Research | Open Access | Volume 9 (3): Article 138 | Published: 20 Aug 2026
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Table 1: Sociodemographic and occupational characteristics of study participants (n = 530)
Table 2: Health and psychosocial outcomes by shift type (n = 530)
Table 3: Association between working hours per shift and health outcomes (n = 530)
Mazin Mohamed Hussein1, Mona Hassan Ahmed1, Afag Elsiddig Elsiddig1, Almozamil Mohamed Mirghani1, Alaa Abdelrahman Hamed1, Humeda Suekit Ahmed2,&
1Federal Ministry of Health, Khartoum, Sudan, 2Department of Physiology, Faculty of Medicine, Alzaiem Al-Azhari University, Khartoum, Sudan
&Corresponding author: Humeda Suekit Ahmed, Department of Physiology, Faculty of Medicine, Alzaiem Al-Azhari University, P.O. Box 1432, Khartoum, Sudan. Email: Humeda2004@hotmail.com ORCID: https://orcid.org/0009-0004-6323-2359
Received: 03 Jun 2026, Accepted: 07 Aug 2026, Published: 20 Aug 2026
Domain: Occupational Health
Keywords: night shift work, sleep quality, job satisfaction, psychosocial outcomes, healthcare workers
©Mazin Mohamed Hussein et al. Journal of Interventional Epidemiology and Public Health (ISSN: 2664-2824). This is an Open Access article distributed under the terms of the Creative Commons Attribution International 4.0 License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Cite this article: Mazin Mohamed Hussein et al. Beyond the shift: The toll of night work and extended hours on healthcare workers in Sudan. Journal of Interventional Epidemiology and Public Health. 2026; 9(3):138. https://doi.org/10.37432/jieph-d-26-00173
Introduction: The impacts of night shift work and lengthened working days on physical, psychosocial and occupational outcomes have been described in some populations; however, evidence from underserved and high demand healthcare in sub-Saharan Africa is limited.
Methods: Data were obtained via a hospital-based cross-sectional survey at two Khartoum, Sudan, tertiary hospitals from August 15, 2021 through January 31, 2022. A total of 530 health care workers completed the structured, self-reporting questionnaires (response rate 100%). Chi-square tests, one-way ANOVA and independent t-tests were performed to evaluate the associations between type of shift and working hours and different health outcomes.
Results: Of the 530 participants, the majority were female (60.6%), aged 20-30 years (85.3%), and single (75.3%). Gastrointestinal symptoms (37.5%) and cardiovascular symptoms (23.6%) were the most commonly reported systemic symptoms. About 80.9% of the participants reported poor sleep quality, 83.0% reported adverse effects on social life, and 80.2% reported adverse effects on family life. Workers performing both day and night shifts had consistently higher rates across all outcome domains than day-shift-only workers (P<0.05). Extended 16–24 h shifts were correlated with large effects for family (P< 0.001) and social life (P< 0.001), and small effects on sleep quality (P< 0.001).
Conclusion: Night shift work and long working hours exert small to moderate physical health effects and moderate to large psychosocial burdens for Sudanese healthcare workers. Workload management, mandatory rest days, and peer social services are viable and clinically necessary interventions, particularly under resource constraints.
Shift work is an integral component of working life in almost every industry around the world, including health services, emergency services, transport and industry. With the world becoming increasingly a 24/7 hour operation, the International Labour Organization (ILO) and the European Foundation for the Improvement of Living and Working Conditions estimated that 1.2 billion workers in 187 countries worldwide experience some form of shift work [1, 2]. The well established adverse health effects of shift work include associations with cardiovascular disease [3,4] and other chronic diseases such as gastrointestinal symptoms and peptic ulcer disease [5], type 2 diabetes mellitus [6] and rheumatoid arthritis [7] as reviewed and meta-analysed in systematic reviews. Night shift work in particular has been associated with an increased risk of breast cancer [8] and a variety of psychological detriments including symptoms of depression and sleep problems [9].
Shift work affects other areas of life too, including social and family life, job satisfaction and health-related quality of life (HRQoL) [10, 11]. Many developing countries including those in sub-Saharan Africa have very challenged healthcare delivery systems. Health care systems in these countries are plagued by a severe lack of an effective healthcare workforce, with numbers of health care workers well below the World Health Organization (WHO) Sustainable Development Goals threshold of 22.8 health workers per 10,000 population [12].
