General Characteristics
The descriptive analysis results are shown in Table 1. (Note: Medical majors include: Clinical Medicine, Stomatology, Pediatrics, Psychiatry, Anesthesiology, Medical Imaging, Clinical Chinese and Western Medicine, Preventive Medicine, Basic Medicine, Nursing, Medical Laboratory Technology, Pharmacy, Clinical Pharmacy, Medical Technology, Food Hygiene and Nutrition. Non medical majors include: Biotechnology, Applied Psychology, Public Utility Management, Biomedical Engineering, and Law.)
Table 1
Sample Descriptive Statistics
Variable | Group | No. of participants (N = 2194) | Percentage (%) | Anxiety | t | Depression | t | Positive Mental Character | t |
Gender | Male | 895 | 40.79 | 1.83 ± 0.75 | -2.385* | 1.73 ± 0.62 | − .3.544*** | 117.91 ± 30.37 | -4.438*** |
Female | 1299 | 59.21 | 1.90 ± 0.72 | 1.85 ± 0.62 | 122.46 ± 28.40 |
Age | aged 18 and below | 1402 | 63.90 | 1.90 ± 0.74 | 2.557* | 1.82 ± 0.64 | 2.199* | 121.64 ± 29.61 | 2.411* |
18 to 30-year-old | 792 | 36.10 | 1.82 ± 0.73 | 1.76 ± 0.60 | 118.77 ± 28.68 |
Major | Medical majors | 1733 | 78.99 | 1.87 ± 0.74 | 0.033 | 1.79 ± 0.62 | -1.661 | 120.57 ± 29.25 | -0.111 |
Non-medical majors | 461 | 21.01 | 1.87 ± 0.72 | 1.84 ± 0.64 | 120.74 ± 29.52 |
Only-child family | Yes | 553 | 25.21 | 1.89 ± 0.74 | 0.890 | 1.81 ± 0.64 | 0.412 | 117.74 ± 29.47 | -2.657** |
No | 1641 | 74.79 | 1.86 ± 0.73 | 1.80 ± 0.62 | 121.57 ± 29.19 |
Birthplace | Urban area | 1835 | 83.63 | 1.87 ± 0.74 | -0.261 | 1.79 ± 0.63 | -0.862 | 119.60 ± 29.44 | -3.634*** |
Rural area | 359 | 16.36 | 1.88 ± 0.71 | 1.83 ± 0.58 | 125.72 ± 28.04 |
Note: * P < 0.05, * * P < 0.01, * * * P < 0.001, the same below. |
The mediating role of positive mental characters in the impact of sleep quality on individual anxiety
The reliability test was conducted on the positive mental characters of the subjects, and the Cronbach's coefficient was 0.9 > 0.7, indicating that the test passed. Take the mean of 62 measurements of the positive mental characters of the participants towards the demand side as the positive psychological quality value. Next, the macro process model 4 in SPSS was used to test the mediating effect of positive mental characters of participants on the impact of sleep quality on individual anxiety, while controlling for gender and age. The results (as shown in Tables 2 and 3) indicate that sleep quality has a significant positive predictive effect on individual anxiety (B = 0.474, t = 20.975, p < 0.001). However, when the mediator variable is added, the direct positive predictive effect of sleep quality on individual anxiety remains significant (B = 0.421, t = 18.406, p < 0.001). The positive predictive effect of positive mental characters is significant (B = 11.404, t = 11.935, p < 0.001), and the predictive effect of positive mental characters on individual anxiety is also significant (B = 0.005, t = 9.379, p < 0.001).
