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Biomedical subjects

R S Koff

Publications and source records attributed to R S Koff.

At least 37 records · Page 2Linked to original sources
PubMed1999

The risk of acute major upper gastrointestinal bleeding among users of aspirin and ibuprofen at various levels of alcohol consumption.

OBJECTIVE: Major upper gastrointestinal bleeding (UGIB) is the most important adverse effect of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). Alcoholic beverages also precipitate UGIB. This analysis was conducted to evaluate whether the deleterious effects of NSAIDs are further increased among drinkers. METHODS: An interview-based, case-control study was conducted in the U.S. and Sweden; 1224 patients hospitalized with acute major UGIB due to newly occurring peptic ulcer or gastritis were compared to 2945 neighbor controls. RESULTS: Compared with those who drank less than one drink/wk, the relative risk of acute UGIB increased with increasing alcohol consumption, rising to 2.8 among those who drank > or = 21 drinks/wk. Among current drinkers, the relative risk of acute UGIB due to the use of aspirin was raised at all levels of alcohol consumption; the estimate for aspirin taken at least every other day (regular use) at doses of > 325 mg among all current drinkers combined was 7.0; for regular use at lower doses, the corresponding estimate was 2.8, and for any occasional use, it was 2.4. All estimates were statistically significant. Data for ibuprofen were more limited, but the relative risk estimates did not appear to vary consistently with level of alcohol consumption. For regular use (all doses combined), the estimate among all drinkers combined was significantly elevated, at 2.7; occasional ibuprofen use was not associated with UGIB (1.2). There were insufficient data to evaluate other NSAIDs according to alcohol consumption. CONCLUSIONS: The findings suggest that acute UGIB is similarly associated with the use of the two most common nonprescription NSAIDs, aspirin and ibuprofen, at all levels of alcohol consumption. As heavy alcohol intake independently increases the risk, the incidence of UGIB is highest among persons who are both heavy drinkers and users of aspirin or ibuprofen.

Acute Disease↗
PubMed1998

Chronic hepatitis C: early intervention.

Chronic hepatitis C infection is the most common liver disease in the United States; it accounts for up to 12,000 deaths annually and is the most common referral for liver transplantation. Recognition of acute infection is desirable because treatment may prevent chronicity. Interferon remains the primary treatment, but new agents and combinations are being developed.

Adult↗
PubMed1998

Hepatitis A.

Explore the source record for details and available documents.

Female↗
PubMed1998

Safety and immunogenicity of hepatitis A vaccine in patients with chronic liver disease.

Acute hepatitis A superimposed on chronic liver disease (CLD) has been associated with severe or fulminant hepatitis. An open, multicenter study was performed to compare the safety and immunogenicity of an inactivated hepatitis A vaccine in patients with CLD with that in healthy subjects. A secondary objective was to compare the safety of the hepatitis A vaccine with that of a commercial hepatitis B vaccine in subjects with chronic hepatitis C. A total of 475 subjects over the age of 18 years were enrolled into 1 of 5 groups according to history, serological data, and previous diagnosis. Patients in groups 1 (healthy adults), 2 (chronic hepatitis B), 3 (chronic hepatitis C), and 5 (other CLD not caused by viral hepatitis) were vaccinated with two doses of inactivated hepatitis A vaccine, 6 months apart. Patients in group 4 (chronic hepatitis C) received 3 doses of a recombinant hepatitis B vaccine, according to a 0-, 1-, and 6-month schedule. Local injection-site symptoms were the most common reactions reported following vaccination in all groups (35.5% of all doses), with the hepatitis B vaccine eliciting fewer injection-site symptoms than the hepatitis A vaccine (19.8% compared with 37.5%). Although a higher percentage of healthy subjects (93%) seroconverted after a single dose of the hepatitis A vaccine than did subjects with chronic hepatitis C (73.7%) or CLD of nonviral etiologies (83.1%), more than 94% of all vaccinees were seropositive for anti-HAV after the complete vaccination course. At each time point, a lower geometric mean concentration of anti-HAV was observed for each group of CLD patients compared with the healthy control subjects. In conclusion, hepatitis A vaccine was well tolerated and induced a satisfactory immune response in patients with chronic hepatitis B, chronic hepatitis C, and miscellaneous CLD.

