Cost-effectiveness of non-invasive methods for assessment and monitoring of liver fibrosis and cirrhosis in patients with chronic liver disease: systematic review and economic evaluation.

BACKGROUND: Liver biopsy is the reference standard for diagnosing the extent of fibrosis in chronic liver disease; however, it is invasive, with the potential for serious complications. Alternatives to biopsy include non-invasive liver tests (NILTs); however, the cost-effectiveness of these needs to be established. OBJECTIVE: To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease. DATA SOURCES: We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists. METHODS: We included studies that assessed the diagnostic accuracy of NILTs using liver biopsy as the reference standard. Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-analysis was conducted using the bivariate random-effects model with correlation between sensitivity and specificity (whenever possible). Decision models were used to evaluate the cost-effectiveness of the NILTs. Expected costs were estimated using a NHS perspective and health outcomes were measured as quality-adjusted life-years (QALYs). Markov models were developed to estimate long-term costs and QALYs following testing, and antiviral treatment where indicated, for chronic hepatitis B (HBV) and chronic hepatitis C (HCV). NILTs were compared with each other, sequential testing strategies, biopsy and strategies including no testing. For alcoholic liver disease (ALD), we assessed the cost-effectiveness of NILTs in the context of potentially increasing abstinence from alcohol. Owing to a lack of data and treatments specifically for fibrosis in patients with non-alcoholic fatty liver disease (NAFLD), the analysis was limited to an incremental cost per correct diagnosis. An analysis of NILTs to identify patients with cirrhosis for increased monitoring was also conducted. RESULTS: Given a cost-effectiveness threshold of £20,000 per QALY, treating everyone with HCV without prior testing was cost-effective with an incremental cost-effectiveness ratio (ICER) of £9204. This was robust in most sensitivity analyses but sensitive to the extent of treatment benefit for patients with mild fibrosis. For HBV [hepatitis B e antigen (HBeAg)-negative)] this strategy had an ICER of £28,137, which was cost-effective only if the upper bound of the standard UK cost-effectiveness threshold range (£30,000) is acceptable. For HBeAg-positive disease, two NILTs applied sequentially (hyaluronic acid and magnetic resonance elastography) were cost-effective at a £20,000 threshold (ICER: £19,612); however, the results were highly uncertain, with several test strategies having similar expected outcomes and costs. For patients with ALD, liver biopsy was the cost-effective strategy, with an ICER of £822. LIMITATIONS: A substantial number of tests had only one study from which diagnostic accuracy was derived; therefore, there is a high risk of bias. Most NILTs did not have validated cut-offs for diagnosis of specific fibrosis stages. The findings of the ALD model were dependent on assuptions about abstinence rates assumptions and the modelling approach for NAFLD was hindered by the lack of evidence on clinically effective treatments. CONCLUSIONS: Treating everyone without NILTs is cost-effective for patients with HCV, but only for HBeAg-negative if the higher cost-effectiveness threshold is appropriate. For HBeAg-positive, two NILTs applied sequentially were cost-effective but highly uncertain. Further evidence for treatment effectiveness is required for ALD and NAFLD. STUDY REGISTRATION: This study is registered as PROSPERO CRD42011001561. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Validation and impact of a new technique for assessment of glomerular filtration rate in patients with liver disease.

OBJECTIVES: Previously we have proposed a technique for the measurement of plasma clearance in patients with ascites. The impact of using the technique was assessed and the results compared with those from a reference technique in 111 patients having glomerular filtration rate measurements as part of their workup for liver transplantation. METHODS: Results of calculations using the new technique were compared with plasma clearance measurements obtained using a conventional slope-intercept technique and with clearance measurements based on urine collection. Discrepancies between the results of plasma clearance and urinary clearance assessments were investigated by using an uncollimated gamma camera to measure the total retention of the tracer. RESULTS: Conventional slope-intercept calculations overestimated clearance compared with the new technique by more than 20% in 21% of the patients. Significant differences between the results of the two methods were more likely in patients with more severe ascites. Results of urine collection-based measurements of Cr-51 EDTA clearance were frequently significantly lower than measurements using the new technique, whereas measurements of urinary clearance of creatinine were higher. Gamma camera measurements suggest that discrepancies between total and urinary clearance of Cr-51 EDTA are due to incomplete urine collection. CONCLUSION: The new technique is a practical method for assessment of kidney function and should be used in patients with liver disease who have or may have ascites.

