1. Background
2. Methods
2.1. Study Design
2.2. Participants
2.3. Inclusion Criteria
2.4. Exclusion Criteria
2.5. Measurement Instruments
| Domains | Intervention | Control | P-Valueb (t-test) |
|---|---|---|---|
| Subjective sleep quality | |||
| Before | 1.71 ± 0.58 | 1.81 ± 0.57 | 0.25 (1.17) |
| After | 0.58 ± 0.49 | 1.90 ± 0.56 | < 0.001 *** (16.83) |
| Mean change | -1.12 ± 0.66 | 0.08 ± 0.38 | < 0.001 *** (14.95) |
| P-value c | < 0.001 *** (-16) | 0.25 (2) | |
| Sleep latency | |||
| Before | 2.04 ± 0.93 | 1.92 ± 1.08 | 0.43 (0.79) |
| After | 0.41 ± 0.44 | 1.62 ± 0.97 | < 0.001 *** (10.77) |
| Mean change | -1.63 ± 0.89 | -0.3 ± 0.93 | < 0.001 *** (9.80) |
| P-value c | < 0.001 *** (-17.52) | 0.32 (-3.06) | |
| Sleep duration | |||
| Before | 2.28 ± 0.74 | 2.28 ± 0.93 | 0.89 (0.00) |
| After | 2.26 ± 0.74 | 2.07 ± 1.04 | < 0.001 (1.41) |
| Mean change | 0.94 ± 0.51 | -0.21 ± 0.06 | < 0.001 *** (8.91) |
| P-value c | < 0.001 *** (0.39) | 0.11 *** (0.89) | |
| Habitual sleep efficiency | |||
| Before | 3 ± 0.53 | 3 ± 0.48 | 0.56 (0.00) |
| After | 0.55 ± 0.12 | 3 ± 0.44 | < 0.001 *** (50.96) |
| Mean change | -2.45 ± 0.49 | 0 | < 0.001 *** (47.43) |
| P-value c | < 0.001 *** (-47.38) | 0.99 (0.00) | |
| Sleep disturbances | |||
| Before | 8.66 ± 3.67 | 9.05 ± 4.05 | 0.50 (0.68) |
| After | 1.17 ± 1.06 | 9.20 ± 2.95 | < 0.001 *** (24.30) |
| Mean change | -7.48 ± 3.48 | 0.14 ± 2.50 | < 0.001 *** (16.87) |
| P-value c | < 0.001 *** (-20.21) | 0.63 (0.54) | |
| Use of sleeping medication | |||
| Before | 0.12 ± 0.39 | 0.07 ± 0.26 | 0.57 (1.01) |
| After | 0 | 0.01 ± 0.105 | 0.32 (0.90) |
| Mean change | -0.12 ± 0.39 | -0.06 ± 0.29 | 0.44 (1.17) |
| P-value c | 0.004 ** (-2.92) | 0.03 ** (-1.94) | |
| Daytime dysfunction | |||
| Before | 2.81 ± 1.07 | 2.90 ± 0.99 | 0.56 (0.58) |
| After | 0.61 ± 0.59 | 3.03 ± 0.77 | < 0.001 *** (23.67) |
| Mean change | -2.20 ± 1.13 | 0.13 ± 0.76 | < 0.001 *** (16.23) |
| P-value c | < 0.001 *** (-18.48) | 0.11 (1.63) | |
| Total score | |||
| Before | 13.75 ± 1.27 | 12.81 ± 1.54 | 0.05 (4.46) |
| After | 2.88 ± 1.36 | 15.1 ± 3.41 | < 0.001 *** (31.57) |
| Mean change | -10.87 ± 0.09 | 2.30 ± 1.87 | < 0.001 *** (66.73) |
| P-value c | < 0.001 *** (-9.65) | < 0.001 *** (11.67) |
a Values are expressed as mean ± SD unless otherwise indicated. * P-value < 0.01, ** P-value < 0.05, *** P-value < 0.001.
