Introduction

The appearance of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes the coronavirus disease of 2019 (COVID-19), declared as a pandemic by the World Health Organization (WHO) on March 11, 2020,¹ has resulted in a succession of changes in all spheres of social life. We must acknowledge that the senior educational system was also unprepared for a disruption of the kind of the COVID-19 pandemic;² consequently, more than 100 countries have been affected by the suspension of teaching activities.¹

Medical education has been affected as well in different regions of the planet,^3,4and the proposals made to mitigate the effects of the discontinuity of teaching are numerous, reaching from the implementation of distance education modalities to the incorporation of students to health care labors;^5-10 in such a way that students becomes an active element in solving the problem and not part of it.

In Cuba, students of finals years of the medical careers have been worked bringing assistance in hospitals and isolation centers for cases suspicious of COVID-19. In addition, some distance teaching modalities have been trialed with good results so far, regarding that they have been never used in Cuban medical education. An element to be emphasized is the massive incorporation of students from all medical careers and academic years to active inquiries work in primary health care, in search of respiratory symptomatic cases, with prior vigorous training for this activity.^11-13

Stress is a widespread health problem in the world.¹³ It is the process or reflex that is set in motion when a person perceives a complex situation in which they find something that is threatening themselves. According to its determination, it is a social phenomenon, and by its nature, it is also a psy-chophysiological singularity,^14,15 which by acting constantly on one individual and added to other factors, becomes a trigger for numerous diseases. University students constitute a vulnerable population for mental health problems because of the changes they experiment in the transition to adult life.^16,17

The COVID-19 pandemic has generated among the population high degrees of stress, anxiety and depression, resultant from the effects of quarantine and social isolation, to which it is added for the specific case of health professionals, the stress generated by health care to the contagious patients and overload of work.^18-20 Regarding these elements, it is necessary to have valid and reliable measurements implemented in a remote manner. In this sense, among other instruments, there is the Cohen scale of stress perceived (PSE)²¹ and a modified version of it for the Colombian population.²² The last one, known as the 10-item stress perceived scale modified in relation to COVID-19 (EEP-10-C), more adapted to the Latin American context, have not been validated among students of the medical sciences or other populations than the Colombian.

In the actual Cuban context, there is an absence of a validated instrument to determine the stress levels perceived toward the COVID-19 pandemic, and specifically among students of the medical sciences, who as well as the health professionals, are individuals with high risk of infection. It worth it to investigate if the scale based on the EEP-10-C is valid among students of the medical sciences, regarding the characteristics of this kind of population, as well as the possibility of facilitating more specific evaluations and interventions in the vulnerable population. The aims of this study were to asses the usefulness of the EPP-10-C scale and to identify the stress levels perceived in Cuban students of the medical sciences during the COVID-19 pandemic.

Methods

Results

Table 1 shows the descriptive analysis of the sample, composed of students from all Medical Universities of Cuba. There was representativeness of all careers, with a wild predominance of Medicine. Students in terminal years (fourth, fifth and sixth) constituted the majority of the group studied, with predominance of young students who stioll lived with their parents. In the medical history analysis, it was found that bronchial asthma was reported by 28% of the students, while 60% did not report the presence of personal pathological antecedents. None of the students referred to have been ill with COVID-19, however 7.5% of those surveyed reported knowing someone who contracted the disease. The active inquiries work predominated among the activities carried out during the epidemic months 77.0%), where only 1.5% of the students reported having been permanently isolated at home.

Table 2 shows that there were no statistically significant differences between genders in terms of answers given in the EEP-10-C questionnaire in any of the items that are evaluated on the scale. The scores obtained on the scale were generally low. Only 2 subjects scored higher than the cut-off point (25) proposed previously for high stress perceived related to COVID-19. The mean of the scale scores was 13.25 ± 5,404, with values between 0 and 29 points.

The measurement instrument validity was confirmed by the exploratory factor analysis EFA), which made it possible to determine that the sample is adequate for the instrument, with association between items. In this analysis, it was found that all the communalities in the extraction were >.4; with a sample adequacy measure of KMO>.5 and a statistical significance of Bartlett sphericity test< .05 (Table 3). These results allow to applie the scale legitimately regarding its validation in the analyzed sample.

Table 4 shows the reliability analysis by applying Cron-bach's alpha coefficient, which allows to evaluate the internal consistency of the instrument. The internal consistency of the EEP-10-C is good (a =.755), which means that the scale has good psychometric properties, representing the high rate to which the items are correlated with each other. The results of the descriptive reliability analysis for Cronbach's alpha if one element is eliminated, did not show any useful results under the assumption of eliminating any of the items to increase the reliability of the scale, thus confirming the validity and precision of the EEP-10-C.