Cost-effectiveness of noninvasive liver fibrosis tests for treatment decisions in patients with chronic hepatitis C.

UNLABELLED: The cost-effectiveness of noninvasive tests (NITs) as alternatives to liver biopsy is unknown. We compared the cost-effectiveness of using NITs to inform treatment decisions in adult patients with chronic hepatitis C (CHC). We conducted a systematic review and meta-analysis to calculate the diagnostic accuracy of various NITs using a bivariate random-effects model. We constructed a probabilistic decision analytical model to estimate health care costs and outcomes (quality-adjusted life-years; QALYs) using data from the meta-analysis, literature, and national UK data. We compared the cost-effectiveness of four treatment strategies: testing with NITs and treating patients with fibrosis stage≥F2; testing with liver biopsy and treating patients with ≥F2; treat none; and treat all irrespective of fibrosis. We compared all NITs and tested the cost-effectiveness using current triple therapy with boceprevir or telaprevir, but also modeled new, more-potent antivirals. Treating all patients without any previous NIT was the most effective strategy and had an incremental cost-effectiveness ratio (ICER) of £9,204 per additional QALY gained. The exploratory analysis of currently licensed sofosbuvir treatment regimens found that treat all was cost-effective, compared to using an NIT to decide on treatment, with an ICER of £16,028 per QALY gained. The exploratory analysis to assess the possible effect on results of new treatments, found that if SVR rates increased to >90% for genotypes 1-4, the incremental treatment cost threshold for the "treat all" strategy to remain the most cost-effective strategy would be £37,500. Above this threshold, the most cost-effective option would be noninvasive testing with magnetic resonance elastography (ICER=£9,189). CONCLUSIONS: Treating all adult patients with CHC, irrespective of fibrosis stage, is the most cost-effective strategy with currently available drugs in developed countries.

The Royal Free Hospital score: a calibrated prognostic model for patients with cirrhosis admitted to intensive care unit. Comparison with current models and CLIF-SOFA score.

OBJECTIVES: Prognosis for patients with cirrhosis admitted to intensive care unit (ICU) is poor. ICU prognostic models are more accurate than liver-specific models. We identified predictors of mortality, developed a novel prognostic score (Royal Free Hospital (RFH) score), and tested it against established prognostic models and the yet unvalidated Chronic Liver Failure-Sequential Organ Failure Assessment (CLIF-SOFA) model. METHODS: Predictors of mortality were defined by logistic regression in a cohort of 635 consecutive patients with cirrhosis admitted to ICU (1989-2012). The RFH score was derived using a 75% training and 25% validation set. Predictive accuracy and calibration were evaluated using area under the receiver operating characteristic (AUROC) and goodness-of-fit χ(2) for the RFH score, as well as for SOFA, Model for End-Stage Liver Disease (MELD), Acute Physiology and Chronic Health Evaluation (APACHE II), and Child-Pugh. CLIF-SOFA was applied to a recent subset (2005-2012) of patients. RESULTS: In-hospital mortality was 52.3%. Mortality improved over time but with a corresponding reduction in acuity of illness on admission. Predictors of mortality in training set, which constituted the RFH score, were the following: bilirubin, international normalized ratio, lactate, alveolar arterial partial pressure oxygen gradient, urea, while variceal bleeding as indication for admission conferred lesser risk. Classification accuracy was 73.4% in training and 76.7% in validation sample and did not change significantly across different eras of admission. The AUROC for the derived model was 0.83 and the goodness-of-fit χ(2) was 3.74 (P=0.88). AUROC for SOFA was 0.81, MELD was 0.79, APACHE II was 0.78, and Child-Pugh was 0.67. In 2005-2012 cohort, AUROC was: SOFA: 0.74, CLIF-SOFA: 0.75, and RFH: 0.78. Goodness-of-fit χ(2) was: SOFA: 6.21 (P=0.63), CLIF-SOFA: 9.18 (P=0.33), and RFH: 2.91 (P=0.94). CONCLUSIONS: RFH score demonstrated good discriminative ability and calibration. Internal validation supports its generalizability. CLIF-SOFA did not perform better than RFH and the original SOFA. External validation of our model should be undertaken to confirm its clinical utility.

