Validation of a self-administered instrument to measure adherence to anticholinergic drugs in women with overactive bladder.
OBJECTIVE
To validate a self-administered instrument, the Medication Adherence Self-Report Inventory (MASRI) for measuring adherence to anti-cholinergic medication for overactive bladder (OAB).


METHODS
Prospective study in 131 women with OAB treated with fesoterodine. Adherence was measured at 8 and 12 weeks using an interviewer administered brief medication questionnaire (BMQ) that assesses barriers to adherence (criterion standard), the MASRI, and pill count. Construct, concurrent and discriminant validity of the MASRI was assessed. We hypothesized that women who were non-adherent as measured by the MASRI would be more likely to have a belief barrier than women who were adherent to medication.


RESULTS
Women diagnosed as non-adherent by the MASRI were more likely to report a belief barrier to taking medication as compared to adherent women at 8 weeks (80% vs. 38%, P < 0.001) and at 12 weeks (70% vs. 40%, P = 0.003). Significant correlations were noted between adherence rates measured by the MASRI and the BMQ at 8 weeks (r = 0.87, P < 0.001) and 12 weeks (r = 0.90, P < 0.001). Moderate correlation was noted between the adherence rate as measured by the MASRI and pill count at 8 weeks (r = 0.49, P = 0.02) but not at 12 weeks (r = 0.05, P = 0.87). The MASRI correctly identified 93% and 96% of non-adherent women at 8 and 12 weeks, respectively. Sensitivity, specificity, and positive likelihood ratio of the MASRI for predicting non-adherence was 91%, 82%, and 5.1 at 8 weeks and 90%, 85% and 6.1 at 12 weeks.


CONCLUSIONS
The MASRI is a valid self-administered tool for measuring adherence to anti-cholinergic medication in women with OAB.
Division of Urogynecology, Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.
Uduak U
UU
Andy
Division of Urogynecology, Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.
Heidi S
HS
Harvie
Division of Urology, Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.
Ariana L
AL
Smith
Department of Biostatistics and Epidemiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.
Kathleen J
KJ
Propert
Department of Family Medicine and Community Health, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.
Hillary R
HR
Bogner
Division of Urogynecology, Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.
Lily A
http://orcid.org/0000-0002-2960-9931
LA
Arya
D000368:Aged; D001294:Attitude to Health; D001559:Benzhydryl Compounds / Q000627:therapeutic use*; D018680:Cholinergic Antagonists / Q000627:therapeutic use; D015331:Cohort Studies; D005260:Female; D006801:Humans; D055118:Medication Adherence; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000627:therapeutic use*; D011446:Prospective Studies; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D053201:Urinary Bladder, Overactive / Q000188:drug therapy*
D001559:Benzhydryl Compounds; D018680:Cholinergic Antagonists; D018727:Muscarinic Antagonists; C526675:fesoterodine
anticholinergics; medication adherence; overactive blabber; questionnaire