Table 4.

Estimates of attenuation factors and correlations with truth for the time-varying and fixed-intake models without covariates (standard errors in parentheses): protein intake among men

		Time-varying intake model		Fixed-intake model
Instrument	Study	Attenuation Factor	Correlation with Truth	Attenuation Factor	Correlation with Truth
FFQa	1	0.158 (0.033)	0.338 (0.069)	0.166 (0.035)	0.337 (0.067)
	2	0.160 (0.082)	0.249 (0.126)	0.146 (0.071)	0.240 (0.114)
	3	0.178 (0.050)	0.269 (0.074)	0.184 (0.049)	0.271 (0.069)
	Weighted Mean	0.163 (0.026)	0.298 (0.047)	0.168 (0.026)	0.295 (0.045)
	pd	0.944	0.721	0.899	0.693
1 × 24HRb	1	0.192 (0.032)	0.380 (0.058)	0.196 (0.032)	0.367 (0.055)
	2	0.058 (0.037)	0.118 (0.074)	0.069 (0.039)	0.149 (0.084)
	3	0.246 (0.030)	0.415 (0.046)	0.302 (0.031)	0.494 (0.039)
	Weighted Mean	0.182 (0.019)	0.355 (0.032)	0.207 (0.019)	0.413 (0.030)
	p	< 0.001	0.001	< 0.001	< 0.001
4 × 24HRc	1	0.327 (0.047)	0.495 (0.067)	0.364 (0.059)	0.500 (0.071)
	2	0.115 (0.072)	0.166 (0.103)	0.138 (0.078)	0.211 (0.117)
	3	0.452 (0.047)	0.562 (0.054)	0.593 (0.052)	0.692 (0.046)
	Weighted Mean	0.344 (0.033)	0.491 (0.047)	0.423 (0.035)	0.594 (0.037)
	p	< 0.001	0.002	< 0.001	< 0.001

^aFood frequency questionnaire

^bSingle 24-hour recall

^cAverage of 4 repeats of a 24-hour recall

^dp-value for heterogeneity across studies