Accuracy of physical activity assessment during pregnancy: an observational study

Table 4 Composite predictors of moderate-vigorous physical activity

Cut-off		True		False		Φ	P-value
PAR (min)	SWA (min)	Positive	Negative	Positive	Negative
280	385	8	36	3	5	0.571	0.0007
182	385	10	32	7	3	0.544	0.0015
259	385	8	35	4	5	0.527	0.0024
280	350	8	35	4	5	0.527	0.0024
210	385	9	33	6	4	0.515	0.0032
168	385	10	31	8	3	0.513	0.0033
280	400	7	36	3	6	0.507	0.0039
259	350	8	34	5	5	0.487	0.0063

Cut-off shows the cut-off time for each modality (PAR = physical activity record, SWA = SenseWear^® armband) in minutes per week. True/false/positive/negative data shows the number of participants in each category (out of a total of 52 participants) compared to the reference standard. Φ is the 2 × 2 contingency correlation coefficient. Significance was set at P < 0.05.

ISSN: 1471-2393