Table 1.

Model parameters

Parameter	Low	Base case	High	Sources
Cohort size	–	100	–	–
Discount rate	–	3%	–	–
Epidemiological parameters
% Venomous snakes	32.5%	65%	97.5%	35*
Mortality following treatment (in severe cases)	5%	10%	15%	3,35–38
Incidence of any amputation (in severe cases)	12.5%	25%	37.5%	1,2,21,37,39
Incidence of finger/toe amputation (if any amputation)	50.75%	72.5%	94.25%	38,39
Mortality without treatment	0.8%	7%	15.2%	3,36
Intervention effectiveness
% Accessing modern health facility (antivenom only)	79%	88.6%	96%	3
% Increase in accessing modern health facility (antivenom/adjunct)	1%	7%	11%	Assumption
% Severe cases (antivenom only)	50.4%	63%	75.6%	33,40*
Absolute % Reduction in severe cases (antivenom + adjunct)	3.9%	13%	22.1%	Assumption
Costs
Supportive treatment cost of severe envenomation (not including AV)	$1,077	$2,153	$3,230	Primary investigation
Supportive treatment cost of mild envenomation (not including antivenom)	$253	$506	$760	Primary investigation
Supportive treatment cost of no envenomation	$50	$101	$151	Primary investigation
Cost of finger/toe amputation	–	$174	–	Primary investigation
Cost of below-knee amputation	–	$522	–	Primary investigation
Cost of antivenom (antivenom only)	$144	$287	$431	Primary investigation
Cost of antivenom (antivenom + adjunct)	$144	$287	$431	Primary investigation
Cost of adjunct	$157	$313	$470	Assumption
Cost of adjunct distribution/storage (per patient treated)	$1.31	$2.61	$3.92	Assumption
Disability weights
Below-knee amputation	0.064	0.164	0.264	41,42
Finger/toe amputation	0.005	0.02	0.035	41,42

Base-case values, data sources, and ranges used in the probabilistic sensitivity analysis.

^*These base-case values took various expert opinions into account in addition to published literature.