Table 5 shows the clusters obtained through the K-means analysis, by means of which three homogeneous but at the same time significantly different from each other groups were created (P = .000) according to the score on the EEP-10-C scale. The centers of the final clusters represent the average values of each cluster, therefore it is understood as the mean score obtained by the subjects belonging to each group.

Cluster 3 was made up of the 56 individuals with the highest scores on the EEP-10-C scale, so its center is proposed as a reference to establish the cut-off point (>20) for high stress perceived related to COVID-19 in the study population.

Table 6 shows the comparison of the sample according to the score achieved on the scale and the classification of the groups using the proposed cut-off point (>20). It was observed that 28 students were identified with high stress perceived related to COVID-19, resulting in the difference between both groups as statistically significant (P< .001).

Discussion

This is the first study applying the 10-item stress perceived scale modified in relation to COVID-19 (EPP-10-C)²² or some version of the Cohen scale²¹ in medical science students in Cuba and in students from Spanish America in general.

Participants in this investigation were all young students of the medical sciences, the majority of whom were male. However, no statistically significant differences were found between gender and responses to the EEP-10-C or high level of stress, which differs from other studies.^23,24

In this investigation, when applying the cut-off point >25, only 2 students had a high degree of stress perceived, with a mean score in the EEP-10-C of 13.25 ± 5.40 points, which indicated low stress perceived in this population. Campo-Arias²² obtained a mean score on the scale of 16.5 ± 7.3, with values between 0 and 36 points, reporting 58 (14.28%) individuals with high stress perceived, but it should be noted that its population was more heterogeneous regarding age, with participants between 19 and 88 years old (mean, 43.9 ± 12.4). Aslan et al.²⁴ evaluated stress perceived in nursing students in Turkey, using a validated version of Cohen's scale, in which they obtained a mean of score on the scale much higher than the present investigation (31.69 ± 6.91).

Other authors have evaluated the psychological impact of COVID-19. In a study that evaluated the stress perceived in students at KSA using the Cohen scale²⁵, mean scores of 22.12 ± 7.33 were shown, which are higher compared to this study, and concerned a higher degree of stress. Similar results to those have been found in researchs carried out on university students in France²⁶, Spain¹, Belarus, and Russia² during the COVID-19 pandemic, where anxiety, stress and depression were reported. The results of these studies may be partly due to the stress generated in the context of quarantine and social distancing,¹⁹ which has affected the whole world, but more severely to countries with higher population density.

Students of the medical sciences in Cuba have been actively participating in labors of antagonizing the disease related to active inquiries work or providing health care. On the other hand, this fact generates a paradox, because although they are not victims of the severe effects of prolonged quarantine and social distancing, they have been exposed to a major risk, given by the low percentage of stress perceived 1% for cutoff point >25 and 14% for cut-off point >20). This last result may be influenced by having up-to-date information on the disease, which has been associated with less psychological impact.^18,29

Not all studies has shown a negative impact of COVID-19 on the mental health of university students. An investigation carried out in China on undergraduate medical students showed that only a minority of this group had moderate (2.7%) or severe (0.9%) anxiety.²

After performing the K-means conglomerate analysis, from which a cut-off point of >20 is proposed in the EEP-10-C for Cuban medical science students, those classified as high stress perceived increase, despite this new group only represent 14% of the total. In another study carried out in Cuba, it was found that medical students who participated in the active inquiries work presented low vulnerability to stress, not being present in 83% of the sample studied.² This result is similar to the obtained in this study, though in that case the instruments used was different from ours and it was not validated for the population on the context of COVID-19.

The limitations of the study include those inherent to cross-sectional studies when establishing statistical associations and not causality. Other limitations include the procedures for the conformation of the sample non-probabilistic) and the virtual form of the survey that could generate recall and selection biases, as well as the short time limit for the students answers. In contrast, stress perceived was not stratified into levels, only the high degree of stress perceived or not was considered. Future research should take this limitation into account and stratify the population according to the level of stress into low, medium, and high levels and look for possible statistical associations between this and sociodemographic factors, which was not possible in this research due to the poor percentage of stress perceived <1%), and even after adjusting the cut-off point to >20 14%)" however, the validity and internal consistency of the EEP-10-C was demonstrated, with the potentiality to generalize its application in Cuba.

The strength of the research is that it is one of the first studies to address aspects of the mental and occupational health of students of the medical sciences in Cuba toward the epidemic, carried out with an easy-to-fill online survey. Another strength is the representativeness of students from all the medical universities of Cuba. The main contribution of the research was the validation of the EEP-10-C for Cuban medical majors, and the proposal of the cut-off point >20 as high stress perceived for this population to be evaluated for other authors in future research.

Other subsequent studies should evaluate the validity of the instrument for the rest of the Cuban population and health professionals, to assess if it is necessary to formulate psychological interventions to improve the mental health of vulnerable populations during the COVID-19 epidemic