Between 2012 and 2050, the aging of the baby boomer generation will generate a dramatic increase in the number of people in the United States who are ≥ 65 years of age.1 More than 20% of the US population will be in this age group by 2020, and the number of people in this age group is projected to nearly double from 43.1 million in 2012 to 83.7 million by 2050.1
Fortunately, life expectancy for men and women in all age groups, including older Americans, is also projected to improve between 2012 and 2050. By 2030, men will account for approximately 45% of the population aged 65 years and older, and women will account for 55% of this age group.1 This steady increase in the number of aging Americans will have a substantial impact on healthcare delivery, resources, and policy in the coming decades.
As the healthcare system continues to evolve in response to far-reaching changes at the national, state, and local levels, there is an increasing demand for payers, providers, and patients to consider both the clinical and economic implications of healthcare decisions—with emphasis on quality, value, and accountability. The aging of the population and major healthcare changes are having a profound impact on urology practices, from business as well as clinical perspectives.
Men’s Health: The Increasing Importance of the Urology Practice
Men’s health issues, particularly those more common in aging men—erectile dysfunction (ED) and low testosterone (Low T)—warrant greater clinical focus. Often underrecognized and underestimated as clinical entities, both ED and Low T are associated with such serious comorbidities as cardiovascular disease, hypertension, diabetes, and depression. Early detection is especially vital, because it may reveal the existence of a life-threatening underlying condition affecting the patient’s overall health. ED and Low T have physical as well as psychosocial components. Effective treatment can improve the physical health and mental well-being of affected men and enhance their quality of life and personal relationship with partners.
Today, urology practices encounter numerous challenges and opportunities. In the current healthcare environment, urology practices are faced with many business-related pressures, and they are exploring strategies to help retain patients and sustain financial viability. Some practices are consolidating with other practices or expanding their coverage area to attract more patients. They may need to maximize referrals from primary care physicians, increase patient volume (workload) by seeing more patents per day, or add evening hours to maximize revenue and better serve their patients. In the midst of sweeping changes in healthcare policy in recent years, notable technological and pharmaceutical innovations have improved outcomes for men with urologic conditions. Progressive urology practices seek to integrate therapeutic innovation and improve surgical techniques to maximize the breadth of service options they can offer their patients.
Based on their specialized training in men’s health issues, urologists are well equipped to play a key role in men’s health. While addressing male health issues, the urologist may also detect comorbidities that are clinically relevant to a man’s overall health and well-being. In fact, in recent years, the urology community has assumed an increasingly active leadership role in men’s health.
The American Urological Association (AUA) created the Committee on Male Health in 2009 to address men’s health issues, including education, community outreach, research, integration with other specialties, and support of local and national initiatives.2 Moreover, in 2012, the AUA published a Men’s Health Checklist to strengthen the urologist’s role in caring for male patients and to improve the coordination of patient care among all physicians. This checklist captures urology-specific and general age-related symptoms and concerns, including androgen deficiency, ED, and Peyronie’s disease, a connective tissue disorder characterized by the formation of fibrous plaques that result in penile deformities during erection.3,4
The evaluation and management of men with ED and Low T has become an important aspect of the urologist’s practice.5 ED and Low T are underrecognized and undertreated, despite the association of these conditions with serious comorbidities. According to Johns Hopkins urologist Kevin Billups, MD, chronic but preventable medical conditions account for more than 50% of premature male deaths in the United States.6 Dr Billups added, “Erectile dysfunction and low testosterone often are associated with chronic illness, but they also can precede a major medical event such as a heart attack or stroke by several years, offering an opportunity for early detection and prevention.”6
Urologists are in a position to improve the lives of men with ED and Low T and to uncover potentially life-threatening comorbidities. They also have a key role in coordinating care with other healthcare providers, particularly for men with ED and Low T who have underlying conditions.
