Validity and repeatability of the EPIC physical activity questionnaire: a validation study using accelerometers as an objective measure

Table 5 Repeatability of the EPIC physical activity questionnaire over 10 months

EPIC questionnaire measure	Mean (SD) difference^a	Correlation (ρ)	95% CI
Continuous measure (MET hours/week)
Total non-occupational activity	-0.6 (59.0)	0.65	0.55, 0.72
Recreational activity	0.7 (47.7)	0.58	0.48, 0.67
Household activity	-1.3 (33.5)	0.73	0.66, 0.79
Vigorous activity, self-rated^b	3.3 (34.7)	0.63	0.54, 0.72
Vigorous activity, MET-assigned^b	1.5 (32.4)	0.71	0.63, 0.78
Light-moderate activity^c	-2.15 (51.0)	0.67	0.58, 0.74
Categorical measure		K _w
Total physical activity index		0.62	0.53, 0.71
Cambridge physical activity index		0.66	0.58, 0.74

P < 0.0001 for all measures.
EPIC, European Prospective Investigation into Cancer and Nutrition; ρ, Spearman rank correlation coefficient; CI, confidence interval; K_w weighted kappa
^a Mean (SD) difference in MET-hours/week: EPIC 10-month minus baseline questionnaire.
^b Vigorous activity was estimated (1) in a separate question about time in activities causing sweating or faster heartbeat, (2) using the sum of time spent in activities with MET values ≥ 6
^c Light-moderate activity was estimated using the sum of time spent in activities with MET values < 6

ISSN: 1479-5868