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Dive into the research topics where Astrid Knott is active.

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Featured researches published by Astrid Knott.


The American Journal of Gastroenterology | 2006

Integrated Psychiatric/Medical Care in a Chronic Hepatitis C Clinic: Effect on Antiviral Treatment Evaluation and Outcomes

Astrid Knott; Eric Dieperink; Mark L. Willenbring; Sara Heit; Janet Durfee; Mary Wingert; James R. Johnson; Paul Thuras; Samuel B. Ho

OBJECTIVES:Psychiatric and substance use disorders are common in hepatitis C patients and represent barriers to antiviral treatment. We evaluated the effect of integrating psychiatric and medical care on evaluation for and initiation of antiviral treatment in a cohort of 184 patients with chronic hepatitis C.METHODS:Integrated care consisted of screening for psychiatric problems with Alcohol Use Disorders Identification Test-Consumption (AUDIT-C), Beck Depression Inventory (BDI), Urine Drug Screen (UDS), and Primary Care Posttraumatic Stress Disorder (PC-PTSD) screens, referral based on specified cutoff scores to an established mental health (MH) provider, to a colocated psychiatric clinical nurse specialist (PCNS), or both. Data were collected retrospectively by chart review.RESULTS:Most patients (149/184, 81.0%) had at least one positive screen, 25.5% had a positive UDS. Among patients with positive screens, 38.3% had established MH providers, 47.0% had no MH provider and were referred to the PCNS, and 15.0% refused any psychiatric referral. Patients receiving integrated care with a colocated PCNS were significantly more likely to complete evaluation for and start antiviral treatment than other patients with positive screens, and at a rate similar to that of patients with negative screens. Patients with positive screens followed by any MH provider had significantly greater adherence to antiviral therapy than patients without positive screens.CONCLUSION:An integrated MH and medical approach was associated with rates of antiviral therapy recommendation and initiation similar to patients without risks for psychiatric or substance use problems. MH care was associated with improved adherence to antiviral therapy. Integrated care offers promise as an approach for addressing psychiatric comorbidity in this traditionally difficult to treat population.


Clinical Gastroenterology and Hepatology | 2015

Development and Performance of an Algorithm to Estimate the Child-Turcotte-Pugh Score From a National Electronic Healthcare Database.

David E. Kaplan; Feng Dai; Ayse Aytaman; Michelle Baytarian; Rena K. Fox; Kristel K. Hunt; Astrid Knott; Marcos Pedrosa; Christine Pocha; Rajni Mehta; Mona Duggal; Melissa Skanderson; Adriana Valderrama; Tamar H. Taddei

BACKGROUND & METHODS The Child-Turcotte-Pugh (CTP) score is a widely used and validated predictor of long-term survival in cirrhosis. The CTP score is a composite of 5 subscores, 3 based on objective clinical laboratory values and 2 subjective variables quantifying the severity of ascites and hepatic encephalopathy. To date, no system to quantify CTP score from administrative databases has been validated. The Veterans Outcomes and Costs Associated with Liver Disease study is a multicenter collaborative study to evaluate the outcomes and costs of hepatocellular carcinoma in the U.S. Veterans Health Administration. We developed and validated an algorithm to calculate electronic CTP (eCTP) scores by using data from the Veterans Health Administration Corporate Data Warehouse. METHODS Multiple algorithms for determining each CTP subscore from International Classification of Diseases version 9, Common Procedural Terminology, pharmacy, and laboratory data were devised and tested in 2 patient cohorts. For each cohort, 6 site investigators (Boston, Bronx, Brooklyn, Philadelphia, Minneapolis, and West Haven VA Medical Centers) were provided cases from which to determine validity of diagnosis, laboratory data, and clinical assessment of ascites and encephalopathy. The optimal algorithm (designated eCTP) was then applied to 30,840 cirrhotic patients alive in the first quarter of 2008 for whom 5-year overall and transplant-free survival data were available. The ability of the eCTP score and other disease severity scores (Charlson-Deyo index, Veterans Aging Cohort Study index, Model for End-Stage Liver Disease score, and Cirrhosis Comorbidity) to predict survival was then assessed by Cox proportional hazards regression. RESULTS Spearman correlations for administrative and investigator validated laboratory data in the HCC and cirrhotic cohorts, respectively, were 0.85 and 0.92 for bilirubin, 0.92 and 0.87 for albumin, and 0.84 and 0.86 for international normalized ratio. In the HCC cohort, the overall eCTP score matched 96% of patients to within 1 point of the chart-validated CTP score (Spearman correlation, 0.81). In the cirrhosis cohort, 98% were matched to within 1 point of their actual CTP score (Spearman, 0.85). When applied to a cohort of 30,840 patients with cirrhosis, each unit change in eCTP was associated with 39% increase in the relative risk of death or transplantation. The Harrell C statistic for the eCTP (0.678) was numerically higher than those for other disease severity indices for predicting 5-year transplant-free survival. Adding other predictive models to the eCTP resulted in minimal differences in its predictive performance. CONCLUSION We developed and validated an algorithm to extrapolate an eCTP score from data in a large administrative database with excellent correlation to actual CTP score on chart review. When applied to an administrative database, this algorithm is a highly useful predictor of survival when compared with multiple other published liver disease severity indices.