ED is a common condition with potentially serious implications, including cardiovascular disease and vascular disease. For most men affected with it, ED is a symptom of an underlying condition7; moreover, ED imposes a physical and psychological burden. ED is defined as the inability to achieve and maintain an erection suitable for sexual intercourse or other activity in the absence of an ejaculatory disorder, including premature ejaculation.8
ED affects an estimated 18 million men in the United States, with an overall prevalence of 18.4% in men ≥ 20 years of age, based on a study by researchers from the Johns Hopkins Bloomberg School of Public Health.9 Age was directly correlated with ED: 70% of men aged ≥ 70 years had ED versus 5% of men aged 20 to 39 years. Nearly 90% of men with ED had at least 1 cardiovascular disease risk factor, including hypertension, poor cholesterol levels, current smoking, or diabetes. In fact, 51.3% of the men with diabetes also had ED, and 50% of men with a history of cardiovascular disease had ED, based on crude and age-adjusted prevalence estimates from this study.9
The study authors concluded as follows: “With the advent of highly effective and widely available pharmacotherapy for ED, physicians should be aggressive in screening for and managing their middle-aged and older patients with this important quality-of-life issue.”9 The authors also acknowledged the importance of diet and exercise as strategies to improve cardiovascular health and diabetes risk factors, thereby slowing the progression of ED.9
The impact of ED extends well beyond quality of life, particularly given its link to a number of other underlying medical conditions, a factor that underscores the importance of early diagnosis and management of ED.
Etiology and Comorbidities
The process of male sexual arousal is complex and involves multiple signals, including the brain, hormones, nerves, emotions, muscles, and blood flow/vessels. ED can result when there are problems in 1 or more of these signals (ie, a combination of physical and psychological issues, or anxiety from a physical problem that worsens ED).10
Psychological factors that interfere with libido may play a role in ED.11 In addition, a number of hormones contribute to ED, including prolactin, adrenocorticotropic hormone, oxytocin, and androgens, especially testosterone.11 Vascular issues that affect blood flow into or within the penis are another common cause of ED.11 Nitric oxide, considered to be the main vasoactive nonadrenergic, noncholinergic neurotransmitter and chemical mediator involved in erectile response, is involved in many of the common etiologies and comorbidities of ED.11
A number of medical conditions are associated with ED (Table 1); obesity and a sedentary lifestyle are independent risk factors, as well.12 ED is an early, independent marker for cardiovascular disease, based on the common risk factors and endothelial dysfunction of these 2 conditions.12
In some cases, ED is a side effect of drugs prescribed to treat other conditions. Medications that can cause ED include antidepressants, antihistamines, diuretics, and antihypertensives, hormonal therapies, chemotherapy, and antiarrythmic agents.13 In addition, the abuse of other substances or drugs, including alcohol, nicotine, amphetamines, marijuana, cocaine, and opiates, can cause or lead to ED.13
According to AUA guidelines, the initial evaluation for ED is conducted in person to review the individual’s medical, sexual, and psychosocial histories.14 At that time, appropriate laboratory tests are performed to identify comorbid conditions that may contribute to ED or contraindicate specific treatments. The physician may also discuss with the patient any changes in sexual desire, ejaculation, and orgasm, the presence of genital pain, a history of sexual function, and lifestyle factors, including sexual orientation and current relationship status with a spouse or partner. Other goals of the evaluation are to distinguish ED from ejaculation and/or orgasm issues, determine the chronology and symptom severity, and assess the patient/partner’s needs and therapeutic expectations.14
The AUA endorses the position statement of the Sexual Medicine Society of North America (SMSNA), which asserts that diagnostic studies used to evaluate the pathophysiology of ED should be based on the individual patient, and that a standard set of diagnostic tests for all patients is not an appropriate practice.15 Rather, tests should be limited to those that are needed to establish treatment options available to the patient, based on the individual patient’s clinical needs and therapeutic preferences.15
The evaluation generally includes a physical examination of the abdomen, penis, testicles, secondary sexual features, and lower extremity pulses. If the use of testosterone is being considered for the treatment of patients with ED, a prostate-specific antigen (PSA) measurement and rectal exam may be performed.14 Other tests, including testosterone level, blood tests, urinalysis, ultrasound, nocturnal erection monitoring, vascular assessment, or neurological assessment may also be warranted for some patients.10,14
ED Treatment Options
Although ED is more common in older men, it need not be viewed as an acceptable consequence of aging, particularly given the availability of effective treatments. Over the past decade or so, the treatment of patients with ED has been transformed by the development of effective therapies.
