The dynamics of chronic gout treatment: medication gaps and return to therapy.
OBJECTIVE
To identify gaps in therapy with urate-lowering drugs for the treatment of gout as well as factors associated with resuming therapy.


METHODS
From 2 integrated delivery systems, we identified patients 18 years or older with a diagnosis of gout who initiated use of a urate-lowering drug from January 1, 2000 through June 30, 2006 and who had a gap in therapy. A gap was defined as a period of over 60 days after the completion of 1 prescription in which no refill for a urate-lowering drug was obtained. Survival curves were used to assess return to therapy of urate-lowering drugs. Cox proportional hazards analysis estimated the association between covariates and return to therapy.


RESULTS
There were 4166 new users of urate-lowering drugs (97% received allopurinol), of whom 2929 (70%) had a gap in therapy. Among those with a gap, in 75% it occurred in the first year of therapy. Fifty percent of patients with a gap returned to therapy within 8 months, and by 4 years it was 75%. Age 45-74 years (<45 referent) and greater duration of urate-lowering drug use before the gap was associated with resuming treatment within 1 year. In contrast, receipt of nonsteroidal anti-inflammatory drugs or glucocorticoids in the year before the gap was associated with a reduced likelihood of resuming therapy.


CONCLUSIONS
The majority of gout patients with gaps in urate-lowering drug use returned to treatment. More investigation is needed to better understand why patients may go for months without refilling prescriptions, given the clinical consequences of nonadherence.
Harrold
Leslie R
LR
Meyers Primary Care Institute, Worcester, Mass., USA. leslie.harrold@umassmed.edu
Andrade
Susan E
SE
Briesacher
Becky
B
Raebel
Marsha A
MA
Fouayzi
Hassan
H
Yood
Robert A
RA
Ockene
Ira S
IS
D000367:Age Factors; D000368:Aged; D000493:Allopurinol / Q000008:administration & dosage; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D016009:Chi-Square Distribution; D002908:Chronic Disease; D015331:Cohort Studies; D003078:Colchicine / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage; D006073:Gout / Q000175:diagnosis* / Q000188:drug therapy*; D006074:Gout Suppressants / Q000008:administration & dosage*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000706:statistics & numerical data*; D011336:Probability; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D013997:Time Factors; D016896:Treatment Outcome; D014527:Uric Acid / Q000097:blood
D000894:Anti-Inflammatory Agents, Non-Steroidal; D005938:Glucocorticoids; D006074:Gout Suppressants; D014527:Uric Acid; D000493:Allopurinol; D003078:Colchicine