Reliability and validity were demonstrated in several chronic disease populations[30]. The Cronbach’s alpha for the PSQI in this study was. 74. Data on demographic CCX282-B chemical information characteristics of age, gender, race, PXD101 chemical information marital status, education, employment status (including whether employed and if so what shift worked), and narcolepsy-related information regarding symptoms (excessive daytime sleepiness, sleep attacks, cataplexy, hypnagogic hallucinations and sleep paralysis). Medication information and time from symptoms to diagnosis were also collected.Statistical AnalysisAnalyses were conducted with IBM SPSS, version 21 (IBM Corp., 2012). Item missing values were replaced using mean substitution. For unit missing data, we determined whether missing data were MCAR (missing completely at random). Missing data occurred randomly. Data were analyzed with descriptive statistics and analysis of variance (ANOVA) was used to compare sample characteristics between groups. Bivariate relationships between key variables were examined with Spearman’s and Pearson correlations. Mann-Whitney U Test was used to compare stigma and HRQOL variables between groups. Hierarchical multiple regression using the “enter” method was employed to identify predictors of the total FOSQ in young adults with narcolepsy. The assumption of normaility of residuals was assessed by a Q-Q plot and variance inflation factors were assessed and found to be < 5. Independent variables were chosen fromPLOS ONE | DOI:10.1371/journal.pone.0122478 April 21,4 /Stigma in Young Adults with Narcolepsythose found to be associated with HRQOL in previous research and those most significantly correlated with HRQOL in our data. Simultaneous relationships among variables were tested using path analysis with IBM SPSS AMOS 22 software. The sample size (122) allowed for 9.4 subjects per parameters to be estimated in the path analysis. Statistical assumptions of normality, linearity, and homoscedasticity were tested, and necessary assumptions were met. The fit of the hypothesized model was tested using maximum likelihood estimation. The path model was refined by removing nonsignificant variables until the theoretically based model with the best fit was determined. Several fit indices were used to evaluate the model fit: chi square, normed fit index (NFI), comparative fit index (CFI), and the root mean square error of approximation (RMSEA).ResultsThe sample consisted of 122 young adults with narcolepsy and 93 young adults without narcolepsy. Sample characteristics are shown in Table 1. Participant ages ranged from 18 to 37 yearsTable 1. Sample characteristics. Characteristics Age (range = 18?5) Female ( ) Race/ethnicity ( ) American Indian/Alaskan Asian Black Hispanic/Latino White/Non-Hispanic Other Educational status ( ) Some high school, high school or vocational Some College, College, and greater than college Student ( ) Marital status ( ) Married or Committed relationship Single Divorced/separated Employment ( ) Employed On sick leave Laid off On disability Homemaker Employment status of those working ( ) Works 20 hours per week Works 21?5 hours per week Works 36 hours per week Previously discharged from a job ( ) 9.0 11.5 41.8 33.0 11.8 12.9 41.9 14.1 0.02 82.8 1.6 0.8 9.8 9.8 95.7 0.0 0.0 0.0 3.2 >0.05 0.003 45.9 49.2 4.9 48.4 47.3 4.3 24.6 75.4 30.3 17.2 82.8 46.2 0.02 0.89 1.6 0.8 3.3 2.5 87.7 4.1 1.1 10.8 3.2 4.3 79.6 1.1 0.002 Narcolepsy (n = 122) 27.1 ?5 77.9 Control (n = 93) 25.7 ?4 63.4 P value 0.02.Reliability and validity were demonstrated in several chronic disease populations[30]. The Cronbach’s alpha for the PSQI in this study was. 74. Data on demographic characteristics of age, gender, race, marital status, education, employment status (including whether employed and if so what shift worked), and narcolepsy-related information regarding symptoms (excessive daytime sleepiness, sleep attacks, cataplexy, hypnagogic hallucinations and sleep paralysis). Medication information and time from symptoms to diagnosis were also collected.Statistical AnalysisAnalyses were conducted with IBM SPSS, version 21 (IBM Corp., 2012). Item missing values were replaced using mean substitution. For unit missing data, we determined whether missing data were MCAR (missing completely at random). Missing data occurred randomly. Data were analyzed with descriptive statistics and analysis of variance (ANOVA) was used to compare sample characteristics between groups. Bivariate relationships between key variables were examined with Spearman’s and Pearson correlations. Mann-Whitney U Test was used to compare stigma and HRQOL variables between groups. Hierarchical multiple regression using the “enter” method was employed to identify predictors of the total FOSQ in young adults with narcolepsy. The assumption of normaility of residuals was assessed by a Q-Q plot and variance inflation factors were assessed and found to be < 5. Independent variables were chosen fromPLOS ONE | DOI:10.1371/journal.pone.0122478 April 21,4 /Stigma in Young Adults with Narcolepsythose found to be associated with HRQOL in previous research and those most significantly correlated with HRQOL in our data. Simultaneous relationships among variables were tested using path analysis with IBM SPSS AMOS 22 software. The sample size (122) allowed for 9.4 subjects per parameters to be estimated in the path analysis. Statistical assumptions of normality, linearity, and homoscedasticity were tested, and necessary assumptions were met. The fit of the hypothesized model was tested using maximum likelihood estimation. The path model was refined by removing nonsignificant variables until the theoretically based model with the best fit was determined. Several fit indices were used to evaluate the model fit: chi square, normed fit index (NFI), comparative fit index (CFI), and the root mean square error of approximation (RMSEA).ResultsThe sample consisted of 122 young adults with narcolepsy and 93 young adults without narcolepsy. Sample characteristics are shown in Table 1. Participant ages ranged from 18 to 37 yearsTable 1. Sample characteristics. Characteristics Age (range = 18?5) Female ( ) Race/ethnicity ( ) American Indian/Alaskan Asian Black Hispanic/Latino White/Non-Hispanic Other Educational status ( ) Some high school, high school or vocational Some College, College, and greater than college Student ( ) Marital status ( ) Married or Committed relationship Single Divorced/separated Employment ( ) Employed On sick leave Laid off On disability Homemaker Employment status of those working ( ) Works 20 hours per week Works 21?5 hours per week Works 36 hours per week Previously discharged from a job ( ) 9.0 11.5 41.8 33.0 11.8 12.9 41.9 14.1 0.02 82.8 1.6 0.8 9.8 9.8 95.7 0.0 0.0 0.0 3.2 >0.05 0.003 45.9 49.2 4.9 48.4 47.3 4.3 24.6 75.4 30.3 17.2 82.8 46.2 0.02 0.89 1.6 0.8 3.3 2.5 87.7 4.1 1.1 10.8 3.2 4.3 79.6 1.1 0.002 Narcolepsy (n = 122) 27.1 ?5 77.9 Control (n = 93) 25.7 ?4 63.4 P value 0.02.
