Table 3.

Reclassification table

		n before addition of OLST to FRAX	Low risk after addition of OLST to FRAX	High risk after addition of OLST to FRAX	Addends to sum to NRIa
Participants with fracture during follow-up	Low risk according to FRAX	34	21	13	+13/40
	High risk according to FRAX	6	2	4	−2/40
Participants without fracture during follow-up	Low risk according to FRAX	288	212	76	−76/309
	High risk according to FRAX	21	10	11	+10/309

The effect of adding one-leg standing time (OLST) to FRAX regarding classification of the study population into a low risk group ≤15% for a hip fracture and a high-risk group with >15% risk. Sensitivity changed from 6/40 to (13 + 4) / 40 = from 15 to 43%. Specificity changed from 288/309 to (212 + 10) / 309 = from 93 to 72%. The positive predictive value changed from 6 / (6 + 21) = 22.2% to (13 + 4) / (13 + 4 + 76 + 11) = 16.3%. The negative predictive value changed from 288 / (288 + 21) = 93% to (212 + 10) / (212 + 10 + 2 + 21) = 91%

^aNRI = 13/40−2/40−76/309 + 10/309 = 0.061