- Email: [email protected]
RE: THE OVERACTIVE BLADDER IN CHILDHOOD: LONG-TERM RESULTS WITH CONSERVATIVE MANAGEMENT
0022-5347/00/1644-1318/0 THE JOURNAL OF UROLOGY® Copyright © 2000 by AMERICAN UROLOGICAL ASSOCIATION, INC.®
Vol. 164, 1318 –1323, October 2000 Printed in U.S.A.
Letters to the Editor RE: RETROGRADE URETEROPYELOSCOPY FOR LOWER POLE CALICEAL CALCULI M. Grasso and M. Ficazzola J Urol, 162: 1904 –1908, 1999 To the Editor. The authors confirm that retrograde ureteropyeloscopy is a safe and effective treatment for lower caliceal calculi, and their results are impressive. The number of endoscopic failures, secondary to the inability to access the lower pole, was 9% (8 of 90 stone burdens). Of these patients 2 had infundibular strictures, while the reasons for access failure in the remainder are unclear. The authors defined an infundibulopelvic angle of less than 45 degrees as acute. Of patients with an acute infundibulopelvic angle 17% were unable to clear the stone burden. However, in our series an acute infundibulopelvic angle, which we defined as less than 25 degrees, was highly statistically significant in predicting failure of access to the lower pole (p ⬍0.0005).1 Mean infundibulopelvic angle in the group in which access was accomplished was 53 degrees (range 33 to 85) versus 16 degrees (range 8 to 25) in the group with failure. Mean lower pole infundibular length in the accessible group was 3.1 cm. versus 3.2 cm. in the nonaccessible group. While we accept that a long (greater than 3 cm.) lower pole infundibulum may be a statistically significant predictor of failure in patients whose lower pole has been accessed, we consider an infundibulopelvic angle of less than 25 degrees to be a more significant factor in predicting the feasibility of access to the lower pole. Hence, we recommend measurement of the infundibulopelvic angle before flexible ureterorenoscopy in patients with lower caliceal stones. Respectfully, P. V. S. Kumar, F. X. Keeley, Jr. and A. G. Timoney Bristol Urological Institute and Southmead Hospital Westbury-on-Trymm Bristol, United Kingdom BS10 5NB 1. Kumar, P. V. S., Joshi, H. B., Keeley, F. X. et al: An acute infundibulopelvic angle: a contraindication to flexible ureterorenoscopy for lower pole stones. J Endourol, suppl., 13: 43A, 1999
RE: TRANSURETEROURETEROSTOMY IN CHILDHOOD AND ADOLESCENCE: LONG-TERM RESULTS IN 69 CASES P.-Y. Mure, P. Mollard and P. Mouriquand J Urol, 163: 946 –948, 2000 To the Editor. The authors presented impressive results indicating the usefulness of transureteroureterostomy in the management of pediatric urological conditions. Not mentioned in the article is the possibility of performing transureteroureterostomy as an extraperitoneal procedure, while undertaking totally extraperitoneal transureteroureterostomy and ureterocystoplasty. We presented our experience with creating an anastomosis between the 2 ureters outside the peritoneum.1 We subsequently performed 5 such procedures including use of a left duplex system. Our results for transureteroureterostomy are similar to those reported by the authors. This new extraperitoneal variation should encourage pediatric urologists to use transureteroureterostomy selectively. Respectfully, Paddy Dewan Department of General Surgery Royal Children’s Hospital Parkville, Victoria Australia
Reply by Authors. Although an extraperitoneal transureteroureterostomy is technically possible, it has limited indications for our group of patients as most of them required a transperitoneal approach for associated procedures, which included mostly bladder augmentation and Mitrofanoff continent diversions.
