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Sexual Dysfunction is Highly Prevalent Among Men with Chronic Hepatitis C Virus Infection and Negatively Impacts Health-Related Quality of Life
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The American Journal of Gastroenterology
Volume 101 Page 1235 - June 2006
Ann Danoff, M.D.1,4,5, Oona Khan, M.D.1,5, David W. Wan, M.D.5, Lainie Hurst, M.D.1,5, Daniel Cohen, M.D.5, Craig T. Tenner, M.D.2,4,5, and Edmund J. Bini, M.D., M.P.H.3,4,5
1Division of Endocrinology,2Division of General Internal Medicine, and 3Division of Gastroenterology, 4VA New York Harbor Healthcare System, and 5NYU School of Medicine, New York, New York
STUDY HIGHLIGHTS
What is Current Knowledge
- It is well known that hepatitis C virus (HCV) is associated with extrahepatic manifestations.
- Limited available data suggest that HCV infection may be associated with sexual dysfunction among men in Italy and Turkey.
- To date, however, it is unknown whether HCV infection is associated with sexual dysfunction among men in the United States.
- Furthermore, since both HCV infection and sexual dysfunction have been associated with depression, it is unclear whether the reported association between HCV infection and sexual dysfunction in prior studies was confounded by depression.
What is New Here
- Sexual dysfunction is highly prevalent in men with chronic HCV infection, is independent of depression, and is associated with a marked reduction in health-related quality of life.
- These findings have important public health implications given that there are over 2 million men with chronic HCV infection in the United States.
"....Our study demonstrates a strong association between chronic HCV infection and sexual dysfunction among men in the United States. Men with chronic HCV infection had markedly reduced sexual function in all the five domains evaluated (sex drive, erectile function, ejaculation, sexual problem assessment, and overall sexual satisfaction) compared to HCV-uninfected controls. These findings have important public health implications given that there are over 2 million men with chronic HCV infection in the United States (2). With an estimated 170 million HCV-infected people worldwide, this is also an important global health issue...."
Figure 1. Sexual dysfunction scores in the HCV positive men and control subjects. The range of the five domain scores of the Brief Male Sexual Function Inventory were 0-8 for sex drive, 0-12 for erectile function, 0-8 for ejaculation, 0-12 for sexual problem assessment, and 0-4 for overall sexual satisfaction. Lower scores indicate greater sexual dysfunction.
ABSTRACT
OBJECTIVES: Although sexual dysfunction has been reported in patients with hepatitis C virus (HCV) infection, little is known about this association. The aims of this study were to determine the prevalence of sexual dysfunction among men with chronic HCV infection and to evaluate the impact of sexual dysfunction on health-related quality of life (HRQOL).
METHODS: We prospectively enrolled 112 HCV positive men and 239 HCV negative controls, and all patients completed validated questionnaires to assess sexual function (Brief Male Sexual Function Inventory [BMSFI]), depression (Beck Depression Inventory), and HRQOL (Medical Outcomes Study Short Form-36). The BMSFI assessed sexual drive, erection, ejaculation, sexual problem assessment, and overall sexual satisfaction.
RESULTS:
HCV positive men had significantly more sexual dysfunction than control subjects across all five domains of the BMFSI. In addition, HCV-infected men were significantly more likely than controls to not be sexually satisfied (53.6%vs 28.9%, p< 0.001) and this remained statistically significant after adjusting for age, race, and other potential confounding variables (OR = 3.36; 95% CI, 1.59-7.13).
In the 241 individuals without depression, HCV positive men were significantly more likely to not be sexually satisfied as compared with control subjects (47.5%vs 11.0%, p< 0.001). HCV-infected men who were not sexually satisfied scored significantly worse in six of eight domains of HRQOL as compared with HCV-infected men who were sexually satisfied.
CONCLUSIONS: Sexual dysfunction is highly prevalent in men with chronic HCV infection, is independent of depression, and is associated with a marked reduction in HRQOL.
Introduction
Hepatitis C virus (HCV) infection is a major public health problem in the United States and worldwide (1). According to the Third National Health and Nutrition Examination Survey (NHANES III), approximately 3.9 million people (1.8% of the population) have been infected with HCV in the United States, and an estimated 2.7 million of these individuals have chronic infection (2). Chronic HCV infection is the leading cause of cirrhosis, hepatocellular carcinoma, and liver transplantation in the United States, and is associated with substantial mortality (3).
