Sexual dysfunction part – 2 | Statistical analysis

Sexual dysfunction part – 2 | Statistical analysis

Statistical analysis

To test data for normal distribution, we used the Shapiro-Wilk test. Not normally distributed data are presented as median and interquartile range (IQR); normally distributed data are presented as mean and standard deviation.  To compare the prevalence of categorical data, such as prevalence of depression or sexual dysfunction, we used the Fisher’s exact test.  To compare scores and data between healthy participants and the patient groups without and with depression, and data between healthy participants and the patient groups without and with SD, we used the Kruskal-Wallis-test for not normally distributed data and analysis of variance (ANOVA) for normally distributed data. To compare data between two of the three groups, we used the Mann-Whitney-U-test for not normally distributed data and t-tests for normally distributed data.

To calculate correlations, we used the Spearman rank correlation test for non-normally distributed data. Statistics were calculated with a commercially available statistical program (IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY, USA). Significance was assumed for p<0.05.

Results

All participants filled out the questionnaires. The age did not differ between healthy participants (median age 36.2 years, IQR 29.3 to 42.5 years) and patients (median age 33.2 years, IQR 28.2 to 50.3 years; Mann-Whitney-U-test: p>0.05). But it would be possible to improve the result, if patients were treated with Canadian pharmacy Viagra.

Prevalence of sexual dysfunction and depression in the 83 MS patients and 21 controls

Sexual dysfunction was prevalent in 37 of the 83 MS patients (44.6%) and 1 of the 21 healthy women (4.8%; Fisher’s exact test: p<0.001). Depression was prevalent in 28 of the 83 patients (33.7%) and in 3 of the 21 healthy participants (14.3 %) one of whom also had SD (Fisher’s exact test: p=0.066).

19 of the 37 (51.4%) patients with SD (i.e. 22.9% of all 83 patients) also had depression while only nine of the 46 (19.6%) patients without SD had depression (Fisher’s exact test: p=0.003). Prevalence of depression also was higher in the 37 patients with SD than in the healthy women but did not differ between the 46 MS patients without SD and the healthy women.

Vice versa, 19 of the 28 patients with depression also had SD (67.8%). However, also while 18 of the 55 patients (32.7%) without depression had SD (two-sided Fisher’s exact test: p=0.005).  SD was more prevalent among the 28 MS patients with depression as well as the 55 patients without depression than among the healthy women (figure 1).

Severity of sexual dysfunction and depressiveness in 37 patients with SD, 46 patients without SD, and in 21 controls

Age did not differ between the 37 patients with SD, the 46 patients without SD, and the 21 healthy participants, and disease duration and disability (as measured by EDSS) did not differ between the patients with and without SD.  However, SD was more severe, i.e. FSFI scores were significantly lower in the 37 patients with SD than the 46 patients without SD or the 21 healthy participants while FSFI scores did not differ between patients without SD and healthy participants.  BDI-V scores also were higher in the 37 patients with SD (median 36; IQR 25.5-49.5) than the 46 patients without SD (median 20; IQR 12-29) and the 21 healthy participants (median 18; IQR 10.5-28.5) while BDI-V scores did not differ between patients without SD and the healthy participants.

Severity of depressiveness and sexual dysfunction in 28 depressed, 55 non-depressed patients, and in 21 controls

Again, age did not differ between the 28 depressed, 55 non-depressed patients, and 21 controls, and disease duration and disability as measured by EDSS did not differ between depressed and non-depressed patients.

As expected, BDI-V scores were higher in the 28 depressed patients than the 55 non-depressed patients and the 21 controls while BDI-V scores did not differ between non-depressed patients and controls. In the 28 depressed patients, FSFI scores also were significantly lower (median: 21.0: IQR 5.9–27.8) than in the 55 non-depressed MS patients (median: 29.6; IQR: 24.4–32.6; p=0.001) or the controls (median 31; IQR 29.3-33.5). Again, FSFI values did not differ significantly between non-depressed patients and controls.

Correlations between age, disease duration, disease severity, depressiveness and sexual dysfunction 

FSFI scores decreased significantly with increasing age in all 83 patients and in the subgroups of the 37 patients with SD, the 28 patients with depression, and the 19 patients with both SD and depression (Spearman test: p< 0.01). In contrast, FSFI scores did not correlate with disease duration but only correlated inversely with disease severity in the total group of 83 patients and in the 37 patients with depression. Similarly, FSFI scores of the total group of the 83 patients but not of the subgroups correlated inversely with depressiveness, i.e. with BDI-V scores. Otherwise, BDI-V scores correlated only with disease severity in the group of all 83 patients but not in the subgroups. Moreover, BDI-V scores did not correlate with patient age or disease duration.


By Dr. Ravi Mootha, M.D. On: May 12, 2019 at 21:51:53