Volume 8 No 1 2020 V2.indd


22 International Journal of Integrated Health Sciences 

in the lower extremities. Several cases of 
venous thrombosis may cause embolization, 
particularly to lungs. The emboli may cause 
partial or complete obstruction of pulmonary 
arteries or its branches.1 

Predisposing factors of venous thrombosis 
may be defined using Virchow triad, consisting 
of: stasis of blood flow, hypercoagulability, 
and endothelial injury. Stasis of blood flow 
may be caused by several conditions, such 
as immobilization, bed rest, congestive 
heart failure, and previous history of venous 

Introduction

Venous thromboembolism is characterized 
with venous thrombosis, frequently occurring 

Original Article

Venous Thromboembolism Prophylaxis and The International Medical 
Prevention Registry on Venous Thromboembolism (IMPROVE) Score in 
Medical Illness Patients

Correspondence: 
Dania Artriana, 
Department of Internal Medicine, Medical Hematology 
Oncology Division, Faculty of Medicine Universitas 
Padjadjaran/Dr. Hasan Sadikin General Hospital 
Bandung, Indonesia
e-mail: daniaartriana@yahoo.com

Dania Artriana Riswandi, Amaylia Oehadian

Department of Internal Medicine, Medical Hematology Oncology Division, Faculty of Medicine Universitas 
Padjadjaran-Dr. Hasan Sadikin General Hospital Bandung, Indonesia

 Abstract 
 
 Objective: To describe applicability of The International Medical 

Prevention Registry on Venous Thromboembolism (IMPROVE) score 
to implement venous thromboembolism prophylaxis in patients with 
medical illness in Hasan Sadikin General Hospital Bandung.

 Methods: This study was descriptive, cross-sectional research from 
database was performed on December 2018. Inclusion criteria in this 
study were all patients hospitalized in Department of Internal Medicine, 
Hasan Sadikin General Hospital in November 2018 with medical illness, 
which is patients with medical condition involves a more systemic, 
pharmaceutical approach to treatment. Exclusion criteria were surgical 
disease, which is requires some form of intervention such as surgery, 
also patients with incomplete medical record were excluded.

 Results: There were 162 patients (56% male and 44% female). Median 
age were higher in males compared to females (53 [18–76] vs. 49 [18–
85]) years. Low-risk (score <2), medium-risk (score 2 – 3), and high-risk 
(score >4) for IMPROVE venous thromboembolism score were 77.2%, 
17.3%, and 5.6% respectively. ). Low-risk (score <7) and high-risk (score 
>7) for IMPROVE bleeding score were 75.9% and 24.1% respectively. 
Medical thromboprophylaxis were given to 14.8% patients, with 91.7% 
and 8.3% of the patients received unfractionated heparin (UFH) and low-
molecular weight heparin (LMWH) respectively. Thromboprophylaxis 
was given in 88.9% of high-risk patients for venous thromboembolism.  
There were 18.7% patients with low-risk and 2.6% with high-risk for 
bleeding that received prophylaxis.

 Conclusion: The majority of inpatients treated with thromboprophylaxis 
had low-risk for both thromboembolism and bleeding. The rate of 
thromboprophylaxis usage was still low; with the most frequently used 
thromboprophylaxis agent was UFH. Most of high-risk patients for 
venous thromboembolism received thromboprophylaxis.

                  
  Keywords:  Bleeding risk, IMPROVE score, thromboembolism risk,   

         thromboprophylaxis

Received:
August 31, 2019

Accepted:
March 31, 2020

pISSN: 2302-1381; 
eISSN: 2338-4506; 
http://doi.org/10.15850/
ijihs.v8n1.1773
IJIHS. 2020;8(1):22–6



International Journal of Integrated Health Sciences 23

thrombosis. Hypercoagulability may be 
found in patients with history of malignancy, 
anticardiolipin antibody, nephrotic 
syndrome, essential thrombocytosis, 
estrogen therapy, heparin usage (heparin-
induced thrombocytopenia), inflammatory 
bowel disease, paroxysmal nocturnal 
hemoglobinuria, disseminated intravascular 
coagulation, and deficiency of several proteins 
(such as protein C, protein S, and antithrombin 
III). Endothelial injury may occur due to 
trauma or internal bleeding.2 

