CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 4, July/August 2014
AFRICA
161
Evaluation criteria
The main evaluation criteria were the proportion of patients
at risk of VTE among patients hospitalised in medicine and
surgery, and the proportion of these patients at risk who
received proper thromboprophylaxis during the first 14 days of
admission. The secondary criteria were the proportion of at-risk
patients by type (medical versus surgical), the proportion of
at-risk patients properly prophylaxed by type (medical versus
surgical), and the factors determining the decision of the type of
prophylaxis given.
Statistical analysis
The primary objective of ENDORSEwas to assess the prevalence
of VTE risk in hospitalised patients. In order to assess the true
prevalence of VTE risk at 50%, confidence interval of 95% with
a precision of
±
3%, a minimum of 1 068 patients were needed.
Based on the assumption of 10% missing data, a minimum of
1 186 patients should be included. The study aimed at including
1 200 patients, with the following split by country: Madagascar:
400; Nigeria: 400; Cameroon: 400; Democratic Republic of
Congo: 300; Namibia: 100 patients.
Population characteristics (including demographics,
medical history, nature, duration and severity of the disease,
co-morbidities, current treatment or no treatment) were
summarised into numbers of non-missing data, mean, standard
deviation, minimum, maximum, median, 95% confidence interval
(CI) of the mean for quantitative variables, and number and
percentage with 95% CI of the population for categorical data.
The prevalence of VTE risk defined as risk factors meeting
the minimum criteria established by the American College of
Chest Physicians (version 2004) and any other valid guidelines
available at the time of data collection were provided for both the
medical and surgical population, with 95% confidence interval
by country. Analysis was carried out based on populations
where level of data was satisfactory. The distribution of patients
by range of VTE risk factors and the distribution of patients
by type of VTE prophylaxis were provided. The prevalence of
prophylaxis for VTE is provided by country and globally.
Results
Between June 2009 and December 2010, eligible patients were
enrolled from 14 hospitals across five sub-Saharan African
countries (Madagascar, Democratic Republic of Congo,
Cameroon, Botswana and Nigeria). A total of 1 623 patients
were surveyed; 567 were medical patients, 1 016 were surgical
patients and 27 were unclassified due to incomplete information.
Twelve subjects violated the protocol while one subject was
below the required age for inclusion. Therefore, the overall
number of subjects assessed was 1 583.
Reasons for hospital admission and general characteristics
of the patients are shown in Tables 1, 2 and 3. The median age
of the surgical patients was 45 (IQR 33–59) years, median body
mass index (BMI) was 24.2 (IQR 20.9–28.9) kg/m
2
, and 290
(51.2%) were female. The median age of the medical patients was
60 (IQR 51–72) years, median BMI was 23.5 (IQR 20.5–26.7)
kg/m
2
, and 521 (51.3%) were male. Due to missing values, the
BMI could only be calculated for 374 surgical and 196 medical
patients. The median length of hospital stay up to the survey
date was five days in the overall study population.
Of the 1 583 enrolled patients, 798 (50.4%) were deemed to
be at risk for VTE; 445 (43.8%) of the 1 016 surgical patients
were at risk, as were 353 (62.3%) of the 567 medical patients.
There were 88 surgical patients who were at medical risk for
VTE. Cardiovascular diseases, endocrine/metabolic diseases
and active malignancy were the commonest conditions and/or
reasons for admission among surgical patients at risk of VTE,
while cardiovascular diseases, endocrine/metabolic diseases, and
infections (including pulmonary) were the commonest among
medical patients.
Of the surgical patients, 454 (44.5%) were admitted with major
trauma, while only three (0.5%) of the medical patients had major
trauma on admission. Among the surgical patients admitted with
Table 1. Characteristics and reasons for admission
of assessable surgical patients
Reason for hospitalisation
Met VTE risk
criteria
(n
=
445) (%)
Did not meet
VTE risk criteria
(n
=
571) (%)
Age, mean
±
SD
45.15
±
16.59
48.95
±
17.24
Gender, M (%)
153 (34.4)
368 (64.4)
F (%)
292 (65.6)
203 (35.6)
Hip replacement
49 (11.0)
2 (0.4)
Knee replacement
7 (1.6)
2 (0.4)
Hip fracture
19 (4.3)
1 (0.2)
Curative arthroscopy
–
1 (0.2)
Other orthopaedic trauma
2 (0.5)
219 (34.8)
Colon/small bowel surgery
47 (10.6)
2 (0.4)
Rectosigmoid surgery
2 (0.5)
2 (0.4)
Gastric surgery
10 (2.3)
–
Hepatobiliary surgery
1 (0.2)
5 (0.9)
Urological surgery
31 (7.0)
1 (0.2)
Vascular surgery
1 (0.2)
7 (1.2)
Thoracic surgery
1 (0.2)
4 (0.7)
Gynaecological surgery
169 (38.0)
1 (0.2)
Other surgery
16 (3.6)
107 (18.6)
Admitted with major trauma
but surgery not done
–
–
Table 2. Assessable surgical patients presenting
with more than one surgery
Reason for hospitalisation
Met VTE risk
criteria
(n
=
445) (%)
Did not meet
VTE risk criteria
(n
=
571) (%)
Age, mean
±
SD
45.15
±
16.59
48.95
±
17.24
Gender, M (%)
153 (34.4)
368 (64.4)
F (%)
292 (65.6)
203 (35.6)
Urological and other surgery
1 (0.2)
1 (0.2)
Hip fracture and other surgery
–
1 (0.2)
Thoracic and other surgery
1 (0.2)
–
Other orthopaedic trauma and
other surgery
–
2 (0.4)
Gastric and hepatobiliary surgery
1 (0.2)
–
Gynaecological and colon/small
bowel surgery
–
1 (0.2)
Hip and knee replacement surgery
–
1 (0.2)
Colon/small bowel and thoracic
surgery
–
1 (0.2)
Hip replacement and hip fracture
–
1 (0.2)
