Psychological Impact of Erectile Dysfunction: Validation of a New Health Related Quality of Life Measure for Patients With Erectile Dysfunction

0022-5347/02/1685-2086/0 THE JOURNAL OF UROLOGY® Copyright © 2002 by AMERICAN UROLOGICAL ASSOCIATION, INC.®

Vol. 168, 2086 –2091, November 2002 Printed in U.S.A.

DOI: 10.1097/01.ju.0000034365.57110.b7

PSYCHOLOGICAL IMPACT OF ERECTILE DYSFUNCTION: VALIDATION OF A NEW HEALTH RELATED QUALITY OF LIFE MEASURE FOR PATIENTS WITH ERECTILE DYSFUNCTION DAVID M. LATINI,* DAVID F. PENSON,† HILARY H. COLWELL, DEBORAH P. LUBECK,* SHILPA S. MEHTA,* JAMES M. HENNING* AND TOM F. LUE‡ From the Department of Urology and Urology Outcomes Research Group, University of California, San Francisco, San Francisco, California, Departments of Urology, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington, and TAP Pharmaceutical Products, Lake Forest, Illinois

ABSTRACT

Purpose: Male erectile dysfunction has a substantial impact on health related quality of life. We examined the psychometric properties of 2 new scales created to measure the psychological impact of erectile dysfunction. Materials and Methods: Patients enrolled in a long-term study of men with erectile dysfunction completed clinical and health related quality of life information at baseline and at 3 followup points. The questionnaire incorporated a number of standard scales of psychosocial characteristics as well as questions developed from comments made during focus groups of men with erectile dysfunction and of their female partners. Principal components analysis was used to identify underlying constructs in response to the new questions. Results: A total of 168 men completed the baseline quality of life questionnaire. The principal components analysis of the psychological impact of erectile dysfunction questions resulted in 2 new scales. Reliability was good with an internal consistency reliability of 0.91 for scale 1 and 0.72 for scale 2. Test-retest reliability was 0.76 and 0.66, respectively. Men reporting a greater psychological impact of erectile dysfunction also reported greater impairment in functional status, lower sexual self-efficacy, greater depression and anxiety at the last intercourse. Each new scale significantly differentiated men with mild/moderate versus severe erectile dysfunction. Conclusions: We developed 2 new scales to measure the psychological impact of erectile dysfunction and they showed good reliability and validity. These new scales, named the Psychological Impact of Erectile Dysfunction instrument, comprehensively capture the psychological effect of erectile dysfunction on health related quality of life, which is not adequately assessed by existing patient centered measures of erectile function. KEY WORDS: penis; impotence; questionnaires; quality of life; psychology, medical

Erectile dysfunction has substantial impact on male quality of life. In addition to the impact on the sexual experience, in many men erectile dysfunction creates psychological distress that affects their relationships with family and friends.1 In a study of a general measure of health related quality of life men with erectile dysfunction reported significantly worse results than normal respondents on measures of social function, role limitations due to emotional problems and emotional well-being.2 In another study men with erectile dysfunction reported significantly lower physical and emotional satisfaction, and lower general happiness than men in the study without the condition.3 Unfortunately few available validated and reliable instruments specifically measure the effect of erectile dysfunction on health related quality of life. Most patient administered questionnaires used for erectile dysfunction are measures of symptoms and functional status or general psychological

functioning.4 While these types of measures provide useful information, they do not capture the wide impact of erectile dysfunction on health related quality of life. Qualitative research in men with the disease showed that an array of emotional consequences of erectile dysfunction are not assessed by current measures. Men with erectile dysfunction have substantial damage to their self-image as males and as sexual beings. They also report that erectile dysfunction impacts not only the emotional intimacy of their primary relationship, but also daily interactions with women or other potential partners.5, 6 To date only 2 instruments have specifically attempted to assess the psychological effect of erectile dysfunction on health related quality of life, namely the Quality of Life-Male Erectile Dysfunction and Erectile Dysfunction Effect on Quality of Life.7 Each has similar limitations. The most important limitation is that they provide a single score rather than separate scores for subscales that measure the different types of psychological impact of erectile dysfunction. In addition, 2 instruments word questions in the negative, which assumes that erectile dysfunction is a problem in the respondent and may bias results. We developed a quality of life instrument that adequately assesses the impact of erectile dysfunction on health related quality of life, including subscales that measure different facets of the psychological consequences of the condition. This instrument, called the Psychological Impact of Erectile