In tertiary health care centers where this study was conducted, night shift work and long working hours are in fact a structural fact of working life in these hospitals rather than something that can be managed by staff with the outflow of staff from these institutions and geographical concentration of staff in the capital, Khartoum. Data on the occupational health of health care workers from sub-Saharan African health care settings is almost non-existent, and using available evidence to inform future research in this area is not possible.
Thus there is an urgent need for more research into the effects of shift and long working hours on health of health care workers in these countries. This study aims to fill this gap by presenting results from the first ever hospital-based study of effects of shift work and long working hours on health of health care workers from Sudan. We assessed the prevalence and severity of self-reported Cardiovascular System (CVS) and Gastrointestinal Tract (GIT) symptoms among health care workers and their association with shift work and long working hours; the prevalence of poor sleep quality among health care workers and its association with shift work and long working hours; the psychosocial determinants of negative effects of night shift work on health care workers’ responsibilities towards their social and family lives; and the association between the adverse effects of shift work and long working hours on health of health care workers.
Study design and settings
This hospital-based cross-sectional study was conducted between August 15, 2021, and January 31, 2022, at two government-funded tertiary healthcare centers in Khartoum State, Sudan: Ibrahim Malik Teaching Hospital (IMTH) and Khartoum Bahri Teaching Hospital (KBTH). Both hospitals operate 24-hour shift systems encompassing 8, 12, 16, and 24-hour shifts. Participants were classified according to their shift type during the study period.
Study population
The study population included all healthcare workers (i.e., physicians (house officers, medical officers, and registrars), nurses, pharmacists, and laboratory technicians) who were recruited from the IMTH or KBTH through postings during the study. All healthcare professionals aged 18-60 years who were working during the study period were included. To avoid confounding self-reported symptom data, workers with a diagnosed psychiatric illness or chronic diseases (diabetes mellitus, hypertension, ischemic heart disease, cardiovascular and GIT diseases, and sleep disorders) were excluded from the study.
Sample size and sampling methods
The two hospitals were selected by cluster sampling and the sample size was a total coverage of 530 participants in the two hospitals, including 236 healthcare providers from Khartoum Bahri teaching hospital and 294 healthcare providers from Ibrahim Malik teaching hospital. Of the 530 questionnaires distributed, all were filled in and returned, yielding a response rate of 100%.
Data collection tool
A structured, self-administered questionnaire was used. The instrument was developed by the investigators and pre-tested on a convenience sample of 20 healthcare workers who were excluded from the primary study. A panel of occupational health and clinical experts determined the content validity. The internal consistency of the job satisfaction subscale was acceptable (Cronbach’s α = 0.76). The questionnaire was administered in English, the language of professional qualifications and clinical work in Sudan. It consisted of six main parts: (1) sociodemographic variables; (2) working environment; (3) physical symptoms (CVS and GIT); (4) psychosocial significance in social and family life; (5) sleep quality; (6) job satisfaction. If the participant reported two or more GIT and CVS symptoms, he was considered as having these symptoms. For social and family lives, the questions were yes or no without details about the domains of each outcome. Job satisfaction was assessed using 5-point Likert scale from strongly agree to strongly disagree.
Data analysis
The data were analysed using SPSS version 26. Independent variables included night shift and extended working hours, and dependent variables included social and family lives, job satisfaction, sleep quality and cardiovascular and GIT symptoms. Categorical data were reported as frequencies and percentages, and continuous data were reported as means and SD. Chi-square (χ²) tests were conducted to investigate relationships between shift type and all categorical outcomes. Independent t-test and ANOVA tests were employed to explore the relationships between working hours per shift (8, 12, and 16–24 hours) and outcomes. Statistical significance was set at P < 0.05.
Ethical considerations
Ethical approval was obtained from the Ethics Committee of the University of Medical Sciences and Technology (reference number: UMST-21-76). Written informed consent was obtained from all participants before distributing the questionnaire. Data were collected anonymously, and all personally identifiable information was kept secure from any type of research-related use.
Of the 530 participants, the majority were female (60.6%), aged 20-30 years (85.3%), and single (75.3%) (Table 1). Doctors represented 50.4% of the sample, followed by nurses (30.9%), laboratory technicians (15.1%), and pharmacists (3.6%). The majority (68.9%) of the participants worked only day and night shifts. The two most frequent shifts were 12-hour (37.9%) and 24-hour shifts (38.3%) (Table 1).
GIT symptoms were reported by 199 (37.5%) participants and CVS symptoms by 125 (23.6%). Poor sleep quality was reported by 429 (80.9%) participants, adverse effects on social life by 440 (83.0%), and on family life by 425 (80.2%) participants. Combined day-and-night shift workers had a consistently greater rate in all outcome domains (P = 0.001, Table 2).
