Researchers identify limited evidence base and uneven clinical application as probable reasons for variation.
This article was originally published in the American Journal of Pharmacy Benefits
An expert panel of the Endocrine Society defined hypogonadism as “a clinical syndrome that results from failure of the testis to produce physiological levels of testosterone (androgen deficiency) and a normal number of spermatozoa due to disruption of one or more levels of the hypothalamic-pituitary-testicular axis” and recommended that a diagnosis of androgen deficiency should be made “only in men with consistent symptoms and signs and unequivocally low serum testosterone levels.” Testosterone therapy is indicated for the treatment of men with hypogonadism and is associated with a favorable risk/benefit ratio. The exact prevalence and incidence of hypogonadism are not known.
The sales of testosterone and other androgenic products have had explosive growth during the past decade in the setting of strong promotion by the pharmaceutical industry; the retail sales exceeded $1.6 billion in 2011 (IMS Inc; data courtesy of Dr Michael Miller, Abbott Laboratories). In the United States, the prescription sales of testosterone grew by 25% to 30% annually between 1993 and 2002. Although the exact distribution of the indications for which testosterone therapy is prescribed in the United States is not known, it has been suspected that a sizable proportion of testosterone use is for conditions such as the age-related decline in testosterone, for which testosterone therapy is currently not approved or recommended.
Total testosterone levels in men decline progressively with age at an average rate of 1.5% per year. This age-related decline in testosterone levels has been associated with adverse cardiometabolic, physical function, and mobility outcomes in older men. However, neither the clinical benefits nor the long-term risks of testosterone therapy have been established in adequately powered randomized trials in older men with age-related decline in testosterone levels. Testosterone therapy currently is not approved for treatment of age-related decline in testosterone levels. The growing use of testosterone in men, particularly older men, without a clear understanding of its benefits or long-term risks, has raised concern among regulatory agencies.
For many years, injectable testosterone esters have been the most frequently used treatment modality for male hypogonadism. Recently, newer treatment modalities have been introduced, including transdermal patches and gels. These new forms, which may be more acceptable to patients, will provide additional options and convenience, and may further contribute to increasing demand for exogenous testosterone therapy.
There have been few systematic investigations of the overall rate of use for exogenous testosterone therapy. The variability in this rate of testosterone use among sites of care or providers is largely unknown. Thus, our first objective was to examine variation in age-adjusted rates of exogenous testosterone administration among sites of care in the Veterans Health Administration (VHA), the nation’s largest integrated healthcare system. Our second objective was to explore the cost implications of the variation in rates of prescription among sites. We expected to find that VHA sites would vary widely in rates of prescription of exogenous testosterone therapy to male veterans, even after adjusting for the age profile at each site. Greater understanding of the site-level variation in testosterone prescribing will be an important first step to understanding the site-level and patient-level predictors of testosterone utilization in the VHA system. It is likely that testosterone is overused at some sites, and in fact it may be underused at other sites. This study will constitute an important first step to promoting a more consistently evidence-based and rational approach to prescribing exogenous testosterone.
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