Annual incidence of venous 
thromboembolism in Europe and United States 
were approximately 50/100,000 persons per 
year. Genetic variability may be noted, with 
lower incidence were found in Asian and 
Hispanic population compared to Caucasians, 
African Americans, Latino, and Asia-Pacific 
populations. No significant incidence between 
both sexes were noted. Increasing trend in 
incidence of lung emboli were noted, with 
annual incidence rate of lung emboli of 1 in 
1000 persons in United States. Pulmonary 
emboli occurs in 60–80% cases of venous 
thromboembolism, 50% of which cases were 
asymptomatic. Lung emboli is one of the most 
frequent cause of death, ranking 3rd and casing 
about 650,000 mortalities each year.3-6

Approximately 100,000 and 300,000 deaths 
related to venous thromboembolism were 
reported annually in United States and Europe, 
respectively. Venous thromboembolism 
related mortalities may be prevented by 
using thromboprophylaxis medications. 
No consensus regarding the dosage of the 
medication has been reached, due to the 
risk of bleeding as a possible side effect 
of thromboprophylaxis medications.7 The 
IMPROVE (International Medical Prevention 

Table 2 IMPROVE Score for Bleeding8

Parameter Score
Previous history of 
gastroduodenal ulcer 4.5

History of bleeding (last 3 
months) 4

Platelet count <50x109 /L 4
Previous history of hepatic failure 
(INR>1.5) 2.5

History of admittance to intensive 
care unit 2.5

History of central venous 
catheter insertion 2

Rheumatic diseases 2
History of malignancy 2
Male sex 1
Age 40–84 vs ≥ 85 years 1.5 vs 3.5
Glomerular filtration rate  30-59 
vs <30 1 vs 2.5

Table 1 IMPROVE score for 
  Thromboembolism8 

Parameter Score
History of thromboembolism 3

Thrombophilia 2

Paralysis of lower extremities 2

Malignancy 2

Immobilization  ≥7 days 1

History of admittance to 
intensive care unit

1

Age >60 years 1

Registry on Venous Thromboembolism) 
predictive score was designed to assesses the 
risk of VTE in hospitalized medical patients. 
IMPROVE scores may be utilized to assess 
the risk of thromboembolism and bleeding.8 
This study aims to assess the risk factors 
associated with venous thromboembolism 
and bleeding according to IMPROVE scores 
and administration of thromboprophylaxis 
medications of inpatients with medical  illness  
in Department of Internal Medicine , Hasan 
Sadikin General Hospital.

Methods

The descriptive, cross-sectional study 
was performed on December 2018. Data 
were collected from database of inpatients 
hospitalized with medical illness in Department 
of Internal Medicine Dr. Hasan Sadikin 
General Hospital Bandung. Inclusion criteria 
in this study were all patients hospitalized in 
November 2018 with medical illness, which 
is patients with medical condition involves a 
more systemic, pharmaceutical approach to 
treatment. Exclusion criteria were surgical 
disease, which is requires some form of 
intervention such as surgery, also patients with 
incompleted medical record were excluded. 
Several variables included in this study are as 
described below.

Risk for venous thromboembolism, 

Dania Artriana Riswandi, Amaylia Oehadian



24 International Journal of Integrated Health Sciences 

categorized according to IMPROVE score: low 
risk (score <2), moderate risk (score 2–3), and 
high risk (score >4) (Table1).

 Risk for bleeding, categorized according to 
IMPROVE score: low risk (score <7) and high 
risk (score >7) (Table 2).

Thromboprophylaxis refers to 
administration of anticoagulants, specifically 
unfractionated heparin (UFH) or low-
molecular weight heparin (LMWH) during the 
period of hospitalization.

Descriptive statistics were used in 
presenting the results. Median, mean, and 
percentage were used as descriptive statistics 
in describing the patients with risk of venous 
thromboembolism and bleeding. 

