Use and knowledge of finasteride in the chemoprevention of prostate cancer: Trends in prescriptions and a survey of VA primary care physicians and urologists
Creators: name: Hamilton, Robert
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2006

description: Background: Little is known about how physicians assimilate evidence regarding prostate cancer prevention. Finasteride, a drug studied as a chemopreventive agent for prostate cancer has produced controversial results. The purpose of this research design paper is to provide background and rationale for my proposed project to examine the current knowledge and use of finasteride among primary care physicians and urologists in the Veterans Health Administration (VHA). Aims: Specifically, I seek to a) identify trends in finasteride prescriptions in the VHA over time, and determine whether these trends correlate with publication of evidence or guidelines; b) identify trends in alpha-blocker prescriptions in the VHA over time to help determine that proportion of finasteride prescriptions attributable to combined treatment for benign prostatic hyperplasia (BPH); and c) determine the knowledge, and use offinasteride as well as the perceptions, characteristics and contextual factors of those physicians who are in a position to utilize finasteride. Study Design: A formal systematic review of the evidence pertaining to several aspects offinasteride use in the prevention of prostate cancer is presented. Thereafter, the first part of my proposed study will involve assessing time trends in prescriptions for finasteride and alpha-blockers from October 1998 to December 2005 using the VHA Pharmacy Benefits Management (PBM) database. The second part will involve surveying VHA primary care physicians (PCPs) and urologists regarding their use and knowledge offinasteride. Hypotheses: I hypothesize that finasteride prescriptions will increase slowly during the late 1990s and early 2000s, but accelerate concomitant with the publication of the Prostate Cancer Prevention Trial (PCPT) and Medical Therapy of Prostate Symptoms (MTOPS) studies. However, prescriptions for alpha-blockers, in particular the selective alpha-blockers, will similarly increase. This would suggest that the overwhelming majority of increased finasteride use is for treatment of BPH rather than chemoprevention. I anticipate this finding will be confirmed in the survey when physicians indicate that they mostly use finasteride to treat BPH. However, I also hypothesize that knowledge of finasteride main effects, side-effects and influence on prostate parameters will be surprisingly low. I anticipate, more urologists than primary care physicians will be comfortable prescribing finasteride in general, and more urologists will report using finasteride as a prostate cancer chemopreventive agent. Impact: Given the potential impact finasteride has on prostate cancer incidence, aggressiveness and screening, the insight gained regarding the current use of finasteride is important. Discovering that many men are currently taking finasteride, but that physicians are not well informed regarding the influence of finasteride on parameters such as PSA, prostate volume and the potential increased risk of high grade tumors may indicate a need for directed educational interventions for both physicians and patients. Understanding physician perceptions of the current evidence for finasteride as a chemopreventive agent will help guide future research and tailor guidelines to address the areas of greatest concern or uncertainty. I will gain insight into the different levels of knowledge and perception between PCPs and urologists. Such information could guide future recommendations for when PCPs should refer a patient to a urologist. Summary: The uncertainty surrounding use of finasteride to prevent prostate cancer is unlikely to be resolved for several years. This study will provide important information regarding how physicians in the VHA perceive the uncertainty and how these perceptions translate into use of finasteride. The VHA is uniquely positioned to study this problem and the results will influence future research and guideline creation.