Measuring physical activity among pregnant women using a structured one-week recall questionnaire: evidence for validity and reliability

Table 4 Comparison of the PIN3 physical activity questionnaire to the accelerometer using Spearman correlation coefficients (SCC) with 95% confidence intervals (CI), using perceived intensity

	Accelerometry in hours/week using cutpoints *
	Freedson et al	Swartz et al	Troiano et al
	SCC (95% CI)	SCC (95% CI)	SCC (95% CI)
Questionnaire (hours/week)
Moderate activity
Full sample**	0.25 (0.11, 0.39)	0.33 (0.18, 0.47)	0.25 (0.11, 0.39)
Complete Actigraph sample***	0.16 (-0.01, 0.34)	0.25 (0.08, 0.43)	0.16 (-0.01, 0.34)
Imputed data sample#	0.20 (0.06, 0.34)	-0.03 (-0.19, 0.12)	0.20 (0.06, 0.35)
Vigorous activity
Full sample**	0.29 (0.13, 0.45)	0.26 (0.11, 0.42)	0.32 (0.16, 0.47)
Complete Actigraph sample***	0.32 (0.13, 0.51)	0.32 (0.13, 0.51)	0.33 (0.14, 0.52)
Imputed data sample#	0.29 (0.14, 0.45)	0.27 (0.11, 0.42)	0.32 (0.16, 0.48)
Moderate to vigorous activity
Full sample**	0.29 (0.15, 0.42)	0.34 (0.20, 0.48)	0.28 (0.14, 0.41)
Complete Actigraph sample***	0.23 (0.06, 0.40)	0.30 (0.13, 0.47)	0.22 (0.05, 0.39)
Imputed data sample#	0.24 (0.10, 0.37)	0.002 (-0.15, 0.16)	0.23 (0.10, 0.37)

*The cutpoints on accelerometer counts per minute were defined as follows:
Freedson et al: 1952-5724 (Moderate); > = 5725 (Vigorous)
Swartz et al: 574-4944 (Moderate); > = 4945 (Vigorous)
Troiano et al: 2020-5998 (Moderate); > = 5999 (Vigorous)
**Full sample n = 177
***Complete Actigraph data (n = 120) was defined as having nonmissing counts over at least 70% of a standard measurement day, with a standard measurement day defined as the length of time in which at least 70% of participants were wearing the monitor. This was defined separately for weekdays and weekends.
#Imputed sample n = 177

ISSN: 1479-5868