models identified here. Late-stage complications such as cirrhosis, decompensated cirrhosis and hepatocellular carcinoma were consistently included, but input data (e.g. costs, utilities and transition probabilities) for late-stage complications were frequently sourced from other liver disease areas. The quality of included studies was heterogenous, and only a small proportion of studies reported internal and external validation processes. CONCLUSION: The health economic models identified in this review are associated with limitations primarily driven by a lack of NASH-specific data. Identified models also largely overlooked the intricate association between NASH and other conditions, including obesity and T2DM, and did not capture the increased risk of cardiovascular events associated with NASH. High-quality, transparent, validated health economic models of NASH will be required to evaluate the cost effectiveness of treatments currently in development, particularly compounds that may target other non-hepatic outcomes.

Nonalcoholic fatty liver disease is associated with benign gastrointestinal disorders.

AIM: To explore associations between nonalcoholic fatty liver disease (NAFLD) and benign gastrointestinal and pancreato-biliary disorders. METHODS: Patient demographics, diagnoses, and hospital outcomes from the 2010 Nationwide Inpatient Sample were analyzed. Chronic liver diseases were identified using International Classification of Diseases, the 9(th) Revision, Clinical Modification codes. Patients with NAFLD were compared to those with other chronic liver diseases for the endpoints of total hospital charges, disease severity, and hospital mortality. Multivariable stepwise logistic regression analyses to assess for the independent association of demographic, comorbidity, and diagnosis variables with the event of NAFLD (vs other chronic liver diseases) were also performed. RESULTS: Of 7800441 discharge records, 32347 (0.4%) and 271049 (3.5%) included diagnoses of NAFLD and other chronic liver diseases, respectively. NAFLD patients were younger (average 52.3 years vs 55.3 years), more often female (58.8% vs 41.6%), less often black (9.6% vs 18.6%), and were from higher income areas (23.7% vs 17.7%) compared to counterparts with other chronic liver diseases (all P < 0.0001). Diabetes mellitus (43.4% vs 28.9%), hypertension (56.9% vs 47.6%), morbid obesity (36.9% vs 8.0%), dyslipidemia (37.9% vs 15.6%), and the metabolic syndrome (28.75% vs 8.8%) were all more common among NAFLD patients (all P < 0.0001). The average total hospital charge ($39607 vs $51665), disease severity scores, and intra-hospital mortality (0.9% vs 6.0%) were lower among NALFD patients compared to those with other chronic liver diseases (all P < 0.0001).Compared with other chronic liver diseases, NAFLD was significantly associated with diverticular disorders [OR = 4.26 (3.89-4.67)], inflammatory bowel diseases [OR = 3.64 (3.10-4.28)], gallstone related diseases [OR = 3.59 (3.40-3.79)], and benign pancreatitis [OR = 2.95 (2.79-3.12)] on multivariable logistic regression (all P < 0.0001) when the latter disorders were the principal diagnoses on hospital discharge. Similar relationships were observed when the latter disorders were associated diagnoses on hospital discharge. CONCLUSION: NAFLD is associated with diverticular, inflammatory bowel, gallstone, and benign pancreatitis disorders. Compared with other liver diseases, patients with NAFLD have lower hospital charges and mortality.

Pioglitazone and vitamin E for nonalcoholic steatohepatitis: a cost utility analysis.

UNLABELLED: Nonalcoholic steatohepatitis (NASH) is the commonest liver disease in developed countries. However, there are no current data on the cost-effectiveness of therapeutic options such as lifestyle modification, pioglitazone, or vitamin E. We undertook a cost utility analysis to compare these strategies. Using a third-party payer perspective, a deterministic Markov model was developed to compare costs and health benefits of lifestyle modification alone or with pioglitazone or vitamin E in a cohort of patients aged 50 years with biopsy-proven NASH and fibrosis level 3 or greater. We assumed an annual cycle length over a lifetime horizon. Probability and utility estimates were derived from a systematic literature review, and uncertainties in parameter estimates were tested using one- and two-way sensitivity analyses. Our outcome measure was the incremental cost-effectiveness ratio (ICER), with $A50,000 or less considered cost-effective. In comparison with lifestyle modification alone, treatment with either pioglitazone or vitamin E in addition to lifestyle modification was cost-effective, with incremental cost-effectiveness ratios of $A2748 and $A8475 per quality-adjusted life year (QALY) gained, respectively. In a direct comparison, pioglitazone was more cost-effective than vitamin E (ICER $A2,056/QALY gained). Sensitivity analyses indicated that pioglitazone was not cost-effective if either the total drug cost was greater than $A16,000 per annum, or the annual probability of developing cirrhosis in advanced fibrosis was less than 2%. CONCLUSION: Our modeled analyses suggest that in patients with advanced fibrosis due to NASH, pharmacological treatment in addition to standard lifestyle modification is likely to be cost-effective.

