Hours of sleep and associated factors in college students during the COVID-19 pandemic

1 Introduction

The world scenario has been marked by the COVID-19 pandemic since 2020. As a result, the World Health Organization (WHO) has recommended measures such as the use of face masks, isolation and social distancing, quarantine and increased frequency of hand and surface hygiene, in addition to other measures to prevent the spread of the disease. The impact of the pandemic, therefore, goes beyond the economic and political fields, reaching the physical, social, educational and mental health domains [1–3].

In this scenario, the various restrictions imposed by the COVID-19 pandemic have caused significant changes in education systems, especially due to the adherence to virtual education or, as in many institutions, the abrupt interruption of classes, internships, projects, research and graduations [4]. Recently, studies have pointed out the negative effects of COVID-19 on university students, including high levels of stress and physical and mental exhaustion, with consequent changes in sleep, mainly related to stress [5–7].

Sleep is a physiological event that aims to contribute to survival due to its regulatory and recuperative characteristics. During sleep, there are cellular repair processes, an improvement in the immune response and an increase in cerebral blood flow. Thus, in situations of sleep deprivation, the ability to remain healthy, with good interpersonal relationships and satisfactory performance of social roles can be affected [8].

Recent research shows that, during the pandemic, there was an increase in the frequency of sleep-related problems and common mental disorders in general when compared to research carried out in non-pandemic years [9, 10]. In the case of university students, these findings can be explained, for example, by changing their daily routine or even their sleep routine during the period of social distancing [11]. This change in routine is marked by stressors, such as fear of contracting the disease, economic tension, uncertainty about the future, need to stay online with intense use of a virtual environment for study and/or work, and loneliness resulting from social isolation. Added to this, changes in the sleep-wake rhythm, use and time devoted to electronic devices before bed may have increased the length of stay in bed, however, with a lower quality sleep and a higher prevalence of insomnia [9, 12].

It is worth noting that in situations of social isolation, it is common to identify sleep alterations or disorders, such as insomnia, difficulty sleeping or excessive sleep, in addition to constant nightmares [13].

Life habits that impair the quality and quantity of sleep, such as consumption of alcohol, tobacco, sedentary lifestyle, among others, increase human vulnerability and, consequently, change sleep-related conditions, especially in populations that are more vulnerable to these issues, such as university students [14]. It is therefore believed that all these variables are related not only to an increase in sleep problems, but also to an increase in depressive and anxiety symptoms, particularly among young people [9, 12].

Studies indicate that issues related to sleep have negative influences that interfere in various clinical conditions, organs and systems of the human body, leading to consequences that compromise the quality of life and the emergence of several diseases, among which the emergence and the increase in non-communicable chronic diseases such as diabetes, hypertension, coronary and respiratory diseases [15]. In addition, university students who had their sleep affected during the COVID-19 pandemic showed altered eating habits with body weight gain, in addition to low levels of physical activity [16], which can worsen the emergence of such chronic diseases.

Associated factors between chronic noncommunicable diseases and sleep-related problems were mediated by the emergence of sadness and nervousness during the COVID-19 pandemic [15, 17]. A study with self-reported data by participating university students who claimed to have their sleep affected by the pandemic points to an increase in the number of visits to health care for mental health problems, the recognition of high anxiety/nervousness, sadness and affective isolation as a result [16]. These factors added to sleep deprivation can have harmful effects for the general population, with greater impact on young adults and women [9]. Thus, the present study aimed to identify the sociodemographic factors and health characteristics associated with the number of hours of sleep of college students during the COVID-19 pandemic.

2 Methods

This was a primary, descriptive, quantitative and cross-sectional study carried out at a multi-campi public university in the State of Bahia, Brazil. This university is geographically present with a Campus based in the state capital, where the central administration of the institution is established, and another 23 campuses distributed in important medium and large municipalities in Bahia. It has a total of 30 departments located on 24 campuses, offering approximately 150 options for undergraduate courses, either face-to-face or distance learning (https://portal.uneb.br/).

The study followed all ethical procedures for research with human beings, following the Declaration of Helsinki and the norms of Resolution 466/12 of the Brazilian Ministry of Health. The study was approved by the University Ethics Committee, with opinion number 4,100,093 and CAEE number 31627020.5.0000.0057. All voluntary participants consented to participation through the Free and Informed Consent Term (FICT).

3 Results

Of the 244 university students in this study, most were aged up to 27 years (72.43%), were female (78.28%), were in the final phase of their course (59.84%) and were students in the health area (50.20%). As for occurrences during the pandemic period, most reported not having presence of illness (78.28%), not having increased use of medication (86.89%), not having used alcohol, tobacco or other drugs (56.97%, 98.49% and 94.67%, respectively), not having COVID-19 diagnosis (98.35%) and having slept less than 7 hours of sleep in the last month (60.66%) (Table 1).