The Journal of Clinical Psychiatry | 2014

Are selective serotonin reuptake inhibitors associated with hepatocellular carcinoma in patients with hepatitis C

Christine Pocha; Astrid Knott; Thomas S. Rector; Eric Dieperink

BACKGROUND AND AIMS Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed for patients with chronic hepatitis C virus (HCV) infection. Research suggests that serotonin promotes the development and growth of hepatocellular carcinoma (HCC). We tested the hypothesis whether exposure to SSRIs is associated with an increased risk of HCC in HCV patients. METHOD Patients who entered the United States Veterans Affairs (VA) Hepatitis C Clinical Case Registry in 2000 to 2009 were analyzed. During the 8 years of follow-up, 36,192 patients filled at least 1 SSRI prescription. Cases of HCC were identified by diagnosis codes (ICD-9 155.0). Multivariable Cox regression analyses estimated adjusted HCC hazard ratios (HRs) for SSRI-exposed versus SSRI-unexposed subjects and categories of average SSRI doses. RESULTS The annual incidence of HCC in the VA registry cohort of 109,736 patients was 0.5% and significantly greater in the 8% with cirrhosis at baseline (HR = 5.2; 95% CI, 4.7-5.7). There was no evidence for significant interactions between the effect of SSRI-exposure and cirrhosis. Baseline characteristics of the exposed (n = 36,192) and unexposed (n = 73,544) subjects were similar. The median (interquartile range [IQR]) follow-up period after SSRI-exposure began was 44 (20-74) months with 18 (3-49) months between the first and last prescription. The median average SSRI dose during follow-up expressed as a fraction of initial recommended doses for depression was 0.94 (IQR, 0.5 to 1.3). The risk of HCC was not significantly increased after SSRI exposure (HR = 0.96; 95% CI, 0.87-1.05) or with increasing SSRI doses. CONCLUSIONS Analysis of a large cohort of HCV patients did not support the hypothesis that SSRIs increase the risk of developing HCC.


General Hospital Psychiatry | 2013

The effect of stimulant use on antiviral treatment in an integrated hepatitis clinic

Eric Dieperink; Astrid Knott; Paul Thuras; Christine Pocha

OBJECTIVE The objective was to determine the impact of stimulant use on antiviral treatment for chronic hepatitis C patients in an integrated hepatitis clinic. METHODS A retrospective chart review of 449 consecutive patients seen in an integrated hepatitis clinic that included co-located mental health clinicians was performed. Psychiatric measures included drug use questionnaire, Beck Depression Inventory (BDI), Alcohol Use Disorders Identification Test-Consumption questions (AUDIT-C), urine drug screen and antiviral treatment outcomes. Patients with stimulant use were compared to patients with no drug use, other drug users and an unknown drug use group using χ(2) and analysis of variance tests. RESULTS Over 15% of hepatitis C patients presenting to the clinic were using stimulants. Stimulant users had higher BDI and AUDIT-C scores. They were more likely to be followed by a co-located mental health clinician than other groups and were just as likely to initiate and finish antiviral therapy. CONCLUSIONS Recent stimulant use is common in hepatitis C patients presenting to a hepatitis clinic. Stimulant users were more depressed and used alcohol to a greater degree than nonusers but were as likely to start antiviral therapy. An integrated mental health/medical care approach appears to be effective in addressing this difficult-to-treat population.


