Association between sleep quality and quality of life among resident doctors in a tertiary hospital in Nigeria: a cross-sectional study

INTRODUCTION

Sleep quality is a term in mental health that continues to attract scholarly reviews across interdisciplinary domains due to its dominant influence on human health globally. It refers to how well an individual sleeps and is often considered essential to general human health.¹ The impact of sleep deprivation cannot be overstated, as poor sleep quality has been linked to increased mortality rates and various health conditions, including neurological problems, cardiovascular diseases, weakened immune function etc.^2-4 Globally, the prevalence of poor sleep quality(PSQ) is estimated at 20 percent in developed countries, compared to approximately 17 percent in the developing world.⁵ Moreover, maintaining good sleep quality is crucial, as it is nearly impossible to perform daily tasks effectively without adequate rest.

On the other hand, quality of life (QOL) is complex to measure. Nevertheless, the World Health Organization (WHO) attempts to define it broadly as an embodied phenomenon that includes a person’s physical health, psychological state, level of independence, social relationships, personal beliefs and relationship to salient features in the environment.⁶ While objectively assessing sleep quality through methods like polysomnography can be costly, especially in low income countries, several sleep questionnaires have made it possible to explore the relationship between sleep quality and quality of life in contexts like Nigeria.⁷

Several studies have explored sleep; quality and sleep disorders among medical students and practitioners in hospital in Nigeria and globally. However, many of the studies exclusive focused on general socioeconomic and health factors among the populace with existing comorbidities like HIV, pregnant women, chronic renal diseases etc, as well as on healthy populations at the community level.^8-10 Despite this growing body of research, there is a significant gap in the literature regarding the impact of sleep quality on QOL of resident doctors, particularly in Nigeria. For instance, in New Zealand, a study was carried out to determine the correlation between medical students’ sleep quality and clinical performance and this revealed a poor relationship between sleep duration and lower assessment scores.¹¹

In addition, another study was conducted to examine the underlying factors affecting sleep quality among Saudi physicians and nurses in a tertiary health care centre. Some of the factors identified align strongly with this study, including burnout levels, workload (work conditions), medical specialities, family issues, and diet. Perhaps there are more similarities between Saudi Arabia and Nigeria because they promote family ties and multicultural and religious communities. Nonetheless, it was noted that poor sleep quality is a subjective intercultural global phenomenon consistent with medical practice, even among Saudi medical students.¹²

The strengths of our study are that the data is more targeted towards Nigerian resident doctors across different specialities, with the potential to unearth areas to improve their academic performance during the training programme. Also, it determines the causal relationship between sleep hygiene and sleep quality and complex and long-term factors underlying poor sleeping quality in a multicultural setting like Nigeria. This study aimed to assess the relationship between sleep quality and QOL among resident doctors in a tertiary hospital located in southwestern Nigeria.

METHODS

Study setting

This study was conducted across various departments offering residency training at the University of Ilorin Teaching Hospital (UITH) in Ilorin, Kwara State, Nigeria. The departments involved in the residency programme include anesthesia, behavioural sciences (psychiatry), ENT (otorhinolaryngology), epidemiology and community health, family medicine, laboratory medicine (chemical pathology, hematology, microbiology, pathology), internal medicine, obstetrics & gynecology, ophthalmology, pediatrics, radiology and surgery.¹³

Study design

This hospital based cross-sectional analytic study was conducted between August 2015 and February 2016.

Study population

The study population were residents in all departments of UITH offering residency training within the study period and who met the inclusion criteria.

Inclusion criterion

All residents who consented to participate in the study.

Exclusion criteria

Exclusion criteria for this study include residents on external rotation at during the study, those with histories of sleep disorders, those unwell and those who were less than 3 months into the residency programme.

Sample size determination

The sample size was estimated using Fisher’s formula for populations <10, 000, with an estimated sample size of at least one hundred and fifty-five (155) participants.¹⁴ However, all consenting resident doctors who met the criteria for the study were included.

