A 6-month, prospective, observational study of PDE5 inhibitor treatment persistence and adherence in Middle Eastern and North African men with erectile dysfunction

Abstract

Background:

Erectile dysfunction (ED) negatively impacts quality of life. Phosphodiesterase type 5 inhibitors (PDE5Is) are effective in treating ED; however, rates of discontinuation remain high.

Objectives:

To assess on-demand PDE5I treatment persistence and adherence through 6 months in Middle Eastern and North African (MENA) men with ED in a prospective, non-interventional, observational trial.

Research design and methods:

Enrolled men were ≥18 years old from Saudi Arabia, Egypt, and the United Arab Emirates, PDE5I naïve, and sexually active. PDE5Is were selected per routine clinical practice. Persistence was defined as use of ≥1 dose during the prior 4 weeks, adherence as compliance with dosing instructions during the most recent dose. Logistic regression models were used to identify factors associated with persistence and adherence.

Main outcome measures:

Persistence and Adherence Questionnaire; Partner Relationship Questionnaire; Self-Esteem and Relationship Questionnaire; International Index of Erectile Function (IIEF); Erectile Dysfunction Inventory of Treatment Satisfaction.

Results:

Patients’ (n = 493) mean age was 49.8 years, mean BMI was 29.3, and the majority (n = 354, 71.8%) were from Saudi Arabia. Tadalafil was the most prescribed PDE5I (69.6%), versus sildenafil (15.4%), or vardenafil (15.0%). Patients’ mean IIEF–Erectile Function scores improved from moderate to mild and Erection Hardness Scores (SD) improved from 1.8 (1.0) at baseline to 3.5 (0.7) at 6 months. At 6 months, 64.9% of patients were treatment persistent (tadalafil, 68.8%, sildenafil, 65.8%, and vardenafil, 45.9%) and 59.6% were adherent. Factors significantly predictive (p < 0.05) of persistence at 6 months included age, employment status, and ED severity. Factors significantly predictive of adherence were age, employment status, and duration of ED. Interpretation of differences between drugs was limited by substantial differences in prescription rates between countries.

Conclusions:

At 6 months, 64.9% of men were treatment persistent. In this study, age, employment status, ED severity, and duration of ED were associated with persistence and/or adherence.

Keywords::

• Adherence
• Erectile dysfunction
• PDE5 inhibitors
• Persistence
• Sildenafil
• Tadalafil
• Vardenafil

Transparency

Declaration of funding

Eli Lilly and Company supported the study in its entirety.

Declaration of financial/other relationships

S.G. and Y.L. are full-time employees and minor stock shareholders of Eli Lilly and Company. A.E.-M. has disclosed that he is a consultant to and on the Speakers’ Bureau of Eli Lilly and Company. D.R., K.A.-M., T.M., and M.I. have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article. T.H. has disclosed that he has received sponsorship from Eli Lilly and Company.

CMRO peer reviewers may have received honoraria for their review work. The peer reviewers on this manuscript have disclosed that they have no relevant financial relationships.

Acknowledgments

The authors thank the principal investigators and their clinical staff as well as the many patients who generously agreed to participate in this clinical trial. We would also like to thank the clinical operations staff for their excellent trial implementation and support. The authors would like to acknowledge the assistance of Thomas Melby MS (Inventiv Health Clinical) in preparing this manuscript.

Previous presentation: Some material contained in this manuscript was originally presented at the World Meeting on Sexual Medicine 2012, Chicago, USA, August 26–30.