Open Medicine Journal | 2016

Antiviral Treatment to Prevent Transmission of Hepatitis C in People Who Inject Drugs

Eric Dieperink; Astrid Knott

The hepatitis C virus (HCV) is common among people who inject drugs (PWID) and causes significant morbidity and mortality. Opiate replacement therapy and needle exchange programs have effectively prevented the transmission of the Human immunodeficiency virus (HIV) but have been less effective for HCV. Other HCV prevention strategies are needed. Antiviral therapy with all oral direct acting antivirals is currently available and appears to be highly effective even in PWID and offers a possible strategy to further prevention efforts. This paper will review current evidence for treatment as prevention for HCV in PWID.


Gastroenterology | 2014

Mo1059 Interim Analysis of HCC Screening and Survival in 1131 Veterans Diagnosed With HCC From 2008-2010

Tamar H. Taddei; David E. Kaplan; Ayse Aytaman; Michelle Baytarian; Kathryn D; Feng Dai; Mona Duggal; Rena K. Fox; Kristel K. Hunt; Astrid Knott; Rajni Mehta; Marcos Pedrosa; Christine Pocha; Adriana Valderrama; Melissa Skanderson

Abbreviations: OS: overall survival in months, LCI, UCI: lower and upper limits of the 95% confidence interval, ECOG PS: Eastern Cooperative Oncology Group Performance Score (13 patients had a score of 1 and one patient had a score of 2), BCLC: Barcelona Clinic Liver Cancer Stage, * = statistically significant difference from the corresponding reference group (ECOG PS approaching statistical significance with p =0.07), + = Liver Decompensation developed after starting sorafenib in 25 patients (2 encephalopathy, 1 variceal bleeding, 1 increased bilirubin, 21 ascites)


Digestive Diseases and Sciences | 2014

All-Cause Mortality and Liver-Related Outcomes Following Successful Antiviral Treatment for Chronic Hepatitis C

Eric Dieperink; Christine Pocha; Paul Thuras; Astrid Knott; Samuel Colton; Samuel B. Ho


Digestive Diseases and Sciences | 2016

Recalibrating the Child–Turcotte–Pugh Score to Improve Prediction of Transplant-Free Survival in Patients with Cirrhosis

David E. Kaplan; Feng Dai; Melissa Skanderson; Ayse Aytaman; Michelle Baytarian; Kathryn D’Addeo; Rena K. Fox; Kristel K. Hunt; Astrid Knott; Rajni Mehta; Marcos Pedrosa; Christine Pocha; Adriana Valderrama; Tamar H. Taddei


American Journal of Pharmacy Benefits | 2013

Interferon-based therapies for hepatitis C: Utilization, costs, and outcomes

Yvonne Jonk; Titilope Cole Adeniyi; Astrid Knott; Eric Dieperink; Samuel B. Ho


Journal of Clinical Oncology | 2015

Interim analysis of hepatocellular carcinoma (HCC) screening and survival in 4,087 veterans diagnosed with HCC from 2008 to 2010.

David E. Kaplan; Tamar H. Taddei; Ayse Aytaman; Kristel K. Hunt; Astrid Knott; Eric Dieperink; Michelle Baytarian; Rena K. Fox; Marcos Pedrosa; Kathryn D'Addeo; Feng Dai; Rajni Mehta; Mona Duggal; Christine Pocha; Melissa Skanderson; Adriana Valderrama

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Christine Pocha

University of South Dakota

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Adriana Valderrama

Bayer HealthCare Pharmaceuticals

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Ayse Aytaman

United States Department of Veterans Affairs

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David E. Kaplan

University of Pennsylvania

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Kristel K. Hunt

Icahn School of Medicine at Mount Sinai

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Marcos Pedrosa

VA Boston Healthcare System

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Rena K. Fox

University of California

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