Persistence and adherence of medications for chronic overactive bladder/urinary incontinence in the california medicaid program.
OBJECTIVE
To investigate persistence and adherence of medication treatment in chronic overactive bladder/urinary incontinence (OAB/UI) patients, and to evaluate OAB/UI-related comorbidity events associated with persistence.


METHODS
Pharmaceutical outcomes research with a health-care provider perspective was conducted on a California Medicaid (Medi-Cal) chronic OAB/UI population. The primary end point was medication possession ratio (MPR), which was used to measure refill adherence. Secondary end points measuring persistence patterns included discontinuation of OAB drug therapy (medication-uncovered interval > 30 days) and time to discontinuation (period from the index date until the first discontinuation date). Significant factors on nonpersistence were found by using a Cox Proportional Hazards model. Factors contributing to nonadherence (MPR < 0.8) and the relationship between OAB/UI comorbidity events and persistence were examined by logistic regressions.


RESULTS
Of 2496 eligible patients, 36.9% had only one OAB/UI prescription. The mean MPR was 0.34 (SD 0.21) and the median was 0.3, indicating that on average only about one-third of period of time since medication initiation was covered by the therapy. Only 122 patients exhibited > 80% adherence during the 6-month follow-up-period. Significant predictors of higher persistence included: white ethnicity, previous hospitalization length, starting with tolterodine or oxybutynin extended-release, and previous use of topical drugs or antipsychotics. Nevertheless, previous depression or urinary tract infection (UTI) diagnosis, polypharmacy, significantly increased the odds of early discontinuation. Treatment discontinuation increased the risk of UTI diagnosis by 37% in the post-treatment period (P = 0.03; OR 1.37; 95% CI 1.03-1.84), but had no significant effect on other OAB/UI-related comorbidities.


CONCLUSIONS
For chronic OAB/UI patients identified in this study, both persistence and adherence with medication treatment were suboptimal. These results suggest that persistence and treatment discontinuation remains problematic for the OAB/UI population.
Yu
Yanni F
YF
Department of Pharmaceutical Economics and Policy, University of Southern California, Los Angeles, CA 90089, USA.
Nichol
Michael B
MB
Yu
Andrew P
AP
Ahn
Jeonghoon
J
D001559:Benzhydryl Compounds / Q000627:therapeutic use; D002140:California / Q000453:epidemiology; D002908:Chronic Disease; D015897:Comorbidity; D003408:Cresols / Q000627:therapeutic use; D003692:Delayed-Action Preparations; D005260:Female; D005422:Flavoxate / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008333:Mandelic Acids / Q000627:therapeutic use; D008484:Medicaid; D008875:Middle Aged; D015999:Multivariate Analysis; D018727:Muscarinic Antagonists / Q000627:therapeutic use*; D010349:Patient Compliance; D010665:Phenylpropanolamine / Q000627:therapeutic use; D016016:Proportional Hazards Models; D000068737:Tolterodine Tartrate; D014549:Urinary Incontinence / Q000188:drug therapy* / Q000453:epidemiology
D001559:Benzhydryl Compounds; D003408:Cresols; D003692:Delayed-Action Preparations; D008333:Mandelic Acids; D018727:Muscarinic Antagonists; D010665:Phenylpropanolamine; D005422:Flavoxate; D000068737:Tolterodine Tartrate; C005419:oxybutynin