Accepted for publication June 7, 2002. Supported in part by TAP Pharmaceutical Products and Veterans Affairs Puget Sound Health Care System, Seattle, Washington. * Financial interest and/or other relationship with TAP Pharmaceutical Products. † Financial interest and/or other relationship with Pfizer, Boehringer Ingelheim, Astra Zeneca and TAP Pharmaceutical Products. ‡ Financial interest and/or other relationship with Bayer, Lilly, ICOS, Pfizer, Pharmacia, TAP Pharmaceutical Products and Upjohn. 2086

PSYCHOLOGICAL IMPACT OF ERECTILE DYSFUNCTION

Dysfunction (PIED), was developed as part of a larger longitudinal study of quality of life in men with erectile dysfunction (see Appendix). We describe the process of item selection, data analysis and validation of the new scales. METHODS

The Exploratory Comprehensive Evaluation of Erectile Dysfunction study. The Exploratory Comprehensive Evaluation of Erectile Dysfunction data base is a longitudinal, observational data base of prospectively collected data on outcomes in men with erectile dysfunction. Participants were followed prospectively for 12 months. Participants: The study enrolled 207 men at 5 North American academic medical centers and 1 Veterans Administration medical center. Participants were men who were diagnosed with primary or secondary erectile dysfunction, able to speak and read English and had no sexual partners younger than age 18 years. Patients fulfilling study criteria were contacted by the participating physician and asked to participate voluntarily in the study. Participants received financial remuneration for participating in the study. The human subjects review board at each of the 6 study sites approved the study procedures. Data Collection: Data were collected at a baseline visit and at 3 followup points 3, 6 and 12 months after enrollment, respectively. The baseline assessment done by the study physician included physical examination, erectile dysfunction, medical and surgical history, body systems review and relevant laboratory tests. Depending on the erectile dysfunction and medical history participants received treatment for erectile dysfunction (85%) or were scheduled for further assessment after completing the baseline clinical information with the physician. After the baseline clinical assessment the participant was asked to complete a health related quality of life questionnaire. The questionnaire included disease specific measures of health related quality of life, including the ejaculation domain of the Brief Male Sexual Function Inventory,8 Sexual Self-Efficacy Scale9 and International Index of Erectile Function (IIEF).10 The questionnaire also included standard measures of depression (Beck Depression Inventory-Short Form11) and anxiety (State-Trait Anxiety-Short Form12). A set of experimental questions was developed to address the psychological aspects of erectile dysfunction based on comments made by patients with this disease and their partners who participated in focus group discussions. These questions were the basis of the PIED instrument described. Followup health related quality of life questionnaires were completed 3, 6 and 12 months after enrollment, and returned by mail to the coordinating center for data entry. Followup data collection instruments included the same health related quality of life questions as at baseline with the addition of questions on health resource use within the study period irrespective of whether it was related to erectile dysfunction. If participants revisited the urologist or used any other medical services during the study period, relevant data from the clinical visit was collected from the site. Development of PIED scales. Item Identification: A study staff member conducted 2 focus groups with 16 men with erectile dysfunction recruited at 2 urology clinics as well as a focus group of 9 women whose partners had erectile dysfunction, including some participants in the male focus groups. Semistructured group interviews explored the impact of erectile dysfunction on self-confidence, sexual satisfaction and marital quality among other quality of life domains. Items were constructed from comments made by focus group participants using the same wording when possible. Data Collection: Responses to the experimental set of questions were collected along with other health related quality of life data at baseline, 3, 6 and 12 months, including 24 statements that related to how erectile dysfunction may have