In addition to being a major cause of liver-related mortality, chronic HCV infection causes substantial morbidity due to disabling symptoms, such as fatigue and depression, as well as extrahepatic manifestations (4-6). Chronic HCV infection has been associated with numerous extrahepatic disorders and autoimmune diseases, including glomerulonephritis, essential mixed cryoglobulinemia, porphyria cutanea tarda, polyarteritis nodosa, non-Hodgkin's lymphoma, and others (7-9).
Chronic HCV infection has also been associated with several endocrine disorders, including autoimmune thyroid disease (10, 11) and diabetes (12). In addition to these endocrine disorders, limited available data suggest that HCV infection may be associated with sexual dysfunction among men in Italy (13) and Turkey (14). To date, it is unknown whether HCV infection is associated with sexual dysfunction among men in the United States. Furthermore, since both HCV infection (6, 15) and sexual dysfunction (16-19) have been associated with depression, it is unclear whether the reported association between HCV infection and sexual dysfunction in prior studies was confounded by depression. Therefore, the aims of our study were to determine the prevalence of sexual dysfunction among men with chronic HCV infection in the United States, to examine whether HCV infection is associated with sexual dysfunction independent of underlying depression, and to evaluate the impact of sexual dysfunction on health-related quality of life (HRQOL).
RESULTS
Demographic and Clinical Characteristics of the Study Subjects
A total of 351 eligible individuals were enrolled in the study, including 112 HCV positive patients and 239 control subjects. HCV positive patients were significantly younger and were more likely to be racial/ethnic minorities than control subjects (Table 1). In addition, HCV positive patients had significantly lower income and education levels, and were less likely to be employed or to be married. Although HCV positive patients were more likely to smoke, they were less likely to currently drink alcohol. As expected, risk factors for HCV infection (injection drug use, blood transfusion prior to 1992, and a prior history of high-risk sexual behavior) were more common among HCV positive patients than in control subjects.
Prevalence of Sexual Dysfunction
Using the BMSFI, we found that sexual dysfunction was significantly more common in HCV-infected subjects than in control patients (Fig. 1). For each of the five domains of the BMSFI, the mean scores were significantly lower in the HCV positive patients than in the control subjects. In addition, the distribution of scores on the overall sexual satisfaction domain demonstrates that HCV-infected patients were significantly more sexually dissatisfied than the control subjects (Fig. 2).
For our primary outcome measure, we used the overall sexual satisfaction domain of the BMSFI to determine the proportion of subjects who were not sexually satisfied (those who were very dissatisfied or mostly dissatisfied with their sex life). HCV positive patients were significantly more likely to report that they were not sexually satisfied than control subjects (53.6%vs 28.9%, p< 0.001), a difference of 24.7% (95% CI, 13.7%-35.7%). After controlling for all of the demographic and clinical characteristics listed in Table 1, HCV infection remained significantly associated with not being sexually satisfied (OR = 3.36; 95% CI, 1.59-7.13; p= 0.002).
In our study, patients with chronic HCV infection were less likely to be married than control subjects. Because marital status could potentially affect sexual satisfaction, we analyzed the association between HCV infection and sexual satisfaction stratified according to marital status. HCV-infected patients were significantly more likely to report that they were not sexually satisfied than control subjects whether married (50.0%vs 21.3%, p= 0.03) or not (54.1%vs 31.5%, p< 0.001).
Since there were significant differences in the baseline characteristics between the two groups, we tested the robustness of our findings by reanalyzing the data for the primary outcome using a matched analysis. For each HCV positive patient, we identified the next HCV negative control subject enrolled in the study matched for age, race/ethnicity, and socioeconomic status (annual income and education level). Similar to the analysis of the entire cohort, the 1:1 matched analysis also demonstrated that HCV positive patients were significantly more likely to report that they were not sexually satisfied than control subjects (53.6%vs 21.4%, p= 0.002 using the McNemar test).
Overall, 45 of the 351 men (12.8%) reported that they used sildenafil citrate (Viagra) at least once during the 30 days prior to enrollment. In addition, HCV positive patients were significantly more likely than control subjects to use sildenafil citrate within the last 30 days (19.6%vs 9.6%, p= 0.009).
Predictors of Sexual Dysfunction in Patients with HCV
We determined the proportion of 112 HCV-infected men who reported that they were not sexually satisfied according to select demographic and clinical characteristics (Table 2). In unadjusted analyses, elevated alanine aminotransferase levels, HCV viral load >2 million copies/mL, and HCV genotype 2 or 3 were significantly associated with not being sexually satisfied.
