Measuring adherence and persistence to disease-modifying agents among patients with relapsing remitting multiple sclerosis.
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.
Lafata
Jennifer Elston
JE
Center for Health Services Research, Henry Ford Hospital, Detroit, MI 48202, USA. jlafata1@hfhs.org
Cerghet
Mirela
M
Dobie
Elizabeth
E
Schultz
Lonni
L
Tunceli
Kaan
K
Reuther
Jacqueline
J
Elias
Stanton
S
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
D007155:Immunologic Factors