T. Abdoolcarrim et al., THE COST AND BENEFIT OF PROPHYLAXIS AGAINST DEEP-VEIN THROMBOSIS IN ELECTIVE HIP-REPLACEMENT, South African medical journal, 87(5), 1997, pp. 594-600
A consensus forum was convened to evaluate the economic considerations
associated with prophylaxis against thrombo-embolic disease in patien
ts undergoing hip replacement therapy in South Africa, This forum cons
ists of orthopaedic surgeons, vascular surgeons and a statistician. Me
thods. The forum was instructed to evaluate the economic costs of the
commonly used forms of prophylaxis of thrombo-embolism in patients und
ergoing hip replacement surgery in South Africa, looking at shortterm
events only. The methods used for the prophylaxis of thrombo-embolism
in South Africa were determined by a postal survey. A decision tree wa
s constructed to determine the events that will occur after a clinical
decision to use no prophylaxis. The probabilities of these events wer
e then determined. Protocols for and costs of prophylaxis and treatmen
t were established. With the decision tree and these costs, the cost o
f the various modalities of prophylaxis was then determined. Results.
The probability, determined by the forum, of developing a deep-vein th
rombosis (DVT) when no prophylaxis is used was 0.5, with a mortality r
ate of 2.1%, The cost of this decision was R875, No prophylaxis given,
but a venogram performed on day 7, reduced the mortality rate to 0.7%
; however, this cost R3 017. The cost of low-molecular-weight heparin
was R1 223 (probability 0.26, mortality rate 1.1%), while unfractionat
ed heparin with a graduated compression stocking (GCS) cost R1 351 (pr
obability 0.24, mortality rate. 1%). Aspirin with a GCS cost R777 (pro
bability 0.35, mortality rate 1.5%). Conclusions. The use of some form
of prophylaxis against DVT formation in patients undergoing elective
hip replacement in South Africa is mandatory, as all the methods commo
nly used reduced the mortality. The use of no prophylaxis but with scr
eening for DVT at day 7 - 10 is not justified as it is very expensive.
Aspirin in combination with a stocking is the cheapest form of prophy
laxis, but does not reduce the prevalence of DVT and does not reduce m
ortality sufficiently to be clinically effective. The heparins (possib
ly in combination with stockings) appear to be most cost-effective but
cost between R350 and R500 more per patient than when no prophylaxis
is used.