Despite advances in ED therapies, a large-population study revealed that of more than 6.2 million men with ED, only 25.4% were treated during the 12-month study period—underscoring the fact that despite ED’s high prevalence with age and comorbidities, most men are not receiving treatment.16 Furthermore, although the stigma associated with ED has lessened somewhat in recent years, some men still avoid or delay seeking medical help. Generally, ED that occurs less than 20% of the time does not require treatment, whereas ED that occurs more than 50% of the time indicates that treatment is warranted.7
Treatment decisions for ED are based primarily on the cause and severity of the condition, underlying health issues, the risks and benefits of treatments, and the individual patient’s needs and preferences.10 Selection of a specific therapy is also based on the patient’s comorbid conditions and current medications. Pharmacologic options for ED are listed in Table 2.
For 70% of men with ED, oral medications have been shown to be effective.17 Oral therapies include phosphodiesterase type 5 (PDE5) inhibitors: avanafil, sildenafil, tadalafil, and vardenafil. These agents, which work by enhancing the effects of nitric oxide and increasing blood flow, vary in dosage, onset, duration of action, and side effect profiles. Some men may experience an adverse reaction with 1 of these agents but not with another.17
Although the PDE5 inhibitors have similar mechanisms of action, they have different pharmacologic properties, which can affect their labeling and usage. For example, unlike other oral ED agents, avanafil, a recently approved PDE5 inhibitor, can be taken as early as 15 minutes before sexual activity.18
The most common adverse reactions associated with the PDE5 inhibitor class of drugs include headache, flushing, nasal congestion, back pain, dyspepsia, and dizziness.18-21 Use of PDE5 inhibitors is contraindicated in patients taking organic nitrates in any form because the PDE5 inhibitors may potentiate the hypotensive effect of nitrates. Similarly, the labeling for these agents includes a warning about the concomitant use of PDE5 inhibitors with alpha-blockers, antihypertensives, or substantial amounts of alcohol, which may also lead to hypotension.18-21
Other medications for ED include alprostadil self-injection, alprostadil intraurethral suppository, and testosterone replacement therapy.10 Alprostadil, a vasodilator, is a synthetic form of prostaglandin E1. Nonpharmacological therapies for ED include the vacuum erection device (penis pump), penile implants, and blood vessel surgery (if leaking or obstructed blood vessels are implicated in ED).10
For ED that is caused by anxiety, stress, or depression, psychological counseling may be recommended.10 Maintaining a healthy diet and healthy weight, exercising regularly, and controlling cholesterol levels may also help prevent or mitigate the severity of ED.7,22
Patient and Practice Management Considerations
The patient has a key role in ED treatment decisions. Therapeutic decisions involve consideration of the biological, psychological, social, and cultural factors that are most important to the ED patient and his partner.23 Patient preferences often hinge on the individual’s age, duration of ED, and the frequency and nature of the sexual relationship, as well as the partner’s age, interest in sexual activity, and other factors. Treatment-specific considerations for the patient include the drug’s rapid onset of action, duration of action, mode of administration, and side effects. Other considerations include convenience and cost.23
Cost is a concern for some patients with respect to the use of pharmacologic treatments.17 Patient cost-sharing for prescription drugs has increased steadily in recent years. In fact, from 2000 to 2009, copayments for prescription drugs increased 25% for generic drugs, 80% for preferred drugs, and 59% for nonpreferred drugs.24 According to a major literature review (160 articles), 85% of the articles showed that increased patient cost for medications was associated with decreased treatment adherence; furthermore, most showed that increased treatment adherence was associated with improved outcomes.25
Other issues that may impact the use of ED drugs include prior authorizations and quantity limits imposed by payers. Health plans generally require a prior authorization for pharmacologic ED treatments to ensure that these agents are being used safely and appropriately. Prior authorization involves consideration of several factors, including the health plan member’s diagnosis, other conditions, and prescription drugs, FDA-approved labeling/prescribing information, and relevant clinical data. Prior authorization requirements for ED treatments may also include steps that are designed to establish medical/clinical justification that extends beyond quality-of-life issues. Moreover, quantity limits are often imposed by health plans to encourage utilization in accordance with product labeling.
Urology practice administrators often play a key role in helping patients gain access to prescribed ED therapies. By navigating prior authorization requirements and generating appropriate medical documentation, administrators and office staff ensure that patients receive medications in a timely manner without undue cost burden.
Low T, also known as androgen deficiency, occurs in men as a natural consequence of aging. Beginning in their 40s, men experience a decline in sex hormone levels, a process that gradually continues as they age.26 This process is sometimes referred to as andropause. Low T is also caused by hypogonadism or other conditions.
