1. Differences in the level of PMS according to the general and menstruation-related characteristics
The mean age of the participants was 22.56 years. Regarding body mass index (BMI), the majority had the normal range weight (n = 95, 66.4%), followed by underweight (n = 24, 16.8%), overweight (n = 13, 9.1%), and obese (n = 11, 7.7%). A higher proportion of participants were engaged in regular exercise (n = 87, 60.8%), did not smoke (n = 134, 93.7%), consumed alcohol (n = 79, 55.2%), skipped breakfast (n = 112,78.3%), and were not on a weight loss diet (n = 109, 76.2%). The highest proportion of participants drank 1-2 cups (200 ml/cup) of coffee per day (n = 131, 91.6%), 3-4 glasses of water per day (n = 50, 35.0%), had menarche at age 12-13 (n = 58, 40.6%), had a regular menstrual cycle (n = 93, 65.0%) with mean cycle of 26-29 days (n = 59, 41.3%), had a mean menstruation period of 5-6 days (n = 85, 59.4%), and felt the amount of menstruation flow normal (n = 103, 72.0%), followed by high (n = 30, 21.0%), and low (n = 10, 7.0%).
The level of dysmenorrhea was assessed with the Numeric Rating Scale (NRS), which resulted in a mean pain level of 6.73±2.16. Based on the pain assessment proposed by McCaffery et al. [36], the perceived intensity of pain in decreasing order was 7-10 points (severe; n = 95, 66.4%), 4-6 points (moderate; n = 34, 23.8%), and 1-3 points (mild; n = 14, 9.8%). The most frequently used strategy to deal with pain was painkiller (n = 104, 72.7%), followed by enduring or resting (n = 26, 18.2%), warm pack (n = 9, 6.3%), and others (n = 4, 2.8%) (Table 1).
The measurement and analysis of the variables for the participants’ characteristics resulted in the following findings: Significant differences in PMS were observed in BMI (F=3.535, p=.017), amount of menstruation flow (F=4.241, p=.016), and menstrual pain intensity (F=4.228, p=.016). In the post-hoc testing, however, only the menstrual pain intensity of 7-10 points (severe) was found to have a significantly higher PMS level than 1-3 points (mild) (Table 1).
[insert Table 1 here]
Table 1. PMS according to general and menstruation-related characteristics (N=143)
|
Variables
|
Categories
|
Mean ± SD
|
n (%)
|
PMS
|
Mean ± SD
|
t/F (p)
|
Age (years)
|
|
22.56±1.91
|
|
|
|
BMI
|
Underweighta)
|
|
24 (16.8%)
|
30.54±8.61
|
3.530 (.017)
|
Normal
|
|
95 (66.4%)
|
36.32±10.94
|
|
Overweightb)
|
|
13 (9.1%)
|
29.54±8.65
|
|
Obesec)
|
|
11 (7.7%)
|
30.00±14.85
|
|
Regular exercise
|
Yes
|
|
56 (39.2%)
|
36.39±11.35
|
1.886 (.061)
|
No
|
|
87 (60.8%)
|
32.86±10.66
|
|
Smoking
|
Yes
|
|
9 (6.3%)
|
36.44±12.49
|
.617(.538)
|
No
|
|
134 (93.7%)
|
34.10±10.96
|
|
Drinking
|
Yes
|
|
79 (55.2%)
|
34.16±10.11
|
-.094 (.925)
|
No
|
|
64 (44.8%)
|
34.34±12.15
|
|
Breakfast
|
Yes
|
|
31 (21.7%)
|
36.35±13.12
|
1.056 (.297)
|
No
|
|
112 (78.3%)
|
33.66±10.37
|
|
Weight loss diet
|
Yes
|
|
34 (23.8%)
|
35.71±12.83
|
.884(.378)
|
No
|
|
109 (76.2%)
|
33.79±10.43
|
|
Daily caffeine intake
(200 ml per cup)
|
1-2 cups
|
|
131 (91.6%)
|
34.19±10.73
|
.022 (.978)
|
3-4 cups
|
|
9 (6.3%)
|
34.67±13.05
|
|
≥ 5 cups
|
|
3 (2.1%)
|
35.33±21.73
|
|
Daily water intake
(200 ml per glass)
|
1-2 glasses
|
|
31 (21.7%)
|
34.55±11.06
|
1.013 (.389)
|
3-4 glasses
|
|
50 (35.0%)
|
32.34±10.53
|
|
5-6 glasses
|
|
36 (25.2%)
|
34.75±10.95
|
|
7-8 glasses
|
|
28(18.2%)
|
36.85±12.01
|
|
Age at menarche
|
< 12 years
|
|
9 (6.3%)
|
33.67±12.69
|
.583 (.627)
|
12-13 years
|
|
58 (40.6%)
|
33.98±11.48
|
|
13-14 years
|
|
31 (21.7%)
|
32.55±10.96
|
|
> 14 years
|
|
45 (31.5%)
|
35.97±10.29
|
|
Regularity of menstrual cycle
|
Regular
|
|
93 (65.0%)
|
34.29±11.46
|
.387 (.680)
|
Irregular
|
|
46 (32.2%)
|
34.57±10.11
|
|
Other
|
|
4 (2.8%)
|
29.50±13.03
|
|
Average menstrual cycle
|
≤ 25 days
|
|
11 (7.7%)
|
32.46±9.56
|
.408 (.748)
|
