Cost-effectiveness of screening and valacyclovir-based treatment strategies for first-trimester cytomegalovirus primary infection in pregnant women in France.

OBJECTIVE: To assess the effectiveness, cost and cost-effectiveness of four screening strategies for first-trimester (T1) cytomegalovirus (CMV) primary infection (PI) in pregnant women in France. METHODS: In a simulated pregnant population of 800 000 (approximate number of pregnancies each year in France), using costs based on the year 2022, we compared four CMV maternal screening strategies: Strategy S1, no systematic screening (current public health recommendations in France); Strategy S2, screening of 25-50% of the pregnant population (current screening practice in France); Strategy S3, universal screening (current medical recommendations in France); Strategy S4, universal screening (as in Strategy S3) in conjunction with valacyclovir in case of T1 PI. Outcomes were total cost, effectiveness (number of congenital infections, number of diagnosed infections) and incremental cost-effectiveness ratio (ICER). Two ICERs were calculated, comparing Strategies S1, S2 and S3 in terms of euros (€) per additional diagnosis, and comparing Strategies S1 and S4 in € per avoided congenital infection. RESULTS: Compared with Strategy S1, Strategy S3 enabled diagnosis of 536 more infected fetuses and Strategy S4 prevented 375 congenital infections. Strategy S1 was the least expensive strategy (€98.3m total lifetime cost), followed by Strategy S4 (€98.6m), Strategy S2 (€106.0m) and Strategy S3 (€118.9m). In the first analysis, Strategy S2 was dominated and Strategy S3 led to an additional €38 552 per additional in-utero diagnosis, compared with Strategy S1. In the second analysis, Strategy S4 led to an additional €893 per avoided congenital infection compared with Strategy S1, and was cost-saving compared with Strategy S2. CONCLUSIONS: In France, current screening practice for CMV PI during pregnancy is no longer acceptable in terms of cost-effectiveness because this strategy was dominated by universal screening. Moreover, universal screening in conjunction with valacyclovir treatment would be cost-effective compared with current recommendations and is cost-saving compared with current practice. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Effectiveness and cost-effectiveness of interventions targeting harm reduction and chronic hepatitis C cascade of care in people who inject drugs: The case of France.

Direct-acting antivirals (DAAs) represent an opportunity to improve hepatitis C virus (HCV) care cascade. This combined with improved harm reduction interventions may lead to HCV elimination especially in people who inject drugs (PWID). We assessed the effectiveness/cost-effectiveness of improvements in harm reduction and chronic hepatitis C (CHC) care cascade in PWID in France. We used a dynamic model of HCV transmission and CHC natural history and evaluated the following: improved needle/syringe programmes-opioid substitution therapies, faster diagnosis/linkage to care, earlier treatment initiation, alone and in combination among active PWID (mean age = 36). Outcomes were as follows: life expectancy in discounted quality-adjusted life years (QALYs); direct lifetime discounted costs; incremental cost-effectiveness ratio (ICER); number of infections/reinfections. Under the current practice, life expectancy was 15.846 QALYs, for a mean lifetime cost of €20 762. Treatment initiation at F0 fibrosis stage alone was less effective and more costly than faster diagnosis/linkage to care combined with treatment initiation at F0, which increased life expectancy to 16.694 QALYs, decreased new infections by 37%, with a ICER = €5300/QALY. Combining these interventions with harm reduction improvements was the most effective scenario (life expectancy = 16.701 QALYs, 41% decrease in new infections) but was not cost-effective (ICER = €105 600/QALY); it became cost-effective with higher initial HCV incidence rates and lower harm reduction coverage than in our base-case scenario. This study illustrated the high effectiveness, and cost-effectiveness, of a faster diagnosis/linkage to care together with treatment from F0 with DAAs. This "Test and treat" strategy should play a central role both in improving the life expectancies of HCV-infected patients, and in reducing HCV transmission.

Cost-effectiveness and budget impact of interferon-free direct-acting antiviral-based regimens for hepatitis C treatment: the French case.

