(151) Evaluation of Downstream Use of Medication Treatment for Overactive Bladder Following Potential Calcium Channel Blocker – Loop Diuretic Prescribing Cascade

Publication Number: 825

Background: The calcium channel blocker (CCB)-edema-loop diuretic prescribing cascade has been consistently described using multiple data sources. The subsequent risk of downstream consequences due to unnecessary use of loop diuretics, especially in older adults, has yet to be explored.

Objectives: To evaluate the risk for treatment of overactive bladder following a potential CCB-edema-loop diuretic prescribing cascade in older adults as a measure of a downstream consequence.

Methods: We created a cohort of CCB initiators aged ≥66 years old without a diagnosis of heart failure and identified first use of a loop diuretic within 180 days (potential prescribing cascade) between 2011 and 2018 using Medicare Fee-For-Service data. Patients who did not initiate a loop diuretic within 180 days served as control patients with their cohort entry date frequency matched to resemble the distribution of time between CCB and loop diuretic initiation. Patients were followed until initiation of overactive bladder (OAB) treatment (antimuscarinic or mirabegron) or censoring event (heart failure diagnosis, death, end of study period; whichever occurred first). A multivariable Cox proportional hazards regression model was used to compare the risk of OAB treatment between patients with and without the potential prescribing cascade after adjusting for age, sex, race, diagnosis of Alzheimer’s disease, frailty, and Charlson Comorbidity Index.

Results: We identified 152,254 CCB initiators, of which 6,029 (4.0%) initiated loop diuretics within 180 days. Incidence of overactive bladder treatment initiation was 2.27 (95% CI 1.86-2.76) per 100 patient-years for patients initiated on loop diuretics compared to 1.78 (95% CI 1.70-1.85) per 100 patient-years among the non-users, resulting in an unadjusted incidence rate ratio of 1.28 (95% CI 1.04-1.56). The adjusted HR of treatment for overactive bladder was 1.04 (95% CI 0.85-1.28) in patients initiating loop diuretics compared with non-users.

Conclusions: Our findings provided no evidence of an increase in OAB treatment following CCB-edema-loop diuretic prescribing cascade compared to non-loop diuretic users.