Table 3 Subjects Characteristics 

Characteristics Total(n=162)
Sex, n (%)

Male 91 (56)
Female 71 (44)

Age (years)

Median (range ) 51 ( 18–85) 
VTE risk, n (%)

Low risk 125 (77,2)
Moderate risk 28 (17,3)
High risk 9 (5,5)

Bleeding risk, n (%)
Low risk 123 (75,9)
High risk 39 (24,1)

Thromboprophylaxis, n (%)
UFH 22 (13,6)
LMWH 2 (1,2)
No thromboprophylaxis 138 (85,2)

VTE risk with 
thromboprophylaxis, n (%)

Low risk 0 (0)
Moderate risk 16 (57,1)
High risk 8 (88,9)

Bleeding risk with 
thromboprophylaxis, n (%)

Low risk 23 (18,7)
High risk 1 (2.6)

Results

Total participants from database who fulfilled 
inclusion were 162 patients, with distribution 
of 56% males and 44% females. Male patients 
were older compared to female patients 
(Median 53 [18–76] vs 49 [18–85]) years.  
Risk of thromboembolism was assessed using 
IMPROVE score: 77.2% low risk patients 
(scores <2); 17.3% moderate risk patients 
(score 2–3); and 5.6% high risk patients 
(scores >4). Risk of bleeding was assessed 
using IMPROVE score: 75.9% low risk patients 
(scores <7) and 24.1% high risk patients 
(scores >7). Thromboprophylaxis medications 
were given to 14.8% of the patients included 
in the study. The medications given were 
unfractionated heparin (UFH) in 91.7% 
patients and low-molecular weight heparin 
(LMWH) in 8.3% patients. 

Patients with low risk for venous 
thromboembolism did not receive 
thromboprophylaxis. There were 57.1% 
medium risk and 88.9% of high risk patients 
for venous thromboembolism that received 
thromboprophylaxis medications. There were 
17.8% low risk and 2.6% medium risk patients 
for bleeding that received thromboprophylaxis 
medications. Subject’s characteristics were 
described in Table 3. 

From 37 patients with venous 
thromboembolism, the majority of these 
patients had previous history of malignancy. 
There were 27 (73%) patients with previous 
history of malignancy and 10 (27%) 
patients with previous history of prolonged 
immobilization. The majority of the patients with 
previous history of malignancy had received 
thromboprophylaxis: 22 (81.5%) patients 
received thromboprophylaxis and 5 (18.5%) 
patients did not receive thromboprophylaxis. 
On subjects with previous history of prolonged 
immobilization, 2 (20%) patients had received 
thromboprophylaxis and 8 (80%) patients did 
not receive thromboprophylaxis. 

There were 3 high risk patients for 
bleeding: 2 (66.7%) of the patients had not 
received thromboprophylaxis and 1 (33.3%) 
patient had received thromboprophylaxis. The 
patient that was given thromboprophylaxis 
had previous history of malignancy. 

Discussion

International Medical Prevention Registry on 
Venous Thromboembolism (IMPROVE) score 
was formulated in order to assess the risk of 
venous thromboembolism and bleeding. The 

Venous Thromboembolism Prophylaxis and The International Medical Prevention Registry on 
Venous Thromboembolism (IMPROVE) Score in Medical Illness Patients



International Journal of Integrated Health Sciences 25

score had listed 7 risk factors in assessing the 
risk of venous thromboembolism: previous 
history of venous thromboembolism; 
thrombophilia; paralysis of lower extremities; 
previous history of malignancy; prolonged 
immobilization (>7 days); and previous 
history of admittance in intensive care unit 
(in patients aged >60 years). There are three 
risk stratifications in thromboembolism risk: 
low risk (score <2), moderate risk (score 
2–3), and high risk (score >4). Assessment of 
risk for bleeding utilize 13 risk factors to be 
examined on the patient: previous history 
of gastroduodenal ulcers; previous history 
of bleeding in the last 3 months; platelet 
count <50x109/L; previous history of hepatic 
failure; previous history of admittance in 
intensive care unit ; previous history of central 
venous catheter insertion; previous history 
of rheumatic diseases; previous history of 
malignancy; age; sex; and glomerular filtration 
rate. The risk is further stratified into low risk 
(score <7) and high risk (score >7). Patients 
with moderate risk for thromboembolism 
(score >2) and low risk for bleeding 
(score <7) are recommended to be given 
thromboprophylaxis medication in order to 
prevent emboli formation. In patients with 
high risk of bleeding (score >7), mechanical 
thromboprophylaxis is recommended in order 
to reduce the risk of emboli formation.9 