Independent t-test showed that most of the outcome categories were significantly associated with longer work hours per shift (P ≤ 0.003). ANOVA test showed a significant association between job satisfaction and working hours (P=0.001, Table 3).
The present research indicated that 23.6% of employees reported experiencing cardiovascular symptoms, while 37.5% exhibited gastrointestinal symptoms. Furthermore, these symptoms were notably more severe during nighttime and in two-shift work schedules.
Additionally, an increase in symptom severity was observed with extended working hours. Night shift employment has been linked to cardiovascular disease biomarkers among female nurses [12]. In addition, shift workers appear to have increased risk of GI symptoms and peptic ulcer disease [13]. Moreover, disruption of circadian physiology, due to sleep disturbance or shift work, may result in various gastrointestinal diseases, such as irritable bowel syndrome (IBS), gastroesophageal reflux disease (GERD) or peptic ulcer disease [14]. The proposed mechanism is disruption of GIT circadian rhythm [13]. The risk of developing cardiovascular disease in night-shift workers has been noted to rise by as much as 40% [13, 14]. The pathophysiological mechanisms connecting shift work to cardiovascular risk factors involve various complex and interconnected pathways. The well-documented mechanism pertains to the effect of irregular sleep patterns on the internal hypothalamic clock, which regulates cycles of wakefulness and sleep alongside secondary internal clocks situated in organs such as the heart, adipose tissue, kidneys, pancreas, and liver. These self-regulating clocks at both central and peripheral levels influence the expression of numerous genetic factors that govern circadian rhythms related to insulin secretion, carbohydrate and lipid metabolism, and adipogenesis [13].
Regarding the effects of night shifts on personal relationships and social lives, over 80% of healthcare professionals acknowledged that their social interactions and family dynamics were negatively affected by night shifts. This observation aligns with previous studies suggesting that night shift work can contribute to a range of health and social challenges, including psychophysiological issues (such as depression and anxiety), cardiovascular conditions (like hypertension and heart disease), as well as diminished family communication [14-16]. A notable correlation exists between night work schedules and nurses’ quality of life.
In this investigation, a significant number of healthcare workers on night shifts reported poor sleep quality (71.7%), particularly among those engaged in two-shift systems or those working longer hours. Numerous studies have pointed out that overall sleep quality for night-shift nurses tends to be significantly worse compared to day or non-rotating shift workers [17, 18]. It has been demonstrated that day- and evening-shift nurses typically benefit from more stable rest-activity cycles than their night-shift counterparts; those who experience fragmented sleep during workdays or exhibit irregular activity patterns tend to report inferior sleep quality; additionally, nurses who suffer from lower sleep quality often show reduced daytime activity levels on working days [18]. Night-shift personnel also noted considerably poorer sleep quality characterized by delayed onset of sleep, reduced duration of slumber, disturbances during sleep periods, increased daytime dysfunctions, along with a link between night shift activities and both sleep quality deterioration and metabolic syndrome [19].
Research concerning circadian misalignment among night-shift nursing staff has highlighted disrupted circadian rhythms coupled with inadequate quantity and quality of sleep as critical factors affecting mental health over time due to prolonged exposure to night shifts [20]. The prevalence rates for insomnia within this demographic can range from 12.8% to 76.4%, surpassing estimates for the general populace. Notably higher rates are found among women and single individuals without significant age or occupational variations noted [21]. However, studies indicate consistently high rates of poor sleep among female hospital nurses regardless of their specific schedules; contributing factors include three-shift rotations along with evening chronotypes leading to leg restlessness during the nighttime hours [22]. These issues may stem from processes affecting both biological functions, such as circadian rhythm disruptions, and social dimensions alike.
Conversely, findings revealed that a majority (53.1%) of healthcare workers either agreed or strongly agreed that working nights adversely affected their job satisfaction levels. Employment during night shifts significantly influences job contentment metrics; research suggests these shifts can result in absenteeism rates increasing alongside boredom levels while also contributing towards difficulties in achieving work-life balance alongside diminished productivity outcomes coupled with heightened occupational stressors and psychological strain [23].
Limitations
We were not able to establish a causal relationship, as this was a cross-sectional study. The questions about the outcome variables test the broad items without testing the domains under each variable.
