The results of the study have revealed that almost a third (32.8%) of employees at this telco were excessively stressed from work and more than three-quarters reported depression in the past week, whereas only a few reported being diagnosed of insomnia in the past year. Age, having dependents at home and work experience were the only respondent characteristics that were significantly associated with exposure to occupational stress. This study also reveals that occupational stress was only a predictor for reported insomnia but not depression among respondents. There was a higher risk of insomnia among those exposed to excessive stress from work compared to those who reported lower exposure. In Africa, a similar prevalence (28.2%) has been recorded among university staff in Ethiopia(23), and higher among Tanzanians (46.5%) (24). In Asia, prevalence varied from high among Indian call centre workers (65.8%)(25) to low among university staff in Malaysia (21.7%) (26). Physicians (51.4%) and nurses (51.2%) who worked in the ICU and anaesthesiology unit at hospitals in Poland(27) were also reported to have work-related stress. However, there is insufficient evidence of the prevalence of occupational stress among telco employees in Africa.
In the current study, workload was the most reported of the four psychosocial stressors assessed whereas role conflict was the least source of stress. This finding is consistent with the observations of other researchers (12,28) who also reported workload as a major stressor in telcos and the hotel industry respectively. Occupational stress was significantly associated with age, having dependents at home and work experience of the employee. Younger employees may have spent a shorter length of time in their roles and may yet be acquiring the needed skills for effective delivery at work as compared to their older counterparts and therefore may be more stressed (29). Similar reasoning is drawn from Sharma and Devi’s (2) finding that a longer duration spent in a job role was inversely related to the job stress reported. Also, employees with dependents may have more stringent allocations for time due to their extra responsibilities at home. Consequently, they may function more effectively under stress compared to those without dependents (30).
Among the respondents of this study, excessive occupational stress was not found to be significantly associated with depression. Tsai, Chi, and Wang (30) reported a similar finding from a longitudinal study conducted on a sample of the older working population in Taiwan. They indicated that their study population comprised of employees nearing retirement (≥50 years) who were more likely to be experiencing diminishing job stress as earlier posited (31). However, they attributed the highest impact on depression to perceived-health stress which was not assessed by this study. Other findings based on cross-sectional (32,33) and longitudinal data (34) reported, contrary to this study, a strong positive association between work-related stress and depression. Yoshizawa et al. (32) specifically indicated social support, job control, and quantitative workload as psychosocial stressors significantly influencing depression among some psychiatric nurses in Japan. Oenning et al. (33) and Romswinkel et al. (34) assessed job stress in general and among community-dwelling workers as opposed to employees from a specific industry which is the case for this current study. In a lower-middle-income country like Egypt, a positive correlation between work stress and depression was reported (35). Similar to this study, these researchers assessed both depression and occupational stress using self-reports except for Oenning et al. (33) who used a diagnostic tool to measure depressive disorder. The robust risk estimation from this study may account for the lack of association between occupational stress and depression. However, the effect of residual confounding on this association from risk factors like income, educational level, life events, personality traits, earlier psychiatric morbidity and family history (36) which were not measured and controlled for in this study cannot be overlooked. Moreover, other stress parameters not measured in the current study such as effort, reward, overcommitment and support were found to influence the level of depression among workers exposed to high levels of occupational stress whereas the workload (demand) was less important than the other variables (37).
Occupational stress has been reported to facilitate the development of sleep problems (7). Elger and Sekera (38) indicated that stressful events predicted insomnia, the most prevalent sleep disorder (39). Also, a recent systematic review involving fifteen (15) countries found a direct relationship between occupational exposure to violence as a stress factor and sleep problems (40). The current study identified occupational stress as an important risk factor of insomnia. Almost all employees reported quantitative workload as a stressor. The aftermath of this exposure to stress could have been after-work fatigue which influences the experience of insomnia. Also, high levels of work rumination may advance worry (9). The daily psychological strain as a consequence of worrying about workload could have contributed to this occupational stress-related insomnia observed in this study. This is informative to employers especially in telcos of the possible effect of workload strain on workers’ psychological health. It has been proven that reducing weekly work hours of employees by a quarter could significantly reduce workload and increase the time they spend on recovery activities on weekdays (41), improve sleep quality (42) and consequently reduce occupational stress (43). Our study indicated a higher risk of insomnia among those who worked overtime compared to those who worked regular hours. Hence, employers in Ghanaian telcos could curb occupational stress and its increased risk of insomnia by putting measures in place to ensure employees spend minimal time working beyond regular hours.
Implications for future research
There is a paucity in literature regarding the impact of occupational stress on depression and insomnia in telcos, especially in Africa. To this end, this study provides preliminary findings which can form the basis for further work, probably longitudinal studies, to document a clear linkage between occupation-related stress and depression as well as insomnia. This will help report on their peculiar experiences of strain and the two psychiatric conditions. Generally, the odds ratios were far higher than the risk ratios estimated from the Poisson regression with CEM in this study, suggesting an overestimation of the strength of prediction by the variables if only odds ratios were used. This analytical method could be adopted in cross-sectional studies to increase the weight of evidence produced on the predictive power of variables and make them comparable to estimates from longitudinal studies.
Study limitations
The findings from this study were mainly based on self-reported measures which are highly subjective. Also, the study categorized stress by dividing the population into two parts using the median as cut-off which is a limitation. Moreover, the evidence from this study as is the case for other cross-sectional studies need supplementation from longitudinal studies. The use of findings from this observational study to estimate relative risk should be interpreted with caution as it may be associated with reverse causality bias although a rigorous statistical procedure was used.