As many as 39% of men aged ≥ 45 years have Low T; in fact, Low T affects 20% of men aged > 60 years, 30% of men aged > 70 years, and 50% of men aged > 80 years, according to the Urology Care Foundation of the AUA.27 One study showed that androgen deficiency occurred in 5.6% of a group of men aged 30 to 79 years and that its prevalence increased substantially with age.28 Another study estimated that 12.2% of men aged between 40 and 69 years may be androgen deficient, whereas 2.3% are definitely androgen deficient.26
As is the case with ED, a number of comorbid conditions are commonly present in men with Low T. In fact, Low T occurs in approximately 40% of men with hypertension, 40% with high cholesterol, 50% with diabetes, and 50% with obesity.27 A longitudinal study revealed that Low T is associated with an increased risk for developing metabolic syndrome.29 Another longitudinal study showed that men with Low T generally have a higher risk of cardiovascular morbidity and mortality, compared with men with higher T levels and women.30 Consequently, the early diagnosis of Low T is particularly important, even in young men, given its associated comorbidities and risk factors for serious health issues.5
The most common symptoms associated with Low T are listed in Table 3. Because the symptoms of Low T are sometimes subtle and vague, some men may downplay their symptoms or delay seeking medical help. Given that some of these symptoms may be caused by other disorders or are normal aspects of aging, the diagnosis of Low T is not made based on symptoms alone.26
Hypogonadism, a condition in which the testicles are not functioning properly, is characterized by Low T and, in some cases, infertility.26 Primary hypogonadism occurs when the brain signals the testicle to produce testosterone and sperm, but the testicles fail to respond to the signaling. The causes of primary hypogonadism are congenital (Klinefelter syndrome, cryptorchidism, varicocele, myotonic dystrophy, some genetic mutations), acquired (infections [ie, orchitis from mumps], chemotherapy or radiation, environmental toxins, alkylating agents, autoimmune damage, glucocorticoids, and other medications), or idiopathic.31,32
Secondary hypogonadism occurs when the brain fails to signal the testicles properly. Men affected by secondary hypogonadism generally have extreme Low T levels and absence of sperm in the semen. Secondary hypogonadism is caused by congenital factors (ie, Kallman syndrome, Prader–Willi syndrome), acquired conditions (hyperprolactinemia, diabetes, obesity, steroid treatment, critical illness), or damage to pituitary function (benign tumors, malignancy, infections, trauma, radiation).31
Secondary hypogonadism can also be caused by hemochromatosis (excess iron in the blood) or certain inflammatory diseases, including sarcoidosis and tuberculosis.32 Moreover, older men may have lower testosterone levels because testosterone production gradually decreases with age.32 Adult men affected by hypogonadism are at a greater risk for complications, including ED, infertility, fatigue, diminished sex drive, muscle loss or weakness, gynecomastia, and osteoporosis.32
Diagnostic Evaluation for Low T
Low T is diagnosed by assessing the patient’s symptoms and conducting a blood test. The diagnostic evaluation for Low T includes the following: a medical history to determine contributing factors, onset, and severity of symptoms; a physical examination, including palpation of the testes to check for volume and consistency and assessment of body hair distribution, musculature, and breast size; and for men ≥ 50 years of age, a digital rectal examination to check prostate size.26 Laboratory tests include a blood test to measure testosterone levels. Other hormones, including luteinizing hormone and follicle-stimulating hormone, may also be measured.26
In some cases, a PSA test is conducted to screen for prostate cancer, and a hematocrit level is measured because an increase in red blood cell count occurs in some men who receive testosterone treatment.27 If a blood test confirms a Low T level, further testing will follow to identify the cause. These tests may include hormone testing, semen analysis, pituitary imaging, genetic studies, or testicular biopsy.
