title: The use of erlotinib in daily practice: a study on adherence and patients' experiences.
abstract: BACKGROUND
  Adherence to pharmacological therapy is a complex and multi-factorial issue that can substantially alter the outcome of treatment. It has been shown that cancer patients, especially when using long-term medication, have similar adherence rates to those of patients with other diseases. The consequences of poor adherence are poor health outcomes and increased health care costs. Only few studies have focused on the use of oral anticancer agents in daily practice. Information about the reasons for non-adherence is essential for the development of interventions that may increase adherence. This paper presents the CAPER-erlotinib protocol, which is designed to study the relationship between adherence to erlotinib and both the plasma concentration and side-effects in patients with NSCLC. Further, the relationships between patient characteristics, disease characteristics, side-effects, quality of life, patient beliefs and attitude towards disease and medication, dose adjustments, reasons for discontinuation and plasma concentration of erlotinib will be explored.
  
  
  METHODS
  In this prospective observational cohort study 65 NSCLC patients of 18 years or older starting treatment with erlotinib will be followed for a period up to 16 weeks. The main study parameters are adherence, the plasma concentration of erlotinib and the number and grade of side-effects. At baseline and on erlotinib treatment in weeks 3-4, 8-9, 12 and 15-16, patients will be asked to fill out a questionnaire. In weeks 3-4, 8-9 and 15-16 blood samples are collected, which will be analysed for plasma concentration of erlotinib. Adherence will be measured using a medication event monitoring system.
  
  
  CONCLUSIONS
  The present study aims to get more insight into patients' experiences with the use of erlotinib in daily practice and the various aspects that govern adherence. We hypothesize that side-effects play an important role in the way patients use erlotinib. We expect that the present study will provide valuable knowledge which will be useful for health care professionals to develop interventions to support patients. This approach will improve the adherence and persistence with the use of erlotinib in order to derive optimal benefit from the medication.
  
  
  BACKGROUND
  NTR1830.
authors: Department of Clinical Pharmacology and Pharmacy, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, the Netherlands. l.timmers@vumc.nl
authors: Lonneke
authors: L
authors: Timmers
authors: Christel C L M
authors: CC
authors: Boons
authors: Dirk
authors: D
authors: Mangnus
authors: Josee E
authors: JE
authors: Moes
authors: Eleonora L
authors: EL
authors: Swart
authors: Epie
authors: E
authors: Boven
authors: Egbert F
authors: EF
authors: Smit
authors: Jacqueline G
authors: JG
authors: Hugtenburg
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D001294:Attitude to Health; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000523:psychology; D003469:Culture; D003627:Data Interpretation, Statistical; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring; D000069347:Erlotinib Hydrochloride; D005500:Follow-Up Studies; D006801:Humans; D007258:Informed Consent; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000523:psychology; D055118:Medication Adherence; D015337:Multicenter Studies as Topic / Q000379:methods*; D018579:Patient Selection; D010361:Patients / Q000523:psychology*; D011446:Prospective Studies; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011788:Quality of Life; D011799:Quinazolines / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D012107:Research Design
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D000069347:Erlotinib Hydrochloride