Variable in the regression models were also performed. In addition, separate multivariate logistic models wererun to compare the subset of patients with limited SSc versus the general population sample, and then the subset of patients with diffuse SSc versus the general population sample. Discrimination and calibration of the logistic regression models were assessed with the c-index and Hosmer-Lemeshow goodnessof-fit test statistic (HL), respectively [34]. The c-index is the percentage of comparisons where 1676428 sexually active (or sexually impaired) patients had a higher predicted probability of being sexually active (or sexually impaired) than inactive patients (or non-get Pentagastrin impaired patients), for all possible pairs of active and inactive patients (or impaired and AN-3199 manufacturer non-impaired patients). The HL is a measure of the accuracy of the predicted number of cases 22948146 of active or impaired patients compared to the number of patients who actually reported sexual activity or impairment across the spectrum of probabilities. A relatively large p value indicates that the model fits reasonably well. In order to identify areas of sexual function that are particularly problematic for women with SSc, sexual domain scores were calculated among women who were sexually active, and analysis of covariance was used to assess the differences 
in each sexual domain score between women with SSc and women from the general population sample, controlling for total FSFI scores. Analyses were also performed using Pearson’s correlations to determine the correlation between domain scores for the domains that were found to have significantly worse scores among women with scleroderma compared to the general population. This was done to assess the degree to which important problem areas for women with SSc seemed to represent general disease severity versus specific problems that may be independent of each other. Finally, among sexually active women in both samples, Pearson’s correlations were used to assess the association between FSFI total and individual sexual domain scores and sexual satisfaction. All analyses were conducted using SPSS version 20.0 (Chicago, IL), and statistical tests were 2-sided with a P,0.05 significance level.Table 1. Comparison of sociodemographic and clinical characteristics of women with systemic sclerosis and women from a UK general population sample.Sociodemographic Characteristics Age in years, mean (standard deviation) Education, n ( ): # High School . High School Not reported Marital Status, n ( ): Married or Living as Married Not Married Clinical Characteristics Time since non-Raynaud’s symptom onset in years, mean (standard deviation)(N = 720) Time since diagnosis of SSc in years, mean (standard deviation)(N = 722) Modified Rodnan skin score, mean (standard deviation)(N = 706) Diffuse SSc, n ( )(N = 681) doi:10.1371/journal.pone.0052129.tSystemic Sclerosis Patients (N = 730) 57.0 (11.3)UK General Population Sample (N = 1,498) 55.4 (11.5)P Value 0.001 ,0.356 (49) 373 (51) 1 (0.1)992 (66) 344 (23) 162 (11) ,0.505 (69) 225 (31)877 (59) 621 (41)12.8 (9.7) 10.0 (8.6) 8.0 (8.4) 171 (25)————————————-Female Sexual Functioning in Systemic SclerosisResults Sample CharacteristicsThere were 800 women with SSc and 1,589 women from the UK general population sample who completed questionnaires. Of these, 44 women with SSc and 84 from the UK did not indicate their sexual activity status. Among sexually active women, 16 with SSc and 7 from the U.Variable in the regression models were also performed. In addition, separate multivariate logistic models wererun to compare the subset of patients with limited SSc versus the general population sample, and then the subset of patients with diffuse SSc versus the general population sample. Discrimination and calibration of the logistic regression models were assessed with the c-index and Hosmer-Lemeshow goodnessof-fit test statistic (HL), respectively [34]. The c-index is the percentage of comparisons where 1676428 sexually active (or sexually impaired) patients had a higher predicted probability of being sexually active (or sexually impaired) than inactive patients (or non-impaired patients), for all possible pairs of active and inactive patients (or impaired and non-impaired patients). The HL is a measure of the accuracy of the predicted number of cases 22948146 of active or impaired patients compared to the number of patients who actually reported sexual activity or impairment across the spectrum of probabilities. A relatively large p value indicates that the model fits reasonably well. In order to identify areas of sexual function that are particularly problematic for women with SSc, sexual domain scores were calculated among women who were sexually active, and analysis of covariance was used to assess the differences in each sexual domain score between women with SSc and women from the general population sample, controlling for total FSFI scores. Analyses were also performed using Pearson’s correlations to determine the correlation between domain scores for the domains that were found to have significantly worse scores among women with scleroderma compared to the general population. This was done to assess the degree to which important problem areas 
for women with SSc seemed to represent general disease severity versus specific problems that may be independent of each other. Finally, among sexually active women in both samples, Pearson’s correlations were used to assess the association between FSFI total and individual sexual domain scores and sexual satisfaction. All analyses were conducted using SPSS version 20.0 (Chicago, IL), and statistical tests were 2-sided with a P,0.05 significance level.Table 1. Comparison of sociodemographic and clinical characteristics of women with systemic sclerosis and women from a UK general population sample.Sociodemographic Characteristics Age in years, mean (standard deviation) Education, n ( ): # High School . High School Not reported Marital Status, n ( ): Married or Living as Married Not Married Clinical Characteristics Time since non-Raynaud’s symptom onset in years, mean (standard deviation)(N = 720) Time since diagnosis of SSc in years, mean (standard deviation)(N = 722) Modified Rodnan skin score, mean (standard deviation)(N = 706) Diffuse SSc, n ( )(N = 681) doi:10.1371/journal.pone.0052129.tSystemic Sclerosis Patients (N = 730) 57.0 (11.3)UK General Population Sample (N = 1,498) 55.4 (11.5)P Value 0.001 ,0.356 (49) 373 (51) 1 (0.1)992 (66) 344 (23) 162 (11) ,0.505 (69) 225 (31)877 (59) 621 (41)12.8 (9.7) 10.0 (8.6) 8.0 (8.4) 171 (25)————————————-Female Sexual Functioning in Systemic SclerosisResults Sample CharacteristicsThere were 800 women with SSc and 1,589 women from the UK general population sample who completed questionnaires. Of these, 44 women with SSc and 84 from the UK did not indicate their sexual activity status. Among sexually active women, 16 with SSc and 7 from the U.