2087

impacted participants psychologically. Each statement had 5 possible responses with a score of 4 to 0, namely 4 —all of the time, 3—most of the time, 2—some of the time, 1—a little of the time and 0 —none of the time. Participants were asked to indicate how often in the 4 weeks before questionnaire completion their emotions were described by each statement. Data Analysis: Principal components analysis was done to identify sets of items that were related to each other and described different dimensions of the psychological impact of erectile dysfunction. All 24 statements underwent the first principal components analysis. Items that loaded at least 0.5 on the first component were further analyzed to determine the internal reliability of the items as a possible scale. Items were removed from the potential scale when they detracted from the internal reliability of the scale. Items that were not retained on the first scale were then submitted to a second principal components analysis and the resulting scale was pruned as described. This process was repeated until no further scales with adequate internal reliability could be identified. Scales were created by summing items that loaded on a particular component. Scale scores were created if at least 80% of the items loading on that scale were completed by a respondent. For respondents who had at least 80% of the items completed but were still missing some items a value for the missing items was imputed using the mean score for the nonmissing items on that scale. After the items were summed the scale scores were transformed into T scores (mean plus or minus SD 50 ⫾ 10). Psychometric Analysis: Reliability (accuracy of measurement) was determined by examining the internal consistency of the new scales with Cronbach’s coefficient ␣.13 Coefficient ␣ scores are between 0 and 1 with 0.7 usually used as the minimum desirable score.14 Another type of reliability relates to the stability of scores for the same person tested at different time points, known as test-retest reliability.15 The shortest interval available for calculating the testretest correlation in this study was 3 months, which was longer than in many health related quality of life studies but still provided useful information about the stability of scores with time. The intraclass correlation coefficient is 0 to 1 with a coefficient of at least 0.5 most desirable. Validity or evidence to confirm the conclusions drawn from the instrument also has more than 1 component. Discriminant validity refers to the relationship of scale scores and some other characteristic on which respondents are known to differ.16 It was hypothesized that PIED scores would be positively associated with patient perceived disease severity (mild, moderate or severe), meaning that men reporting more severe erectile dysfunction would also report greater psychological impairment. It was also hypothesized that PIED scores would be negatively associated with sexual self-efficacy, overall sexual satisfaction (IIEF) and intercourse satisfaction (IIEF). Convergent validity refers to the hypothesized relationship of scale scores and other measures shown to be related in previous research. Based on earlier research on erectile dysfunction it was hypothesized that PIED scores would correlate more highly with depression and anxiety at the last intercourse. Variability refers to the extent to which the full range of item responses and scale scores are reported in the data. Optimal variability suggests patient responses at each end of the scale as well as the middle. Scales that are skewed positively or negatively tend to be less responsive to changes in therapy or disease progression.17 Descriptive statistics on the new scales were calculated and response variability was examined. RESULTS

Sample characteristics. A total of 168 men completed the baseline health related quality of life questionnaire. Participants

2088

PSYCHOLOGICAL IMPACT OF ERECTILE DYSFUNCTION

were categorized with mild, moderate or severe erectile dysfunction based on the baseline self-report. For analysis purposes the small number of men with mild or moderate erectile dysfunction were combined into 1 group and comparisons were made of the 55 with mild/moderate and the 113 with severe disease. Participants were primarily middle-aged, white and well educated with a mean age of 57.4 years and 74% were married. No significant differences were observed in men with mild/moderate and severe erectile dysfunction except for the level of education. Men with severe erectile dysfunction reported significantly higher levels of education (chi-square test 13, 5 df, p ⬍0.05). Most participants reported that erectile dysfunction was severe (67%), more than 1 year in duration (69%) and always present (84%) (table 1). Not surprisingly those with more severe disease were significantly more likely to report that disease was always present (chi-square test 28.2, 2 df, p ⬍0.0001). Many participants reported previous treatment for erectile dysfunction, primarily oral therapy (52%) such as sildenafil citrate. Scale construction. Data on all 168 men with health related quality of life data at baseline were used in the principal components analysis. The majority of the items loaded on 1 component that accounted for 33.9% of the variance. Internal consistency of the items loading on the first component was examined by calculating item intercorrelations and the Cronbach coefficient ␣. Items less closely related to the larger group of items were discarded, which resulted in an 11 item scale with a coefficient ␣ of 0.91 describing the psychological impact of erectile dysfunction on the sexual experience. Higher scores represented a greater negative impact on the patient sexual relationship. All items not loading on the sexual experience component were included in second principal components analysis. The first component accounted for 21% of the variance and included 5 items. The Cronbach coefficient ␣ for the scale was 0.72 and the items had adequate intercorrelations. The scale score of these 5 items was calculated per patient with higher scores reflecting a greater negative impact on patient emoTABLE 1. Clinical characteristics of patients at baseline Characteristic

