Evaluation of a Brief Educational Intervention in Enhancing Venous Thromboembolism Knowledge Among Surgical Patients and Health-Care Providers: A Prospective Study

Introduction

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common complication among post-operative patients, and is associated with significant morbidity and mortality.¹ VTE is highly preventable through various prophylactic measures, ranging from conservative measures such as early mobilisation, to mechanical prophylaxis such as intermittent pneumatic compression (ICP), and pharmacological prophylaxis such as peri-operative anticoagulation. Despite well-established guidelines from professional societies,^1–3 VTE prophylaxis practices vary widely across institutions. Evidence suggests a considerable gap between optimal thromboprophylaxis as suggested by experts and real-world implementation.⁴ Many healthcare-providers (HCPs) and at-risk patients either lack awareness of VTE risks or are uncertain about applying prophylactic measures effectively.⁴ Knowledge of VTE plays a pivotal role in adherence to the optimal thromboprophylaxis, and studies have suggested that a multifaceted educational approach could significantly improve VTE prophylaxis utilization.^5,6 Various methods, including educational videos, administrative interventions, and continuing medical education programs, can be used to improve the knowledge of patients and HCPs.^7–9 However, no prospective study has systematically evaluated the impact of an educational program on VTE knowledge among post-operative patients and their HCPs, nor examined whether knowledge improvement translates into better adherence to prophylaxis guidelines. To address this gap, we conducted a prospective, non-randomised controlled study to evaluate the impact of a brief education material on VTE knowledge among post-operative patients and their HCPs. This study will assess knowledge levels before and after exposure to educational materials and examine whether increased awareness leads to improved utilisation of and adherence to VTE prophylaxis. The findings of this study could help inform strategies for enhancing compliance and reducing the burden of VTE in patients undergoing surgery.

Materials and Methods

This prospective, single-centre, non-randomised, controlled trial was conducted at a 1,700 beds university-affiliated hospital. The study duration was 12 months, and it involved of patients aged ≥18 years scheduled for elective major surgical operations (group A) and their HCPs (group B, including ward nurses and nursing assistants). The major exclusion criteria were: 1. Inability to provide informed consent, and 2. Inability to comprehend the study protocol, 3. Visually or auditorily impairment affecting participation, or 4. History of VTE.

VTE knowledge was assessed using validated questionnaires, adapted and modified from previous studies.^10–13 Separate sets of questionnaires were used for patients (Set A, total score 45, Supplementary Appendix 1A) and their HCPs (Set B, Supplementary Appendix 1B), with scores expressed as the percentage of correct response. The overall knowledge was categorized, using Bloom’s cut-off point, as good if the score was between 80 and 100%, moderate if the score was between 60 and 79%, and poor if the score was less than 60%.¹⁴ The questionnaires were initially developed in English, translated into Chinese, and back-translated to ensure accuracy. A panel of experts—including surgeons, vascular specialists, internal medicine physicians, and nurse consultants —reviewed the study instruments for face and content validity. The questionnaires were tested on 15 volunteers, and internal reliability was evaluated using Cronbach’s alpha coefficient, which demonstrated strong consistency, yielding a Cronbach’s alpha coefficient of 0.86. Patient’s satisfaction with VTE thromboprophylaxis was assessed using existing hospital patient survey form which assesses patients’ experiences on a 5-point Likert scale.

The intervention consisted of 2-minute educational videos, developed using PowerPoint^® slides with audio narration. The educational material for patients was adapted from publicly available patient education resources (Video S1), whereas the educational material for the HCPs was sourced from Continuous Medical Education (CME) platforms (https://www.smartpatient.ha.org.hk/en/smart-patient-web/disease-management/disease-information/disease/DeepVeinThrombosis). Both videos were administered using a mobile device, with optional headphone use.