We evaluated the cost-effectiveness and the budget impact of new DAA-based regimen use in France. A Markov model simulated chronic hepatitis C (CHC) treatment interventions with IFN-based and IFN-free regimens at stage of fibrosis ≥F3, ≥F2 or regardless of fibrosis stage, and treatment either with the least or the most expensive combination. It estimated quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs). It also assessed the budget impact over 5 years of treating all CHC-screened patients, regardless of fibrosis, assuming ≤20 000 patients treated/year and priority to ≥F3. Sensitivity analyses were also conducted. For genotypes (G) 1-4, the initiation of IFN-free regardless of fibrosis was a cost-effective strategy compared to prior standard of care (SOC) initiated at stage F2: €40 400-88 300/QALY gained in G1; similar results were obtained for patients infected with G4. Considering G2-3, the most cost-effective strategy was IFN-based regimens regardless of fibrosis compared to prior SOC initiated at stage F2: €21 300 and €19 400/QALY gained, respectively; the strategy with IFN-free regimens being more effective but not cost-effective at current costs. The budget impact of treating all CHC-screened patients over 5 years would range between 3.5 and 7.2 billion €, depending on whether one considers the least or the most expensive combination of new DAAs and whether one treats G2-3 with IFN-based or IFN-free new DAAs. In France, treatment initiation with new DDAs regardless of fibrosis stage is cost-effective, but would add 3.5-7.2 billion € to an already overburdened medical care system.

Dynamic modelling of hepatitis C virus transmission among people who inject drugs: a methodological review.

Equipment sharing among people who inject drugs (PWID) is a key risk factor in infection by hepatitis C virus (HCV). Both the effectiveness and cost-effectiveness of interventions aimed at reducing HCV transmission in this population (such as opioid substitution therapy, needle exchange programmes or improved treatment) are difficult to evaluate using field surveys. Ethical issues and complicated access to the PWID population make it difficult to gather epidemiological data. In this context, mathematical modelling of HCV transmission is a useful alternative for comparing the cost and effectiveness of various interventions. Several models have been developed in the past few years. They are often based on strong hypotheses concerning the population structure. This review presents compartmental and individual-based models to underline their strengths and limits in the context of HCV infection among PWID. The final section discusses the main results of the papers.

The state of hepatitis B and C in the Mediterranean and Balkan countries: report from a summit conference.

The burden of disease due to chronic viral hepatitis constitutes a global threat. In many Balkan and Mediterranean countries, the disease burden due to viral hepatitis remains largely unrecognized, including in high-risk groups and migrants, because of a lack of reliable epidemiological data, suggesting the need for better and targeted surveillance for public health gains. In many countries, the burden of chronic liver disease due to hepatitis B and C is increasing due to ageing of unvaccinated populations and migration, and a probable increase in drug injecting. Targeted vaccination strategies for hepatitis B virus (HBV) among risk groups and harm reduction interventions at adequate scale and coverage for injecting drug users are needed. Transmission of HBV and hepatitis C virus (HCV) in healthcare settings and a higher prevalence of HBV and HCV among recipients of blood and blood products in the Balkan and North African countries highlight the need to implement and monitor universal precautions in these settings and use voluntary, nonremunerated, repeat donors. Progress in drug discovery has improved outcomes of treatment for both HBV and HCV, although access is limited by the high costs of these drugs and resources available for health care. Egypt, with the highest burden of hepatitis C in the world, provides treatment through its National Control Strategy. Addressing the burden of viral hepatitis in the Balkan and Mediterranean regions will require national commitments in the form of strategic plans, financial and human resources, normative guidance and technical support from regional agencies and research.

Efficacy of new antiretroviral drugs in treatment-experienced HIV-infected patients: a systematic review and meta-analysis of recent randomized controlled trials.

