Venous thromboembolism risk assessment and prophylaxis in hospitalised medical patients in the Cape Town metropole, South Africa

Abstract

Background. Venous thromboembolism (VTE) is regarded as the most preventable cause of inpatient death in hospital settings globally. VTE can be prevented through the provision of non-pharmacological and/or pharmacological thromboprophylaxis following individualised risk screening. The Caprini risk assessment model (RAM) offers a validated and well-established approach for VTE risk assessment in medical inpatients. Literature findings describe a trend towards inappropriate and under-prescribing of thromboprophylaxis in this population. Together with concerns regarding clinicians’ perceived importance of VTE risk assessment, the need to clarify these aspects of practice is evident. Objectives. To describe VTE risk assessment and prophylaxis practices of medical practitioners in public sector hospitals in Western Cape Province, South Africa (SA). Methods. A retrospective, cross-sectional study design was employed in the medical wards of two district hospitals and one regional hospital in the Cape Town metropole, Western Cape. Medical folders of adult medical inpatients admitted between January and July 2020 were reviewed to assess VTE risk using the Caprini RAM. Thromboprophylaxis therapy prescribed and contraindications to chemoprophylaxis were also evaluated. Results. Of 380 patients included in the review, 51.6% were female, and the average age was 52.1 years (range 18 - 96); 21.3% had their weight recorded, while none had their height documented. Infectious disease was the predominant diagnosis (49.2%) detected in the sample. Common VTE risk factors identified included bed rest/restricted mobility for <72 hours (76.3%) and serious infection (67.4%). A total of 97.1% of patients (n=369) were found to be at moderate or higher risk of VTE (Caprini score ≥2). Of this at-risk group, 24.1% were eligible to receive chemoprophylaxis, yet no prescription for thromboprophylaxis was identified. Seventy percent of patients (n=266) were prescribed chemoprophylaxis, with enoxaparin accounting for 98.5% of regimens. Contraindications to chemoprophylaxis were recorded in 13.4% of patients. Conclusions. Although rates of VTE prophylaxis in medical inpatients may be improving, thromboprophylaxis still remains critically underutilised in this population. This study highlighted a consequence of this trend, with inappropriate chemoprophylaxis prescribing becoming more evident. Mechanical prophylaxis prescribing in medical inpatients is lacking, despite the associated benefits. RAMs should be adapted for the SA setting, where infectious diseases are prevalent. Future research should assess RAM use by clinicians, as this could provide insight into improving RAM uptake and thromboprophylaxis prescribing.