26-29 days
|
|
59 (41.3%)
|
33.37±11.94
|
|
30-33 days
|
|
43 (30.1%)
|
35.33±10.53
|
|
≥ 34 days
|
|
30 (21.0%)
|
35.07±10.64
|
|
Average menstrual period
|
< 3 days
|
|
4 (2.8%)
|
29.75±6.08
|
.630 (.597)
|
3-4 days
|
|
34 (23.8%)
|
33.62±9.50
|
|
5-6 days
|
|
85 (59.4%)
|
34.09±12.27
|
|
≥ 7 days
|
|
20 (14.0%)
|
36.75±8.29
|
|
Amount of Menstruation
|
Lowa)
|
|
10 (7.0%)
|
40.30±12.96
|
4.241 (.016)
|
Normal
|
|
103 (72.0%)
|
32.65±10.92
|
|
Highb)
|
|
30 (21.0%)
|
37.70±9.48
|
|
Menstrual pain intensity (NRS)
|
1-3a)
|
6.73±2.16
|
14 (9.8%)
|
28.00±11.40
|
4.228 (.016)
|
4-6
|
|
34 (23.8%)
|
32.06±9.54
|
(a<b)
|
7-10b)
|
|
95 (66.4%)
|
35.95±11.11
|
|
Main strategy to deal with menstrual pain
|
Enduring or resting
|
|
26 (18.2%)
|
32.46±13.17
|
.576 (.632)
|
Warm pack
|
|
9 (6.3%)
|
37.00±10.20
|
|
Painkiller
|
|
104 (72.7%)
|
34.59±10.38
|
|
Other
|
|
4 (2.8%)
|
30.75±16.38
|
|
2. Level of PMS, depression, stress, sleep disturbances, and eating attitude problems
The levels of PMS by variable were: Total mean score = 34.25±11.03 (Range: 10–60), depression = 15.55±11.87 (Range: 0–60), stress = 17.48±5.22 (Range: 0–40), sleep disturbances = 54.94±13.80 (Range: 0–147), eating attitude problems = 8.80±8.36 (Range: 0–78) (Table 2).
Table 2. Level of PMS, depression, stress, sleep disturbance, and eating attitude (N=143)
|
Variables
|
|
n(%)
|
Range of Score
|
Mean±SD
|
PMS
|
Normal (≦26)
|
39(27.3%)
|
10-60
|
34.25±11.03
|
PMDD (≧27)
|
104(72.7%)
|
0-40
|
17.48±5.22
|
Stress
|
|
|
0-60
|
15.55±11.87
|
Depression
|
Normal (1-20)
|
104(72.7%)
|
|
|
Probable depression (21-40)
|
34(23.8%)
|
|
|
Definite depression (41-60)
|
5(3.5%)
|
|
|
Sleep disturbances
|
|
|
0-147
|
54.94±13.80
|
Eating attitude problem
|
Normal (0-21)
|
131(91.6%)
|
0-78
|
8.80±8.36
|
Possible eating disorder (22-26)
|
6(4.2%)
|
Severe eating disorder (27-78)
|
6(4.2%)
|
3.Correlation between PMS, depression, stress, sleep disturbance, and eating attitude problems
PMS was positively correlated with depression (r=.284, p=.001), stress (r=.274, p =.001), sleep disturbances (r=.440, p <.001), and eating attitude problems (r=.266, p =.001) (Table 3).
Table 3. Correlations between PMS, depression, stress, sleep disturbances, and eating attitude problems (N=143)
|
|
PMS
|
Stress
|
Depression
|
Sleep disturbances
|
Eating attitude problems
|
PMS
|
1
|
|
|
|
|
Stress
|
.274
(.001)
|
1
|
|
|
|
Depression
|
.284
(.001)
|
.548
(<.001)
|
1
|
|
|
Sleep disturbances
|
.440
(<.001)
|
.411
(<.001)
|
.594
(<.001)
|
1
|
|
Eating attitude problems
|
.266
(.001)
|
.259
(.002)
|
.254
(.002)
|
.227
(.006)
|
1
|
4. Influencing factors on PMS
Multiple regression analysis was performed by inputting the menstrual pain intensity, which showed post-hoc differences among the participants’ general characteristics and major variables (depression, stress, sleep disturbances, and eating attitude problems). In the analysis of multicollinearity between independent variables, the tolerance limit was greater than 0.1 (0.933–0.975) and the VIF was less than 10 (1.026–1.072), demonstrating that there was no problem of multicollinearity. As a results of multiple regression analysis, menstrual pain intensity (β=.204), sleep disturbances (β =.375), and eating attitude problems (β =.202) were found to have an effect on PMS. The regression model was significant (F= 16.553, p < .001) with an explanatory power of 24.7% (Table 4).
Table 4. Influencing factors on PMS (N=143)
|
Dependent variable
|
Independent variable
|
B
|
S.E.
|
β
|
t (p)
|
PMS
|
Constant
|
12.279
|
3.406
|
|
3.605 (<.001)
|
Pain
|
4.747
|
1.716
|
.204
|
2.766 (.006)
|
Sleep disturbances
|
.300
|
.060
|
.375
|
4.979 (<.001)
|
Eating attitude problems
|
.267
|
.099
|
.202
|
2.685 (.008)
|
F(p)=16.553(<.001), R=.513, R2=.263, Adj.R2=.247, D-W=1.987
NRS ≤ 7 (Severe) → 1
|