Table 3 Hazard ratios and 95% confidence intervals for incident metabolic syndrome by serum total bilirubin quartiles in men and women before and after propensity score matching

Q1 (≤ 0.46)

Q2 (0.47–0.62)

Q3 (0.63–0.82)

Q4 (≥ 0.83)

Q1 (≤ 0.38)

Q2 (0.39–0.49)

Q3 (0.50–0.65)

Q4 (≥ 0.66)

Before matching

Total, n

796

781

754

758

544

510

532

510

New cases of metabolic syndrome, n

371

360

336

327

342

275

262

248

Mean follow-up (years)

9.5 (5.3)

10.0 (5.2)

10.0 (5.2)

10.1 (5.2)

8.2 (5.6)

9.6 (5.6)

9.7 (5.7)

10.0 (5.5)

Person-years of follow-up

7572

7783

7559

7677

4480

4891

5139

5090

Incidence rate per 1000 person-year

49.0

46.3

44.5

42.6

76.3

56.2

51.0

48.7

Model 1

1.00 (ref)

0.96 (0.83–1.12)

0.94 (0.81–1.10)

0.93 (0.79–1.08)

1.00 (ref)

0.80 (0.68–0.94)

0.78 (0.66–0.93)

0.75 (0.64–0.89)

Model 2

1.00 (ref)

0.96 (0.83–1.11)

0.94 (0.80–1.09)

0.92 (0.78–1.08)

1.00 (ref)

0.79 (0.67–0.93)

0.78 (0.65–0.92)

0.75 (0.63–0.88)

Model 3

1.00 (ref)

0.95 (0.82–1.11)

0.88 (0.75–1.03)

0.88 (0.75–1.04)

1.00 (ref)

0.80 (0.67–0.94)

0.78 (0.68–0.95)

0.75 (0.64–0.89)

After matching

Total, n

422

422

422

422

326

326

326

326

New cases of metabolic syndrome, n

197

195

189

174

194

165

157

165

Mean follow-up (years)

9.7 (5.3)

9.9 (5.3)

10.0 (5.2)

10.4 (5.2)

9.1 (5.6)

10.1 (5.5)

10.0 (5.6)

10.0 (5.5)

Person-years of follow-up

4103

4164

4203

4398

2969

3297

3248

3275

Incidence rate per 1000 person-year

48.0

46.8

45.0

39.6

65.3

50.0

48.3

50.4

Model 1

1.00 (ref)

1.00 (0.82–1.22)

0.98 (0.80–1.21)

0.88 (0.71–1.09)

1.00 (ref)

0.77 (0.62–0.96)

0.75 (0.60–0.93)

0.80 (0.65–0.99)

Model 2

1.00 (ref)

1.00 (0.82–1.22)

0.98 (0.80–1.20)

0.88 (0.71–1.09)

1.00 (ref)

0.77 (0.62–0.96)

0.74 (0.60–0.92)

0.80 (0.65–0.99)

Model 3

1.00 (ref)

1.03 (0.84–1.27)

1.01 (0.82–1.24)

1.00 (0.80–1.24)

1.00 (ref)

0.77 (0.62–0.96)

0.74 (0.59–0.92)

0.80 (0.65–0.99)