. 2014 Jun 26;8(6):e2952. doi: 10.1371/journal.pntd.0002952

Table 2. Estimated standard deviation and bias in PRNT₇₅ estimates using the different models.

Model	Proportion of assays	Variance (log₁₀ scale)	Bias (log₁₀ scale)
		[95% confidence interval]
Probit regression	100%	0.036 [0.030–0.040]	0.042 [0.035–0.049]
Logistic regression	100%	0.036 [0.030–0.040]	0.055 [0.049–0.063]
Cloglog regression	100%	0.025 [0.021–0.030]	0.027 [0.021–0.033]
Four-parameter non-linear regression	63%	0.022 [0.017–0.027]	0.059 [0.052–0.066]

Values are averages from the different viruses and serum pools, weighted by the number of experiments.

Table 2. Estimated standard deviation and bias in PRNT75 estimates using the different models.