Can non-invasive measurements aid clinical assessment of volume in patients with cirrhosis?

AIM: To evaluate the non-invasive assessments of volume status in patients with cirrhosis. METHODS: Echocardiography and multifrequency bioimpedance analysis measurements and short synacthen tests were made in 20 stable and 25 acutely decompensated patients with cirrhosis. RESULTS: Both groups had similar clinical assessments, cortisol response and total body water (TBW), however the ratio of extracellular water (ECW)/TBW was significantly greater in the trunk (0.420 ± 0.004 vs 0.404 ± 0.005), and limbs (R leg 0.41 ± 0.003 vs 0.398 ± 0.003, P < 0.05, and L leg 0.412 ± 0.003 vs 0.399 ± 0.003) with decompensated cirrhosis compared to stable cirrhotics, P < 0.05). Echocardiogram derived right atrial and ventricular filling and end diastolic pressures and presence of increased left ventricular end diastolic volume and diastolic dysfunction were similar in both groups. The decompensated group had lower systemic blood pressure, mean systolic 101.8 ± 4.3 vs 122.4 ± 5.3 and diastolic 58.4 ± 4.1 mmHg vs 68.8 ± 3.1 mmHg respectively, P < 0.01, and serum albumin 30 (27-33) vs 32 (31-40.5) g/L, P < 0.01. CONCLUSION: Decompensated cirrhotics had greater leg and truncal ECW expansion with lower serum albumin levels consistent with intravascular volume depletion and increased vascular permeability.

Development of a modified sampling and calculation method for isotope plasma clearance assessment of the glomerular filtration rate in patients with cirrhosis and ascites.

AIM: The aim of this study was to identify a practical sampling regimen and calculation method that could be used to measure the glomerular filtration rate in patients with ascites using plasma sampling. PATIENTS AND METHODS: Thirteen potential liver transplant patients with cirrhosis and ascites were injected with Cr-51 ethylenediaminetetraacetic acid, and plasma samples were obtained at up to 16 time points for each patient. Reference clearance values were calculated using the area under the plasma clearance curve, which was calculated using all the available data points. Clearance calculations were then performed using three and four data points from each patient and three different calculation methods to identify a sampling regimen and calculation method that yielded good agreement with the reference values. RESULTS: The reference clearances ranged from 6 to 80 ml/min. Sampling at 2, 4, 8 and 24 h and calculation of the area under the plasma clearance curve using a log-linear trapezoidal rule with extrapolation to zero and infinity yielded a relative root mean square difference from the reference of less than 7%. CONCLUSION: This method for measuring glomerular filtration rate in patients with cirrhosis and ascites was found to be more accurate than the slope-intercept technique and is a practical alternative to urine collection.

Digital image analysis of collagen assessment of progression of fibrosis in recurrent HCV after liver transplantation.