tional life. Although some remaining items appeared conceptually similar, further examination of the remainder yielded no interpretable components with acceptable internal consistency. Variability. To examine the variability of PIED scales in this sample we calculated the descriptive statistics for the raw nonstandardized scores on each scale (table 2). Scores were fairly well distributed. No obvious skewness in response was detected. Reliability. The reliability of the 2 new scales was evaluated by calculating the Cronbach coefficient ␣ for each scale using data from all men at baseline and by calculating testretest reliability in a subsample of 144 men with data available at baseline and 3-month followup. The 2 new scales performed well. For the impact of erectile dysfunction on the sexual experience test-retest reliability was 0.76. For the impact of erectile dysfunction on emotional life reliability was 0.66. Validity. To examine the validity of PIED measures we calculated the correlations of PIED scores with measures of disease specific health related quality of life and psychological characteristics that have been shown in the literature to be related to erectile dysfunction (table 3). Correlations were in the expected direction. PIED scales, on which higher scores indicate a greater negative impact of erectile dysfunction, significantly correlated negatively (⫺0.23 to ⫺0.61) with all 7 disease specific measures of health related quality of life, on which higher scores indicate more positive functioning. On the 2 measures of psychological functioning that were shown to be related to erectile dysfunction in past research PIED scores correlated positively, indicating that men reporting a greater psychological impact of erectile dysfunction also reported more depression and more anxiety at the last intercourse. We hypothesized that PIED scale scores should differ significantly in men who reported mild or moderate and more severe erectile dysfunction. That hypothesis was supported (table 4). Significant differences were noted on each PIED scale. Scores were in the expected direction with significantly higher scores in men reporting severe erectile dysfunction, indicating more negative psychological impact of the disease on sexual experiences and emotional life.

Overall Mild/Moderate Severe

No. pts. 168 No. erectile dysfunction onset (%): New (within last 3 mos.) 9 (5) Recently (greater than 3 mos. ago 43 (26) but less than 1 yr.) Long standing (greater than 1 yr.) 112 (67) Problematic since first sexual ac4 (2) tivity No. erectile dysfunction frequency (%):* Episodic 7 (4) Intermittent 20 (12) Always 141 (84) No. erectile dysfunction etiology physician assessment (%): Psychogenic 14 (8) Neurogenic 20 (12) Vasculogenic 35 (21) Penile/cavernous 13 (8) Hormonal 4 (2) Multiple etiologies 81 (48) No. erectile dysfunction therapy (%): Current 42 (26) Previous* 87 (53) No. therapy type (%):† Oral erectile 97 (52) Vacuum constriction devices 31 (17) Intracavernous injection 36 (19) Intraurethral suppository 10 (5) Oral herbal 5 (3) Hormone supplementation 5 (3) Psychosexual counseling 2 (1) * p ⬍0.01. † More than 1 type possible per patient.

55

113

2 (4) 15 (27)

7 (6) 28 (25)

38 (69) 0

74 (65) 4 (4)

2 (4) 17 (31) 36 (65)

5 (4) 3 (3) 105 (93)

6 (11) 4 (7) 13 (24) 6 (11) 2 (4) 23 (42)

8 (7) 16 (14) 22 (19) 7 (6) 2 (2) 58 (51)

18 (33) 21 (38)

24 (22) 66 (61)

25 (52) 11 (23) 6 (13) 0 3 (6) 3 (6) 2 (1)

72 (52) 20 (14) 30 (22) 10 (7) 2 (1) 2 (1) 2 (1)

DISCUSSION

In the past studies of the impact of erectile dysfunction on quality of life have focused primarily on functional status and failed to capture the broader impact of this condition on patient daily existence. The primary reason has been the lack of a patient centered instrument that adequately captures the effect of erectile dysfunction on patient emotional and psychological health in addition to functional status. Using data from a longitudinal observational study of 168 North American men with erectile dysfunction we report the development and validation of a new erectile dysfunction specific health related quality of life instrument that comprehen-

TABLE 2. Descriptive statistics of raw baseline scores on PIED scales Erectile Dysfunction Impact Scale Sexual Experience

Emotional Life

No. pts. 165 162 Score: Mean ⫾ SE 17.6 ⫾ 0.79 7.3 ⫾ 0.3 Range 0–44 0–18 Median 18 7 % Pts. possible score: Lowest 3 1.9 Highest 3 1.2 Higher scores indicate greater negative psychological impact of erectile dysfunction.