Night shift duties combined with extended hours have been associated with adverse physical health effects along with negative psychosocial outcomes for healthcare professionals based in Khartoum, Sudan. These findings correspond with existing global literature supporting tailored interventions aimed at improving occupational health conditions. Three cost-effective recommendations are proposed: limit consecutive night shifts to no more than two per week while ensuring a minimum rest period of 24 hours between shifts; implement minor occupational health screenings during existing handover sessions; foster peer-support groups specifically for junior staff handling night shifts. Future research should focus on generating objective results through longitudinal designs aimed at clarifying causal relationships alongside analyzing post-conflict impacts from events beyond 2023 on healthcare worker health statuses.
What is already known about the topic
What this study adds
Mazin Mohamed Hussein and Mona Hassan Ahmed were equally involved in this study. They jointly spearheaded the conceptualization and design of the study, data collection at both study sites, and the first manuscript draft. Among others, Afag Elsiddig Elsiddig, Almozamil Mohamed Mirghani and Alaa Abdelrahman Hamed have been involved with methodological design, data collection and curation and critically appraised the manuscript. Overall care and supervision were provided by Humeda Suekit Ahmed, who contributed to the conceptualization of the study, conducted the formal statistical analysis, and critically reviewed the manuscript for intellectual content. All authors accepted written feedback and agreed that each author reviewed and accepted the final manuscript and that they were responsible for the entire content of the study.
| Variable | Frequency (n=530) | Percent (%) |
|---|---|---|
| Gender | ||
| Female | 321 | 60.6 |
| Male | 209 | 39.4 |
| Age (years) | ||
| 20–30 | 452 | 85.3 |
| 31–40 | 61 | 11.5 |
| > 40 | 17 | 3.2 |
| Marital status | ||
| Single | 399 | 75.3 |
| Married | 119 | 22.5 |
| Divorced | 12 | 2.3 |
| Hospital | ||
| Ibrahim Malik Teaching Hospital | 294 | 55.5 |
| Khartoum Bahri Teaching Hospital | 236 | 44.5 |
| Occupation | ||
| Physician | 267 | 50.4 |
| Nurse | 164 | 30.9 |
| Laboratory technician | 80 | 15.1 |
| Pharmacist | 19 | 3.6 |
| Shift type | ||
| Day shift only | 38 | 7.2 |
| Night shift only | 127 | 24.0 |
| Both day and night shifts | 365 | 68.9 |
| Working hours per shift | ||
| 8 hours | 27 | 5.1 |
| 12 hours | 201 | 37.9 |
| 16 hours | 99 | 18.7 |
| 24 hours | 203 | 38.3 |
| Work experience | ||
| 1–3 years | 391 | 73.8 |
| 4–6 years | 75 | 14.2 |
| 7–9 years | 20 | 3.8 |
| > 9 years | 44 | 8.3 |
| Outcome | Day shift n (%) | Night shift n (%) | Both shifts n (%) | χ² | P value |
|---|---|---|---|---|---|
| CVS symptoms | 3 (7.9) | 26 (20.5) | 96 (26.3) | 15.92 | 0.001 |
| GIT symptoms | 5 (13.2) | 36 (28.3) | 158 (43.3) | 48.57 | 0.001 |
| Poor sleep quality | 22 (57.9) | 90 (70.9) | 317 (86.8) | 68.90 | 0.001 |
| Social life affected | 26 (68.4) | 78 (61.4) | 336 (92.1) | 68.92 | 0.001 |
| Family life affected | 30 (78.9) | 79 (62.2) | 316 (86.6) | 35.26 | 0.001 |
| Reduced job satisfaction (agree/strongly agree) | 19 (50.0) | 57 (44.9) | 213 (58.4) | 26.57 | 0.001 |
| Outcome | Working Hours (Mean) | Working Hours (SD) | P value |
|---|---|---|---|
| CVS symptoms | 0.003 | ||
| Yes | 18.98 | 5.83 | |
| No | 16.57 | 5.56 | |
| GIT symptoms | 0.001 | ||
| Yes | 18.90 | 5.64 | |
| No | 16.10 | 5.50 | |
| Family life affected | 0.001 | ||
| Yes | 17.80 | 5.72 | |
| No | 14.43 | 4.79 | |
| Social life affected | 0.001 | ||
| Yes | 17.79 | 5.71 | |
| No | 13.96 | 4.49 | |
| Sleep quality | 0.001 | ||
| Normal | 16.00 | 5.37 | |
| Poor | 17.41 | 5.76 | |
| Job satisfaction | 0.001 | ||
| Strongly disagree | 8.62 | 5.35 | |
| Disagree | 13.85 | 4.53 | |
| Neutral | 15.09 | 5.16 | |
| Agree | 17.62 | 5.78 | |
| Strongly agree | 19.22 | 5.60 |