Occurrence of Venous Thromboembolism and Outcomes of Preventive Protocols at the Bangkok Hospital Medical Center: a Retrospective Review of Years 2012-2013

Abstract

OBJECTIVE:To determine the occurrence of venous thromboem¬bolism (VTE) of patients at the Bangkok Hospital Medical Center (BMC). To collect data of VTE patients at the BMC about their characteristics, underlying diseases, presenting symptoms and out¬comes of diseases. Evaluate the outcome of preventive methods of VTE when using the BMC protocol.MATERIALS AND METHODS:The retrospective review was conducted from January 1, 2012 to December 31, 2013. The total number of patients diagnosed with VTE is 190 patients. The patients were divided into two groups; in the first group were patients who had been diagnosed in the year 2012, and were not using the preventive protocol, and the second group, were patients who had been diagnosed in the year 2013, and were using the preventive protocol. In both groups, data was collected about their characteristics, underlying diseases, presenting symptoms, and outcomes. Then we further divided patients from both groups into two categories by using BMC protocol criteria; high thrombosis risk and low thrombosis risk. Following this categorisation, we used the Statistical Package for the Social Sciences (SPSS) program to analyze the data collected. We compared populations across both years to verify if there was any difference in any aspect of the baseline characteristics. We evaluated the outcomes of patients who did not develop VTE as a result of using the preventive protocol by comparing high thrombosis risk patients to low thrombosis risk patients across both years to verify if there were any differences in the number of patients who did not receive the protocol (2012), and patients who received the protocol (2013).RESULTS:There were 190 patients with VTE, 104 patients in 2012 (54.73%) and 86 patients in 2013 (45.27%). Their mean age was 63.52 ± 17.70 years. Ninety two patients (48.42%) are Thai nationals, while 98 patients (52.58%) are non-Thai nationals. There were 76 inpatient department (IPD) patients (40%) and 114 outpatient department (OPD) patients (60%). In IPD patients, there were 71 patients with a high thrombosis risk, 39 patients (37.50%) in 2012 and 32 patients (37.21%) in 2013. There are two statistically significant differences in the populations between both years, first the mean thrombosis risk score (which in 2013 had a higher thrombosis risk score ( 4.94 vs. 5.86)) and second, the number of patients that died from VTE (with more deaths occurring in year 2012 (10 vs. 1)). Patients who have a high thrombosis risk score in 2012 represent 37.50% of cases, and in 2013 these patients represented 37.21% of cases. The odd ratio (OR) is 1.013 (0.561 - 1.828), relative risk is 1.008 (0.696 - 1.459), relative risk reduction is 0.77 and numbers needed to treat (NNT) is 344.82. CONCLUSION:From our study we showed a reduction of risk in a number of high thrombosis risk VTE patients when using the risk assessment protocol of BMC with the number need to treat of 344.82. Although it is not statistically significant, due to the limitations of the study, we have seen a trend towards using the protocol to decrease the number of high thrombosis risk VTE patients.