***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Interferon therapy may exacerbate health-related quality of life ( HRQL ) deficits associated with hepatitis C virus ( HCV ) early in the course of therapy . Treatment with polyethylene glycol-modified interferon ( peginterferon ) alfa-2a ( 40 kd ) provides improved sustained response over interferon alfa-2a , but its effect on HRQL is unknown . The objective of this study was to ( 1 ) evaluate the effect of sustained virologic response on HRQL in patients with HCV and ( 2 ) determine whether impairment of HRQL during treatment contributes to early treatment discontinuation . Data consisted of a pooled secondary analysis of patients ( n = 1,441 ) across 3 international , multicenter , open-label , r and omized studies that compared peginterferon alfa-2a ( 40 kd  ) with interferon alfa-2a . ANCOVA was used to examine the effect of sustained virologic response on HRQL . Repeated- measures mixed-models ANCOVA was used to compare Fatigue Severity Scale ( FSS ) and SF-36 scores during treatment by treatment group . Logistic regression analysis was used to examine the association between changes at baseline in on-treatment HRQL and early treatment discontinuation . Sustained virologic response was associated with marked improvements from baseline to end of follow-up in all subjects , including patients with cirrhosis . During treatment , patients receiving peginterferon alfa-2a ( 40 kd ) had statistically significantly better scores on both the SF-36 and FSS . Baseline to 24-week changes in fatigue and SF-36 mental and physical summary scores significantly predicted treatment discontinuation . In conclusion , sustained virologic response is associated with improvements in quality of life in patients with or without advanced liver disease . This parameter may be an important consideration in maximizing treatment adherence The new Cobas Core Anti-HCV EIA was evaluated in two centers for its ability to detect antibodies directed to hepatitis C virus in human serum . This assay , which can be run fully automated on a r and om access analyzer , was compared with three other commercially available screening tests : the Ortho HCV 3.0 ELISA , the Murex anti-HCV , and the Abbott HCV EIA second generation . Positive or discrepant results were further investigated using the Wellcozyme HCV Western Blot or the Abbott Matrix HCV assays . The results obtained from analyzing 5045 serum sample s showed a high correlation between the Cobas Core Anti-HCV EIA and the other screening assays , ranging from 98.9 % to 99.9 % . Diagnostic specificities and sensitivities ranged from 99.7 % to 100 % and from 98.8 % to 100 % , respectively . In this study , the Cobas Core Anti-HCV EIA proved to be a very convenient test , able to perform at the highest levels of sensitivity and specificity The risk of complications from percutaneous liver biopsy is low , but discomfort is common and complications require hospitalization in approximately 4 % of patients . The optimal method of performing these biopsies is unknown . The goal of our study was to determine whether the use of ultrasonography in the biopsy room immediately prior to or during the procedure would lessen the risk of complications and to compare the safety and efficacy in obtaining tissue by use of a Trucut needle versus an automatic biopsy needle .  Between 1992 and 1994 , 836 patients were entered into a r and omized study ( 489 in Rochester , MN ; 347 in Barcelona , Spain ) . Patients were r and omized immediately prior to liver biopsy into four groups : Trucut needle , or automatic biopsy needle , and with or without ultrasonography . Fisher 's Exact Test and a logistic regression model were also used to assess the effect of needle and ultrasonography on the odds for complications . The four biopsy groups were well-matched at entry with respect to age , sex , underlying liver disease , hemoglobin , prothrombin time , and platelet count . The use of ultrasound was associated with a decreased rate of hospitalization for pain , hypotension , or bleeding ( 2 vs. 9 , P < .05 ) . No difference in safety was found between the two types of needles . The number of passes needed to obtain specimens was similar for all four groups . The average length of the specimen was slightly greater with ultrasonographic-guided