RE: THE OVERACTIVE BLADDER IN CHILDHOOD: LONGTERM RESULTS WITH CONSERVATIVE MANAGEMENT M. J. Curran, M. Kaefer, C. Peters, E. Logigian and S. B. Bauer J Urol, 163: 574 –577, 2000 To the Editor. The authors may leave less experienced practitioners with unclear concepts about bladder disorders in children. The accompanying editorial comment is helpful but falls short of making practical recommendations. The first source of confusion is semantic. I believe that the terms enuresis and daytime incontinence should be used specifically. Although many children with daytime wetting have nocturnal enuresis, the term enuresis should be reserved for those with monosymptomatic nocturnal enuresis without daytime symptoms. Secondly, the definition of refractory is also highly questionable. How can a symptom be called refractory when the common treatment, in this case anticholinergic medication, has not been tried? The main problem with the study is that the characteristics of the children included indicated invasive urodynamic testing, which is traumatic by the admission of the authors. Is that testing necessary? For many years I evaluated children with daytime incontinence with or without nocturnal wetting and without a history of urinary tract infections in a minimally invasive way. A pediatric urologist should be capable of performing an adequate neurological examination without systematic referral to a pediatric neurologist. After the urine is examined, a second voiding is used to determine urine flow and post-void residual on ultrasound. In the setting of a normal examination, no history of infection, an uninterrupted flow pattern with a bell-shaped curve and little or no residual urine, there is no need to suspect detrusor-sphincter dyssynergia or an occult neurological disorder. There is also no need for invasive urodynamics or further neurological investigations. Instead the parents should be educated about the nature of bladder instability and the child should be given a trial of anticholinergic medication, starting at low doses. In those with a good response to the medication (about 70%) the diagnosis and therapy are obvious. I believe that to perform invasive urodynamics in these children is unnecessary and potentially harmful.1 I recommend that urologists obtain detailed histories, perform good examinations and make use of noninvasive tests, such as flow studies and ultrasonic residual volumes, and reserve more invasive examinations for those children with staccato flows, incomplete bladder emptying, history of recurrent infections or other physical findings suggestive of underlying problems. By following this protocol few neurologically intact children will require invasive urodynamics. Respectfully, Ricardo Gonza´lez Department of Pediatric Urology University of Miami Miami, Florida 33101 1. Fernandes, E., Vernier, R. and Gonza´lez, R.: The unstable bladder in children. J Pediatr, 118: 831, 1991
Reply by Authors. We agree that “enuresis should be reserved for patients with monosymptomatic nocturnal enuresis without daytime 1. Dewan, P. A. and Condron, S. K.: Extraperitoneal ureterocysto- symptoms.” This is a matter of semantics and we should have made plasty with transureteroureterostomy. Urology, 53: 634, 1999 this differentiation in the text. With regard to our definition of 1318
1319
LETTERS TO THE EDITOR refractory, we stated that these children had been on anticholinergic or antispasmodic medications before undergoing urodynamic testing. In addition, we reiterated that point in the results by stating, “A total of 18 children had previously been treated medically and 7 required additional medication in the regimen during treatment.” Thus, the majority of these patients were truly refractory for their daytime symptoms. We agree that the term “refractory” is highly questionable when referring to the nocturnal enuresis portion of the symptom complex only. Because the patients had refractory daytime symptoms we performed urodynamic studies and not because of the nighttime symptoms only. We completely agree that urodynamic testing is not needed in the overwhelming majority of patients who have nighttime or even night and daytime symptoms unless medical therapy has failed.
RE: ANDROPAUSE: A MISNOMER FOR A TRUE CLINICAL ENTITY A. Morales, J. P. W. Heaton and C. C. Carson, III
Clearly, more research is needed to establish the definition of andropause. Much research has been conducted on female menopause and much needs be done in understanding andropause, especially regarding hormone replacement for men. Some of the symptoms related to andropause can be easily reversed with testosterone replacement.3 Respectfully, Robert Tan Geriatrics Section Department of Family Practice University of Texas Houston, Texas 77030 1. Tan, R. S., and Philip, P. S.: Perceptions of and risk factors for andropause. Arch Androl, 43: 97, 1999 2. Vermuelen, A.: Environment, human reproduction, menopause and andropause. Environ Health Perspect, suppl., 101: 91, 1993 3. Tan, R. S. and Bransgrove, L.: Testosterone replacement therapy. What is its potential in elderly men? Postgrad Med, 103: 249, 1998