Study instruments

Sociodemographic data were collected from participants using a structured questionnaire. Variables collected included age, sex, marital status, clinical variables like previous history of sleep disorders and work-related variables. The Pittsburgh sleep quality index (PSI), a standardized self-rated questionnaire developed by Buysse et al was used to measure sleep quality.¹⁵ This PSQI consists of 24 items that generate seven components: sleep disturbances, use of sleep medication, sleep duration, habitual sleep efficiency, sleep latency, and daytime dysfunction. These components are summed to produce a global sleep quality score ranging from 0 to 21, with higher scores indicating poor sleep quality. A cutoff score 5, validated for use in Nigeria, was used to distinguish between good and poor sleep quality.¹⁶

The WHO quality of life screening instrument (WHOQOL-BREF) questionnaire was used to assess the quality of life. This 26-item instrument uses a 5-point Likert scale to capture respondents perceived quality of life across four domains: physical health, psychological health, social relationship and environment factors. Before the main study, a pilot study involving 20 consenting junior intern doctors at UITH to validate the research instrument was carried out.

Sampling technique

A comprehensive list of all resident doctors in each department was obtained from the Association of Resident Doctors (ARD) and confirmed with the chief resident doctor in each department. Participants were allotted a unique numerical code, recorded on the complete questionnaire to maintain confidentiality. Data collection involved administering the Pittsburgh sleep quality index (PSQI) and the WHO quality of life-BREF (WHOQOL-BREF). Trained research assistants were able to administer the tools. During the data collection, residents with poor sleep quality were advised to seek further evaluation and support from relevant specialist consultants.

Data analysis

All data collected were analyzed using the Statistical Package for Social Sciences (SPSS) version 18. Frequency distribution of the variable was carried out and statistical weighting was done to validate the true prevalence of sleep disorders. Where appropriate, binary logistic regression analysis examined the associations between sleep quality and quality of life. A statistically significant level of less than 0.05 (p<0.05) was used to identify meaningful relationship between variables.

Ethical considerations

Permission to undertake the study with reference number: UITH/CAT/189/21B/659 was obtained from the ethical and research committee of UITH. Also, written approval was sought and obtained from the head of the department of each of the specialty. Informed consent was obtained before participating in the study.

RESULTS

Social- demographic variables of participants

Table 1 shows that the age of participants was 34.14±3.54. The majority (65.4%) were in the age group 31-35 years, there were more males (70.7%) than females (29.3%), 56.3% were Christians, and 43.8% were Muslims. About nine out of ten (89.9%) were married, with most participants having 1-2 children and 161 (77.4%) were Yoruba, 10.1% Hausa, 4.3% Igbo, while the remaining 8.2% were of the other tribes.

Sociodemographic variables of participants (work-related)

Table 2 shows that more than half (62.5%) of the participants were senior registrars, 36.5% of participants have 25-36 months duration of residency; 12-24 months (27.9%), 37-48 months (25.5%), while the remaining 10.1% had a duration of more than 48 months. Participants in the surgical-related departments constituted 46.2% with the departments of surgery and obstetrics and gynecology having the highest percentage of 13.0% respectively. The medical-related departments had 45.7% of the participants with department of community health having the highest percentage of 12.0%.

In contrast, the laboratory-related departments constituted 8.2% of the participants with department of morbid anatomy and hematology having the highest percentage of 2.4%.

Table 3 shows that nearly all (97.1%) of the participants had an interest in their job, of which 88.5% reported that the workload was high, 52.9% working for 51-80 hours per week, 62.0% working on the average of 160-200 hours on call duty per month. More than half (57.7%) attempted part one exam once, 30.0% twice and 12.3% thrice or more before passing. 52.4% of the participants said they rarely/sometimes had financial difficulties. About half (49.5%) of the participants never had time for recreation.

Figure 1 shows that more than half (53.8%) of the participants had good sleep quality while the remaining 46.2 percent had poor quality of sleep. This categorization was based on their global performance on PSQI with a cut-off point 5.

Quality of life of resident doctors

Table 4 shows that participants with poor quality of life had the following scores on all the domains: environment domain (23.6%), physical health (22.6%), social relationship (22.1%), and 17.3% of the participants on the psychological health domain.

Individual’s overall perception of quality of life and perception of their health

Table 5 shows that only 2.4% of the participants perceived that they had a poor quality of life, and 4.3% of the participants were dissatisfied with their health.