Questionnaire Set A was first administered to a group of patients after admission, serving as the control group. After a four-week interval, a separate group of patients and their HCPs completed Set A (patients) and Set B (HCPs), both before and immediately after the intervention. The four-week interval between the control and intervention groups was chosen arbitrarily to minimize behavioural influence on the patients and HCPs. The flow of this study is summarized in Figure 1.

Figure 1 Study flow diagram.

Data Collectable and Outcomes

Baseline patient demographics, medical and surgical backgrounds, laboratory results, clinical presentations, and operative records were collected. The VTE risk was calculated using the Caprini risk score.¹⁵ The prescription of VTE prophylactic measures such as early mobilisation, intermittent pneumatic compression, gradual compression stockings, and pharmacological thromboprophylaxis, were recorded. The occurrence of VTE such as DVT or PE within 30 days of hospital admission as confirmed by imaging studies was documented.

The primary outcome measured in this study was the difference in VTE knowledge between the control group, and intervention group following the intervention. The secondary outcomes measured in this study were changes in HCP knowledge before and after the intervention, differences in VTE thromboprophylaxis utilisation, patient satisfaction and VTE occurrence rate between the two patient groups.

Statistical Methods

Data analysis was performed using the STATA version 15 software (College Station, TX, USA). Data are reported as mean ± standard deviation (SD) or frequency (%). Comparisons between groups were made using the unpaired Student’s t-test for continuous variables, Fisher’s exact test for categorical variables, or Mann–Whitney U-test for ordinal variables. Based on previous research, the estimated difference in VTE knowledge score was 0.25–0.57.^5,8,10,12 Therefore, an estimated sample size of 200 patients (100 patients in each group) was required to detect a difference at a 5% significance level and 80% power.

Ethics

Written informed consent was collected from individuals when they were enrolled. This study was conducted in accordance with the Declaration of Helsinki. The application for research ethics was granted by the Joint CUHK-NTEC Clinical Research Ethics Committee (HA-RE001F3) and was registered at Clinicaltrials.gov (NCT05548010).

Results

A total of 200 patients (mean age 59.1, 46.5% female) and 17 HCPs (mean age 34.5, 64% female) participated in this study, and their characteristics are shown in Tables 1 and 2. Baseline demographics, including the Caprini score, were comparable between the two patient groups. The Majority (95.0%) of the participants underwent major surgery, defined by the Caprini score, as procedures requiring general or regional anaesthesia for >45 min, including open, laparoscopic, or arthroscopic procedures.¹⁵ 42% had a current or history of malignancy, whereas 48% had chronic cardiopulmonary disease. The mean Caprini score was 6.2, with 24.5% scoring 7 or higher, indicating a high (>1.8%) risk of postoperative VTE.¹⁶

Table 1 Characteristics of the Study Participants

Table 2 VTE Knowledge of the HCPs

Baseline VTE knowledge was similarly low between the two groups, with scores of 29.4% and 29.6%, respectively. Majority (92% and 91%) of subjects exhibited poor knowledge. A higher education level was significantly associated with higher scores (coefficient of interaction=5.49, p=0.026), whereas age and gender showed no such association. After the educational material, the VTE knowledge in the intervention group significantly improved by 16.4 points (55% increase), reaching 46.1% (Table 3 and Figure 2). The portion of subjects with moderate knowledge increased significantly from 9% to 18% (Figure 3). The breakdown of the different aspects of the VTE knowledge component is presented in Table 4. At baseline, most participants were unable to identify the risk factors, signs and symptoms, complications, and measures of thromboprophylaxis for VTE, although the majority recognised that VTE is a preventable disease. After the intervention, significant improvements were observed across various knowledge domains. Despite an enhanced understanding of VTE thromboprophylaxis, the proportion of patients willing to receive pharmacological thromboprophylaxis remained low (20%). Among the overall cohort, 42.5% received VTE thromboprophylaxis and only 4.5% received pharmacological thromboprophylaxis. The utilisation rates of VTE thromboprophylaxis were similar across groups (Table 3) and no VTE events were recorded during the study period. Overall, 66% of patients expressed satisfaction (score of ≥ 3 on the Likert scale) with their thromboprophylaxis at baseline, which was similar between the groups. After the intervention, satisfaction increased significantly by 26% to 93% in the intervention group. The HCPs demonstrated satisfactory knowledge level at baseline (73.5%), with a statistically insignificant improvement to 77.5% following the intervention (Table 2).