We then performed multivariable logistic regression analysis to identify independent variables that were associated with not being sexually satisfied. In the multivariable analysis, elevated alanine aminotransferase levels (OR = 9.32; 95% CI, 3.32-26.18; p< 0.001) and HCV viral load >2 million copies/mL (OR = 6.59; 95% CI, 2.35-18.48; p< 0.001) were independently associated with an increased odds of not being sexually satisfied, whereas Hispanic ethnicity was independently associated with a decreased odds of not being sexually satisfied as compared with non-Hispanic white patients (OR = 0.11; 95% CI, 0.02-0.51; p= 0.005). Age was not significantly associated with sexual satisfaction in either the univariate or multivariable analyses.
Although a liver biopsy was not part of our study protocol, this procedure had been performed for clinical reasons in 38 of the 112 HCV positive patients and 12 (31.6%) had stage 3 or 4 fibrosis. Patients with stage 3 or 4 fibrosis were more likely to not be sexually satisfied than those with less severe fibrosis (75.0%vs 50.0%, p= 0.15), although this difference was not statistically significant.
Depression and Sexual Dysfunction
The median BDI score was 9.0 (IQR, 4.0-18.8) in patients with HCV and 5.0 (IQR, 2.0-9.0) in control subjects (p< 0.001). Among HCV positive patients, the BDI scores were weakly correlated with the sexual problem assessment and overall sexual satisfaction domains of the BMSFI (Table 3). The correlation between the BDI score and ejaculation domain was of borderline significance, while there was no correlation with the BDI score and either sex drive or erectile function. In contrast, the correlation between the BDI score and each of the five domains of the BMSFI was stronger in control subjects, with all the five analyses achieving statistical significance.
Among HCV positive patients, 59 (52.7%) had normal scores on the BDI, 25 (22.3%) had mild to moderate depression, 22 (19.6%) had moderate to severe depression, and 6 (5.4%) had severe depression. This differed significantly (p< 0.001) from control subjects in whom 182 (76.2%) had normal scores on the BDI, 51 (21.3%) had mild to moderate depression, 5 (2.1%) had moderate to severe depression, and 1 (0.4%) had severe depression.
The proportion of HCV positive patients that were not sexually satisfied did not differ according to the severity of depression (p= 0.38). In contrast, the proportion of control subjects that were not sexually satisfied increased with the severity of depression (p< 0.001). In the 241 individuals without depression (BDI score < 10), HCV positive patients were still significantly more likely to not be sexually satisfied as compared with control subjects (47.5%vs 11.0%, p< 0.001).
To determine whether the association between HCV infection and sexual dysfunction was independent of depression, we performed multivariable logistic regression analysis. After controlling for depression as well as all of the demographic and clinical characteristics listed in Table 1, we found that HCV infection remained significantly associated with not being sexually satisfied (OR = 3.83; 95% CI, 1.61-9.10; p= 0.002).
HRQOL and Sexual Dysfunction
Using the SF-36 questionnaire, we found that HCV positive men had significantly worse HRQOL than control subjects across all eight domains (p< 0.01 for all comparisons; data not shown). In addition, the physical component summary scores (41.4 ± 11.6 vs 46.6 ± 10.5, p< 0.001) and mental component summary scores (43.7 ± 12.6 vs 51.0 ± 11.4, p< 0.001) were significantly lower in HCV positive men than in control subjects.
To determine the impact of sexual dysfunction on HRQOL in HCV positive men, we compared SF-36 score between individuals who were and those who were not sexually satisfied (Table 4). HCV positive patients who were not sexually satisfied had significantly lower scores than HCV positive patients who were satisfied in six of the eight domains and in both summary scales. Similar findings were also noted in control subjects, with the p value being <0.001 across all eight domains of HRQOL and in both summary scales for the comparison between individuals who were and those who were not sexually satisfied (data not shown).
DISCUSSION
Our study demonstrates a strong association between chronic HCV infection and sexual dysfunction among men in the United States. Men with chronic HCV infection had markedly reduced sexual function in all the five domains evaluated (sex drive, erectile function, ejaculation, sexual problem assessment, and overall sexual satisfaction) compared to HCV-uninfected controls. These findings have important public health implications given that there are over 2 million men with chronic HCV infection in the United States (2). With an estimated 170 million HCV-infected people worldwide, this is also an important global health issue (1).