J Urol, 163: 705–712, 2000 To the Editor. Given the likely multifactorial etiology of this clinical entity, including but not limited to, multiple endocrine changes, androgen decline in the aging male (ADAM) remains a confusing misnomer. If an acronym is essential then perhaps changing hormones in the aging man (CHAM) would be more accurate, since not all hormones decline, for example insulin often increases in production but is relatively ineffective. My primary disappointment was that the recommendations did not address the frequent clinical dilemma of the man in his 40s or 50s with somewhat low free testosterone but normal luteinizing and follicle-stimulating hormones. The algorithm states in that situation to investigate the hypothalamus and pituitary but we simply cannot afford to do so in all of these men, especially without any evidence of the frequency of hypothalamic or pituitary disease as opposed to idiopathic blunting of the response. Of course, when the luteinizing hormone is low, the investigations are mandatory but our growing clinical experience and the literature1 suggest that a normal luteinizing hormone response to subnormal free testosterone is common in this age group. Respectfully, Rosemary Basson Departments of Psychiatry, and Obstetrics and Gynecology Vancouver Hospital and Health Sciences Center Echelon Building 855 West 12th Ave. Vancouver, British Columbia, Canada V5Z 1M9 1. Korenman, S. G., Morley, J. E., Mooradian, A. D. et al: Secondary hypogonadism in older men: its relation to impotence. J Clin Endocrinol Metabol, 71: 963, 1990
To the Editor. To an extent I agree that andropause is a true misnomer and that ADAM is clinically more appropriate terminology, especially because of the gradual decline in the hormonal status in males rather than the sharp decline in females at the time of menopause. ADAM is also associated with a decrease of other hormones besides testosterone, and a direct causality between manifestation and alteration of specific hormones has not been fully established. Our research reveals that not all men undergo male menopause to the same degree or extent. In a study of 302 older men who described changes of andropause 46% had erectile dysfunction, 41% weakness and 36% memory loss.1 The age of onset of andropause is also variable with men presenting between ages 51 and 60 years, followed by those 61 to 70 years old. This entity seems to develop in some men more than others. The authors report that ADAM is unpredictable, and its manifestations subtle and variable. However, smokers are more likely than nonsmokers to report symptoms related to andropause.1 Multivariate analysis revealed that smoking more than 10 cigarettes a day was independently associated with an earlier onset of andropause (odds ratio 2.5, confidence interval 1.2 to 5.3, p ⫽ 0.01). Nicotine can have a negative effect on the gonadotropin releasing hormone pulse generator, thereby affecting the hormonal mileu.2
RE: CHRONIC TREATMENT WITH FINASTERIDE DAILY DOES NOT AFFECT SPERMATOGENESIS OR SEMEN PRODUCTION IN YOUNG MEN J. W. Overstreet, V. L. Fuh, J. Gould, S. S. Howards, M. M. Lieber, W. Hellstrom, S. Shapiro, P. Carroll, R. S. Corfman, S. Petrou, R. Lewis, P. Toth, T. Shown, J. Roy, J. P. Jarow, J. Bonilla, C. A. Jacobsen, D. Z. Wang and K. D. Kaufman J Urol, 162: 1295–1300, 1999 To the Editor. The conclusion of the authors minimizes the effect of 1 mg. finasteride on semen production. In this study ejaculate volume was analyzed in a placebo controlled trial for daily finasteride use (1 mg. formulation only) in young men. The authors state, “For assessing ejaculatory volume a 10% equivalency criterion based on the 90% confidence interval (CI) around the difference between treatment effects was prespecified.” The results indicated that at the end of the 48-week treatment period the 90% CI for the difference between 1 mg. finasteride and placebo groups with respect to the median percent reduction in ejaculate volume was ⫺10.4% to 13.1%. However, the authors suggest that chronic treatment with finasteride daily does not affect semen production in young men, based on the fact that a comparison of this reduction between the finasteride and placebo treatment groups did not reach statistical significance (p ⫽ 0.915). Concluding equivalence based on observing a nonsignificant test result is inappropriate.1 In equivalence studies “statistical analysis should be based on the use of CIs. Equivalence is inferred when the entire CI falls within the equivalence margins.”1 In this study the 90% CI for the difference between treatment groups falls outside the prespecified equivalence margin of ⫾10%. Thus, the findings do not support equivalence between 1 mg. finasteride and placebo in terms of reduction of ejaculate volume. Also, to estimate equivalence a 95% CI is commonly used, which would be even wider than the reported 90% CI of ⫺10.4% to 13.1%. To calculate the power of the study with respect to ejaculate volume reduction, it is necessary to know the number of patients having such measurements at the end of treatment. This information is not available in the article, although table 1 shows that at baseline 1 mg. finasteride and placebo groups included 40 and 39 patients, respectively. A rough estimate suggests that assuming a significance level of 5%, the study had approximately 30% to 35% power to detect a difference of 10% between treatments for ejaculate volume change. Thus, if there was an actual difference of 10%, then there is a 65% to 70% probability that this difference would not be detected, because of sample size inadequacy. Therefore, it is premature for the authors to imply that finasteride products, when given daily, would not affect semen production. The proper conclusion should be, “As the 90% CI falls outside the prespecified equivalence margin of plus or minus 10%, the study does not support or exclude equivalence between 1 mg. finasteride and placebo for changes in ejaculate volume.” The views in this letter are solely those of the
Vol. 164, 1318 –1323, October 2000 Printed in U.S.A.