2089

PSYCHOLOGICAL IMPACT OF ERECTILE DYSFUNCTION TABLE 3. Internal scale consistency scores and interscale correlations for erectile dysfunction quality of life questionnaires Sexual Experience

Sexual Self-Efficacy Scale IIEF: Erectile function Intercourse satisfaction Orgasmic function Sexual desire Overall satisfaction Brief Male Sexual Function Inventory ejaculation State-Trait Anxiety at last intercourse Beck Depression Inventory

p Value

␣ ⫽ 0.72

p Value

⫺0.57

⬍0.0001

⫺0.51

⬍0.0001

⫺0.4 ⫺0.36 ⫺0.32 ⫺0.36 ⫺0.53 ⫺0.24 0.61 0.56

⬍0.0001 ⬍0.0001 ⬍0.0001 ⬍0.0001 ⬍0.0001 ⬍0.01 ⬍0.0001 ⬍0.0001

⫺0.34 ⫺0.34 ⫺0.23 ⫺0.31 ⫺0.47 ⫺0.21 0.5 0.6

⬍0.0001 ⬍0.0001 ⬍0.01 ⬍0.0001 ⬍0.0001 ⬍0.01 ⬍0.0001 ⬍0.0001

TABLE 4. Baseline scale scores according to patient reported severity of erectile dysfunction Erectile Dysfunction Impact Scale* No. pts. Mean sexual experience ⫾ SE Mean emotional life ⫾ SE p ⬍0.0001. * Mild/moderate (mean 45.9) in 55 patients.

Emotional Life

␣ ⫽ 0.91

Severe

t Test

108 52.2 52.1

4.2 4.1

sively measures the psychological impact of erectile dysfunction, that is the PIED scales. When combined with existing functional scales in erectile dysfunction such as the IIEF, the PIED scales broadly capture the impact of erectile dysfunction on health related quality of life. The new scales measure 2 dimensions not assessed by other instruments, namely the impact of erectile dysfunction on the sexual experience and on patient emotional life. While other, more general scales of psychological functioning have been used to measure constructs such as depression, the 2 new scales address the patient psychological state as he perceives it to be impacted by erectile dysfunction. These scales provide useful new tools for assessing disease specific health related quality of life in men who present with erectile dysfunction as a primary complaint or who present with other conditions, such as prostate cancer or diabetes, which frequently result in erectile dysfunction. The new scales are relatively brief and easy to use, making them attractive not only to researchers, but also to clinicians, who can apply the new instrument to determine whether a given therapy for erectile dysfunction is actually benefiting a patient. Our results show that the PIED scales are reliable and valid. Each scale was internally consistent. Test-retest reliability was also good. The scales were valid and discriminated men with mild/moderate versus severe erectile dysfunction. The hypothesized relationships of the new scales to existing measures of functional status and sexual selfefficacy were confirmed since men reporting a greater psychological impact of erectile dysfunction also reported greater impairment in functional status and sexual self-efficacy. Those with higher scores on the measures of depression and anxiety at the last intercourse also reported a greater psychological impact of erectile dysfunction. Earlier instruments have attempted to capture the psychosocial impact of erectile dysfunction on health related quality of life. For example, Wagner et al developed the Quality of Life-Male Erectile Dysfunction7 and MacDonagh et al recently developed a similar instrument, namely the Erectile Dysfunction Effect on Quality of Life.17 Each generates a single summary score. The newly developed PIED scales represent a significant advance of the previous instruments, in that they capture the multidimensional nature of the psychological consequences of erectile dysfunction by generating 2 subscale scores. While scores on the 2 PIED scales correlated highly in the current sample, it is likely that some men may be affected more in 1 area than in another. For example, men in a committed relationship may experience a

