

[3]
Buvat J, Maggi M, Guay A, Torres LO. Testosterone deficiency in men: systematic review and standard operating procedures for diagnosis and treatment. J Sex Med 2013;10:245–84.[4]
Millar AC, Lau AN, Tomlinson G, et al. Predicting low testosterone in aging men: a systematic review. CMAJ 2016;188:E321–30.[5]
Wu FC, Tajar A, Beynon JM, et al. Identification of late-onset hypo- gonadism in middle-aged and elderly men. N Engl J Med 2010;363: 123–35.[6]
Rastrelli G, Corona G, Tarocchi M, Mannucci E, Maggi M. How to define hypogonadism? Results from a population of men consulting for sexual dysfunction. J Endocrinol Invest 2016;39:473–84.[7]
Rastrelli G, Carter EL, Ahern T, et al. Development of and Recovery from secondary hypogonadism in aging men: prospective results from the EMAS. J Clin Endocrinol Metab 2015;100:3172–82.[8]
Corona G, Isidori AM, Buvat J, et al. Testosterone supplementation and sexual function: a meta-analysis study. J Sex Med 2014;11: 1577–92.[9]
Hedges LV, Olkin I. Statistical Methods for Meta-analysis. Orlando: Academic Press; 1985.[10]
Wilkinson L. Task Force on Statistical Inference. Statistical methods in psychology journals: guidelines and explanations. Am Psychol 1999;54:594–604.[11]
Isidori AM, Giannetta E, Gianfrilli D, et al. Effects of testosterone on sexual function in men: results of a meta-analysis. Clin Endocrinol (Oxf) 2005;63:381–94.[12]
Jain P, Rademaker AW, McVary KT. Testosterone supplementation for erectile dysfunction: results of a meta-analysis. J Urol 2000;164:371–5.
[13]
Bolon˜a ER, Uraga MV, Haddad RM, et al. Testosterone use in men with sexual dysfunction: a systematic review and meta-analysis of randomized placebo-controlled trials. Mayo Clin Proc 2007;82: 20–8.
[14]
Corona G, Rastrelli G, Vignozzi L, Maggi M. Emerging medication for the treatment of male hypogonadism. Expert Opin Emerg Drugs 2012;17:239–59.
[15]
Corona G, Maseroli E, Maggi M. Injectable testosterone undecano- ate for the treatment of hypogonadism. Expert Opin Pharmacother 2014;15:1903–26.[16]
Huo S, Scialli AR, McGarvey S, et al. Treatment of men for ‘‘low testosterone’’: a systematic review. PLoS One 2016;11:e0162480.
[17]
Rosen RC, Riley A, Wagner G, Osterloh IH, Kirkpatrick J, Mishra A. The international index of erectile function (IIEF): a multidimen- sional scale for assessment of erectile dysfunction. Urology 1997;49:822–30.
[18]
Rosen RC, Cappelleri JC, Smith MD, Lipsky J, Pen˜a BM. Development and evaluation of an abridged, 5-item version of the International Index of Erectile Function (IIEF-5) as a diagnostic tool for erectile dysfunction. Int J Impot Res 1999;11:319–26.
[19]
Cappelleri JC, Rosen RC, Smith MD, Mishra A, Osterloh IH. Diagnos- tic evaluation of the erectile function domain of the International Index of Erectile Function. Urology 1999;54:346–51.[20]
Corona G, Jannini EA, Maggi M. Inventories for male and female sexual dysfunctions. Int J Impot Res 2006;18:236–50.
[21]
Rosen RC, Allen KR, Ni X, Araujo AB. Minimal clinically important differences in the erectile function domain of the International Index of Erectile Function scale. Eur Urol 2011;60:1010–6.
[22] Higgins JPT, Green S. Cochrane Handbook for Systematic Reviews
of Interventions. Version 5.0.1 [updated September 2008]. The
Cochrane Collaboration.
2008.
Available from:
www. cochrane-handbook.org .[23]
Cohen J. Statistical Power Analysis for the Behavioral Sciences. New York: Academic Press; 1977.
[24]
Cavallini G, Caracciolo S, Vitali G, Modenini F, Biagiotti G. Carnitine versus androgen administration in the treatment of sexual dys- function, depressed mood, and fatigue associated with male aging. Urology 2004;63:641–6.