OBJECTIVES: We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the overall efficacy of new antiretroviral drugs, as well as the factors associated with increased efficacy. We compared CD4 cell count increases associated with chemokine (C-C motif) receptor 5 (CCR5) inhibitors or other new drugs, using indirect comparison. METHODS: We included RCTs published in 2003-2010 that assessed the 48-week immunological and virological efficacy of adding new antiretroviral drugs vs. placebo to optimized background therapy (OBT) in treatment-experienced subjects. These drugs included maraviroc, vicriviroc, enfuvirtide, raltegravir, etravirine, tipranavir and darunavir. We collected baseline descriptive characteristics, CD4 cell count changes and virological suppression proportions (percentage with HIV RNA <50 HIV-1 RNA copies/mL). RESULTS: We identified 10 studies which included a total of 6401 patients. New drugs were associated with increased virological suppression (pooled odds ratio 2.97) and larger CD4 count increases (pooled nonstandardized difference 39 cells/µL) compared with placebo. OBT genotypic sensitivity scores (GSSs) were also associated with larger differences in virological suppression (P<0.001 for GSS=0,≤1 and ≤2) and CD4 cell count increase (GSS=0, P<0.001; GSS ≤1, P=0.002; GSS ≤2, P=0.015) between the two groups. CCR5 inhibitors were not associated with significant gains in CD4 cell counts (P=0.22) compared with other new drugs. CONCLUSIONS: Our study confirmed the overall immunological and virological efficacy of new antiretroviral drugs in treatment-experienced patients, compared with placebo. The main predictive factor for efficacy was the number of fully active drugs. CCR5 inhibitors did not increase CD4 cell count to a greater extent than other new drugs.

Expected increase in prevalence of HCV-related cirrhosis and its complications in the United States: no effect of current antiviral treatment coverage?

Davis et al. projected the future prevalence of chronic hepatitis C (CHC) and its complications in the United States, using a multicohort natural history model with a tree model. First, the model predicted that in 2010 many patients have already progressed to F4, including to decompensated cirrhosis and HCC. Second, the model emphasized that cirrhosis and its complications are most common after 60 years old, regardless of when the infection occurred. Finally, the model showed that current treatment patterns will have little effect on the incidence of the complications hepatitis C.

Costs and cost-effectiveness of different follow-up schedules for detection of occupational hepatitis C virus infection.

OBJECTIVE: The purpose of this study was to compare the costs and cost-effectiveness (C/E) of early hepatitis C virus (HCV) RNA testing (alternative-US recommendations) after occupational exposure to HCV with existing follow-up strategies: (1) French, anti-HCV antibodies and alanine transaminase (ALT) activity at months 1, 3 and 6; (2) European, monthly ALT activity for 4 months and anti-HCV antibodies at month 6; (3) and baseline-US, anti-HCV antibodies and ALT activity at month 6. METHODS: A decision tree simulated each strategy for 7300 healthcare workers (HCWs) exposed to HCV each year in France, taking into account the impact of early diagnosis on the response to antiviral treatment and the deterioration of HCW quality of life after exposure. RESULTS: For a HCV transmission risk of 0.5% after exposure, the French strategy led to the highest costs/person (181.40 euros) and the baseline-US strategy to the lowest (126.60 euros) (178.50 euros) for alternative-US). The shortest mean time to HCV infection diagnosis (1 month) and the lowest number of chronic hepatitis C (CHC) patients (1.9/7300 HCWs exposed) was obtained with the alternative-US strategy (vs 6 months and 7.9 CHC, respectively with baseline-US). Compared with the alternative-US, the French strategy was associated with higher costs and lower utilities, and the European with a higher incremental C/E ratio. Compared with the baseline-US strategy, the alternative-US strategy C/E ratio was 2020 euros per quality-adjusted life year saved. CONCLUSION: In HCWs exposed to HCV, a strategy based on early HCV RNA testing shortens the period during which the HCW's wait for his HCV status, leads to lower risk of progression to CHC and is reasonably cost-effective.

ABCB1 allele polymorphism is associated with virological efficacy in naïve HIV-infected patients on HAART containing nonboosted PIs but not boosted PIs.

OBJECTIVE: To assess the effect of the multidrug resistance-1 single nucleotide polymorphism (ABCB1 SNP) C3435T in exon 26 on the virological responses to first-line protease inhibitor (PI)-containing HAART regimens. METHOD: A cohort of 182 HIV-infected patients with a PI-containing HAART regimen initiated from 1997 to 2004 was enrolled. Time to the first indetectable viral load (VL) was determined in patients with the CC, CT, or TT genotype. RESULTS: There were 37%, 44%, and 19% of patients who had the CC, CT and TT genotypes, respectively. The median estimated times to VL indetectability in the CC, CT, and TT groups were respectively 5.9, 3.9, and 4.8 months (p= .06). In patients on a non-boosted PI regimen, ABCB1 genotype was associated with time to VL indetectability that was shorter in patients with the CT than CC genotype (CT vs. CC, hazard ratio [HR]=0.62, p= .02; TT vs. CC, HR= 0.72, p= .21). This association was not found in patients with first-generation boosted PI-containing regimens and especially not with second-generation boosted PI-containing regimens. CONCLUSION: Our results show that the ABCB1 SNP in exon 26 is associated with virological efficacy in HIV-infected patients treated with non-boosted PI-containing regimens but not with those containing boosted PIs, particularly of the second generation.