Letters to the Editor RE: RETROGRADE URETEROPYELOSCOPY FOR LOWER POLE CALICEAL CALCULI M. Grasso and M. Ficazzola J Urol, 162: 1904 –1908, 1999 To the Editor. The authors confirm that retrograde ureteropyeloscopy is a safe and effective treatment for lower caliceal calculi, and their results are impressive. The number of endoscopic failures, secondary to the inability to access the lower pole, was 9% (8 of 90 stone burdens). Of these patients 2 had infundibular strictures, while the reasons for access failure in the remainder are unclear. The authors defined an infundibulopelvic angle of less than 45 degrees as acute. Of patients with an acute infundibulopelvic angle 17% were unable to clear the stone burden. However, in our series an acute infundibulopelvic angle, which we defined as less than 25 degrees, was highly statistically significant in predicting failure of access to the lower pole (p ⬍0.0005).1 Mean infundibulopelvic angle in the group in which access was accomplished was 53 degrees (range 33 to 85) versus 16 degrees (range 8 to 25) in the group with failure. Mean lower pole infundibular length in the accessible group was 3.1 cm. versus 3.2 cm. in the nonaccessible group. While we accept that a long (greater than 3 cm.) lower pole infundibulum may be a statistically significant predictor of failure in patients whose lower pole has been accessed, we consider an infundibulopelvic angle of less than 25 degrees to be a more significant factor in predicting the feasibility of access to the lower pole. Hence, we recommend measurement of the infundibulopelvic angle before flexible ureterorenoscopy in patients with lower caliceal stones. Respectfully, P. V. S. Kumar, F. X. Keeley, Jr. and A. G. Timoney Bristol Urological Institute and Southmead Hospital Westbury-on-Trymm Bristol, United Kingdom BS10 5NB 1. Kumar, P. V. S., Joshi, H. B., Keeley, F. X. et al: An acute infundibulopelvic angle: a contraindication to flexible ureterorenoscopy for lower pole stones. J Endourol, suppl., 13: 43A, 1999
RE: TRANSURETEROURETEROSTOMY IN CHILDHOOD AND ADOLESCENCE: LONG-TERM RESULTS IN 69 CASES P.-Y. Mure, P. Mollard and P. Mouriquand J Urol, 163: 946 –948, 2000 To the Editor. The authors presented impressive results indicating the usefulness of transureteroureterostomy in the management of pediatric urological conditions. Not mentioned in the article is the possibility of performing transureteroureterostomy as an extraperitoneal procedure, while undertaking totally extraperitoneal transureteroureterostomy and ureterocystoplasty. We presented our experience with creating an anastomosis between the 2 ureters outside the peritoneum.1 We subsequently performed 5 such procedures including use of a left duplex system. Our results for transureteroureterostomy are similar to those reported by the authors. This new extraperitoneal variation should encourage pediatric urologists to use transureteroureterostomy selectively. Respectfully, Paddy Dewan Department of General Surgery Royal Children’s Hospital Parkville, Victoria Australia
Reply by Authors. Although an extraperitoneal transureteroureterostomy is technically possible, it has limited indications for our group of patients as most of them required a transperitoneal approach for associated procedures, which included mostly bladder augmentation and Mitrofanoff continent diversions.
