Presence of central nervous system, cardiovascular and overall co‐morbidity burden in patients with overactive bladder disorder in a real‐world setting
Authors: Asche Carl V. , Kim Jaewhan , Kulkarni Amit S. , Chakravarti Paula , Andersson Karl‐Erik 
Published: July 2011

Study Type – Therapy (individual cohort)

Level of Evidence 2b

What's known on the subject? and What does the study add?

It has been documented that currently used anti‐muscarinics can cause adverse effects on the CNS.

This study adds knowledge that the OAB population has more CNS disorders that make them vulnerable to the potential CNS effects of OAB anti‐muscarinics.

OBJECTIVE

To determine the proportion of patients with overactive bladder (OAB) potentially at risk for adverse events by assessing their pre‐existing central nervous system (CNS), cardiovascular (CV) and other co‐morbidities.

PATIENTS AND METHODS

The GE Centricity Electronic Medical Record database was utilized to identify patients with a diagnosis of OAB using International Classification of Diseases, Ninth Revision (ICD‐9) codes or a prescription between 1 January 1996 and 30 March 2007 for an OAB anti‐muscarinic agent.

Matched non‐OAB patients were assigned the same index date as the corresponding OAB patient. Based on the presence of ≥ one pharmacy claim for an OAB anti‐muscarinic agent, the OAB cohort was stratified as treated or untreated. A random sample of age‐ and gender‐matched patients formed a non‐OAB control cohort.

An additional and separate analysis focusing on all co‐morbidities was performed examining non‐OAB patients who were matched to OAB patients on 1:1 propensity score matching, based on age, body mass index (BMI) and gender at baseline.

Charlson Comorbidity Index (CCI), using ICD‐9 codes, and the Chronic Disease Score (CDS), using prescribed drugs, were calculated.

RESULTS

When compared with non‐OAB patients (N= 77 272; 83.2% women; median age 64 years), OAB patients (N= 41 440; 83.6% women; median age 65 years) had more overall CNS co‐morbidities (45.4 vs 29.0%; P < 0.001).

In addition, OAB patients had a higher use of medications with anti‐muscarinic effects (39.6 vs 25.4%; P < 0.001). OAB patients were also more likely to have CV co‐morbidities (57.6 vs 44.6%; P < 0.001).

CNS co‐morbidities were slightly more common in untreated (n= 8 106) than in treated (n= 33 334) OAB patients (47.2 vs 45.0%; P < 0.001). CV co‐morbidities were higher in treated OAB patients (58.8 vs 53.7%; P < 0.001).

In the additional separate analysis, which focused on all co‐morbidities, patients with OAB had higher mean CCI and CDS scores than patients without OAB (CCI: 1.17 vs 1.11 [P < 0.001]; CDS: 2.95 vs 1.74 [P < 0.001]).

After controlling for other covariates, the linear regressions (n= 22 544) showed that OAB patients had higher CCI and CDS than patients without OAB.

CONCLUSIONS

Among OAB patients, CNS, CV and all co‐morbidities were more prevalent than in non‐OAB patients.

Prior exposure to CNS medications was more prevalent in OAB patients who received anti‐muscarinic treatment than in those who did not.

Co‐morbidities and concomitant medications affecting the CNS and the CV system should be taken into account when making the decision on the most appropriate OAB treatment option for each individual patient.