[Risk factors for hepatitis C virus transmission to Health Care Workers after occupational exposure: a European case-control study]. / Facteurs de risque de transmission accidentelle du VHC au personnel soignant au décours d'un accident exposant au sang: une étude cas-témoins européenne.

BACKGROUND: Factors that influence the risk for HCV infection after occupational exposure to hepatitis C virus (HCV) have not yet been determined. The objective of this study was to assess potential risk factors for Hepatitis C seroconversion after occupational exposure to HCV. METHODS: We conducted a European matched case-control study from 01/01/1991 through 31/12/ 2002. Cases were Health Care Workers (HCWs) who were HCV seronegative at the time of exposure, sustained a documented exposure to HCV, and present documented HCV seroconversion temporally associated with the exposure. Controls-HCWs had a documented exposure to HCV, were HCV seronegative at the time of exposure, and remained so at least 6 months later. Controls were matched to cases for the center and the time period of the exposure occurrence. RESULTS: 60 cases and 204 controls were included. All cases were exposed to HCV-infected materials through percutaneous injuries. Those for whom information was available (61.6%) were exposed to viremic source patients. Multivariate conditional logistic regression analysis, in which HCV viral load was not introduced because of missing values, identified needle placed in the source patient's vein or artery (Odds Ratio [OR]=100.1; 95% Confidence Interval [CI]=7.3-1365.7), deep injury (OR=155.2; 95%CI=7.1-3417.2), and HCW's gender (M vs. F: OR=3.1; 95%CI=1.0-10.0) as risk factors for HCV infection. In univariate unmatched analysis the risk of HCV transmission was increased 11-fold (C195%=1.1-114.1) in HCWs exposed to sources with a viral load>6 log10 copies/mL when compared to sources with a HCV viral load<4 log10 copies/mL. CONCLUSION: The risk of HCV transmission after percutaneous exposure increases with a larger volume of blood, and, a higher titer of HCV in the source patient's blood. The role of HCW's gender need to be further investigated. The results of this study have important implications for counselling and follow-up of HCWs after exposure.

Risk factors for hepatitis C virus transmission to health care workers after occupational exposure: a European case-control study.

BACKGROUND: Additional studies are required to identify risk factors for hepatitis C virus (HCV) transmission to health care workers after occupational exposure to HCV. METHODS: We conducted a matched case-control study in 5 European countries from 1 January 1991 through 31 December 2002. Case patients were health care workers who experienced seroconversion after percutaneous or mucocutaneous exposure to HCV. Control subjects were HCV-exposed health care workers who did not experience seroconversion and were matched with case patients for center and period of exposure. RESULTS: Sixty case patients and 204 control subjects were included in the study. All case patients were exposed to HCV-infected fluids through percutaneous injuries. The 37 case patients for whom information was available were exposed to viremic source patients. As risk factors for HCV infection, multivariate analysis identified needle placement in a source patient's vein or artery (odds ratio [OR], 100.1; 95% confidence interval [CI], 7.3-1365.7), deep injury (OR, 155.2; 95% CI, 7.1-3417.2), and sex of the health care worker (OR for male vs. female, 3.1; 95% CI, 1.0-10.0). Source patient HCV load was not introduced in the multivariate model. In unmatched univariate analysis, the risk of HCV transmission increased 11-fold for health care workers exposed to source patients with a viral load >6 log(10) copies/mL (95% CI, 1.1-114.1), compared with exposures to source patients with a viral load < or =4 log10 copies/mL. CONCLUSION: In this study, HCV occupational transmission was found to occur after percutaneous exposures. The risk of HCV transmission after percutaneous exposure increased with deep injuries and procedures involving hollow-bore needle placement in the source patient's vein or artery. These results highlight the need for widespread adoption of needlestick-prevention devices in health care settings, together with other preventive measures.

Mean cost of a first combination antiretroviral therapy in HIV-infected patients in France, and determinants of expensive drugs prescription.

