Table 1.
General characteristics of the selected studies, ordered by year of publication.
| Authors (year) | Journal of publication | Country of origin | Study design | Sample (n) | Prevalence of insomnia | Diagnostic criterion | Participants' occupation |
|---|---|---|---|---|---|---|---|
| Jung & Lee (2016)14 | Shift work and health | South Korea | Cross-sectional descriptive | 1.431 | 1.094 (76.4%) | Insomnia Severity Index | Nurses |
| Gumenyuk et al. (2015)15 | Sleep | United States | Observational laboratory and field study | 37 | 23 (62.2%) | Insomnia Severity Index | Industrial and healthcare workers |
| Yazdi et al. (2012)17 | Work | Iran | Cross-sectional descriptive | 160 | 69 (43,1%) | Pittsburg Sleep Quality and Insomnia Severity Index | Female nurses |
| Ursin et al. (2009)16 | Scand J Work Environ Health | Norway | Cross-sectional descriptive | 7.782 (2.046 shift workers) | 262 (12,8%) | Karolinska Sleep Questionnaire and Frequency Scale | Diverse* |
| Takahashi et al. (2008)18 | Applied Ergonomics | Japan | Cross-sectional descriptive | 731 (509 shift workers) | 207 (40,6%) | Questionnaire about sleep problems | Nursing home caregivers |
*
Legislators, senior officials, managers, service providers (health personnel, teachers, police), primary occupations (farmers, fishery workers), craft and related workers, construction workers, plant and machine operators and drivers.