Relationship between sleep quality and socio-demographic variables (work-related)

Table 6 shows that most participants with poor quality of sleep were in the surgical-related departments (58.3%), senior registrars (54.2%), and participants who had 12-24 months duration of residency (35.4%). The work-related factors of the participants showed significant relationship with sleep quality (p<0.05).

χ²: Chi square; Y: Yates corrected chi square; *: p value <0.05.

χ²: Chi square; Y: Yates corrected chi square; *: p value <0.05.

χ²: Chi square; *: p value <0.05.

B: Coefficient of logistic regression; OR: Odds ratio; 95% CI: 95% confidence interval. *: p value <0.05; R²: 0.455; Predictive value: 76.9%; χ²: 86.627; p value: <0.001*

Relationship between sleep quality and family-related factors

Table 7 shows the relationship between quality of sleep and family factors of the participants with poor quality of sleep were those that lived with nuclear family (81.3%), while majority of those who had cordial relationship with spouse (98.0%), children (97.6%), family (98.2%) had better sleep quality. An extended family size of 5-6 (46.9%), those who do not sleep alone (87.5%) had poorer sleep quality. Only the family size and type of residence where participants lived had statistical significance among family factors (p<0.05).

Relationship between sleep quality and quality of life

Table 8 shows that poor sleep quality was more in those who had poor perception of their overall quality of life and health (27.1% and 25.0% respectively), poor physical health (36.5%), poor psychological health (27.1%), poor social relationship (31.3%) and poor environment domain scores (36.5%). There was a significant relationship between sleep quality and all domains of the quality of life (p<0.05).

Table 9 shows that significant associations of poor sleep are being in a surgical-related departmental group, living in a three-bedroom apartment, duration of residency, perceived overall poor health and presence of psychiatric morbidity. Residents in surgical related departments have 3.2 times the odds of poor sleep, monthly increase in duration of residency training increases the odds of having poor sleep by about 1.1 times, living in a 3-bedroom apartment increases the odds of having poor sleep about 7.7 times while the presence of psychiatric morbidity increases the odds of having poor sleep quality by 8.3 times.

DISCUSSION

To the author’s knowledge, this is the first study that reports on the association between sleep quality and QOL among doctors in Nigeria. In this study, less than half of the participants were found to have poor sleep quality, with variations observed based on medical specialties and level of seniority. This contrasts with findings from similar studies conducted in countries like Turkey and Pakistan, where poor sleep quality was lower and appeared unaffected by specialty or seniority.^17,18 This discrepancy may be attributed to differences in the structure and rigorous residency training programme, as the Nigerian system places immense significance on academic and professional qualifications, which puts more pressure on the resident doctors’ physical and mental health.

Although not statistically significant, the present study, like the one conducted in Pakistan, discovered that poor sleep quality was more prevalent among female participants.¹⁸ This finding validates existing literature that suggests sleep disturbances are generally more prevalent among women.^19,20 In the African context, additional pressures such as family responsibilities and household obligations, when combined with the demands of medical training, may further contribute to the higher prevalence of poor sleep quality among female resident doctors.

The study also revealed that resident doctors who had attempted their first professional examination three or more times were more likely to experience poor sleep quality. This may be attributed to institutional policies that require residents to pass the examination within four attempts, beyond which they risk dismissal from the residency programme. The pressure and anxiety associated with this policy likely contribute to sleep disturbances. It is widely recommended that adults obtain at least eight hours of sleep per night, and sleep deprivation has been shown to negatively functioning negatively.^21,22 Insufficient sleep impairs clinical judgement and increases the risk of medical errors in the medical field.²¹

Although not statistically significant, this study also observed that residents working more than 80 hours per week tended to have poor sleep quality. Similar findings have been reported in other studies, linking extended work hours with high levels of sleep deprivation, reduced job performance, and increased likelihood of errors.²² At the study site, it was common for residents to work beyond 80 hours per week, mainly due to the high workload and staffing shortages. This situation is exacerbated by the ongoing brain drain in Nigeria’s healthcare sector, which has placed additional strain on the remaining workforce and negatively impacted their well-being, including sleep quality.^23,24

This study identified a significant association between sleep quality and several work-related factors, including departmental classification, professional rank, and duration of residency training. Residents in surgical departments had poorer sleep quality compared to their counterparts in medical and laboratory-based departments. This disparity may be attributed to the intense demands of surgical call duties, which often involve late-night operations due to limited access to essential facilities such as operating theatres and emergency services.

