Z Gastroenterol 2012; 50 - K060
DOI: 10.1055/s-0032-1323995

Patient adherence: The influence of non-virological factors in a real world setting

T Witthöft 1, R Link 2, S Christensen 3, HW Busch 3, W Gickler 4, H Steffens 5, C John 5, S Holm 6, A von Lucadou 7, E Zehnter 8, HJ Cordes 9, D Hüppe 10, H Blaak 11, A Heuser 11, M Bilzer 11
  • 1Gastroenterologische Facharztpraxis, Stade, Germany
  • 2St. Josefshospital, Offenburg, Germany
  • 3Centrum für Interdisziplinäre Medizin, Münster, Germany
  • 4DRK-Krankenhaus, Neuwied, Germany
  • 5Internistische Facharztpraxis, Berlin, Germany
  • 6Praxis Georgstraße, Hannover, Germany
  • 7Internistische Facharztpraxis, Nürnberg, Germany
  • 8Gastroenterologische Facharztpraxis, Dortmund, Germany
  • 9Interdisziplinäres Facharztzentrum Sachsenhausen, Frankfurt, Germany
  • 10Gastroenterologische Facharztpraxis, Herne, Germany
  • 11MSD Pharma GmbH, Haar, Germany

Aims: Only few data are available on adherence to combination HCV therapy with pegylated interferon (PegIFN)/ribavirin (RBV) in real-world settings, despite its acknowledged importance. Such information might help clinicians to improve adherence and thereby virologic response to PegIFN/RBV therapy, also in combination with new antivirals.

Methods: In this prospective observational multicenter study (@dhere study) 746 treatment-naïve patients with chronic HCV infection were treated with PegIFN alfa-2b 1.5µg/kg/wk + weight-based RBV (800–1200mg/day) for up to 48 wks at 42 sites in Germany. Patients who received at least 80% of each of the 2 medications for at least 80% of the expected duration of therapy were classified as adherent. Multivariate logistic regression was used to determine factors predicting adherence to HCV treatment. SVR was defined as undetectable serum HCV-RNA 24 wks after end of treatment.

Results: Median age of patients was 43 years, 40% were female, 3% had HIV co-infection and HCV genotypes (G) were distributed as follows: G1 62%, G2 6%, G3 28%, G4 3%, other 1%. Overall SVR rates were 47.1% and 59.9% for G1/4 and G2/3 infection in contrast to 76.5%/74.9% and 22.5%/28.6% in adherent/non-adherent patients, respectively. In a multivariate logistic regression model to determine non-virological factors associated with adherence, drug-related adverse events (odds ratio 2.02, p=0.008) and recommended supportive psychotherapy (odds ratio 0.476, p<0.013) were independently associated with a higher/lower likelihood of adherence. Other factors such as detailed demonstration of PegIFN alfa-2b pen device before therapy (odds ratio 0.99, p=0.33), number of telephone contacts with the treating physician (odds ratio 1.11, p=019), consumption of soft drugs (odds ratio 0.67, p=0.16) or alcohol (odds ratio 0.55, p=0.10) and the experience of physicians by number of HCV patients treated per year (odds ratio 0.99, p=0.24) were not significantly associated with adherence.

Conclusions: Adherence to HCV treatment increases the likelihood of SVR. Drug-related adverse events are associated with high adherence. Presence of a psychiatric diagnosis lowers adherence but may be modifiable with growing experience.