However, by analyzing the data, the upper and lower limits of the confidence interval (Bootstrap 95%) for the mediating effect of positive mental characters do not include zero, indicating that sleep quality can not only directly predict individual anxiety positively, but also predict individual anxiety through the mediating effect of positive mental characters. The direct effect (0.470) and mediating effect (0.068) account for 88.809% and 11.191% of the total effect (0.523), respectively. Therefore, the mediating role of positive mental characters in the impact of sleep quality on individual anxiety is established
Table 2
A test of mediation modeling of positive mental characters
Variable | PPQS | GAD | GAD |
B | se | t | B | se | t | B | se | t |
Age | -2.179** | 0.831 | -2.623 | -0.057** | 0.020 | -2.891 | -0.047* | 0.019 | -2.418 |
Gender | 2.821* | 1.241 | 2.272 | 0.010 | 0.029 | 0.334 | -0.003 | 0.029 | -0.115 |
ISI | 11.401*** | 0.955 | 11.935 | 0.474*** | 0.023 | 20.975 | 0.421*** | 0.023 | 18.406 |
PPQS | | | | | | | 0.005*** | 0.001 | 9.379 |
R-sq | 0.070 | 0.173 | 0.205 |
F | 54.982 | 152.966 | 141.274 |
Table 3
Summary Table of Intermediary, Direct and Total Effects
| Effect | BootSE | BootLLCI | BootULCI | Percentage |
The mediating effect of positive mental characters | 0.053 | 0.007 | 0.039 | 0.068 | 11.191% |
Direct effects | 0.421 | 0.025 | 0.372 | 0.470 | 88.809% |
Total effect | 0.474 | 0.025 | 0.425 | 0.523 | |
The mediating role of positive mental characters in the impact of sleep quality on individualdepression
The reliability test was conducted on the positive mental characters of the subjects, and the Cronbach's coefficient was 0.9 > 0.7, indicating that the test passed. Take the mean of 62 measurements of the positive mental characters of the participants towards the demand side as the positive psychological quality value. Next, the macro process model 4 in SPSS was used to test the mediating effect of positive mental characters of participants on the impact of sleep quality on individual depression, while controlling for gender and age. The results are shown in Tables 4 and 5.
It indicates that sleep quality has a significant positive predictive effect on individual depression (B = 0.456, t = 24.576, p < 0.001), and even after adding mediating variables, the direct positive predictive effect of sleep quality on individual depression remains significant (B = 0.409, t = 21.832, p < 0.001). The positive predictive effect of positive mental characters is significant (B = 11.401, t = 11.935, p < 0.001), and the predictive effect of positive mental characters on individual anxiety is also significant (B = 0.004, t = 10.309, p < 0.001).
However, by analyzing the data, the upper and lower limits of the confidence interval (Bootstrap 95%) for the mediating effect of positive mental characters do not include zero, indicating that sleep quality can not only directly predict individual depression positively, but also predict individual depression through the mediating effect of positive mental characters. The direct effect (0.409) and mediating effect (0.048) account for 89.546% and 10.454% of the total effect (0.456), respectively. Therefore, the mediating role of positive mental characters in the impact of sleep quality on individual depression is established.
Table 4
A test of mediation modeling of positive mental characters
Variable | PPQS | PHQ | PHQ |
B | se | t | B | se | t | B | se | t |
Age | -2.179** | 0.831 | -2.623 | -0.044** | 0.016 | -2.696 | -0.034* | 0.016 | -2.179 |
Gender | 2.821* | 1.241 | 2.272 | 0.058* | 0.024 | 2.402 | 0.046 | 0.024 | 1.956 |
ISI | 11.401*** | 0.955 | 11.935 | 0.456*** | 0.019 | 24.576 | 0.409*** | 0.019 | 21.832 |
PPQS | | | | | | | 0.004*** | 0.000 | 10.309 |
R-sq | 0.070 | 0.226 | 0.262 |
F | 54.982 | 213.551 | 194.432 |
Table 5
Summary Table of Intermediary, Direct and Total Effects
| Effect | BootSE | BootLLCI | BootULCI | Percentage |
The mediating effect of positive mental characters | 0.048 | 0.006 | 0.036 | 0.060 | 10.454% |
Direct effects | 0.409 | 0.021 | 0.367 | 0.450 | 89.546% |
Total effect | 0.456 | 0.020 | 0.417 | 0.496 | |