IMPROVE scoring system has been 
routinely utilized in 12 countries: Australia, 
Brazil, Canada, Colombia, France, Germany, 
Italy, Japan, Spain, England, United States, 
and Venezuela. Previously, a multicenter 
study conducted in 52 hospitals from the 12 
aforementioned counties were performed 
during the period of July 2002–September 
2006, with total of 15,156 individuals 
diagnosed with venous thromboembolism; 
3,410 of subjects in United States and 11,746 
in other countries. The patients’ age range 
were 52–79 years old with median of 68 years 
old; the majority of the patients were females 
(50.6% vs. 49.4%). Compared to the previous 
study, this study had lower median (51 years 
old) and range for age (18 – 85 years old). The 
patients in our study were predominantly 
male (56% vs. 44%).10,11 

In this study, 22.8% of patients had high 
risk for venous thromboembolism with 64.9% 
of the patients had received medication 
(UFH or LMWH) for thromboprophylaxis. In 
comparison with other studies, less number of 
patients were at high risk for thromboembolism 
despite the higher rate of thromboprophylaxis 
medication. In other study, 52% patients 

in United States and 43% patients in other 
countries had moderate to high risk for venous 
thromboembolism. There were 7,640 (50%) 
patients that had received either medical 
or mechanical thromboprophylaxis. There 
were 33% patients in United States and 47% 
patients in other countries that had received 
UFH or LMWH as thromboprophylaxis. 
The study had suggested several factors 
that may be associated with lower usage 
of thromboprophylaxis, notably the lack of 
awareness regarding thromboprophylaxis 
usage, lack of thromboprophylaxis algorithms 
in the said institution, and risk of bleeding 
that may occur during thromboprophylaxis 
procedure.10-12 

Other countries, in contrast, had preferred 
the usage of LMWH compared to UFH (82.1% 
vs. 17.9%). Overall, higher usage of LMWH 
was found in the study compared to the UFH 
usage (74.8% vs. 25.2%). In our study, the 
vast majority of the patients were treated 
with UFH (91.7% vs. 8.35). The choice for 
medical thromboprophylaxis were similar 
with studies from United States, which UFH 
usage was preferred compared to LMWH in 
thromboprophylaxis. Costs in utilizing LMWH 
was not significantly different compared to 
usage of UFH, thus, LMWH may be safer that 
UFH, particularly in minimizing the risk of 
heparin induced thrombocytopenia (HIT).10-14 

In this study, there were 75.9% patients 
with low risk (score <7) and 24.1% patients 
with high risk (score >7) for bleeding. In 
comparison, a retrospective study consisted of 
12,082 subjects from Academic Health System 
in United States during the period of October 
1, 2012–July 31, 2014, had found the majority 
(81% vs. 19%) of the patients had low risk of 
bleeding. Other study had noted that 90.3% 
of patient had low risk for bleeding and 
9.7% had high risk for bleeding. The results 
of these studies concur with our study, that 
the majority of the patients in Hasan Sadikin 
General Hospital had low risk for bleeding.7

According the previous study from Academic 
Health System, bleeding had occurred on 2.6% 
patients with venous thromboembolism, with 
1.8% patients had major bleeding (defined as 
bleeding that cause decrease of hemoglobin 
>2 g/dL or may require 2 units of blood 
transfusion). Major bleeding may occur as 
intracranial, intraocular, adrenal gland, and/
or pericardial hemorrhage. In other studies, 
3.2% of patients had suffered from bleeding 
after thromboprophylaxis therapy, with 
1.2% of these patients had suffer from major 
bleeding.7 In contrast, no cases of bleeding 

Dania Artriana Riswandi, Amaylia Oehadian



26 International Journal of Integrated Health Sciences 

after thromboprophylaxis therapy were found 
on our patients.

In this study there were 162 subjects 
with mean age 51 years old. Most of subjects 
were male (56% vs. 44%). There were 
22.8% of patients had high risk for venous 
thromboembolism with 64.9% of the patients 
had received medication (UFH or LMWH) 
for thromboprophylaxis. There were 75.9% 
patients with low risk (score <7) and 24.1% 
patients with high risk (score >7) for bleeding. 

The majority of inpatients had low risk for 
both venous thromboembolism and bleeding. 
The administration of thromboprophylaxis 
is still uncommonly performed, only given 
in 14.8% subjects. Thromboprophylaxis was 
given in 88.9% of high risk patients for venous 
thromboembolism .The majority of patients 
with high risk of venous thromboembolism 
received UFH as thromboprophylaxis 
medication. 

Venous Thromboembolism Prophylaxis and The International Medical Prevention Registry on 
Venous Thromboembolism (IMPROVE) Score in Medical Illness Patients

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