A General Latent Class Model for Performance Evaluation of Diagnostic Tests in the Absence of a Gold Standard: An Application to Chagas Disease

Table 3

Location and scale hyperparameter values of the normal prior distributions (6) for model ModII (𝐿=6, 𝑀=3, 𝑉=2).

Sensitivity	𝛼1𝑘∼𝑁(5.8,2.0)	𝑘=1,2,3,5,6
	𝛼14∼𝑁(−0.5,0.25)
	𝛾1𝑘𝑐∼𝑁(0,100)	𝑐=1,2,3, 𝑘=1,2,3,4,5,6
Specificity	𝛼0𝑘∼𝑁(3.5,2.0)	𝑘=1
	𝛼0𝑘∼𝑁(6.5,3)	𝑘=2,3,6
	𝛼0𝑘∼𝑁(100,1𝐸−100)	𝑘=4
	𝛼0𝑘∼𝑁(2,1)	𝑘=5
	𝛾0𝑘𝑐∼𝑁(0,100)	𝑐=1,2,3, 𝑘=1,2,3,5,6
	𝛾0𝑘𝑐∼𝑁(0,0)	𝑐=1,2,3, 𝑘=4
Prevalence	𝛼𝑣∼𝑁(0.5,0.25)	𝑣=1
	𝛼𝑣∼𝑁(−2,1)	𝑣=2
	𝛾𝑣𝑐∼𝑁(0,100)	𝑐=1,2,3, 𝑣=1,2

𝑐=1: AGE-age (≤30, >30 years); 𝑐=2: GEN-gender (male, female); 𝑐=3: RFE-presence of at least two of three risk factors epidemiological (origin from an endemic region, contact with the vector transmitting the disease and family history of Chagas’ disease); Stratum I (𝑣=1) donors with negative or positive serology and Stratum II (𝑣=2) with inconclusive serology in the screening test; 𝛾_1𝑘𝑐: effect of the cth covariate on the sensitivity of kth test; 𝛾_0𝑘𝑐: effect of the cth covariate on the specificity of kth test; 𝛾_𝑣𝑐: effect of the cth covariate on disease prevalence in vth stratum.