Furthermore, senior registrars reported poorer sleep quality, likely due to the compounded responsibilities associated with their role. These include increased clinical and administrative duties, research commitments, and the added pressure of preparing for and successfully passing the second professional examination within a set timeframe. The cumulative stress from these expectations may significantly impair their ability to rest adequately. Also, family-related factors were associated with poor sleep quality in this study. Specifically, residents with a Family size of 5-6 members and those living in 3-bedroom accommodation reported poor sleep quality. While a study conducted in Iran did not establish a significant association between family size and sleep quality, the findings in the present study may be explained by increased stress and responsibilities that often accompany larger household sizes.²⁵ Managing the needs of a larger family can contribute to psychological strain and reduced rest.

Finally, most participants with poor sleep quality also reported lower scores across physical, psychological, social relationship and environmental domains of QOL. Numerous studies have highlighted the connection between poor sleep quality and various mental health issues, as well as physical conditions such as hypertension, diabetes etc.^26-28 The findings of this study further reinforce their relationship, showing a significant association between sleep quality and quality of life. This suggests that sleep deprivation among resident doctors has a detrimental impact on their overall wellbeing and QOL.

This study was conducted in a single centre in Nigeria. The study’s results may not accurately represent of the experience of all doctors in Nigeria since it was conducted in one region of the country.

CONCLUSION

This study has highlighted several key associations between sleep quality and QOL among doctors, particularly, resident doctors in Nigeria. Notably, work-related factors such as being in a special speciality, holding the position of senior registrar, and having spent 12-24 months in residency influence sleep quality. The study also reveals a high prevalence of poor sleep quality among resident doctors, significantly affecting their overall quality of life during their residency training programme.

ACKNOWLEDGEMENTS

Authors appreciate the resident doctors and heads of departments at the University of Ilorin Teaching Hospital.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee reference number: UITH/CAT/189/21B/659