RE: THE OVERACTIVE BLADDER IN CHILDHOOD: LONGTERM RESULTS WITH CONSERVATIVE MANAGEMENT M. J. Curran, M. Kaefer, C. Peters, E. Logigian and S. B. Bauer J Urol, 163: 574 –577, 2000 To the Editor. The authors may leave less experienced practitioners with unclear concepts about bladder disorders in children. The accompanying editorial comment is helpful but falls short of making practical recommendations. The first source of confusion is semantic. I believe that the terms enuresis and daytime incontinence should be used specifically. Although many children with daytime wetting have nocturnal enuresis, the term enuresis should be reserved for those with monosymptomatic nocturnal enuresis without daytime symptoms. Secondly, the definition of refractory is also highly questionable. How can a symptom be called refractory when the common treatment, in this case anticholinergic medication, has not been tried? The main problem with the study is that the characteristics of the children included indicated invasive urodynamic testing, which is traumatic by the admission of the authors. Is that testing necessary? For many years I evaluated children with daytime incontinence with or without nocturnal wetting and without a history of urinary tract infections in a minimally invasive way. A pediatric urologist should be capable of performing an adequate neurological examination without systematic referral to a pediatric neurologist. After the urine is examined, a second voiding is used to determine urine flow and post-void residual on ultrasound. In the setting of a normal examination, no history of infection, an uninterrupted flow pattern with a bell-shaped curve and little or no residual urine, there is no need to suspect detrusor-sphincter dyssynergia or an occult neurological disorder. There is also no need for invasive urodynamics or further neurological investigations. Instead the parents should be educated about the nature of bladder instability and the child should be given a trial of anticholinergic medication, starting at low doses. In those with a good response to the medication (about 70%) the diagnosis and therapy are obvious. I believe that to perform invasive urodynamics in these children is unnecessary and potentially harmful.1 I recommend that urologists obtain detailed histories, perform good examinations and make use of noninvasive tests, such as flow studies and ultrasonic residual volumes, and reserve more invasive examinations for those children with staccato flows, incomplete bladder emptying, history of recurrent infections or other physical findings suggestive of underlying problems. By following this protocol few neurologically intact children will require invasive urodynamics. Respectfully, Ricardo Gonza´lez Department of Pediatric Urology University of Miami Miami, Florida 33101 1. Fernandes, E., Vernier, R. and Gonza´lez, R.: The unstable bladder in children. J Pediatr, 118: 831, 1991
Reply by Authors. We agree that “enuresis should be reserved for patients with monosymptomatic nocturnal enuresis without daytime 1. Dewan, P. A. and Condron, S. K.: Extraperitoneal ureterocysto- symptoms.” This is a matter of semantics and we should have made plasty with transureteroureterostomy. Urology, 53: 634, 1999 this differentiation in the text. With regard to our definition of 1318
1319
LETTERS TO THE EDITOR refractory, we stated that these children had been on anticholinergic or antispasmodic medications before undergoing urodynamic testing. In addition, we reiterated that point in the results by stating, “A total of 18 children had previously been treated medically and 7 required additional medication in the regimen during treatment.” Thus, the majority of these patients were truly refractory for their daytime symptoms. We agree that the term “refractory” is highly questionable when referring to the nocturnal enuresis portion of the symptom complex only. Because the patients had refractory daytime symptoms we performed urodynamic studies and not because of the nighttime symptoms only. We completely agree that urodynamic testing is not needed in the overwhelming majority of patients who have nighttime or even night and daytime symptoms unless medical therapy has failed.
RE: ANDROPAUSE: A MISNOMER FOR A TRUE CLINICAL ENTITY A. Morales, J. P. W. Heaton and C. C. Carson, III
Clearly, more research is needed to establish the definition of andropause. Much research has been conducted on female menopause and much needs be done in understanding andropause, especially regarding hormone replacement for men. Some of the symptoms related to andropause can be easily reversed with testosterone replacement.3 Respectfully, Robert Tan Geriatrics Section Department of Family Practice University of Texas Houston, Texas 77030 1. Tan, R. S., and Philip, P. S.: Perceptions of and risk factors for andropause. Arch Androl, 43: 97, 1999 2. Vermuelen, A.: Environment, human reproduction, menopause and andropause. Environ Health Perspect, suppl., 101: 91, 1993 3. Tan, R. S. and Bransgrove, L.: Testosterone replacement therapy. What is its potential in elderly men? Postgrad Med, 103: 249, 1998