Adolescent↗
PubMed1998

Clinical aspects of upper gastrointestinal bleeding associated with the use of nonsteroidal antiinflammatory drugs.

OBJECTIVE: The aim of this study was to compare the clinical features of major upper gastrointestinal bleeding among patients exposed to nonsteroidal antiinflammatory drugs (NSAID) and those not taking these drugs. METHODS: Using data from a multicenter international case-control study designed to evaluate the role of drugs in the etiology of major upper gastrointestinal bleeding (UGIB), patients with a confirmed first episode of major UGIB were divided into two groups: those exposed to NSAIDs during the week before the onset of bleeding, and those not exposed. The groups were compared according to age and sex, clinical appearance and site of the bleeding, preceding symptoms, and requirement for transfusion and acute surgery. RESULTS: The median age was significantly higher and the proportion of women was slightly higher among the NSAID users. There was no significant difference between users and nonusers according to the clinical presentation, the site of the bleeding, or the frequency of preceding symptoms. Forty percent in each group had no symptoms before the onset of bleeding. Slightly more NSAID users received blood transfusions, although the same median amount of blood per transfusion was given in both groups. There was no difference in the frequency of surgical intervention. CONCLUSIONS: There are no important differences in the clinical presentation of major UGIB according to whether or not an individual is an NSAID user. An important finding is the frequent absence of preceding symptoms in patients with major UGIB, regardless of NSAID use.

Adolescent↗
PubMed1997

Treatment of chronic hepatitis C with interferon alfa-n3: a multicenter, randomized, open-label trial.

We studied the antiviral effectiveness and safety of interferon alfa-n3, a natural alpha interferon which contains multiple interferon species, in the treatment of previously untreated patients with chronic hepatitis C. Seventy-seven patients were randomized to receive either 1.0, 2.5, 5.0, or 10.0 million units (MU) of interferon alfa-n3 three times a week for 24 weeks and were then followed for an additional 24 weeks. At the end of therapy, 67% of patients in the 10 MU group normalized serum alanine transaminase (ALT) levels and 59% had no hepatitis C virus (HCV) RNA detected by polymerase chain reaction. At the end of the follow-up period, 44% of patients in the 10 MU group maintained normal ALT, and 24% had nondetectable HCV RNA. Lower doses were much less effective. Interferon alfa-n3 was well tolerated and no patient developed neutralizing anti-interferon antibodies during or after the treatment period. Interferon alfa-n3 appears to be effective against hepatitis C virus and deserves further study in larger randomized controlled trials.

Adult↗
PubMed1997

Therapy of hepatitis C: cost-effectiveness analysis.

The natural history of untreated chronic hepatitis C is controversial, and direct knowledge of the long-term clinical and economic outcomes of current alpha interferon treatment regimens remains limited. Decision analytic models using available information on outcome probabilities and associated health care costs in the United States have been developed but are available only in abstract form. They suggest that chronic hepatitis C is a life-shortening disease and that alpha interferon treatment, for 6 or 12 months, despite its up-front costs and failure to induce a prolonged therapeutic response in most patients, increases life expectancy (which nevertheless is still reduced). It does so with a marginal cost-effectiveness well within the acceptable range of medical interventions in the United States. Even empiric therapy, without regard to viral level, genotype, and baseline histology, is within an acceptable cost-effectiveness range. Improving the response rate is likely to make treatment even more cost-effective and possibly cost-saving. Discounting at 3% would also lower the marginal cost-effectiveness; treatment of younger patients would likely lead to cost-savings. Future needs include the development of better databases and cost data for estimating outcomes.

Antiviral Agents↗
PubMed1997

Prevention of hepatitis C virus infection.

Despite the promising progress made in the development of experimental HCV hyperimmune globulin preparations and recombinant vaccines, prevention of HCV infection will continue to be an important research front for many years. Until effective and safe immunoprophylaxis is available, preventive efforts will require further understanding of risk factors associated with infection and implementation of strategies to reduce such exposures.