BACKGROUND & AIMS: Histological assessment of fibrosis progression is currently performed by staging systems which are not continuous quantitative measurements. We aimed at assessing a quantitative measurement of fibrosis collagen proportionate area (CPA), to evaluate fibrosis progression and compare it to Ishak stage progression. METHODS: We studied a consecutive cohort of 155 patients with recurrent HCV hepatitis after liver transplantation (LT), who had liver biopsies at one year and were subsequently evaluated for progression of fibrosis using CPA and Ishak staging, and correlated with clinical decompensation. The upper quartile of distribution of fibrosis rates (difference in CPA or Ishak stage between paired biopsies) defined fast fibrosers. RESULTS: Patients had 610 biopsies and a median follow-up of 116 (18-252) months. Decompensation occurred in 29 (18%) patients. Median Ishak stage progression rate was 0.42 units/year: (24 (15%) fast fibrosers). Median CPA fibrosis progression rate was 0.71%/year (36 (23%) fast fibrosers). Clinical decompensation was independently associated by Cox regression only with CPA (p=0.007), with AUROCs of 0.81 (95% CI 0.71-0.91) compared to 0.68 (95% CI 0.56-0.81) for Ishak stage. Fast fibrosis defined by CPA progression was independently associated with histological de novo hepatitis (OR: 3.77), older donor age (OR: 1.03) and non-use/discontinuation of azathioprine before 1 year post-LT (OR: 3.85), whereas when defined by Ishak progression, fast fibrosers was only associated with histological de novo hepatitis. CONCLUSIONS: CPA fibrosis progression rate is a better predictor of clinical outcome than progression by Ishak stage. Histological de novo hepatitis, older donor age and non-use/discontinuation of azathioprine are associated with rapid fibrosis progression in recurrent HCV chronic hepatitis after liver transplantation.

The use of fatty liver grafts in modern allocation systems: risk assessment by the balance of risk (BAR) score.

OBJECTIVE: To integrate the amount of hepatic steatosis in modern liver allocation models. BACKGROUND: The aim of this study was to combine the 2 largest liver transplant databases (United States and Europe) in 1 comprehensive model to predict outcome after liver transplantation, with a novel focus on the impact of the presence of steatosis in the graft. METHODS: We adjusted the balance of risk (BAR) score for its application to the European Liver Transplant Registry (ELTR) database containing 11,942 patients. All liver transplants from ELTR and United Network for Organ Sharing with recorded liver biopsies were then combined in one survival analysis in relation to the presence of graft micro- (n = 9,677) and macrosteatosis (n = 11,516). RESULTS: Microsteatosis, regardless of the amount, was associated with a similar relationship between mortality and BAR score as nonsteatotic livers. Low-grade macrosteatotic liver grafts (≤30% macrosteatosis) resulted in 5-year graft-survival rates of 60% or more up to BAR 18, comparable to nonsteatotic grafts. However, use of moderate or severely steatotic liver grafts (>30% macrosteatosis) resulted in acceptable outcome only if the cumulative risk at transplant was low, that is, BAR score of 9 or less. CONCLUSIONS: Microsteatotic or 30% or less macrosteatotic liver grafts can be used safely up to BAR score of 18 or less, but liver grafts with more than 30% macrosteatotis should be used with risk adjustment, that is, up to BAR score of 9 or less.

New therapeutic paradigm for patients with cirrhosis.

Cirrhosis is a major health problem, being the 5th cause of death in the U.K. and 12th in the U.S., but 4th in the 45 to 54 age group. Until recently cirrhosis was considered a single and terminal disease stage, with an inevitably poor prognosis. However, it is now clear that 1-year mortality can range from 1% in early cirrhosis to 57% in decompensated disease. As the only treatment for advanced cirrhosis is liver transplantation, what is urgently needed is strategies to prevent transition to decompensated stages. The evidence we present in this review clearly demonstrates that management of patients with cirrhosis should change from an expectant algorithm that treats complications as they occur, to preventing the advent of all complications while in the compensated phase. This requires maintaining patients in an asymptomatic phase and not significantly affecting their quality of life with minimal impairment due to the therapies themselves. This could be achieved with lifestyle changes and combinations of already licensed and low-cost drugs, similar to the paradigm of treating risk factors for cardiovascular disease. The drugs are propranolol, simvastatin, norfloxacin, and warfarin, which in combination would cost £128/patient annually-equivalent to U.S. $196/year. This treatment strategy requires randomized controlled trials to establish improvements in outcomes. In the 21st century, cirrhosis should be regarded as a potentially treatable disease with currently available and inexpensive therapies.

