Introduction

In the past decades, travelling has changed irreversibly. Air travel has become increasingly accessible due to reduced ticket prices, expanded flight networks, and the growing number of airline carriers. At the same time, the number of hours spent in the plane by a single person in a sitting position has increased as well. Prolonged sitting in confined spaces with limited mobility during long flights is a major risk factor for travel-associated venous thromboembolism, commonly known as economy class syndrome (ECS). The syndrome refers to both deep vein thrombosis (DVT) and pulmonary embolism (PE) that occur following prolonged immobility during travel [1]. The longer the flight, the higher the risk [2]. A common saying states that it is wiser and easier to prevent than to treat. Studies show that neither flight attendants nor the passengers present a sufficient level of awareness on the matter [3]. Whereas, according to available studies, confirmed, cost-efficient prevention measures are within the grasp [4, 5].

According to aviation statistics, approximately 30 million passengers travelled by air during the first half of 2025, representing a 12.3% increase compared with the same period in 2024 [6]. In order to establish a proper level of awareness, it is crucial to start at an early stage of education. One might expect that students with a medical background will be more aware of the risks associated with ECS than those from other fields.

The aim of the present study was to assess the level of knowledge regarding ECS among university students and to compare knowledge levels between medical and non-medical fields of study. Secondary objectives were set to define individual factors that may impact the level of awareness, as well as aspects of ECS that are more likely to be unfamiliar to the study subjects (such as prophylactic measures).

Material and methods

A cross-sectional survey was conducted using an anonymous online questionnaire distributed among university students in Poland. The questionnaires were distributed online via social network platforms in the form of a Microsoft Forms URL along with information on the specifics and purpose of the study. The study was addressed to all students regardless of their scientific background. Information explained the anonymous and voluntary character of the study and instructed the participants on the possibility of withdrawing their data at any stage during the study. Inclusion criteria were being an active student, having experience in travelling by plane, and completing the questionnaire. The data were collected from September to December 2024.

The questionnaire consisted of 28 items covering demographic characteristics, air-travel habits, knowledge of ECS and venous thromboembolism, and preventive behaviours. Due to its original character, the questionnaire used in the following study, has not been validated, its contents were however consulted with specialists working in the field of vascular surgery prior to its implementation.

The study group comprised 114 students (mean age 22.3 years, 18–29; standard deviation 1.8) from various universities in Poland. The majority of the students (66 people, 57.9%) came from the medical field, whereas the control group (48, 42.1%) consisted of individuals from other fields of science. Both groups were quite homogeneous. Detailed characteristics are presented in Table 1.

Statistical analysis has been carried out with the use of RStudio Software (R language vR 4.4.1). The analysis included basic characteristics and Shapiro-Wilk and Mann-Whitney U tests as well as ² test (for categorical data) with a correction for continuity (if it was required). Data with a p < 0.05 were considered statistically significant.

Results

The espondents have been given a set of answers regarding ECS, including the basic definition (3 options). Study participants associated with medical fields of study pointed out the proper definition of ECS more often
compared to those from non-medical fields (87.9% vs. 79.2%, p = 0.212). The difference was also noticed in reference to DVT, but unlike ECS this one was statistically significant (100% vs. 83.3%; p < 0.001). The definition of PE was more likely to be recognised by medical students, which was expected, but at the same time, it was quite challenging for non-medical students (95.5% vs. 68.8%). When asked about the most commonly reported symptoms of ECS, DVT and PE, the differences were also visible and unsatisfactory for both groups.

The expected answer for DVT, which included symptoms like sudden limb pain, swelling, limb redness and stiffness, was again more likely to be indicated by the medical students. At the same time, the percentage of proper answers might be considered worrisome as it was relatively low in both groups (59% vs. 23%). The situation presented better when students had been asked to point out symptoms of PE (right answer: bloody cough, shortness of breath on exertion and at rest, sudden chest pain) – scores were higher for both groups (84.9% vs. 79.2%, respectively), but the difference was not statistically significant (p = 0.44).

As a next step, students have been asked about the possible causes for DVT. Results were definitely in favour of medical students as it is presented in Table 2 (p < 0.05).

When asked about the potential prophylactic measures that may be taken to minimise the risk of ECS, study participants were given 12 different suggestions (of which 8 were correct). The mean number of correct measures for the entire studied population (n = 114) was 5.3 per person, indicating room for improvement in both groups. At the same time, 69.7% of the participants in the medical student group had a score over 5.3, showing a deeper understanding of the matter. Whereas in the non-medical group, only 27.1% managed to surpass the mean. Less than half of all participants recognised anticoagulants as a form of ECS prevention. The effective method which was least likely to be reported was the breathing exercises (22.8% of all people) (Table 3).