Table 3 Difference in VTE Knowledge, Thromboprophylaxis Utilization and Patient Satisfaction

Table 4 Breakdown of Items of VTE Knowledge Questionnaire

Figure 2 Differences in VTE knowledge between groups.

Figure 3 Bloom’s categories of patients’ VTE knowledge level.

Discussion

This prospective study revealed a low level of knowledge regarding VTE among patients undergoing surgery, which is consistent with previously published studies.^{5–7,10,12,17} Participants demonstrated insufficient awareness of DVT causes, symptoms, and complications, yet showed greater familiarity with PE, particularly its symptoms, likely due to educated guesses given the context of the question. For example, participants might be able to guess that respiratory symptoms such as difficulty breathing and fast breathing are symptoms of PE, simply because PE is a condition that affects the respiratory system. However, the association between DVT and PE was poorly understood by the participants. The participants also lacked awareness of the key VTE risk factors. The most recognised risk factor was prolonged immobility, which is consistent with the results of previous studies. However, other key risk factors, such as hospitalisation, surgery, and cancer, were less well-recognised by the participants. These findings underscore the need to improve education regarding VTE prevention in high-risk patients.

Despite the gap in specific knowledge, most participants correctly recognised VTE as a serious, potentially fatal, but preventable condition, in contrast to international studies, where only 45% of patients believed that blood clots could be prevented.¹¹ Regarding VTE thromboprophylaxis, only 24% of the participants believed that pharmacological thromboprophylaxis was safe and effective and only 20% were willing to receive it. This contrasts with findings from Jordan, where 89.8% perceived VTE thromboprophylaxis as safe, and 60.4% were willing to receive it.¹⁷ This reluctance may reflect cultural preferences, particularly among older Chinese patients who favour noninvasive treatments over Western medications.¹⁸

The 2-minutes education materials significantly enhanced patient knowledge, particularly in awareness of VTE causes and symptoms, underscoring the effectiveness of structured educational tools.^8,9 Increased patient satisfaction with VTE thromboprophylaxis post intervention suggests better acceptance and the potential for improved adherence in high-risk populations, although this was not significant in our cohort. Despite the significant improvement in score after the intervention, the knowledge level remained suboptimal, with notable deficient persisting in patients understanding of VTE risk factors, complications, and thromboprophylaxis measures. These gaps highlight the need for enhanced educational strategies. Incorporating additional emphasis on these areas, supplemented by interactive question-and-answer sessions after the intervention may further improve patient comprehension and engagement.

HCPs exhibited adequate baseline knowledge of VTE prophylaxis, surpassing the levels reported in previous studies from other regions.¹³ The intervention did not significantly improve HCP knowledge, likely because of the high baseline scores. However, despite the incentives, the low participation rate among HCPs may introduce potential bias and limit the generalisability of the study results. Future studies should explore alternative strategies for improving HCP engagement.

Limitations

This study has several limitations. First, although we used a validated set of questions, closed-ended questions may have enabled participants to guess the answers rather than responding within the limits of their knowledge. Second, despite reaching the sample size estimation, the cohort remained small, restricting the strength of the conclusions and generalisability. Another factor limiting the generalisation is the single-centre setting, which further hinders the applicability of our findings beyond the study setting.

Conclusion

This study highlights a low baseline level of VTE knowledge among surgical patients and demonstrates that educational materials could effectively improve the knowledge level and patient satisfaction with thromboprophylaxis. Given the high risk of VTE in surgical populations, routine patient education regarding VTE should be integrated into the perioperative care protocols.