The diagnosis of Low T presents a number of challenges: serum T levels are affected by time of day, season, age, illness, and some medications; total testosterone (TT) concentrations are affected by changes in sex-hormone binding globulin, which may also be affected by medications and comorbid conditions; and the assays for measuring T levels vary. The correlation of TT with free testosterone relative to symptomatic androgen deficiency is still a subject of debate within the medical community.5
While efforts are under way to optimize assay platforms and standardize evidence-based normal assay ranges, there is currently no generally accepted T-concentration threshold to distinguish eugonadal men from hypogonadal men. Consequently, laboratory results require interpretation within the appropriate clinical setting. The FDA uses a TT level of < 300 ng/dL to define hypogonadism for the purpose of clinical trials.5
In a 2013 white paper, the AUA concluded that “the diagnosis of hypogonadism should be based as much on the presence of signs and symptoms as on serum T measurement.”5 The position statement further states, “Based on overall poor quality of T testing in most clinical laboratories and age bias of published reference ranges, no patient should be denied coverage for treatment based solely on payer defined cut-off points if need for such treatment is established by a health professional.”5
Treatment of Low T
Low T is treated with testosterone replacement therapy in appropriate patients. Testosterone therapy is indicated in men with documented Low T in addition to the signs and symptoms of Low T.33 According to the SMSNA, “Treatment of T deficiency improves symptoms as well as several indicators of general health.”33 The therapeutic goals for Low T are to achieve but not exceed the normal testosterone range while minimizing adverse effects on cardiovascular function, the prostate, serum lipids, and liver and lung function. Treatment selection is based on patient-specific factors, including age, needs, and preferences.26 Other considerations include treatment preparation, side effects, convenience of administration, and cost.
Testosterone is an androgen (steroid), a class of drugs that develop and maintain male sex characteristics. Testosterone therapies are available in several formulations, as shown in Table 4: long-acting and short-acting intramuscular injections; a buccal mucoadhesive held between the cheek and the gums; transdermal gels; subcutaneously implanted pellets; and transdermal and scrotal patches. The gel preparation is the most widely used form of testosterone therapy.27 The use of oral methyltestosterone, a synthetic derivative of testosterone, is no longer prescribed or supported by relevant professional societies because of its substantial risk for liver toxicity.26
Generally, testosterone therapy is tried for up to 3 months, during which time testosterone levels and symptoms are monitored.26 If therapy is beneficial and continued, the patient should be monitored for symptoms at 3-month intervals, with testosterone levels checked, for the first year of treatment.26 Long-term use of oral hormone replacement is not recommended due to the risk of liver problems.32
Testosterone therapy may be associated with an increased risk for benign prostatic hyperplasia symptoms.27 Other risks associated with testosterone replacement include sleep apnea, gynecomastia (enlarged breasts), limited sperm production, erythrocytosis (increased production of red blood cells), formation of blood clots in the veins, fluid retention, stimulation of noncancerous prostate growths, and stimulation of the growth of existing prostate cancer.33,34 Because many men aged > 80 years may have subclinical (nonsymptomatic) prostate cancer, age is an important consideration when discussing testosterone therapy.26
Although further studies are warranted, testosterone therapy has also been linked to an increased risk for heart attack, according to recent studies. In January 2014, the FDA issued a safety announcement stating that the agency was investigating the risk of stroke, heart attack, and death in men taking FDA-approved testosterone medications.35 This alert was based on data from 2 observational studies. One study suggested a 30% increase in the risk of stroke, heart attack, and mortality in men receiving testosterone therapy (average age, 60 years; many had underlying cardiovascular disease). The other study reported a 2-fold to 3-fold increased risk of heart attack among men ≥ 65 years of age within the first 90 days following their first testosterone prescription.35
The FDA has not yet concluded that testosterone therapy increases these cardiovascular risks and has informed patients not to stop taking prescribed medication without discussing questions or concerns with their clinician. In the announcement, healthcare professionals are instructed to weigh the benefits and risks of treatment and to follow FDA-approved prescribing information.35
Urology practices are evolving in order to stay competitive and keep pace with the changing healthcare landscape. They must balance the clinical and business aspects of the practice in an era where quality, value, and accountability are increasingly scrutinized. Management of men’s health issues, including ED and Low T, are likely to become a larger focus for urology practices in the coming years, particularly as the number of aging men increases over the next few decades.
The health implications of ED and Low T often extend beyond quality of life. In recent years, strides have been made in the collective dialogue about men’s sexual health issues. Nevertheless, further improvements are warranted in addressing the clinical significance of ED and Low T, particularly considering the medical significance of these underrecognized, undertreated conditions.