Comparison of the sequential organ failure assessment score with the King's College Hospital criteria and the model for end-stage liver disease score for the prognosis of acetaminophen-induced acute liver failure.

Acetaminophen-induced acute liver failure (ALF) is a complex multiorgan illness. An assessment of the prognosis is essential for the accurate identification of patients for whom survival without liver transplantation (LT) is unlikely. The aims of this study were the comparison of prognostic models [King's College Hospital (KCH), Model for End-Stage Liver Disease, Sequential Organ Failure Assessment (SOFA), and Acute Physiology and Chronic Health Evaluation II (APACHE II)] and the identification of independent prognostic indicators of outcome. We evaluated consecutive patients with severe acetaminophen-induced ALF who were admitted to the intensive care unit. At admission, demographic, clinical, and laboratory parameters were recorded. The discriminative ability of each prognostic score at the baseline was evaluated with the area under the receiver operating characteristic curve (AUC). In addition, using a multiple logistic regression, we assessed independent factors associated with outcome. In all, 125 consecutive patients with acetaminophen-induced ALF were evaluated: 67 patients (54%) survived with conservative medical management (group 1), and 58 patients (46%) either died without LT (28%) or underwent LT (18%; group 2). Group 1 patients had significantly lower median APACHE II (10 versus 14) and SOFA scores (9 versus 12) than group 2 patients (P < 0.001). The independent indicators associated with death or LT were a longer prothrombin time (P = 0.007), the inspiratory oxygen concentration (P = 0.005), and the lactate level at 12 hours (P < 0.001). The KCH criteria had the highest specificity (83%) but the lowest sensitivity (47%), and the SOFA score had the best discriminative ability (AUC = 0.79). In conclusion, for patients with acetaminophen-induced ALF, the SOFA score performed better than the other prognostic scores, and this reflected the presence of multiorgan dysfunction. A further evaluation of SOFA with the KCH criteria is warranted.

Non-invasive assessment of liver fibrosis.

The presence and degree of hepatic fibrosis is crucial in order to make therapeutic decisions and predict clinical outcomes. Currently, the place of liver biopsy as the standard of reference for assessing liver fibrosis has been challenged by the increasing awareness of a number of drawbacks related to its use (invasiveness, sampling error, inter-/intraobserver variability). In parallel with this, noninvasive assessment of liver fibrosis has experienced explosive growth in recent years and a wide spectrum of noninvasive methods ranging from serum assays to imaging techniques have been developed. Some are validated methods, such as the Fibrotest/ Fibrosure and transient elastography in Europe, and are gaining a growing role in routine clinical practice, especially in chronic hepatitis C. Large-scale validation is awaited in the setting of other chronic liver diseases. However, noninvasive tests used to detect significant fibrosis and cirrhosis, the two major clinical endpoints, are not yet at a level of performance suitable for routine diagnostic tests, and there is still no perfect surrogate or method able to completely replace an optimal liver biopsy. This article aims to review current noninvasive tests for the assessment of liver fibrosis and the perspectives for their rational use in clinical practice.

Intra-operative vs pre-operative endoscopic sphincterotomy in patients with gallbladder and common bile duct stones: cost-utility and value-of-information analysis.

