Table 5.

First- and second-order term for age from fractional polynomial models with predicted costs of health care utilization as dependent variable, by participant characteristics

Group	First term	Second term
Men	X3 − 657.2 (p < 0.001)	X3 × ln(X) − 1421.4 (p < 0.001)
Women	X3 − 696.5 (p < 0.001)	X3 × ln(X) − 1519.7 (p < 0.001)
Surviving	X3 − 669.4 (p < 0.001)	X3 × ln(X) − 1451.8 (p < 0.001)
Died in year	X−2 − 0.0123 (p < 0.001)	X−2 × ln(X) − 0.0270 (p < 0.001)

	Surviving	Died	Surviving	Died
Number of morbidities
0	X−2 − 0.0126 (p < 0.001)	X−2 − 0.0120 (p < 0.001)	X−2 × ln(X) − 0.0276 (p < 0.001)	X−2 × ln(X) − 0.0266 (p < 0.001)
1–3	X3 − 670.0 (p < 0.001)	X−2 − 0.0121 (p < 0.001)	X3 × ln(X) − 1453.2 (p < 0.001)	X−2 × ln(X) − 0.0267 (p < 0.001)
4–6	X3 − 668.0 (p < 0.001)	X−2 − 0.0123 (p < 0.001)	X3 × ln(X) − 1448.4 (p < 0.001)	X−2 × ln(X) − 0.0271 (p < 0.001)
≥7	X3 − 660.3 (p < 0.001)	Age − 88.90 (p < 0.001)	X3 × ln(X) − 1429.0 (p < 0.001)	–
Number of impairments
0	X−2 − 0.0133 (p < 0.001)	X3 − 706.8 (p < 0.001)	X−2 × ln(X) − 0.0287 (p < 0.001)	X3 × ln(X) − 1545.7 (p < 0.001)
1–3	X3 − 662.6 (p < 0.001)	X−2 − 0.0124 (p < 0.001)	X3 × ln(X) − 1434.8 (p < 0.001)	X−2 × ln(X) − 0.0272 (p < 0.001)
4–6	X3 − 698.9 (p < 0.001)	X0.5 − 3.0 (p < 0.001)	X3 × ln(X) − 1525.7 (p < 0.001)	–
≥7	X3 − 725.2 (p < 0.001)	Age − 91.6 (p < 0.001)	X3 × ln(X) − 1592.2 (p < 0.001)	–

X refers to age/10