[25]
Svartberg J, Aasebø U, Hjalmarsen A, Sundsfjord J, Jorde R. Testos- terone treatment improves body composition and sexual function inmen with COPD, in a 6-month randomized controlled trial. Respir Med 2004;98:906–13.[26]
Chiang HS, Hwang TI, Hsui YS, et al. Transdermal testosterone gel increases serum testosterone levels in hypogonadal men in Taiwan withimprovementsin sexualfunction.IntJImpotRes 2007;19:411–7.
[27]
Allan CA, Forbes EA, Strauss BJ, McLachlan RI. Testosterone therapy increases sexual desire in ageing men with low-normal testoster- one levels and symptoms of androgen deficiency. Int J Impot Res 2008;20:396–401.
[28]
Chiang HS, Cho SL, Lin YC, Hwang TI. Testosterone gel monotherapy improves sexual function of hypogonadal men mainly through re- storing erection: evaluation by IIEF score. Urology 2009;73:762–6.
[29]
Giltay EJ, Tishova YA, Mskhalaya GJ, Gooren LJ, Saad F, Kalinchenko SY. Effects of testosterone supplementation on depressive symp- toms and sexual dysfunction in hypogonadal men with the meta- bolic syndrome. J Sex Med 2010;7:2572–82.[30]
Aversa A, Bruzziches R, Francomano D, Spera G, Lenzi A. Efficacy and safety of two different testosterone undecanoate formulations in hypogonadal men with metabolic syndrome. J Endocrinol Invest 2010;33:776–83.
[31]
Jones TH, Arver S, Behre HM, et al. Testosterone replacement in hypogonadal men with type 2 diabetes and/or metabolic syndrome (the TIMES2 study). Diabetes Care 2011;34:828–37.
[32]
Hackett G, Cole N, Bhartia M, Kennedy D, Raju J, Wilkinson P. Testosterone replacement therapy with long-acting testosterone undecanoate improves sexual function and quality-of-life param- eters vs. placebo in a population of men with type 2 diabetes. J Sex Med 2013;10:1612–27.
[33]
Gianatti EJ, Dupuis P, Hoermann R, Zajac JD, Grossmann M. Effect of testosterone treatment on constitutional and sexual symptoms in men with type 2 diabetes in a randomized, placebo-controlled clinical trial. J Clin Endocrinol Metab 2014;99:3821–8.
[34]
Basaria S, Harman SM, Travison TG, et al. Effects of testosterone administration for 3 years on subclinical atherosclerosis progres- sion in older men with low or low-normal testosterone levels: a randomized clinical trial. JAMA 2015;314:570–81.
[35]
Paduch DA, Polzer PK, Ni X, Basaria S. Testosterone replacement in androgen-deficient men with ejaculatory dysfunction: a random- ized controlled trial. J Clin Endocrinol Metab 2015;100:2956–62.
[36]
Brock G, Heiselman D, Knorr J, Ni X, Kinchen K. 9-Month efficacy and safety study of testosterone solution 2% for sex drive and energy in hypogonadal men. J Urol 2016;196:1509–15.
[37]
Snyder PJ, Ellenberg SS, Farrar JT. Testosterone treatment in older men. N Engl J Med 2016;375:90.
[38]
Tsertsvadze A, Fink HA, Yazdi F, et al. Oral phosphodiesterase-5 inhibitors and hormonal treatments for erectile dysfunction: a systematic review and meta-analysis. Ann Intern Med 2009;151: 650–61.
[39]
DerSimonian R, Laird N. Meta-analysis in clinical trials. Control Clin Trials 1986;7:177–88.
[40]
Cornell JE, Mulrow CD, Localio R, et al. Random-effects meta- analysis of inconsistent effects: a time for change. Ann Intern Med 2014;160:267–70.[41]
Novianti PW, Roes KCB, van der Tweel I. Estimation of between-trial variance in sequential meta-analyses: a simulation study. Contemp Clin Trials 2014;37:129–38.
[42]
Hatzimouratidis K, Salonia A, Adaikan G, et al. Pharmacotherapy for erectile dysfunction: recommendations from the FourthE U R O P E A N U R O L O G Y 7 2 ( 2 0 1 7 ) 1 0 0 0 – 1 0 1 1
1010