title: A randomized controlled trial of negative co-payments: the CHORD trial.
abstract: OBJECTIVE
  Value-based insurance designs are being widely used. We undertook this study to examine whether a financial incentive that lowered co-payments for blood pressure medications below $0 improved blood pressure control among patients with poorly controlled hypertension.
  
  
  METHODS
  Randomized controlled trial.
  
  
  METHODS
  Participants from 3 Pennsylvania hospitals (n = 337) were randomly assigned to: a) be paid $8 per medication per month for filling blood pressure prescriptions, b) a computerized behavioral intervention (CBI), c) both payment and CBI, or d) usual care. The primary outcome was change in blood pressure between baseline and 12 months post enrollment. We also measured adherence using the medication possession ratio in a subset of participants.
  
  
  RESULTS
  There were no significant interactions between the incentive and the CBI interventions. There were no significant changes in medication possession ratio in the treatment group. Blood pressure decreased among all participants, but to a similar degree between the financial incentive and control groups. Systolic blood pressure (SBP) dropped 13.7 mm Hg for the incentive group versus 10.0 mm Hg for the control group (difference = –3.7; 95% CI, –9.0 to 1.6; P = .17). The proportion of patients with blood pressure under control 12 months post enrollment was 35.6% of the incentive group versus 27.7% of the control group (odds ratio, 1.4; 95% CI, 0.8-2.5; P = .19). Diabetics in the incentive group had an average drop in SBP of 12.7 mm Hg between baseline and 12 months compared with 4.0 mm Hg in the control group (P = .02). Patients in the incentive group without diabetes experienced average SBP reductions of 15.0 mm Hg, compared with 16.3 mm Hg for control group nondiabetics (P = .71).
  
  
  CONCLUSIONS
  Among patients with poorly controlled blood pressure, financial incentives—as implemented in this trial—did not improve blood pressure control or adherence except among patients with diabetes.
authors.affiliation: Center for Health Equity Research & Promotion, Philadelphia Veterans Affairs Medical Center, PA
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Volpp
authors.forename: Andrea B
authors.initials: AB
authors.lastname: Troxel
authors.forename: Judith A
authors.initials: JA
authors.lastname: Long
authors.forename: Said A
authors.initials: SA
authors.lastname: Ibrahim
authors.forename: Dina
authors.initials: D
authors.lastname: Appleby
authors.forename: J Otis
authors.initials: JO
authors.lastname: Smith
authors.forename: Jane
authors.initials: J
authors.lastname: Jaskowiak
authors.forename: Marie
authors.initials: M
authors.lastname: Helweg-Larsen
authors.forename: Jalpa A
authors.initials: JA
authors.lastname: Doshi
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Kimmel
mesh_terms: D000959:Antihypertensive Agents / Q000191:economics* / Q000627:therapeutic use; D003669:Deductibles and Coinsurance; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D010414:Pennsylvania
chemical_list: D000959:Antihypertensive Agents