Hepatitis C↗
PubMed1996

Risk of aspirin-associated major upper-gastrointestinal bleeding with enteric-coated or buffered product.

BACKGROUND: Aspirin products are known to cause irritation and injury to the gastric mucosa. The belief that enteric-coated and buffered varieties are less likely to occasion major upper-gastrointestinal bleeding (UGIB) than plain aspirin was tested in data from a multicentre case-control study. METHODS: 550 incident cases of UGIB admitted to hospital with melaena or haematemesis and confirmed by endoscopy, and 1202 controls identified from population census lists, were interviewed about use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) during the 7 days before the onset of bleeding (cases) or interview (controls). Relative risks of UGIB for each type of aspirin used regularly (at least every other day) were calculated overall, and according to dose, by multiple logistic regression, with control for age, sex, marital status, date, education, cigarette smoking, alcohol use, and use of NSAIDs. FINDINGS: The relative risks of UGIB for plain, enteric-coated, and buffered aspirin at average daily doses of 325 mg or less were 2.6, 2.7, and 3.1, respectively. At doses greater than 325 mg, the relative risk was 5.8 for plain and 7.0 for buffered aspirin; there were insufficient data to evaluate enteric-coated aspirin at this dose level. There were no important differences in risk attributable to the three aspirin forms according to bleeding site (gastric vs duodenal), or when users of NSAIDs were excluded. INTERPRETATION: Use of low doses of enteric-coated or buffered aspirin carries a three-fold increase in the risk of major UGIB. The assumption that these formulations are less harmful than plain aspirin may be mistaken.

Adolescent↗
PubMed1995

Gastroenterology and hepatology.

Development of colon cancer is now believed to result from a series of inherited or acquired mutations in DNA. Convincing evidence that colonoscopic polypectomy prevents colorectal cancer is now available. A consensus panel recommended that all patients with duodenal and gastric ulcers who are infected with H pylori on first presentation be treated with antimicrobial agents.

Gastroenterology↗
PubMed1995

Cost-effectiveness of interferon-alpha 2b treatment for hepatitis B e antigen-positive chronic hepatitis B.

OBJECTIVE: To estimate the cost-effectiveness of interferon-alpha 2B for the treatment of patients with chronic hepatitis B infection who are positive for hepatitis B e antigen (HBeAg). DESIGN: Meta-analysis of nine randomized controlled trials and cost-effectiveness analysis, projecting the clinical and economic outcomes expected from changes in serologic markers of hepatitis B viral replication. DATA SOURCES: MEDLINE search, expert panel opinion, hospital cost data, and adjusted physician charges. PATIENTS: 552 patients with confirmed chronic hepatitis B infection who were positive for HBeAg. INTERVENTION: Interferon-alpha 2b. MEASUREMENTS: Lifetime incidence of cirrhosis and hepatocellular carcinoma; life expectancy; quality-adjusted life expectancy; and costs and marginal cost-effectiveness ratios from a societal perspective. RESULTS: Interferon-alpha 2b increases the likelihood of becoming negative for HBeAg from 9.1% to 45.6% (difference, 36.5%; 95% CI, 23.7% to 49.2%) and of becoming negative for hepatitis B surface antigen from 1.7% to 7.7% (difference, 6.0%; CI, 2.8% to 9.3%) in the first year. For a 35-year-old person with chronic hepatitis B who is HBeAg positive, our analysis suggests that interferon-alpha 2b will increase life expectancy by 3.1 years or 3.4 quality-adjusted life-years and will decrease projected lifetime costs, even if future savings are discounted; thus, interferon-alpha 2b is the dominant strategy. Even with the model biased strongly in favor of standard care, the marginal cost-effectiveness ratio of interferon did not exceed $12,000 per life-year gained. CONCLUSIONS: Interferon-alpha 2b should prolong life and lower costs for patients with chronic hepatitis B who are HBeAg positive.

Adolescent↗