Table 1.

Markov model estimates and sources.

Variable	Base case value	Low and high values	Distribution	Source
Costs ($)a			Gamma
Per treatment cost of MDA	0.27	0.22–0.31		Cost analysis (2020)
Per treatment cost of school-based targeted PC	0.43	0.29–0.60
Cost of drug	0.04			30
Health states and disability weights for hookworm infectionb			Triangular	25,26
Children
Light intensity infection	0.005	0.004–0.046
Moderate intensity infection	0.095	0.005–0.056
Heavy intensity infection	0.036	0.020–0.101
No hookworm	0.000
Adults
Light intensity infection	0.025	0.001–0.053
Moderate intensity infection	0.032	0.003–0.056
Heavy intensity infection	0.063	0.017–0.101
No hookworm	0.000
Population description			Dirichlet	8,22,23
Preschool children
No hookworm infection	138,274
Light intensity hookworm infection	6777
Moderate intensity hookworm infection	0
Heavy intensity hookworm infection	0
Schoolchildren
No hookworm infection	243,514
Light intensity hookworm infection	29,700
Moderate intensity hookworm infection	4785
Heavy intensity hookworm infection	5125
Adults
No hookworm infection	885,143
Light intensity infection	474,135
Moderate intensity hookworm infection	48,291
Heavy intensity hookworm infection	50,487
PC coverage			Triangular
School-based targeted PC–school children	0.98	0.75–1.00		NND
School-based targeted PC–adults, adolescents, and preschoolc	N/A
MDA–school children	0.95	0.75–1.00		8
MDA–adults, adolescents, and preschool	0.90	0.75–1.00		8
Transition probabilities–annual			Dirichlet
No treatmentd	0.000
School-based targeted PC				8
From no infection
To no infection	0.974
To light intensity infection	0.022
To moderate intensity infection	0.002
To heavy intensity infection	0.002
From light intensity infection
To no infection	0.490
To light intensity infection	0.457
To moderate intensity infection	0.036
To heavy intensity infection	0.016
From moderate intensity infection
To no infection	0.306
To light intensity infection	0.500
To moderate intensity infection	0.083
To heavy intensity infection	0.111
From heavy intensity infection
To no infection	0.267
To light intensity infection	0.311
To moderate intensity infection	0.133
To heavy intensity infection	0.289
Mass drug administration				8
From no infection
To no infection	0.973
To light intensity infection	0.027
To moderate intensity infection	0.000
To heavy intensity infection	0.000
From light intensity infection
To no infection	0.668
To light intensity infection	0.310
To moderate intensity infection	0.021
To heavy intensity infection	0.000
From moderate intensity infection
To no infection	0.611
To light intensity infection	0.333
To moderate intensity infection	0.028
To heavy intensity infection	0.028
From heavy intensity infection
To no infection	0.583
To light intensity infection	0.250
To moderate intensity infection	0.083
To heavy intensity infection	0.083

MDA, mass drug administration; PC, preventive chemotherapy; NND, Nguyen Ngoc Dinh personal communication.

^aVND adjusted to 2020 using consumer price index¹⁹; and converted to $ (rate: $1 = VND 22,750).²⁰

^bAll hookworm infections are associated with morbidity due to anaemia, and heavy intensity infection has additional disease-specific morbidity. Disability weight of anaemia was obtained by multiplying the disability weight of anaemia due to hookworm disease²⁵ by the probability of anaemia developing from a case of hookworm infection.²⁶

^cNot treated.

^dAssumed to not change status.