Despite the high worldwide prevalence of chronic HCV infection, little is known about sexual dysfunction in this population. In a Letter to the Editor, Ferri et al. (13) reported that erectile dysfunction was present in 39% of 207 Italian men with chronic HCV infection and in 14% of age-matched control subjects. Although these findings were intriguing, there are several potential limitations of that study that may have biased the results. The investigators only evaluated erectile dysfunction instead of studying the full spectrum of sexual function, and nearly half of the HCV-infected patients had cryoglobulinemic vasculitis. Furthermore, the control group was selected from a database of Italian men who were evaluated for erectile dysfunction in the past.
In a study of 46 HCV-infected Turkish patients, Soykan and colleagues (14) found that sexual dysfunction was present in 35% of patients, including 21% of the 24 men and 50% of the 22 women. However, that study did not include a control group of patients without HCV infection, making the results difficult to interpret. Our study builds upon these prior investigations from other countries and clearly demonstrates that sexual dysfunction is significantly more common in HCV-infected men than in control subjects without HCV in the United States. In addition, the prevalence of sexual dysfunction in our control subjects was similar to the prevalence reported among men of similar age in other population-based studies in the United States, lending further validity to our findings (21, 30, 31).
Although we and others (13, 14) have demonstrated a strong association between chronic HCV infection and sexual dysfunction, the reasons for these findings are not known. Patients with chronic diseases commonly have sexual dysfunction, especially those with diabetes, renal failure, decompensated cirrhosis, prostate cancer, alcohol abuse, and others (32-34). However, we excluded patients with these disorders from our study. As in other diseases, disruption of vascular, neurologic, hormonal, or psychological integrity may result in sexual dysfunction in HCV-infected men. Although depression is a known cause of sexual dysfunction (16-19), we found that chronic HCV infection was strongly associated with sexual dysfunction even after adjusting for the severity of depression and other potential confounding variables. Furthermore, sexual dysfunction was significantly more common in our HCV-infected patients than in control subjects even after excluding individuals with underlying depression. These findings are in agreement with Soykan et al. (14) who found that sexual dysfunction was not significantly correlated with the severity of depression in 24 men with chronic HCV infection.
It is possible that biologic or virologic factors may be contributing to sexual dysfunction in our patients with chronic HCV infection. Using multivariable logistic regression analysis, we found that elevated alanine aminotransferase levels and high plasma HCV RNA levels were independently associated with sexual dysfunction among our HCV-infected patients, whereas Hispanic ethnicity was independently associated with decreased odds of sexual dysfunction. The increased odds of sexual dysfunction among HCV-infected men with elevated alanine aminotransferase levels and high plasma HCV RNA levels is interesting and the reasons for this association require further study. However, we were surprised to find that age was not significantly associated with sexual satisfaction among our HCV-infected patients since other studies in men without liver disease have shown that sexual dysfunction increases with age (31, 33, 34).
Another potential reason for the high prevalence of sexual dysfunction among our HCV-infected men is an abnormality of one or several components of the hypothalamic-pituitary-gonadal axis. It is well-known that primary, secondary, and tertiary hypogonadism may be associated with sexual dysfunction in men without liver disease (35, 36). Alcoholic cirrhosis (37, 38), hemochromatosis (39), and other causes of advanced cirrhosis may also cause primary and/or central hypogonadism, or may result in sexual dysfunction because of an abnormal androgen to estrogen ratio (37, 40). However, little is known about gonadal steroid levels in men with chronic HCV infection who do not have advanced cirrhosis. Ferri et al. (13) reported that free testosterone levels in Italian patients with chronic HCV infection were significantly lower in patients with erectile dysfunction than in those without sexual problems. Interestingly, they found that neither erectile dysfunction nor testosterone levels were correlated with the severity of liver disease.
A study of 34 German men with chronic HCV infection found that treatment with interferon alpha and ribavirin was associated with worsening sexual function and a decline in serum levels of total and free testosterone, although hormone levels remained within the normal range throughout treatment (41). In contrast, another study of 18 Italian men with chronic HCV infection reported that interferon alpha monotherapy resulted in only slight decreases in serum levels of total testosterone and sex hormone-binding globulin, whereas serum free testosterone and other sex hormone levels remained essentially unchanged during treatment (42). Four of the 18 men in that study developed sexual dysfunction during treatment, and sexual dysfunction was unrelated to changes in hormonal levels. These conflicting findings underscore the need for well-designed prospective studies using reliable androgen assays in cirrhotic and non-cirrhotic men with chronic HCV infection to further evaluate the relationship between sexual dysfunction and the components of the hypothalamic-pituitary-gonadal axis.