To estimate the cost of the first combination antiretroviral drug therapy (cART) in HIV-infected patients and to determine factors associated with expensive prescriptions, 1698 patients starting cART between September 2002 and September 2007 were selected from the Dat'AIDS cohort. A multivariate linear regression model was used to assess associations between the cost of first cART and patient characteristics, clinical centre and cART adequacy. At cART initiation, the median age was 39 years, median CD4 count was 223 cells/mm(3), median viral load (VL) was 5.2 log copies/mL and 18.3% presented with AIDS. cART was concordant with the French guidelines in 88.7%. The mean cost of cART varied from €26.69/day/person in 2002-2003 to €32.23 in 2006-2007 (P < 0.0001), cost was associated with previous AIDS diagnosis (€31.83/day/person) versus (29.49; P < 0.0001), baseline VL > 5 log copies/mL (€30.99/day/person) versus (28.33; P < 0.0001) and centre. cART regimen not concordant with guidelines were more expensive (€38.31/day/person) versus (29.07; P < 0.0001). After adjusting for the year of initiation, the previous AIDS diagnosis, VL and recommended cART regimen, differences were still found between centres (from €27.81/day/person) to (33.12; P < 0.0001). Cost should be considered when choosing a first cART regimen, especially when considering clinically equivalent regimens.

Blood-borne viruses in health care workers: prevention and management.

Three pathogens account for most cases of occupationally acquired blood-borne infection: hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV). The highest proportion of occupational transmission is due to percutaneous injury (PI) via hollow-bore needles with vascular access. We briefly review prevention and management of blood-borne pathogens in health care workers (HCWs) in developed countries. HCW compliance with standard precautions is necessary for prevention of PI. Safety-engineered devices are now being increasingly promoted as an approach to decreasing the rate of PI. Prevention of HBV transmission requires HCW immunization through vaccination against HBV. In non-vaccinated HCWs (or HCWs with an unknown antibody response to vaccination) exposed to an HbsAg-positive or an untested source patient, post-exposure prophylaxis with HBV vaccine, hepatitis B immunoglobulin or both must be started as soon as possible. Although no available prophylaxis exists for HCV, it is crucial to identify HCV exposure and infection in health care settings and to consequently propose early treatment when transmission occurs. Following occupational exposure with potential for HIV transmission, use of antiretroviral post-exposure prophylaxis must be evaluated. Patients need to be protected from blood-borne pathogen-infected HCWs, and especially surgeons performing exposure-prone procedures (EPPs) with risk of transmission to the patient. However, HCWs not performing EPPs should be protected from arbitrary administrative decisions that would restrict their practice rights. Finally, it must be emphasized that occupational blood exposure is of great concern in developing countries, with higher risk of exposure to blood-borne viruses because of a higher prevalence of the latter than in developed countries, re-use of needles and syringes and greater risk of sustaining PI, since injection routes are more frequently used for drug administration than in developed countries.

Cost-effectiveness of QuantiFERON-TB test vs. tuberculin skin test in the diagnosis of latent tuberculosis infection.

OBJECTIVE: To evaluate the cost-effectiveness of the tuberculin skin test (TST), the QuantiFERON-TB Gold test (QFT) and a combination of TST and QFT (TST+QFT) for diagnosing latent tuberculosis infection (LTBI) in France in a bacille Calmette-Guérin (BCG) vaccinated population. METHODS: A decision analysis model evaluated three strategies among simulated adults in close contact with tuberculosis (TB). We calculated direct lifetime medical costs, life expectancies and incremental cost-effectiveness ratios (ICERs). RESULTS: The discounted direct medical costs of care per patient of no testing, TST, QFT and TST+QFT were respectively euro417, euro476, euro443 and euro435, while discounted life expectancies were respectively 25.030, 25.071, 25.073 and 25.062 years. TST had higher costs and lower efficacy than QFT; TST+QFT was associated with an ICER of euro560 per year of life gained (YLG) compared to no testing, and QFT was associated with an ICER of euro730/YLG compared to TST+QFT. The only scenario where QFT was associated with an ICER of >euro75 000/YLG was when the prevalence of LTBI around TB was low (<5%) and TST specificity high (>90%). CONCLUSIONS: In France, for the diagnosis of LTBI after close contact with TB, the TST is more expensive and less effective than QFT. Although it is more expensive, QFT is more effective and cost-effective than TST+QFT under a wide range of realistic test performance scenarios.