REFERENCES

1. 1. National Institutes of Health. Good Sleep for Good Health: Get the Rest You Need. NIH News Health. 2021. Available from: https://newsinhealth.nih.gov/sites/newsinhealth/files/2021/April/NIHNiHApr2021.pdf. Accessed on 3 May 2025.
2. 2. Rod NH, Kumari M, Lange T, Kivimäki M, Shipley M, Ferrie J. The joint effect of sleep duration and disturbed sleep on cause-specific mortality: Results from the Whitehall II cohort study. PLoS One. 2014;9(4).
3. 3. Tochikubo O, Ikeda A, Miyajima E, Ishii M. Effects of insufficient sleep on blood pressure monitored by a new multibiomedical recorder. Hypertension. 1996;27(6):1318-24.
4. 4. van Leeuwen WM, Lehto M, Karisola P, Lindholm H, Luukkonen R, Sallinen M, Härmä M, Porkka-Heiskanen T, Alenius H. Sleep restriction increases the risk of developing cardiovascular diseases by augmenting proinflammatory responses through IL-17 and CRP. PloS One. 2009;4(2):e4589.
5. 5. Stranges S, Tigbe W, Gómez-Olivé FX, Thorogood M, Kandala NB. Sleep problems: an emerging global epidemic? Findings from the INDEPTH WHO-SAGE study among more than 40,000 older adults from 8 countries across Africa and Asia. Sleep. 2012;35(8):1173-81.
6. 6. WHO. A glossary of terms for community health care and services for older persons. Ageing Health Tech Rep. 2004;5.
7. 7. Mendonça F, Mostafa SS, Morgado-Dias F, Ravelo-Garcia AG, Penzel T. A review of approaches for sleep quality analysis. IEEE Access. 2019;7:24527-46.
8. 8. Olutola BF, Adejuwon AG. Sleep quality components as predictors of health-related quality of life domains among primigravida in Ibadan, Nigeria. J Sleep Sci. 2021;5(4):146-54.
9. 9. Adejumo OA, Edeki IR, Mamven M, Oguntola OS, Okoye OC, Akinbodewa AA, et al. Sleep quality and associated factors among patients with chronic kidney disease in Nigeria: a cross-sectional study. BMJ Open. 2023;13(12):e074025.
10. 10. Jemilohun AC, Fasesan OA, Ajiro TO, Akande KO, Elikwu CJ, Adeleye OO. Sleep quality in a Nigerian community: prevalence of poor sleep quality, risk factors and health-related quality of life. West Afr J Med. 2022;39(7):729-36.
11. 11. Falloon K, Bhoopatkar H, Moir F, Nakatsuji M, Wearn A. Sleep well to perform well: The association between sleep quality and medical student performance in a high-stakes clinical assessment. SLEEP Adv. 2022;3(1):1-8.
12. 12. Talaia A, Sowidan A, Fahim A, Elzohery A, Hammoda A, Kabbash I. Sleep hygiene practices and sleep quality among medical students in Egypt: a cross-sectional study. Sleep Sci Pract. 2025;9(1):6.
13. 13. University of Ilorin Teaching Hospital, Ilorin, Kwara State. 2025. Available from; https://www.uithilorin.org.ng/about. Accessed on 5 June, 2025
14. 14. Kasiulevičius V, Šapoka V, Filipavičiūtė R. Sample size calculation in epidemiological studies. Gerontologija. 2006;7(4):225-31.
15. 15. Buysse DJ, Reynolds III CF, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh sleep quality index: a new instrument for psychiatric practice and research. Psychiatr Res. 1989;28(2):193-213.
16. 16. Aloba OO, Adewuya AO, Ola BA, Mapayi BM. Validity of the Pittsburgh sleep quality index (PSQI) among Nigerian university students. Sleep Med. 2007;8(3):266-70.
17. 17. Tür FÇ, Toker İ, Tür B, Hacar S, Türe B. Assessment of the Pittsburgh sleep quality index among physician’s speciality who work night shifts. Emerg Med Open J. 2015;1(1):5-11.
18. 18. Surani A, Surani A, Zahid S, Ali S, Farhan R, Surani S. To assess sleep quality among Pakistani junior physicians (house officers): a cross-sectional study. Ann Med Health Sci Res. 2015;5(5):329.
19. 19. Klink M, Quan SF. Prevalence of reported sleep disturbances in a general adult population and their relationship to obstructive airways diseases. Chest. 1987;91(4):540-6.
20. 20. Asghari A, Farhadi M, Kamrava SK, Ghalehbaghi B, Nojomi M. Subjective sleep quality in urban population. Arch Iran Med. 2012;15(2):95-8.
21. 21. Puvanendran K, Venkatramani J, Jain A, Farid M. Sleep deprivation in junior doctors- house officers in Singapore. Ind Health. 2005;43(1):129-32.
22. 22. Mustahsan SM, Ali SM, Khalid F, Ali AA, Ahmed H, Hashmi SA, et al. Sleep deprivation and its consequences on house officers and postgraduate trainees. J Pak Med Assoc. 2013;63(4):540-3.
23. 23. Ajoseh S, Langer A, Amoniyan O, Uyah UA. Navigating brain drain: understanding public discourse on legislation to retain medical professionals in Nigeria. Glob Health. 2024;20(1):1-11.
24. 24. Osigbesan OT. Medical brain drain and its effect on the Nigerian healthcare sector. Walden University. 2021.
25. 25. Taavoni S, Ekbatani N, Haghani H. Postmenopausal women’s quality of sleep and its related factors. J Midlife Health. 2015;6(1):21.
26. 26. Kasasbeh E, Chi D, Krishnaswamy G. Inflammatory aspects of sleep apnea and their cardiovascular consequences. South Med J. 2006;99:58-68.
27. 27. Knutson KL, Ryden AM, Mander BA, Van Cauter E. Role of sleep duration and quality in the risk and severity of type 2 diabetes mellitus. Arch Intern Med. 2006;166(16):1768-74.
28. 28. Wall TD, Bolden RI, Borrill CS, Carter AJ, Golya DA, Hardy GE, et al. Minor psychiatric disorder in NHS trust staff: occupational and gender differences. Br J Psychiatr. 1997;171(6):519-23.