Another interesting and important finding of our study was the strong association between sexual dysfunction and poor HRQOL among patients with chronic HCV infection. HCV-infected men in our study scored significantly worse than HCV-infected men without sexual dysfunction on six of the eight domains and in both summary scales of the SF-36 questionnaire. To the best of our knowledge, no prior studies have evaluated the impact of sexual dysfunction on HRQOL in men with chronic HCV infection. Previous studies in men without HCV infection clearly demonstrated that sexual dysfunction was associated with a worse HRQOL as compared with men who did not report sexual dysfunction and also found that HRQOL improved in men who were treated for erectile dysfunction (19, 43-45). It remains to be determined whether treatment of sexual dysfunction in men with chronic HCV infection improves HRQOL.
The strengths of the present study include the prospective study design, collection of detailed demographic and clinical data, inclusion of a HCV antibody negative control group, exclusion of patients with medical disorders that could adversely affect sexual function, and the use of validated questionnaires to evaluate sexual dysfunction, depression, and HRQOL. However, there are some limitations of this study that should be considered when interpreting our findings. First, this study was conducted at a single VA medical center and only included men. Therefore, our findings may not be generalizable to other VA medical centers, non-VA settings, or women. Second, we did not perform laboratory testing for testosterone, other sex hormones, and serum cryoglobulins.
Third, we used a generic HRQOL instrument (SF-36) instead of an HCV-specific questionnaire. Although the SF-36 was utilized to allow us to compare HRQOL between HCV positive patients and control subjects, it is possible that a HCV-specific questionnaire would have detected additional differences in HRQOL among those with HCV infection. Finally, another potential limitation of our study was the absence of a control group of patients with chronic hepatitis due to another viral agent (e.g., hepatitis B) matched for age, race/ethnicity, and the severity of liver disease. Because such a control group would be difficult to identify, we elected to compare HCV positive patients to control subjects who were HCV antibody negative. Therefore, it is possible that our findings may be due to underlying liver disease, rather than HCV infection per se. To address these limitations, future studies should evaluate sexual dysfunction in both men and women with chronic HCV infection and chronic hepatitis B infection along with measurements of sex hormone levels.
In conclusion, we found that chronic HCV infection was strongly associated with sexual dysfunction in men and this association was independent of underlying depression. Furthermore, HRQOL was significantly worse in HCV-infected men with sexual dysfunction than in those with normal sexual function. Based on these findings, we suggest that HCV infection should be considered in the differential diagnosis of sexual dysfunction in men. Additional studies are needed to determine the pathophysiologic mechanisms underlying the association between chronic HCV infection and sexual dysfunction, and to evaluate the impact of HCV eradication on sexual function.
METHODS
Study Population
The study population included men recruited from the Primary Care and Gastroenterology Clinics at the Veterans Affairs (VA) New York Harbor Healthcare System in New York City from January 2004 through March 2005. Patients with chronic HCV infection were eligible for this study if they were 18 yr of age or older, had a positive HCV antibody, had detectable HCV plasma RNA, did not have decompensated cirrhosis (ascites, encephalopathy, or prior variceal bleeding), and had not received interferon, ribavirin, or any other HCV treatment within 6 months of enrollment.
For comparison, we enrolled a control group of HCV antibody negative men 18 yr of age and older who were seen in the same outpatient clinics during the study period. Control subjects were identified by reviewing the clinic list for patients who tested negative for HCV antibodies.
For both the HCV positive and control groups, patients were excluded from this study if they had chronic hepatitis B or other causes of chronic liver disease, diabetes, HIV infection, prostate or other cancer, prior prostate surgery, renal failure, thyroid disease, consumed three or more drinks a day, were using illicit drugs, if they were taking methadone, or if they had any significant medical problems or were taking medications that could adversely affect sexual function. The study was reviewed and approved by the Institutional Review Board at our medical center, and all patients provided written informed consent to participate.
Study Design
Patients who met the eligibility criteria were interviewed in a private room by a trained research assistant. Detailed demographic and clinical information that was collected included age, self-reported race/ethnicity, education, annual income, employment status, marital status, use of tobacco and alcohol, risk factors for HCV infection, current and past medical history, and medications. The results of laboratory and other diagnostic testing were recorded on standardized data collection sheets. After the interview, patients were asked to complete three validated self-administered questionnaires to assess sexual function, depression, and HRQOL.