different effect of erectile dysfunction on health related quality of life than those without a regular partner. Men in the former group have an established relationship in which insertive sexual activity may be only a part, while those in the latter group may have fewer opportunities for sexual relations or believe that they must prove themselves by achieving erection with a new partner.18 Only a multidimensional instrument such as the PIED scales with its 2 subscales captures the different psychosocial impact of erectile dysfunction in these 2 groups. While the PIED scales are useful research measures, they also have clinical value. The instrument is well received by patients and easy to use in the clinical setting. For clinicians the summary scores and responses to individual items may provide useful discussion points with patients about the erectile dysfunction experience. Particularly some PIED statements may be an indication for referral to a mental health professional for additional psycho-educational interventions. PIED scales offer the clinician a method of assessing the efficacy of erectile dysfunction therapy on a more comprehensive level than the IIEF alone. In addition, the scales may be useful for guiding additional intervention. Because of the substantial correlation of PIED scales with measures of depression and anxiety, it may be unnecessary to use separate measures of those constructs unless they are one of the primary outcomes of the research study or clinical treatment administered. However, correlations with measures of sexual function such as the IIEF were more modest, indicating that measures of functional status should be used in addition to the PIED scales. While the new scales represent substantial enhancement of our ability to measure health related quality of life in men with erectile dysfunction, some limitations should be noted. Recently published research confirms that men with erectile dysfunction report substantial psychological distress, including not only disruptions in intimate relationships, but also in masculine self-concept and nonsexual relationships with women.7 The PIED scales include questions that address masculine confidence and nonsexual areas, such as negative emotions related to the experience of having erectile dysfunction. A limitation of the current version of the instrument is that it does not adequately capture some interpersonal dynamics described by Bokhour et al.5 Ongoing development and refinement of the instrument is planned to address this concern. While the scales showed good convergent and discriminant validity, no effort was made to assess criterion validity. An approach to assessing criterion validity would have been to compare scores on the PIED scales to physiological measures of erectile functioning. No such objective measures of erectile functioning were used. Instead the study relied on the physician-patient assessment of erectile dysfunction severity and on patient responses on the IIEF. Future research is needed to confirm the criterion validity of the new instrument.

2090

PSYCHOLOGICAL IMPACT OF ERECTILE DYSFUNCTION CONCLUSIONS

The measures in this study have been shown to be reliable and valid scales for assessing disease specific health related quality of life in men with erectile dysfunction. The 2 newly developed scales address aspects of psychological functioning not assessed by more general measures of psychological func-

tioning or other erectile dysfunction specific health related quality of life measures. In addition to existing measures of functional status, these new scales provide a more complete picture of health related quality of life in men with erectile dysfunction and may be useful to clinicians and researchers alike.

APPENDIX: PSYCHOLOGICAL IMPACT OF ERECTILE DYSFUNCTION, VERSION 1.0

Over the past 4 weeks . . . (Please check the response that fits best by marking the box) All of the time

Most of the time

Some of the time

A little of the time

None of the time

1. I am more irritable than I used 䊐 䊐 䊐 䊐 䊐 to be 2. At times, I have felt so devas䊐 䊐 䊐 䊐 䊐 tated by the performance of my penis that I wanted to die 3. My erectile dysfunction makes 䊐 䊐 䊐 䊐 䊐 me feel like less of a man 4. I lack masculine confidence 䊐 䊐 䊐 䊐 䊐 5. I am easily frustrated by little 䊐 䊐 䊐 䊐 䊐 things 6. When I have trouble with my 䊐 䊐 䊐 䊐 䊐 erection, I feel disgusted by my penis 7. I feel proud of my penis 䊐 䊐 䊐 䊐 䊐 8. My erectile dysfunction makes 䊐 䊐 䊐 䊐 䊐 me feel sexually unattractive 9. When I can’t have intercourse, 䊐 䊐 䊐 䊐 䊐 I don’t feel like having any sex at all 10. Sex feels like it is not worth 䊐 䊐 䊐 䊐 䊐 the effort 䊐 䊐 䊐 䊐 䊐 11. I feel there’s something missing in my sex life when I can’t have intercourse 12. I avoid sexual opportunities 䊐 䊐 䊐 䊐 䊐 13. I don’t quite believe my part䊐 䊐 䊐 䊐 䊐 ner(s) when they say they are satisfied with my sexual performance 14. I am afraid to touch my part䊐 䊐 䊐 䊐 䊐 ner in ways that will make her want to have sex with me 15. I feel I could not sustain a new 䊐 䊐 䊐 䊐 䊐 relationship because of my erectile dysfunction 16. My frustration over my erectile 䊐 䊐 䊐 䊐 䊐 dysfunction has a negative effect on my sexual relationship(s) Scoring instructions: Scale 1) Psychological impact of erectile dysfunction on sexual experience. Score only if at least 8 of the 11 items have been completed. Impute a value for missing items by assigning the mean value of the nonmissing items. Calculate the sum of items 3, 4, 6, 8, 9, 10, 11, 12, 14, 15 and 16. Transform the summed score into a T score (mean ⫾ SD 50 ⫾ 10). Higher scores indicate greater psychological impact. Scale 2) Psychological impact of erectile dysfunction on emotional life. Reverse code item 7. Score only if at least 4 of the 5 items have been completed. Impute a value for missing items by assigning the mean value of the nonmissing items. Calculate the sum of items 1, 2, 4, 7 and 13. Transform the summed score into a T score (mean 50 ⫾10). Higher scores indicate greater psychological impact. PIED, Psychological Impact of Erectile Dysfunction, ©1999–2002 TAP Pharmaceutical Products Inc.

