Table 3 Number of vertebra with each combination of individual radiographic features.

Osteophyte	Sclerosis	Narrowing	Observed	Predicted*	Predicted†
0	3	0	0	3.8	0
0	3	1	0	1.5	0
0	3	2	0	0.4	0
1	3	2	0	0.8	0.2
0	2	3	0	1.1	0.2
0	2	2	0	1.8	0.2
2	3	0	0	2.2	0.2
0	2	0	0	15.9	0.4
2	3	1	0	0.9	0.6
2	3	2	0	0.3	0.9
3	0	3	0	5.3	1.1
3	3	1	0	0.4	2.1
1	3	0	1	6	−0.9
1	3	1	1	1.8	−0.9
1	3	3	1	−0.5	−0.7
0	2	1	1	5.3	−0.7
3	3	0	1	−0.1	−0.3
2	3	3	1	−0.8	1.1
0	3	3	2	−1.7	−2
0	1	3	2	3.9	0
1	2	3	2	0.1	1.3
3	3	2	2	−1.9	2
3	0	2	3	5.6	−0.4
0	1	2	3	6.7	1.4
1	2	1	4	7.7	0.8
2	2	0	4	5.3	2.1
3	1	3	4	−2.5	5.6
1	2	0	5	24.6	−0.8
2	0	3	5	7.5	−0.5
3	2	0	5	−1	1.4
1	2	2	6	−2.6	−2.7
3	2	1	7	−5.4	4
1	0	3	8	31.6	15.1
0	0	3	10	11.3	−5.1
2	2	2	10	−8.9	−2.8
3	1	2	10	−7.6	2
2	2	1	11	−7.3	−2.4
3	2	2	11	−10.5	0.3
1	1	3	12	−0.9	2.6
2	2	3	13	−12.3	−4.2
3	3	3	13	−12.9	−2.2
2	0	2	13	−7.2	−0.3
0	1	1	13	20	14.4
3	2	3	14	−13.7	2.7
1	1	2	15	3	12
3	0	1	17	12.4	−8.4
2	1	3	19	−15.5	−5
3	0	0	19	55.7	−1.8
3	1	1	21	−12.8	0.6
0	0	2	23	11.6	−2.8
0	1	0	23	60.8	25.2
2	1	2	28	−22.3	−6.8
3	1	0	32	−11.1	−8.7
1	0	2	48	16.3	−3.2
1	1	1	54	7.3	18.4
2	0	1	56	12.9	−4.5
2	1	0	63	−14.1	−1.6
2	1	1	67	−47.7	−20.4
2	0	0	82	92.8	43.4
0	0	1	114	4	7.8
1	1	0	123	32.6	−6.7
1	0	1	220	−0.9	1.5
0	0	0	446	−146.6	−5.9
1	0	0	683	−127	−26.1

*Difference between predicted and observed counts based on model with no interactions.

†Difference between predicted and observed counts based on model with interactions.