title: Potential cost-effectiveness of therapeutic drug monitoring in patients with resistant hypertension.
abstract: BACKGROUND
  Nonadherence to drug therapy poses a significant problem in the treatment of patients with presumed resistant hypertension. It has been shown that therapeutic drug monitoring (TDM) is a useful tool for detecting nonadherence and identifying barriers to treatment adherence, leading to effective blood pressure (BP) control. However, the cost-effectiveness of TDM in the management of resistant hypertension has not been investigated.
  
  
  METHODS
  A Markov model was used to evaluate life-years, quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios in resistant hypertension patients receiving either TDM optimized therapy or standard best medical therapy. The model ran from the age of 30 to 100 years or death, using a cycle length of 1 year. Efficacy of TDM was modeled by reducing risk of hypertension-related morbidity and mortality. Cost analyses were performed from a payer's perspective. Deterministic and probabilistic sensitivity analyses were conducted.
  
  
  RESULTS
  In the age group of 60-year olds, TDM gained 1.07 QALYs in men and 0.97 QALYs in women at additional costs of €3854 and €3922, respectively. Given a willingness-to-pay threshold of €35,000 per QALY gained, the probability of TDM being cost-effective was 95% or more in all age groups from 30 to 90 years. Results were influenced mostly by the frequency of TDM testing, the rate of nonresponders to TDM, and the magnitude of effect of TDM on BP.
  
  
  CONCLUSIONS
  Therapeutic drug monitoring presents a potential cost-effective healthcare intervention in patients diagnosed with resistant hypertension. Importantly, this finding is valid for a wide range of patients, independent of sex and age.
authors.affiliation: aDepartment of Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany bHypertension Section & Urology Department, University of Texas Southwestern Medical Center, Dallas, Texas, USA cUniversity Outpatient Clinic Potsdam, Sports Medicine and Sports Orthopaedics, University of Potsdam dDepartment of Cardiology, Angiology, and Conservative Intensive Care Medicine, Klinikum Ernst von Bergmann, Potsdam eDepartment of Cardiology and Pneumology, Heart Center, Georg-August-University of Göttingen, Göttingen, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Chung
authors.forename: Wanpen
authors.initials: W
authors.lastname: Vongpatanasin
authors.forename: Klaus
authors.initials: K
authors.lastname: Bonaventura
authors.forename: Yair
authors.initials: Y
authors.lastname: Lotan
authors.forename: Christian
authors.initials: C
authors.lastname: Sohns
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Haverkamp
authors.forename: Marc
authors.initials: M
authors.lastname: Dorenkamp
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure; D001795:Blood Pressure Determination; D003362:Cost-Benefit Analysis; D016903:Drug Monitoring / Q000191:economics*; D005260:Female; D005858:Germany; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000191:economics / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018803:Models, Economic; D010349:Patient Compliance
chemical_list: D000959:Antihypertensive Agents