Medical students were more likely to perform ankle joint exercises (43.9% vs. 10.4%). They were also the only ones who reported using stockings (4.6%). Unlikely use of stockings might be associated with the age of the study group (with a mean age of 22.3 years). It is likely that for the same reason, only a small portion of the study participants experienced DVT or PE first-hand (only 2 cases – 1.8%) or within their among close associates (17 cases – 14.9%). Some participants were partially familiar with the topic through cases reported in close associates (17 people, 14.9%). The following information shows that for most students, medical studies are the initial source of knowledge for the analysed topic.

The level of knowledge was not related to anthropometric measures of the study participants. The Spearman rank correlation between the level of knowledge and the BMI of the study participants was considered weak and not significant (r_s = 0.079, p = 0.575).

Discussion

As flying becomes more available and common, the need for proper education on syndromes like ECS increases. Education on DVT, PE and ECS, including the risk factors/causes, is part of the curriculum for all medical fields. Our study shows that the non-medical students would benefit from a better understanding of the matter. Furthermore, according to our results, this is also true for medical students, as some questions were not obvious for a major percentage of this group. The differences between the groups were quite visible, yet gaps in knowledge for the medical students may appear a bit surprising.

According to Wendelboe et al. [7], in a study which included 7233 participants, the level of knowledge on DVT (44%) and PE (54%) was average (for a general population), lower than in the following study (our non-medical students – 83.3% and 68.8%, respectively). It should be noted that the levels of knowledge for DVT and PE in the Wendelboe et al. study [7] were significantly lower than for hypertension, breast cancer, prostate cancer and AIDS. On one hand knowledge increased with age, on the other hand it decreased when details were considered (potential risks of surgical procedures, risk factors).

Our findings for medical students are in alignment with the other studies. Urbanek et al. [8] (400 medical students) reported that although the study curriculum covers the topic of venous thromboembolism, the students did have some major gaps in knowledge in terms of epidemiology and risk factors. Similar findings (also 400 medical students) were published by Wołkowski et al. [9] – in this case, 43% of the participants pointed out the proper definition of DVT and PE. Although it is a significantly lower rate than in our own study (100% and 95%. respectively) it should be emphasised that these results are likely to be affected by the study construction (i.e. the number of answers to choose from, accepted definition). They all show however that most students know in general how to define the problem but they get a little bit lost when the details get involved. Wołkowski et al. [9] emphasise that usually students recognise the connection between long-haul flights and vein issues and have a good knowledge on the prophylactic measures.

Kucharzewski et al. [10] reached out to the airline passengers in order to assess their knowledge on DVT. The authors noticed that participants highlighted prophylactic measures such as walking or stretching during the flight (58%), using medication (45%), using low-molecular-weight heparin (28%) or stockings (23%). In our study medical students were definitely more likely to point out the following prevention measures, whereas the non-medical students scored higher or at the similar level. It should also be noted that the results of some measures are still considered controversial (i.e. compression for some groups of patients) [11]. In the following study authors listed anticoagulant drugs as a preventive measure but it should be emphasised that typically it is reserved for patients at a high risk of venous thromboembolism. Since our study was focused of the level of knowledge on the preventive measures, we decided to include anticoagulant drugs, as other authors did. At the same time it is our belief that the majority of travellers should focus on non-pharmacological preventive strategies such as mobility and hydration.

In a previous study by Gattermayer et al. [3] authors noticed a troubling lack of knowledge on ECS and DVT in a group of travellers (transatlantic flights). In that study 84% of the participants have never heard about the ECS and DVT and only 10% used any prevention measures. Considering our current study and the above mentioned papers, it appears that the level of knowledge is definitely on the rise. At the same time, there is still definitely room for improvement regardless of the medical background or not.

Despite our best efforts, the following study had some limitations the authors were unable to overcome. Most of these are associated with the anonymous nature of the study. The authors were unable to confirm some of the inconsistencies in the reported questionnaires. In those cases the questionnaires were not included in the analysis and withdrawn from the database. The other limitation might be related to the specificity of knowledge assessment as various studies use different medical definitions and might have analysed other prophylactic measures (therefore questionnaires differed across studies). Due to an increased heterogeneity of studies, the comparison of study results remains challenging, as mentioned by others [12]. Due to the open access of the study questionnaire authors did not have an impact on the distribution of students who participated (medical vs. non-medical field). Hence the disproportion between the groups (58% vs. 42%) – which might be considered a study limitation. Lastly, the number of participants enrolled in the study does not allow us to draw meaningful conclusions appropriate for the general population. Also it should be emphasised that the original questionnaire used in the study was not previously validated.

Conclusions

The general level of knowledge on ECS, DVT and PE for medical students is higher than that of non-medical
students. Both medical and non-medical students would benefit from improved education regarding travel-associated venous thromboembolism, particularly with respect to risk factors and evidence-based preventive strategies.

Disclosures

1. Institutional review board statement: The study was approved by the Jagiellonian University Ethics Committee (approval decision no. 118.0043.1.238.2024, dated: 30.07. 2024) and followed the principles of the Helsinki Declaration of the World Medical Association.

2. Assistance with the article: None.

3. Financial support and sponsorship: None.

4. Conflicts of interest: None.

References