Sexual function was assessed using the Brief Male Sexual Function Inventory (BMSFI). The BMSFI was developed by O'Leary et al. (20) in 1995 and includes 11 questions that assess sexual function over the past 30 days across five domains, including sexual drive (2 questions), erectile function (3 questions), ejaculation (2 questions), sexual problem assessment (3 questions), and overall sexual satisfaction (1 question). Each question is scored on a scale from 0 to 4, with domain scores equaling the sum of the individual questions comprising the domain. Therefore, the range of the domain scores were 0-8 for sex drive, 0-12 for erectile function, 0-8 for ejaculation, 0-12 for sexual problem assessment, and 0-4 for overall sexual satisfaction. Lower domain scores indicate greater sexual dysfunction. This questionnaire has been shown to be a valid and reliable measure of sexual function in men, and community-based normal scores from men in the United States have also been published (20, 21).
Depression was assessed using the Beck Depression Inventory (BDI) (22). This questionnaire evaluates depression over the past week and includes a total of 21 questions. Each question is scored from 0 to 3, and a total depression score is obtained by adding up the score from each of the 21 questions. The total score ranges from 0 to 63, with higher scores indicating more severe depression. Scores from 0 to 9 indicate no depression, scores from 10 to 18 indicate mild to moderate depression, scores from 19 to 29 indicate moderate to severe depression, and scores from 30 to 63 indicate severe depression. This questionnaire has been extensively validated in various populations, including patients with chronic HCV infection (23).
HRQOL was assessed using the Medical Outcomes Study Short Form 36 (SF-36) (24). This questionnaire evaluates HRQOL across eight domains, including physical functioning, social functioning, physical role limitation, emotional role limitation, mental health, energy and fatigue, pain, and general health perception. The scores for each domain range from 0 to 100, with higher scores indicating better HRQOL. In addition, physical component summary and mental component summary scales were scored using standard algorithms (25). These summary scales for the physical component and mental component are each standardized using norm-based scoring to have a mean of 50 and a standard deviation of 10 in the general U.S. population. Therefore, any summary score less than 50 falls below the general population mean, and each point represents 1/10th of a standard deviation. The SF-36 has demonstrated good validity and reliability in chronic disease populations, including those with chronic HCV infection (24, 26-29).
Study Outcomes
The primary outcome being evaluated was the proportion of HCV-infected patients and control subjects who reported that they were not sexually satisfied. Using the single question from the BMSFI that assessed overall sexual satisfaction, the number of subjects who were not sexually satisfied was calculated by adding up the proportion of men who reported that they were very dissatisfied or mostly dissatisfied with their sex life.
The secondary outcomes that were evaluated included the mean scores for each of the five domains of the BMSFI and the association between sexual dysfunction and underlying depression in the HCV positive and control subjects. In addition, we determined factors associated with not being sexually satisfied and the impact of sexual dysfunction on HRQOL among subjects with chronic HCV infection.
Statistical Analysis
A previously published study of community-based subjects demonstrated that 24% of men of similar age to our target population reported that they were not sexually satisfied (21). Based on the assumption that 39% of HCV-infected patients would report that they were not sexually satisfied and enrolling 2 controls for each HCV positive patient, a total of 112 HCV-infected patients and 224 controls would be needed to detect a difference of 15% at a power of 80% and a 2-tailed alpha of 0.05.
Continuous variables were compared using an unpaired t-test or the Mann-Whitney U-test as appropriate. Data are expressed as means ± SD for those variables that were normally distributed, and medians and interquartile range (25th percentile-75th percentile) for those with a non-normal distribution. Categorical variables are expressed as proportions and were compared using the X2 test or Fisher's exact test.
Univariate analysis was utilized to identify factors associated with not being sexually satisfied (score of 0 or 1 on the overall sexual satisfaction domain of the BMSFI). Subsequently, a multivariable logistic regression model was created using a forward stepwise approach in order to identify variables that were independently associated with not being sexually satisfied. In constructing the multivariable logistic regression model, we included age, race/ethnicity, and all variables from the univariate analysis with a p value of <0.05. The strength of the association between covariates and not being sexually satisfied are expressed as odds ratios (OR) with 95% confidence intervals (CI). Statistical analysis was performed using SPSS software version 13.0 for Windows (SPSS Inc., Chicago, IL) and a 2-tailed p value of <0.05 was considered statistically significant.
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