biopsies ( 1.7 mm vs. 1.6 mm , P < .05 ) and with biopsies obtained using the automatic biopsy needle when compared with the Trucut needle ( 1.7 mm vs. 1.5 mm , P < .05 ) , but this did not seem to be clinical ly important . The addition of ultrasonography reduces complications in patients undergoing percutaneous liver biopsy . The type of needle appears to offer little difference in safety or yield of diagnostic tissue . The use of ultrasonography for guidance of percutaneous liver biopsy will lead to a lower rate of complications . The value of this benefit must be weighed against the added cost of ultrasonographic guidance BACKGROUND A sustained virological response ( SVR ) rate of 41 % has been achieved with interferon alfa-2b plus ribavirin therapy of chronic hepatitis C. In this r and omised trial , peginterferon alfa-2b plus ribavirin was compared with interferon alfa-2b plus ribavirin . METHODS 1530 patients with chronic hepatitis C were assigned interferon alfa-2b ( 3 MU subcutaneously three times per week ) plus ribavirin 1000 - 1200 mg/day orally , peginterferon alfa-2b 1.5 microg/kg each week plus 800 mg/day ribavirin , or peginterferon alfa-2b 1.5 microg/kg per week for 4 weeks then 0.5 microg/kg per week plus ribavirin 1000 - 1200 mg/day for 48 weeks . The primary endpoint was the SVR rate ( undetectable hepatitis C virus [ HCV ] RNA in serum at 24-week follow-up ) . Analyses were based on patients who received at least one dose of study medication . FINDINGS The SVR rate was significantly higher ( p=0.01 for both comparisons ) in the higher-dose peginterferon group ( 274/511 [ 54 % ] ) than in the lower-dose peginterferon ( 244/514 [ 47 % ] ) or interferon ( 235/505 [ 47 % ] ) groups . Among patients with HCV genotype 1 infection , the corresponding SVR rates were 42 % ( 145/348 ) , 34 % ( 118/349 ) , and 33 % ( 114/343 ) . The rate for patients with genotype 2 and 3 infections was about 80 % for all treatment groups . Secondary analyses identified bodyweight as an important predictor of SVR , prompting comparison of the interferon regimens after adjusting ribavirin for bodyweight ( mg/kg ) . Side-effect profiles were similar between the treatment groups . INTERPRETATION In patients with chronic hepatitis C , the most effective therapy is the combination of peginterferon alfa-2b 1.5 microg/kg per week plus ribavirin . The benefit is mostly achieved in patients with HCV genotype 1 infections BACKGROUND Chronic hepatitis C virus ( HCV ) infection in patients with cirrhosis is difficult to treat . In patients with chronic hepatitis C but without cirrhosis , once-weekly administration of interferon modified by the attachment of a 40-kd branched-chain polyethylene glycol moiety ( peginterferon alfa-2a ) is more efficacious than a regimen of unmodified interferon . We examined the efficacy and safety of peginterferon alfa-2a in patients with HCV-related cirrhosis or bridging fibrosis . METHODS We r and omly assigned 271 patients with cirrhosis or bridging fibrosis to receive subcutaneous treatment with 3 million units of  interferon alfa-2a three times weekly ( 88 patients ) , 90 microg of peginterferon alfa-2a once weekly ( 96 ) , or 180 microg of peginterferon alfa-2a once weekly ( 87 ) . Treatment lasted 48 weeks and was followed by a 24-week follow-up period . We assessed efficacy by measuring HCV RNA and alanine aminotransferase and by evaluating liver-biopsy specimens . A histologic response was defined as a decrease of at least 2 points on the 22-point Histological Activity Index . RESULTS In an intention-to-treat analysis , HCV RNA was undetectable at week 72 in 8 percent , 15 percent , and 30 percent of the patients treated with interferon alfa-2a and with 90 microg and 180 microg of peginterferon alfa-2a , respectively ( P=0.001 for the comparison between 180 microg of peginterferon alfa-2a and interferon alfa-2a ) . At week 72 , alanine aminotransferase concentrations had normalized in 15 percent , 20 percent , and 34 percent of patients , respectively ( P=0.004 for the comparison between 180 microg of peginterferon alfa-2a and interferon alfa-2a ) . In the subgroup of 184 patients with paired liver-biopsy specimens , the rates of histologic response at week 72 were 31 percent , 44 percent , and 54 percent , respectively ( P=0.02 for the comparison between 180 microg of