J Urol, 163: 705–712, 2000 To the Editor. Given the likely multifactorial etiology of this clinical entity, including but not limited to, multiple endocrine changes, androgen decline in the aging male (ADAM) remains a confusing misnomer. If an acronym is essential then perhaps changing hormones in the aging man (CHAM) would be more accurate, since not all hormones decline, for example insulin often increases in production but is relatively ineffective. My primary disappointment was that the recommendations did not address the frequent clinical dilemma of the man in his 40s or 50s with somewhat low free testosterone but normal luteinizing and follicle-stimulating hormones. The algorithm states in that situation to investigate the hypothalamus and pituitary but we simply cannot afford to do so in all of these men, especially without any evidence of the frequency of hypothalamic or pituitary disease as opposed to idiopathic blunting of the response. Of course, when the luteinizing hormone is low, the investigations are mandatory but our growing clinical experience and the literature1 suggest that a normal luteinizing hormone response to subnormal free testosterone is common in this age group. Respectfully, Rosemary Basson Departments of Psychiatry, and Obstetrics and Gynecology Vancouver Hospital and Health Sciences Center Echelon Building 855 West 12th Ave. Vancouver, British Columbia, Canada V5Z 1M9 1. Korenman, S. G., Morley, J. E., Mooradian, A. D. et al: Secondary hypogonadism in older men: its relation to impotence. J Clin Endocrinol Metabol, 71: 963, 1990
To the Editor. To an extent I agree that andropause is a true misnomer and that ADAM is clinically more appropriate terminology, especially because of the gradual decline in the hormonal status in males rather than the sharp decline in females at the time of menopause. ADAM is also associated with a decrease of other hormones besides testosterone, and a direct causality between manifestation and alteration of specific hormones has not been fully established. Our research reveals that not all men undergo male menopause to the same degree or extent. In a study of 302 older men who described changes of andropause 46% had erectile dysfunction, 41% weakness and 36% memory loss.1 The age of onset of andropause is also variable with men presenting between ages 51 and 60 years, followed by those 61 to 70 years old. This entity seems to develop in some men more than others. The authors report that ADAM is unpredictable, and its manifestations subtle and variable. However, smokers are more likely than nonsmokers to report symptoms related to andropause.1 Multivariate analysis revealed that smoking more than 10 cigarettes a day was independently associated with an earlier onset of andropause (odds ratio 2.5, confidence interval 1.2 to 5.3, p ⫽ 0.01). Nicotine can have a negative effect on the gonadotropin releasing hormone pulse generator, thereby affecting the hormonal mileu.2
RE: CHRONIC TREATMENT WITH FINASTERIDE DAILY DOES NOT AFFECT SPERMATOGENESIS OR SEMEN PRODUCTION IN YOUNG MEN J. W. Overstreet, V. L. Fuh, J. Gould, S. S. Howards, M. M. Lieber, W. Hellstrom, S. Shapiro, P. Carroll, R. S. Corfman, S. Petrou, R. Lewis, P. Toth, T. Shown, J. Roy, J. P. Jarow, J. Bonilla, C. A. Jacobsen, D. Z. Wang and K. D. Kaufman J Urol, 162: 1295–1300, 1999 To the Editor. The conclusion of the authors minimizes the effect of 1 mg. finasteride on semen production. In this study ejaculate volume was analyzed in a placebo controlled trial for daily finasteride use (1 mg. formulation only) in young men. The authors state, “For assessing ejaculatory volume a 10% equivalency criterion based on the 90% confidence interval (CI) around the difference between treatment effects was prespecified.” The results indicated that at the end of the 48-week treatment period the 90% CI for the difference between 1 mg. finasteride and placebo groups with respect to the median percent reduction in ejaculate volume was ⫺10.4% to 13.1%. However, the authors suggest that chronic treatment with finasteride daily does not affect semen production in young men, based on the fact that a comparison of this reduction between the finasteride and placebo treatment groups did not reach statistical significance (p ⫽ 0.915). Concluding equivalence based on observing a nonsignificant test result is inappropriate.1 In equivalence studies “statistical analysis should be based on the use of CIs. Equivalence is inferred when the entire CI falls within the equivalence margins.”1 In this study the 90% CI for the difference between treatment groups falls outside the prespecified equivalence margin of ⫾10%. Thus, the findings do not support equivalence between 1 mg. finasteride and placebo in terms of reduction of ejaculate volume. Also, to estimate equivalence a 95% CI is commonly used, which would be even wider than the reported 90% CI of ⫺10.4% to 13.1%. To calculate the power of the study with respect to ejaculate volume reduction, it is necessary to know the number of patients having such measurements at the end of treatment. This information is not available in the article, although table 1 shows that at baseline 1 mg. finasteride and placebo groups included 40 and 39 patients, respectively. A rough estimate suggests that assuming a significance level of 5%, the study had approximately 30% to 35% power to detect a difference of 10% between treatments for ejaculate volume change. Thus, if there was an actual difference of 10%, then there is a 65% to 70% probability that this difference would not be detected, because of sample size inadequacy. Therefore, it is premature for the authors to imply that finasteride products, when given daily, would not affect semen production. The proper conclusion should be, “As the 90% CI falls outside the prespecified equivalence margin of plus or minus 10%, the study does not support or exclude equivalence between 1 mg. finasteride and placebo for changes in ejaculate volume.” The views in this letter are solely those of the