The symptoms of ED and Low T are often vague, and for some men, the stigma and embarrassment of seeking medical help for these conditions persists. Given the potentially serious underlying conditions associated with ED and Low T and the challenges inherent in diagnosing and managing Low T, the specialized training and clinical expertise of urologists are vital. While a number of effective therapies are available to treat ED and Low T, treatment decisions involve a layered approach that considers patient-specific factors, including the patient’s comorbidities, medications, needs, and preferences, as well as the cost of a specific treatment/formulation.
Urologists have an essential role in providing and coordinating appropriate care for men with ED, Low T, and other conditions that impact men’s health. Effective treatment of these conditions can improve outcomes for affected men, including quality of life and personal relations. In addition, early diagnosis of ED and Low T may uncover associated chronic conditions and, in some cases, prevent the life-threatening consequences of these conditions. Urology practice administrators have a crucial role in supporting clinicians in the practice by facilitating timely access to treatments for patients without undue cost burden. Their role is likely to increase in importance as more patients seek medical attention for ED and Low T and more products enter the market in the future.
- Ortman JM, Velkoff VA, Hogan H; for US Census Bureau. An aging nation: the older population in the United States. Current population reports. www.census.gov/prod/2014pubs/p25-1140.pdf. Published May 2014. Accessed October 9, 2014.
- Elterman DS, Kaplan SA, Pelman RS, et al. How ‘male health’ fits into the field of urology. Nat Rev Urol. 2013;10:606-612.
- Levine LA. The clinical and psychosocial impact of Peyronie’s disease. Am J Manag Care. 2013;19(suppl 4):S55-S61.
- American Urological Association. AUA men’s health checklist. www.auanet.org/common/pdf/education/clinical-guidance/Mens-Health-Checklist.pdf. Accessed October 9, 2014.
- Paduch DA, Brannigan RE, Fuchs EF, et al; American Urological Association. The laboratory diagnosis of testosterone deficiency. www.auanet.org/common/pdf/education/clinical-guidance/Testosterone-Deficiency-WhitePaper.pdf. Accessed October 9, 2014.
- Grauer NA. Treating the whole man. Dome. 2013;64:7. www.hopkinsmedicine.org/news/publications/dome/dome_january_2013/treating_the_whole_man. Accessed October 9, 2014.
- Cleveland Clinic. Diseases & conditions. Erectile dysfunction. http://my.clevelandclinic.org/disorders/Erectile_Disorder_impotence/hic_Erectile_Dysfunction_Overview.aspx. Updated February 11, 2014. Accessed October 9, 2014.
- Lakin M, Wood H; Cleveland Clinic Center for Continuing Education. Erectile dysfunction. www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/endocrinology/erectile-dysfunction/. Published November 2012. Accessed October 9, 2014.
- Selvin E, Burnett AL, Platz EA. Prevalence and risk factors for erectile dysfunction in the US. Am J Med. 2007;120:151-157.
- Mayo Clinic. Diseases and conditions. Erectile dysfunction. www.mayoclinic.org/diseases-conditions/erectile-dysfunction/basics/definition/con-20034244?p=1. Published February 10, 2012. Accessed October 9, 2014.
- Lasker GF, Maley JH, Kadowitz PJ. A review of the pathophysiology and novel treatments for erectile dysfunction. Adv Pharmacol Sci. 2010. www.hindawi.com/journals/aps/2010/730861/. Accessed October 9, 2014.
- Jackson G, Rosen RC, Kloner RA, et al. The second Princeton consensus on sexual dysfunction and cardiac risk: new guidelines for sexual medicine. J Sex Med. 2006;3:28-36.
- Cleveland Clinic. Diseases & conditions. Medications that may cause erectile dysfunction. http://my.clevelandclinic.org/disorders/Erectile_disorder_impotence/hic_Medications_That_May_Cause_Erectile_Dysfunction.aspx. Updated April 7, 2011. Accessed October 9, 2014.
- Montague DK, Jarow JP, Broderick GA, et al; for American Urological Association. Erectile dysfunction. The management of erectile dysfunction (2005) [abridged]. www.auanet.org/education/guidelines/erectile-dysfunction.cfm. Accessed October 9, 2014.
- American Urological Association. Diagnostic evaluation of erectile dysfunction. www.auanet.org/about/policy-statements/evaluation-of-erectile-dysfunction.cfm. Updated May 2012. Accessed October 9, 2014.