PSYCHOLOGICAL IMPACT OF ERECTILE DYSFUNCTION REFERENCES

1. NIH Consensus Development Panel conference. Impotence. JAMA, 270: 83, 1993 2. Litwin, M. S., Nied, R. J. and Dhanani, N.: Health-related quality of life in men with erectile dysfunction. J Gen Intern Med, 13: 159, 1998 3. Laumann, E. O., Paik, A. and Rosen, R. C.: Sexual dysfunction in the United States: prevalence and predictors. JAMA, 281: 537, 1999 4. Lenderking, W. R., Sweeney, S. L., Pashos, C. L. and Flanders, S. C.: Measuring erectile dysfunction from the patient’s perspective: a critical review of the literature. Unpublished data 5. Bokhour, B. G., Clark, J. A., Inui, T. S., Silliman, R. A. and Talcott, J. A.: Sexuality after treatment for early prostate cancer: exploring the meanings of “erectile dysfunction.” J Gen Intern Med, 16: 649, 2001 6. Lenderking, W. R., Flanders, S., Sweeney, S. W., Pashos, C. L. and Lewis, R.: Men and women describe the impact of erectile dysfunction on quality of life and marriage. Lake Forest, Illinois: TAP Pharmaceutical Products, unpublished data 7. Wagner, T. H., Patrick, D. L., McKenna, S. P. and Froese, P. S.: Cross-cultural development of a quality of life measure for men with erection difficulties. Qual Life Res, 5: 443, 1996 8. O’Leary, M. P., Fowler, F. J., Lenderking, W. R., Barber, B., Sagnier, P. P., Guess, H. A. et al: A brief male sexual function inventory for urology. Urology, 46: 697, 1995 9. Libman, E., Rothenberg, I., Fichten, C. S. and Amsel, R.: The

10.

11. 12. 13. 14. 15. 16. 17.

18.

2091

SSES-E: a measure of sexual self-efficacy in erectile functioning. J Sex Mar Ther, 11: 233, 1985 Rosen, R. C., Riley, A., Wagner, G., Osterloh, I. H., Kirkpatrick, J. and Mishra, A.: The International Index of Erectile Function (IIEF): a multidimensional scale for assessment of erectile dysfunction. Urology, 49: 822, 1997 Beck, A. T. and Beck, R. W.: Screening depressed patients in family practice: a rapid technique. Postgrad Med, 52: 81, 1972 Spielberger, C. D.: State-Trait Anxiety Inventory for Adults. Palo Alto, California: Mind Garden, 1983 Cronbach, L. J.: Coefficient alpha and the internal structure of tests. Psychometrika, 16: 297, 1951 Tulsky, D. S.: An introduction to test theory. Oncology, 4: 43, 1990 Crocker, L. and Algina, J.: Introduction to Classical and Modern Test Theory. Ft. Worth, Texas: Harcourt Brace Jovanovich College Publishers, 1986 SAC Instrument review criteria. Scientific Advisory Committee. Med Outcomes Trust Bull, p. 1, September 1995 MacDonagh, R., Ewings, P. and Porter, T.: The effect of erectile dysfunction on quality of life: psychometric testing of a new quality of life measure for patients with erectile dysfunction. J Urol, 167: 212, 2002 McCarthy, B. W.: Treatment of erectile dysfunction with single men. In: Erectile Disorders: Assessment and Treatment. Edited by R. C. Rosen and S. R. Leiblum. New York: Guilford Press, pp. 313–340, 1992