Insulin sensitisers in the treatment of non-alcoholic fatty liver disease: a systematic review.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is closely linked with obesity and the prevalence of NAFLD is about 17% to 33% in the Western world. There is a strong association of NAFLD with insulin resistance and, hence, insulin sensitisers have been tried. This systematic review examined the clinical effectiveness of insulin sensitisers in patients with NAFLD, to help decide whether or not a trial or trials of the insulin sensitisers was necessary and also to explore whether or not non-invasive alternatives to liver biopsy were available that could be used in a large trial of the insulin sensitisers. OBJECTIVE: To review the use of insulin sensitisers in the treatment of NAFLD. REVIEW METHODS: A systematic review of the clinical effectiveness of metformin, rosiglitazone and pioglitazone was carried out, including reviews and randomised controlled trials (RCTs). Databases searched were MEDLINE, 1950 to June 2010; EMBASE, 1980 to June 2010; Science Citation Index Expanded, June 2010; Conference Proceedings Citation Index - Science June 2010; The Cochrane Library 2005-10. Abstracts were screened independently by two researchers. A narrative review of diagnostic methods was conducted. RESULTS: Clinical effectiveness. We identified 15 RCTs (one available as abstract). Four papers explored efficacy of pioglitazone, one rosiglitazone, eight metformin; two compared metformin and rosiglitazone, although one used both metformin and rosiglitazone. The duration of most trials was between 6 and 12 months. Many trials had a small number of participants and the quality of the studies was mixed. Pioglitazone improved all parameters of liver histology. Metformin showed mixed results, with ultrasound changes in two studies showing some improvement in steatosis, whereas there were no changes in the other two. Metformin, however, showed no improvement in non-alcoholic steatohepatitis (NASH) stages. Metformin showed greater reduction in glycosylated haemoglobin (-0.23% to -1.2% vs -0.2% to -0.7%) and fasting plasma glucose (+0.05 to -3.19 mmol/l vs -0.17 to -1.11 mmol/l) compared with pioglitazone. Metformin led to weight reduction (-4.3 to -6.7 kg), whereas participants on pioglitazone gained weight (+2.5 to +4.7 kg). Alanine aminotransferase levels were reduced with both metformin and pioglitazone; however, the reduction in levels with pioglitazone was not different to that caused by vitamin E. Most studies suggested that metformin led to a significant reduction in insulin resistance. Diagnosis. Non-invasive methods of diagnosing NAFLD without liver biopsy, using combinations of clinical history, laboratory tests and ultrasound, have been explored, but so far liver biopsy is the only proven method of distinguishing simple steatosis from NASH. Transient elastography appears useful, but less so in obese individuals. Magnetic resonance spectroscopy shows promise, but is expensive and not readily available. LIMITATIONS: Mixed quality of trials, with lack of detail as to how some trials were conducted. Many trials had small numbers of patients. CONCLUSIONS: The main need for drug trials is at the NASH stage. However, at present, any trial in the more advanced forms of NAFLD would have to use liver biopsy. The highest priority for research may, therefore, be in the diagnosis of NAFLD, and the differentiation between steatosis and NASH. The newer agents, the glucagon-like peptide-1 analogues such as liraglutide, may be more worthy of a trial. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Economic impact of extracolonic findings at computed tomographic colonography.

OBJECTIVE: To determine the prevalence of extracolonic findings at computed tomographic colonography (CTC) and estimate the cost of the workup of newly discovered potentially significant lesions. SUBJECTS AND METHODS: An electronic information system was used to review all patient data before and after the CTC in a mixed cohort of 376 patients. Extracolonic findings were categorized into the CT Colonography Reporting and Data System classification. The impact of additional diagnostic workup was estimated using Medicare reimbursement for relevant extra services. RESULTS: There were 51 patients (13.6%) with E3 and 16 (4.3%) with E4 findings. At least 1 extracolonic finding was found in 272 patients (72.3%). There were 520 extracolonic findings, of which, 447 (86.0%) were classified as low clinical significance, E2. Only 7 (12.5%) of 56 E3 lesions and 7 (41.2%) of 17 E4 lesions received additional diagnostic workup. The total additional cost of evaluating E3 and E4 lesions was $13.07 per CTC. CONCLUSIONS: A mixed (screening and nonscreening) CTC population has a low prevalence of high-risk lesions, and the additional cost of their evaluation is relatively small.

Impact of fatty liver disease on health care utilization and costs in a general population: a 5-year observation.

BACKGROUND & AIMS: Fatty liver disease is a common condition in the Western world. Fatty liver may progress to steatohepatitis and cirrhosis. It is not yet known whether fatty liver disease results in higher health care utilization and costs. METHODS: We used data from the Study of Health in Pomerania (SHIP), Germany, to assess the relation of fatty liver disease to self-reported health care utilization and costs at baseline and 5 years. The SHIP is a general population cohort study of 4310 adults aged 20 to 79 years at baseline in Pomerania. Fatty liver disease was defined as the presence of a hyperechogenic pattern of the liver and elevated serum alanine aminotransferase (ALT) levels. RESULTS: In multivariable analyses, average annual overall health care costs at baseline and follow-up measurement were significantly higher for individuals with sonographic fatty liver and increased serum ALT levels. For example, controlling for comorbid conditions, subjects with sonographic fatty liver disease and increased serum ALT levels had 26% higher overall health care costs at 5-year follow-up. Analyses also suggest that diabetes and cardiovascular disease might mediate the relation of fatty liver disease and health care utilization and costs. CONCLUSIONS: Policies seeking to minimize costs associated with fatty liver disease might want to consider addressing behavioral risk factors of fatty liver disease.