title: Measuring adherence and persistence to disease-modifying agents among patients with relapsing remitting multiple sclerosis.
abstract: OBJECTIVE
  To measure disease-modifying agent adherence and persistence among patients with multiple sclerosis (MS).
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Multispecialty, salaried group practice in southeast Michigan, between June 1, 2004, and June 30, 2006.
  
  
  METHODS
  224 insured adult patients with relapsing remitting MS with an outpatient visit.
  
  
  METHODS
  Medical record-documented receipt of medication recommendation and prescription. Pharmacy claims data-derived measures of dispensing and among patients with two or more dispensings, medication possession ratios (MPRs), and proportion of gap days were estimated. Among those initiating agent use, persistence was estimated.
  
  
  RESULTS
  Mean cohort age was 47.6 years, while 77% of participants were women and 39% were black. Of patients, 81.8% had a recommendation for a disease-modifying agent, 75.0% had a prescription, and 66.5% had two or more dispensings. Among those with two or more dispensings, mean MPR between the first and last dispensing date was 83.8% (95% CI 80.8-86.8), while mean MPR for the entire 24-month period was 68.0% (64.4-71.7). MPR for the 24-month period decreased with increasing drug copayments and was lower among black patients, while MPR between the first and last dispensing date increased with increasing age. Among those initiating therapy, 43% were nonpersistent with medications within 14 months.
  
  
  CONCLUSIONS
  Medication adherence and persistence among patients with relapsing remitting MS is far from monolithic. Measuring medication adherence and persistence among defined populations is useful for understanding the relationship between medication use and outcomes in practice and for targeting patients and programs to improve medication adherence.
authors.affiliation: Center for Health Services Research, Henry Ford Hospital, Detroit, MI 48202, USA. jlafata1@hfhs.org
authors.forename: Jennifer Elston
authors.initials: JE
authors.lastname: Lafata
authors.forename: Mirela
authors.initials: M
authors.lastname: Cerghet
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Dobie
authors.forename: Lonni
authors.initials: L
authors.lastname: Schultz
authors.forename: Kaan
authors.initials: K
authors.lastname: Tunceli
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Reuther
authors.forename: Stanton
authors.initials: S
authors.lastname: Elias
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D000367:Age Factors; D000553:Ambulatory Care; D015331:Cohort Studies; D017047:Cost Sharing / Q000191:economics; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D007356:Insurance, Pharmaceutical Services / Q000191:economics; D008297:Male; D055118:Medication Adherence; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy*; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D007155:Immunologic Factors