bt-test: Comparison of between groups
c Paired t-test: Comparison of within groups
| Domains | Intervention | Control | P-Value b (t-test) |
|---|---|---|---|
| Adequate and fair compensation | |||
| Before | 6.91 ± 0.19 | 7.46 ± 2.10 | 0.06 (2.47) |
| After | 13.20 ± 1.96 | 6.67 ± 2.26 | < 0.001 *** (20.71) |
| Mean change | 6.28 ± 3.03 | -0.78 ± 2.26 | < 0.001 *** (17.49) |
| P-value c | < 0.001 *** (19.62) | < 0.02 ** (-3.12) | |
| Safe and healthy working environment | |||
| Before | 9.01 ± 0.34 | 11.57 ± 4.05 | 0.03 ** (5.97) |
| After | 22.71 ± 2.07 | 10.87 ± 4.45 | < 0.001 *** (22.88) |
| Mean change | 12.28 ± 4.27 | -0.7 ± 3.74 | < 0.001 *** (21.69) |
| P-value c | < 0.001 *** (27.3) | 0.08 (-1.79) | |
| Opportunity to develop human capacities | |||
| Before | 9.01 ± 2.95 | 10.65 ± 4.24 | 0.08 (3.01) |
| After | 19.41 ± 2.33 | 9.58 ± 4.09 | < 0.001 *** (19.81) |
| Mean change | 10.40 ± 3.14 | -1.06 ± 3.84 | < 0.001 *** (21.92) |
| P-value c | < 0.001 *** (33.5) | 0.01 ** (-2.58) | |
| Opportunity for continuous growth and job security | |||
| Before | 6.65 ± 2.35 | 7.66 ± 3.11 | 0.01 ** (2.46) |
| After | 15.50 ± 2.01 | 6.97 ± 2.89 | < 0.001 *** (23.02) |
| Mean change | 8.84 ± 3.14 | -0.68 ± 3.32 | < 0.001 *** (19.76) |
| P-value c | < 0.001 *** (26.78) | 0.06 (-1.94) | |
| Social coherence in work organization | |||
| Before | 6.36 ± 2.24 | 7.60 ± 3.21 | 0.08 (3.005) |
| After | 15.66 ± 1.68 | 7.12 ± 3.10 | < 0.001 *** (22.97) |
| Mean change | 9.30 ± 3.05 | -0.47 ± 3.13 | < 0.001 *** (21.21) |
| P-value c | < 0.001 *** (29.06) | 0.15 (-1.42) | |
| Regulations and rule orientation | |||
| Before | 6.57 ± 2.31 | 7.38 ± 3.08 | 0.07 (1.99) |
| After | 15.62 ± 1.77 | 7.14 ± 3.37 | < 0.001 *** (21.13) |
| Mean change | 9.04 ± 3.06 | -0.24 ± 2.67 | < 0.001 *** (21.67) |
| P-value c | < 0.001 *** (28.25) | 0.38 (-0.86) | |
| Work and total life space | |||
| Before | 4.54 ± 1.62 | 5.04 ± 2.10 | 0.07 (1.78) |
| After | 11.95 ± 1.37 | 5.40 ± 2.21 | < 0.001 *** (23.89) |
| Mean change | 7.41 ± 2.23 | 0.35 ± 2.49 | < 0.001 *** (20.03) |
| P-value c | < 0.001 *** (32.22) | 0.18 (1.34) | |
| Social dependency | |||
| Before | 7.06 ± 2.29 | 9.10 ± 3.84 | 0.09 (4.33) |
| After | 19.72 ± 1.63 | 8.40 ± 3.95 | < 0.001 *** (25.13) |
| Mean change | 12.65 ± 2.95 | -0.70 ± 3.28 | < 0.001 *** (28.71) |
| P-value c | < 0.001 *** (8.54) | 0.04 ** (-2) | |
| Total score | |||
| Before | 57.55 ± 12.27 | 66.50 ± 20.33 | 0.02 ** (3.58) |
| After | 133.78 ± 9.22 | 62.18 ± 19.68 | < 0.001 *** (31.25) |
| Mean change | 76.23 ± 17.59 | -4.31 ± 12.60 | < 0.001 *** (35.31) |
| P-value c | < 0.001 *** (41.20) | 0.02 ** (-3.24) |
a Values are expressed as mean ± SD unless otherwise indicated. * P-value < 0.01, ** P-value < 0.05, *** P-value < 0.001.
bt-test: Comparison of between groups
c Paired t-test: Comparison of within groups
2.6. Randomization
2.7. Procedure
2.8. Implementation of Benson Relaxation Technique
2.9. Statistical Analysis
2.10. Ethical Considerations
3. Results
3.1. Characteristics of Sample
| Variables | Intervention (N = 90) | Control (N = 90) | Total (N = 180) | P-Value b |
|---|---|---|---|---|
| Age (y) | 31.65 ± 4.85 | 30.63 ± 4.79 | 31.14 ± 4.82 | 0.157 |
| Gender | 0.87 | |||
| Male | 31 (34.4) | 32 (35.6) | 63 (53) | |
| Female | 59 (65.6) | 58 (64.4) | 117 (65) | |
| Marital status | 0.45 | |||
| Married | 53 (58.9) | 48 (53.3) | 101 (56.1) | |
| Single | 37 (41.1) | 42 (46.7) | 79 (43.9) | |
| Educational degree | 0.58 | |||
| Bachelor | 78 (86.7) | 76 (84.4) | 154 (85.6) | |
| Undergraduate | 12 (13.3) | 13 (14.4) | 25 (13.9) | |
| Employment status | 0.73 | |||
| Permanent civil | 40 (44.4) | 36 (40) | 76 (42.2) | |
| Contractual | 14 (15.6) | 19 (21.1) | 33 (18.3) | |
| Quasi-contractual | 1 (1.1) | 2 (2.2) | 3 (1.7) | |
| Corporate | 15 (16.7) | 11 (12.2) | 26 (14.4) | |
| Passing training period | 20 (22.2) | 22 (24.4) | 42 (23.3) | |
| Work experience | 0.50 | |||
| < 10 years | 50 (55.6) | 49 (54.4) | 99 (55) | |
| 10 - 20 years | 40 (44.4) | 41 (45.06) | 81 (45) | |
| Night shift | 0.86 | |||
| 1 - 5 | 68 (75.6) | 78 (86.7) | 146 (80) | |
| 6 - 10 | 22 (23.3) | 12 (13.3) | 34 (20) | |
| Number of work shifts | 0.60 | |||
| 1 - 5 | 36 (40) | 35 (38.9) | 71 (39.4) | |
| 6 - 10 | 36 (40) | 30 (33.3) | 66 (36.7) | |
| 11 - 15 | 14 (15.6) | 21 (23.3) | 35 (19.4) | |
| > 15 | 4 (4.4) | 4 (4.4) | 8 (4.4) |
a Values are presented as mean ± SD or No. (%).
b **P-value < 0.05.

