Therapeutic Non-adherence: An Ongoing Problem
No matter how much pharmacologic therapy advances, patient behavior will remain a significant factor in the outcomes achieved.
Therapeutic non-adherence is a clinical challenge that likely has vexed doctors for centuries, perhaps millennia. If patients fail to take their medications or keep appointments to receive maintenance therapies, the conditions for which they are prescribed treatment cannot be controlled, potentially leading to increased morbidity and mortality. As with other medical specialties, nephrology and urology have their share of non-adherent patients, as illustrated by 2 studies presented at the American Urological Association (AUA) annual meeting and which we report on.
In a study of patients with non-muscle invasive bladder cancer, Alexander M. Helfand, BA, a fourth-year medical student, and colleagues found poor adherence to maintenance therapy, with “realworld” rates of adherence lower than those observed in most clinical trials. Only 10% of patients on the Lamm schedule completed 3 years of treatment with 21 maintenance instillations, Helfand's group reported. In the other study, Yooni Yi, MD, and colleagues found that only 50% of patients with kidney stones adhered to their prescribed medical therapy. Being placed on combination therapy and female gender were independently associated with lower odds of adherence.
These findings resonate with some of the published literature on nonadherence. Last year, in the Journal of Nephrology (2014;27:673-679), investigators published the results of an 8-week study of 135 hemodialysis (HD) patients showing that each week, about half of patients were adherent (missing less than 1 total daily dose per week) to phosphate binder treatment. Over the 8-week period, only 22% of patients were totally adherent (missing less than 1 total daily dose per week, every week). Living with a partner, greater social support, and better physical quality of life were associated with being totally adherence, the investigators reported.
Pill burden has emerged as a possible reason for non-adherence to phosphate binder therapy. A study of 233 dialysis patients found that the median daily pill burden was 19, with phosphate binders accounting for about half of this, according to a study published in the Clinical Journal of the American Society of Nephrology (2009;4:1089-1096). “The daily pill burden in dialysis patients is one of the highest reported to date in any chronic disease state,” the authors concluded. Results showed that 62% of subjects were non-adherent. A study of 8,616 HD patients found that a higher pill burden was associated with lower adherence, and lower adherence was associated with higher mean phosphorus levels, researchers reported in Nephrology Dialysis Transplantation (2014;29:2092-2099).
The aforementioned new studies presented at the AUA meeting should serve as reminders that no matter how much pharmacologic therapy advances, patient behavior will remain a significant factor in the outcomes achieved.