As seen in Table 2, the study revealed that fewer hours of sleep (≤7 hours) were significantly more frequent in older individuals (80.60%), who were in the last semesters of the courses (67.12%) and with previous illnesses (73.58%). It was noted that more hours of sleep (≥8 hours) were significantly more frequent (81.82%) in those who used tobacco. No significant differences were observed in the other variables analyzed (p > 0.05).

In the analysis of crude associations, the final model was adjusted by the variables age, semester, presence of illness and tobacco use, as there was an improvement in the statistical significance of the variables included in the binary logistic regression. Thus, we observed that students aged 28 years or older are 3.75x more likely to have fewer hours of sleep when compared to younger students (ORaj: 3.75; CI: 1.81–7.75; p < 0.01). Regarding the course period, it was found that students enrolled in the final semesters of the courses (semester ≥7) are 85% more likely to have reduced hours of sleep when compared to those enrolled in the initial semesters (semester ≥6) of the courses (ORaj: 1.85; CI: 1.05–3.25; p < 0.03). Students who reported having some type of illness were 2.18 times more likely to sleep less (ORaj: 2.18; CI: 1.05–4.50; p < 0.03). Students who report tobacco use were less likely to sleep less when compared to those whose did not report tobacco use. In other words, those exposed have a 92% lower chance of developing the outcome compared to those not exposed (ORaj: 0.08; CI: 0.01–0.45; p < 0.001) (Table 3).

The aim of the present study was to identify the sociodemographic factors and health characteristics associated with the number of hours of sleep of college students during the COVID-19 pandemic. Most participants (60.66%) had sleep restrictions, considering hours of sleep ≤7 hours in the month prior to the survey. Similar results were observed by Almojali et al. [19], as 73.4% of a sample of 306 university students in Saudi Arabia reported sleeping less than seven hours a night. Becker et al. [20] in a study conducted with university students from six different universities in the United States and Araújo et al. [14] in a study conducted with university students in the city of Fortaleza, Ceará –Brazil, observed that a third [20] and that the majority (81.4%) [14] of students reported sleeping less than eight hours a night, respectively. These data demonstrate that the restriction of sleeping hours at night is a common problem for university students. This population has probably experienced the consequences of this deprivation, such as daytime drowsiness, difficulty concentrating, irritability, difficulty making decisions, proneness to stress and mental suffering, and impaired attention [20].

By revealing that a higher frequency of fewer hours of sleep were observed in older individuals and among those who were in the last semesters of the courses, this study corroborates the results presented by Haregu et al. [21] who showed that with increasing age of students there is an increase in the prevalence of sleep disorders, which are directly related to the occurrence of psychiatric disorders that can be a result of pressures related to jobs and socioeconomic issues. In addition, other studies [22, 23] observed that the worst quality of sleep progresses with the years of graduation, according to the perception of students of medicine and physiotherapy courses, confirming the data found in this study.

Sleep-related problems and the presence of non-communicable chronic diseases were reported in a recent study [15], carried out in Brazil with 45,161 people aged 18 years and over, where 44.9% of the participants reported an increase in sleep-related problems during the COVID-19 pandemic and 33.9% reported at least one chronic non-communicable disease.

The study [15] also revealed that the likelihood of sleep problems was higher among people with diabetes (OR: 1.34; 1.05–1.71), hypertension (OR: 1.26; CI: 1.06–1.50) and with coronary heart disease (OR: 1.36; CI: 1.13–1.65) or respiratory diseases (OR: 1.42; CI: 1.04–1.93). These findings converge with the findings of this research, where university students who reported having some type of previous illness were 2.18 times more likely to have poor sleep (ORaj: 2.18; CI: 1.05–4.50; p < 0.03).

The data shown alert us to the care that is necessary during the COVID-19 pandemic with regard to caring for the emotional state and sleep in those with chronic diseases, as people with chronic diseases can develop sleep-related problems.