Estimating the future health burden of chronic hepatitis C and human immunodeficiency virus infections in the United States.

The aim of this work was to estimate the future disease burden of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections in the United States until the year 2030. Two back-calculation models of the HIV and the HCV epidemic were developed. They were based on US epidemiological data regarding prevalence, age and gender of incident cases, AIDS, hepatocellular carcinoma (HCC) mortality and general population mortality from the Centers for Disease Control and WHO. Based on the HCV back-calculation model, HCV incidence peaked in 1984 at 350,000 new infections and then fell to about 77,000 in 1998. Based on the HIV back-calculation model, HIV incidence reached its maximum in 1989 at 142,000 new infections and then declined to 79,000 in 1998. Mortality related to HCV (death from liver failure or HCC) rose from about 3,700 in 1998 and is expected to peak at about 13,000 in 2030. Predicted HCV mortality would fall only if increased access to or more effective antiviral therapy occurs. For comparison, observed HIV-related mortality was 14,400 in 1998 and projected to be 4,200 for 2030. With the availability of effective highly active antiretroviral therapy for HIV infection, mortality from HIV appears to have declined substantially, whereas HCV-related deaths as a result of pre-1999 infections will likely continue to increase over the next 25 years.

Impact of opportunistic diseases on chronic mortality in HIV-infected adults in Côte d'Ivoire.

OBJECTIVE: To estimate incidence rates of opportunistic diseases (ODs) and mortality for patients with and without a history of OD among HIV-infected patients in Côte d'Ivoire. METHODS: Using incidence density analysis, we estimated rates of ODs and chronic mortality by CD4 count in patients in a cotrimoxazole prophylaxis trial in Abidjan before the highly active antiretroviral therapy (HAART) era. Chronic mortality was defined as death without a history of OD or death more than 30 days after an OD diagnosis. We used Poisson's regression to examine the effect of OD history on chronic mortality after adjusting for age, gender, and current CD4 count. RESULTS: Two hundred and seventy patients (40% male, mean age 33 years, median baseline CD4 count 261 cells/microl) were followed up for a median of 9.5 months. Bacterial infections and tuberculosis were the most common severe ODs. Of 47 patients who died, 9 (19%) died within 30 days of an OD, 26 (55%) died more than 30 days after an OD, and 12 (26%) died with no OD history. The chronic mortality rate was 31.0/100 person-years for those with an OD history, and 11.1/100 person-years for those with no OD history (rate ratio (RR) 2.81, 95% confidence interval (CI): 1.43 - 5.54). Multivariate analysis revealed that OD history remained an independent predictor of mortality (RR 2.15, 95% CI: 1.07 - 4.33) after adjusting for CD4 count, age and gender. CONCLUSIONS: Before the HAART era, a history of OD was associated with increased chronic HIV mortality in Côte d'Ivoire, even after adjusting for CD4 count. These results provide further evidence supporting OD prophylaxis in HIV-infected patients.

Quantification of fibrosis progression in patients with chronic hepatitis C using a Markov model.

The knowledge of fibrosis progression in chronic hepatitis C and the impact of new treatments on progression is limited by the number of available liver biopsies per patient. Moreover, liver biopsies identify a patient's stage of fibrosis at a given point in time, but cannot quantify the time spent in that stage nor the date of transition to that stage. This paper assesses the potential of Markov modelling to overcome these difficulties. The data from interferon-treated (n=185) and untreated patients (n=102) are analysed to illustrate the power of this technique. The model accurately reproduced the distributions of patients in the different fibrosis stages at two subsequent biopsies. A quantification of the role of cofactors in the progression of the disease, and the impact of interferon treatment are given. In subjects who are 40 years old and have been infected for 10 years, the model predicted that 274 of 1000 untreated patients, but only 42 of 1000 treated patients, would progress from F0 or F1 to F3 or F4 fibrosis over the next 5 years. The model also confirms that as age and duration of infection increase, the risk of fibrosis progression increases, while the impact of treatment with interferon decreases. Hence Markov modelling is an accurate tool in the analysis of fibrosis progression in chronic hepatitis C. It will be valuable for the quantification of the effect of new treatments on fibrosis progression in hepatitis C.