peginterferon alfa-2a and interferon alfa-2a ) . All three treatments were similarly tolerated . CONCLUSIONS In patients with chronic hepatitis C and cirrhosis or bridging fibrosis , 180 microg of peginterferon alfa-2a administered once weekly is significantly more effective than 3 million units of st and ard interferon alfa-2a administered three times weekly Seroprevalence data from the Third National Health and Nutrition Examination Survey ( 1984 to 1999 ) suggest that 3 million persons in the United States are infected with the hepatitis C virus ( HCV ) ( 1 ) . Treatment fails to clear the virus in 80 % to 85 % of acutely infected persons . Not all persons who remain infected eventually develop progressive liver disease ( 2 ) , but in those who do , clinical evidence of liver damage may not appear until decades later ( 3 ) . It is widely believed that progression of liver disease in persons with chronic HCV infection is enhanced by concomitant heavy alcoholism ( 4 - 12 ) . We sought to quantify the association of transfusion-associated HCV infection and history of alcohol abuse with development of cirrhosis among patients followed from the time of acute HCV infection . Methods The source of this investigation , described in detail elsewhere ( 13 ) , is a long-term follow-up study of acute non-A , non-B hepatitis in patients included in earlier prospect i ve studies of transfusion-related HCV infection . All patients provided informed consent , and the study was approved by the relevant institutional review boards . Briefly , non-A , non-B hepatitis was identified by otherwise unexplained elevations in serum alanine aminotransferase ( ALT ) levels developing 2 to 24 weeks after transfusion , in the absence of serologic evidence of hepatitis A or B ( 13 ) . The ALT level had to be elevated on two consecutive measurements , and at least one of the values had to exceed twice the upper limit of normal . Stored sera from case- patients and controls from three of the prospect i ve studies the second Veterans Administration Cooperative study ( 14 ) , the Transfusion-Transmitted Viruses study ( 15 ) , and the National Institutes of Health Blood Bank Study (16)were tested for anti-HCV by enzyme immunoassay ( HCV EIA 2.0 , Abbott Laboratories , North Chicago , Illinois ) . Transfusion-associated HCV infection was diagnosed if anti-HCV appeared and persisted , was temporally related to elevated ALT levels , and was confirmed by using the supplementary recombinant immunoblot assay ( RIBA version 3.0 , Ortho Diagnostics , Raritan , New Jersey ) . Because repository sample s were not optimally stored for minimizing nucleic acid loss , HCV RNA testing was not performed . Controls consisted of transfused patients from the original three prospect i ve studies who had not developed hepatitis ( 13 ) . Controls were matched to case- patients by initial treatment center , sex , ethnicity , use of hepatitis immune globulin , presence or absence of a history of alcoholism , age , number of units of blood transfused , and date of transfusion . We excluded patients with anti-HCVpositive sample s that pre date d the index transfusion and those with anti-HCV reactivity but no confirmatory test . Anti-HCVpositive/RIBA-negative and anti-HCVnegative patients were classified as having transfusion-associated non-A , non-B , non-C hepatitis . Controls with anti-HCV in repository sample s were excluded . We used a multifaceted approach to gather information on each patient 's history of liver disease from participation in the prospect i ve studies through initiation of the follow-up study ( 13 ) . Vital status was ascertained through search es of death registries , and copies of death certificates were obtained . Patients or their design ated proxies ( if the patient was deceased or incompet 
    Output:
    
Data from Large Observational Studies on Independent Risk Factors for Positive Status on Tests for AntiHepatitis C Virus Antibody All 4 large population -based studies also found an independent association between HCV infection and high-risk sexual behaviors ( variably defined , but usually considered sex with multiple partners or sex with an HCV-infected person ) .
In most setting s with a low prevalence of intravenous drug use , high-risk sexual behaviors are the strongest risk factor for HCV infection ( 56 - 60 ) .