The reduction in hours of sleep was also associated with the advancement of undergraduate semesters, age and the presence of illness, which may demonstrate that, as the years go by and with the arrival of adulthood, students are more likely to have reduced hours of sleep. On the other hand, it seems that in crisis contexts, a possible escape to smoke may have a protective effect on sleep hours, as more sleep hours were observed in those who smoked. Research carried out with university students entering and graduating from a university in Pelotas, Rio Grande do Sul, Brazil showed that smoking had a direct relationship with age and the current semester, where the older the university student and the more advanced the semester studied, the greater the likelihood of tobacco consumption [24]. Another study carried out in the state of Pernambuco with university students revealed a prevalence of smoking in 52.3% of new university students and 67.5% of graduates [25]. However, unlike our study, which found a greater amount of sleep associated with smoking, the results of the aforementioned studies show that in addition to age, semester and presence of illness, tobacco use seems to help these students sleep more hours per night. These findings allow us to suggest the need for interventions to mitigate future illnesses among students and further investigations regarding the smoking habit. Although we are relating longer hours of sleep with better sleep quality, in this cross-sectional study it is not possible to confirm whether in fact longer hours of sleep necessarily mean higher quality sleep, because hours of sleep are only one dimension of sleep. Additionally, a healthy sleep is characterized by other dimensions such good quality, appropriate timing, regularity and the absence of disturbances [26].

The social isolation generated by the COVID-19 pandemic is related to poor sleep, as it is strongly associated with situations related to stress and anxiety, a fact described in a study carried out in Hubei, China, in a sample of 939 individuals [27]. A convenience sample with 197 members from a University in Lebanon observed that during the COVID-19 pandemic, issues related to confinement at home, economic crisis and stress were associated with an increase in smoking [28]. The description of the association between poor sleep and the increase in tobacco use was also found in the studies by Altena et al. [29] and Malta et al. [30] who mentioned the worsening of sleep as an important factor in the increase in tobacco consumption. This reinforces our caution in interpreting the finding of this study in relation to sleep and smoking habits.

A possible justification is that tobacco use has an action of discharging stress, leading to a potential effect of relieving overload, promoting increased hours of sleep during the COVID-19 Pandemic. For Araújo et al. [14] the search for different sensations and stress relief seems to be related to the persistence of tobacco use among the 662 university students who participated as sample of a study conducted in Fortaleza, Brazil. Considering the important influence of sleep on emotional regulation, sleep disorders cause changes in emotional behavior and can promote increased tobacco consumption. The findings of this study encourage policies at the public health level coordinated by the University administration in order to promote better lifestyles and avoid serious health consequences on the students’ mental health.

Nonetheless, the significant finding in relation to smoking needs to be interpreted with caution, particularly because only 11 participants (4.5% of the sample) use the substance. In this sense, future studies are recommended to elucidate other points, such as the fact that the decrease in hours of sleep also reflects the responsibilities of modern society, bad life habits, increased workload and social instability. As mentioned in the literature [26], the pandemic directly affected sleep due to the infection itself, the severity of the symptoms or vaccination, and indirectly due to the social isolation, lockdown and absence of psychological support. All these factors are related, can explain the alterations of sleep and mental health consequences.

The following limitations need to be pointed out in this study: the small number of students in the sample, the limitations inherent to cross-sectional studies, the non-use of standardized scales that could measure sleep quality beyond sleep hours. Despite the cut-off of ≤7 hours used in this study might be a limitation and contradictory argument to explain sleep quality, there is a consistent indication in the literature [31, 32] that fewer hours of sleep per night can increase the risk for depression in young, particularly during the college period. However, our results were able to demonstrate important associations that need to compose the University administration’s action strategies to improve the health and quality of life of students during the COVID-19 pandemic. Another limitation of our study is regarding the use of self-report questionnaires, as they depend on the participants self-assessment, which can lead to errors in memory, interpretation or even the omission of relevant information. Additionally, the lack of an interviewer to clarify questions or provide contextualization may result in inaccurate responses. Another issue is the low response rate, as not all participants may feel motivated or willing to complete the questionnaires. Taking into account the large number of students enrolled in the courses, we expected higher response rate than we had. However, most of the students are from very poor locations in the countryside of the State and no internet connection was part of the routine of these students during the pandemic.

5 Conclusion

Sleep restriction was common among participating college students, but if it has intensified due to the COVID-19 pandemic then its restrictions should be further investigated. Significant associations for fewer hours of sleep were found for those older, enrolled in the final semesters of undergraduate courses, with a self-reported diagnosis of COVID-19. Increased sleep was also found for those who smoked in the six months prior to the survey. Further studies are needed to better understand the implications of the COVID-19 pandemic and remote teaching on sleep quality among college students. Our findings encourage more specific public health guidelines that can address the health and sleep quality of this population.

Ethical approval

Ethical approval was obtained from the human research ethics committee of the State University of Bahia (no. 31627020.5.0000.0057, date June 19, 2020).

Informed consent

All participants signed an informed consent form and completed the online survey.

Conflict of interest

The authors have no conflict of interest to report.