BACKGROUND: Patients with gallbladder and common bile duct stones are generally treated by pre-operative endoscopic sphincterotomy (ES) followed by laparoscopic cholecystectomy (POES). Recently, a meta-analysis has shown that intra-operative ES during laparoscopic cholecystectomy (IOES) results in fewer complications than POES, with similar efficacy. The cost effectiveness of IOES versus POES is unknown. OBJECTIVE: The objective of this study was to compare the cost effectiveness of IOES versus POES from the UK NHS perspective. METHODS: A decision-tree model estimating and comparing costs to the UK NHS and QALYs gained following a policy of either IOES or POES was developed with a time horizon of 3 years. Uncertainty was investigated with probabilistic sensitivity analysis, and the expected value of perfect information (EVPI) and partial information (EVPPI) were also calculated. RESULTS: IOES was less costly than POES (approximately -£623 per patient [year 2008 values]) and resulted in similar quality of life (+0.008 QALYs per patient) as POES. Given a willingness-to-pay threshold of £20 000 per QALY gained, there was a 92.9% probability that IOES is cost effective compared with POES. Full implementation of IOES could save the NHS £2.8 million per annum. At a willingness to pay of £20 000 per QALY gained, the 10-year population EVPI was estimated at £0.6 million. CONCLUSIONS: IOES appears to be cost effective compared with POES.

Assessment of fibrosis and cirrhosis in liver biopsies: an update.

The liver biopsy specimen represents valuable material for the assessment of fibrosis and cirrhosis. Despite limitations related to sampling and interpretation, histologic examination remains the gold standard for staging chronic liver diseases. Hepatic fibrosis is currently viewed as a dynamic process that may often regress after successful treatment of chronic liver diseases. Even the excess fibrous tissue of cirrhotic livers may sometimes regress over time. Distinguishing between the amount of hepatic fibrosis and the disease stage is important for the assessment of the effects of antifibrotic treatments. Recent studies suggest that the proportion of the liver biopsy specimen occupied by collagen is correlated with the hepatic venous pressure gradient in liver transplant recipients with hepatitis C virus infection, with or without cirrhosis, and represents a predictor of clinical decompensation. This parameter has also been found to correlate with liver stiffness measurements of patients with chronic viral hepatitis obtained by transient elastography. Therefore, quantitative assessment of hepatic fibrosis in liver biopsy specimens holds promise as a prognostic marker, and as a means to validate noninvasive markers of fibrosis.

Assessment of adrenocortical reserve in stable patients with cirrhosis.

BACKGROUND & AIMS: Adrenal insufficiency (AI) is reported in critically ill patients with cirrhosis and is associated with increased mortality. It is unclear if AI is an underlying condition or triggered by critical events (e.g. sepsis). We investigated AI in cirrhosis without infection or hemodynamic instability. METHODS: A total of 101 consecutive patients with cirrhosis were studied. AI was defined by a total serum cortisol (TC) <18 µg/dl at 20 or 30 min after injection of 1 µg of tetracosactrin. Transcortin, calculated free cortisol (cFC), and free cortisol index (FCI) were assessed in a subgroup of 41 patients, with FCI>12 representing normal adrenal function. RESULTS: AI was present in 38 patients (38%). Child score (median, 10 vs 7, p<0.0001), MELD score (median, 17 vs 12, p<0.0001), ascites (68% vs 37%, p<0.01), basal TC (median,7.6 vs 14.9 µg/dl, p<0.001), albumin (28 ± 0.8 vs 33 ± 0.7 g/L, p<0.0001), INR (median, 1.6 vs 1.2, p<0.0001), total bilirubin (median, 51 vs 31 µmol/L, p<0.05), total cholesterol (median, 120 vs 142, p<0.05), and LDL (median, 76 vs 81, p<0.05) were significantly different between those with and without AI. ROC curves showed a basal TC ≤ 12.8 µg/dl to be a cut-off value closely associated with AI. The cFC was significantly related to TC for baseline values (R=0.94, p<0.0001), peak values (R=0.90, p<0.0001), and delta values (R=0.95, p<0.0001), in patients with and without AI. However, no patient had a FCI<12. CONCLUSIONS: AI defined by an abnormal response to 1 µg tetracosactrin is frequent in stable patients with cirrhosis, in the absence of infections or hemodynamic instability and is related to the severity of liver disease. However, evaluation of the true incidence of AI should comprise direct assays of free cortisol. Clinical consequences of AI need to be explored.