title: Assessing medication adherence in solid-organ transplant recipients.
abstract: OBJECTIVE
  We sought to determine and compare the prevalence of nonadherence in lung, kidney, and liver transplant recipients, and identify potential risk factors for nonadherence.
  
  
  METHODS
  This cross-sectional, single-center, retrospective cohort study, evaluated 225 outpatient lung, kidney, and liver transplant recipients' adherence to immunosuppressant medication. Based on immunosuppressant dosages and dispensing records, medication possession ratio (days of medication supplied/actual days) and gaps in prescription refills (> 30-day lapse between expected depletion of supply and next refill) were used as surrogate markers in assessing adherence for 2 years. Patients were adherent to their immunosuppressant medication regimens if their medication possession ratio was ≥ 80%.
  
  
  RESULTS
  The mean age of the subjects was slightly greater than 50 years of age, and they were a median of 2.0, 1.3, and 1.1 years posttransplant at the start of data collection for lung, kidney, and liver recipients. Overall medication possession ratios were 95.4% ± 7.5%, 95.9% ± 7.6%, and 92.7% ± 12.3% in our lung, kidney, and liver recipients. Only 7.1% of patients had a medication possession ratio lower than 80%, which was the cutoff for nonadherence. No statistical analyses were performed to identify potential factors for nonadherence because of the small number of nonadherent patients.
  
  
  CONCLUSIONS
  Immunosuppressant medication adherence at our center was high for all 3 organ cohorts, as measured by a medication possession ratio of 80% or better. Further study is needed to evaluate immunosuppressant adherence over time after transplant, and confirm the clinical factors that optimize adherence in high-risk patients.
authors.affiliation: Lower Mainland Pharmacy Services, Vancouver General Hospital, Vancouver, British Columbia, Canada.
authors.forename: Gloria Chun-Wei
authors.initials: GC
authors.lastname: Su
authors.forename: Erica D
authors.initials: ED
authors.lastname: Greanya
authors.forename: Nilufar
authors.initials: N
authors.lastname: Partovi
authors.forename: Eric M
authors.initials: EM
authors.lastname: Yoshida
authors.forename: R Jean
authors.initials: RJ
authors.lastname: Shapiro
authors.forename: Robert D
authors.initials: RD
authors.lastname: Levy
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006084:Graft Rejection / Q000276:immunology / Q000517:prevention & control*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D016030:Kidney Transplantation / Q000706:statistics & numerical data*; D016031:Liver Transplantation / Q000706:statistics & numerical data*; D016040:Lung Transplantation / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000706:statistics & numerical data*; D010353:Patient Education as Topic; D010817:Physician-Patient Relations; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D007166:Immunosuppressive Agents