- Frederick LR, Cakir OO, Arora H, et al. Undertreatment of erectile dysfunction: claims analysis of 6.2 million patients. J Sex Med. 2014;11:2546-2553.
- Cost can limit choice of erectile function drug, from the June 2014 Harvard Men’s Health Watch [news release]. Boston, MA: Harvard Health Publications; 2014. www.health.harvard.edu/press_releases/cost-can-limit-choice-of-erectile-function-drug. Accessed October 9, 2014.
- Stendra [package insert]. Chesterbrook, PA: Auxilium Pharmaceuticals, Inc; 2014.
- Cialis [package insert]. Indianapolis, IN: Eli Lilly & Co; 2014.
- Levitra [package insert]. Whippany, NJ: Bayer HealthCare Pharmaceuticals Inc; 2014.
- Viagra [package insert]. New York, NY: Pfizer Inc; 2014.
- Cleveland Clinic. Diseases & conditions. Erectile dysfunction and lifestyle changes: diet and exercise. http://my.clevelandclinic.org/disorders/Erectile_Disorder_Impotence/hic_Erectile_Dysfunction_and_Lifestyle_Changes_Diet_and_Exercise.aspx. Updated July 18, 2008. Accessed October 9, 2014.
- Morales AM, Casillas M, Turbi C. Patients’ preference in the treatment of erectile dysfunction. A critical review of the literature. Int J Impot Res. 2011;23:1-8.
- Kaiser Family Foundation. Prescription drug trends. http://kaiserfamilyfoundation.files.wordpress.com/2013/01/3057-08.pdf. Published May 2010. Accessed October 9, 2014.
- Eaddy MT, Cook CL, O’Day K, et al. How patient cost-sharing trends affect adherence and outcomes: a literature review. P T. 2012;37:45-55.
- Cleveland Clinic Glickman Urological & Kidney Institute. Androgen deficiency. http://my.clevelandclinic.org/urology-kidney/diseases-conditions/androgen-deficiency.aspx. Accessed October 9, 2014.
- Urology Care Foundation. Low testosterone (hypogonadism). www.urologyhealth.org/urology/index.cfm?article=132. Updated June 2014. Accessed September 11, 2014.
- Araujo AB, Esche GR, Kupelian V, et al. Prevalence of symptomatic androgen deficiency in men. J Clin Endocrinol Metab. 2007;92:4241-4247.
- Haring R, Volzke H, Felix SB, et al. Prediction of metabolic syndrome by low serum testosterone levels in men: results from the study of health in Pomerania. Diabetes. 2009;58:2027-2031.
- Haring R, John U, Volzke H, et al. Low testosterone concentrations in men contribute to the gender gap in cardiovascular morbidity and mortality. Gend Med. 2012;9(6):557-568.
- Cleveland Clinic. Diseases & conditions. Hypogonadism. http://my.clevelandclinic.org/disorders/testicular_cancer/hic-hypogonadism.aspx. Updated April 26, 2013. Accessed October 9, 2014.
- Mayo Clinic. Diseases and conditions. Male hypogonadism. www.mayoclinic.org/diseases-conditions/male-hypogonadism/basics/definition/con-20014235. Published July 10, 2014. Accessed October 9, 2014.
- Sexual Medicine Society of North America, Inc. Position statements. Testosterone therapy and cardiovascular risks. www.smsna.org/V1/index.php/about/position-statements. Accessed October 9, 2014.
- Nippoldt TB; for Mayo Clinic. What are the heart risks associated with testosterone therapy? www.mayoclinic.org/healthy-living/mens-health/expert-answers/testosterone-therapy-side-effects/faq-20090015. Published July 11, 2014. Accessed October 9, 2014.
- US Food and Drug Administration. FDA drug safety communication: FDA evaluating risk of stroke, heart attack and death with FDA-approved testosterone products. www.fda.gov/drugs/drugsafety/ucm383904.htm. Published January 31, 2014. Updated June 20, 2014. Accessed October 9, 2014.
- Cleveland Clinic. Diseases & conditions. Sexual dysfunction and disease. http://my.clevelandclinic.org/health/diseases_conditions/hic_An_Overview_of_Sexual_Dysfunction/hic_Sexual_Dysfunction_and_Disease. Published January 10, 2007. Accessed October 9, 2014.