Table 3

HRs (95% CIs) for risk of total knee replacement according to intake of fibre: the Singapore Chinese Health Study (1993–2017)

Quartiles of energy-adjusted food intakeQ1Q2Q3Q4P for trend*
Total fibre
 Median, g/day†8.559.4312.1917.70
 Cases/ person-years528/2 75 050712/280 456767/284 394809/287 955
 Multivariate model 11.001.08 (0.96 to 1.21)1.12 (1.00 to 1.26)1.18 (1.05 to 1.32)0.003
 Multivariate model 21.001.06 (0.95 to 1.19)1.09 (0.97 to 1.22)1.11 (0.99 to 1.24)0.088
Grain products‡
 Median, g/day†374.45420.21507.04793.28
 Cases/person-years744/289 413808/283 836684/280 047580/274 558
 Multivariate model 11.001.07 (0.96 to 1.18)0.93 (0.83 to 1.03)0.91 (0.82 to 1.02)0.024
 Multivariate model 21.001.09 (0.98 to 1.21)0.96 (0.86 to 1.06)0.95 (0.85 to 1.06)0.110
 Multivariate model 31.001.09 (0.98 to 1.21)0.95 (0.85 to 1.06)0.94 (0.82 to 1.06)0.120
Legumes
 Median, g/day†0.110.432.117.01
 Cases/ person-years638/ 80 170754/278 001756/280 407668/289 275
 Multivariate model 11.000.97 (0.87 to 1.09)0.95 (0.84 to 1.06)0.84 (0.76 to 0.94)<0.001
 Multivariate model 21.000.98 (0.87 to 1.09)0.94 (0.84 to 1.06)0.86 (0.77 to 0.96)0.004
 Multivariate model 31.000.98 (0.87 to 1.09)0.95 (0.84 to 1.06)0.86 (0.76 to 0.96)0.004
Nuts and seeds
 Median, g/day†0.510.651.385.14
 Cases/ person-years687/284 256689/280 907773/278 760667/282 854
 Multivariate model 11.000.84 (0.75 to 0.94)0.91 (0.81 to 1.02)0.87 (0.78 to 0.97)0.033
 Multivariate model 21.000.83 (0.74 to 0.92)0.90 (0.08 to 1.01)0.88 (0.79 to 0.98)0.175
 Multivariate model 31.000.83 (0.74 to 0.93)0.92 (0.82 to 1.03)0.89 (0.79 to 1.00)0.246
Soy food
 Median, g/day†43.6061.0598.94197.60
 Cases/ personyears568/276 720725/2 79 030760/283 782763/288 322
 Multivariate model 11.001.06 (0.94 to 1.19)1.05 (0.93 to 1.17)1.04 (0.93 to 1.16)0.742
 Multivariate model 21.001.09 (0.97 to 1.22)1.05 (0.94 to 1.17)1.01 (0.91 to 1.13)0.717
 Multivariate model 31.001.10 (0.98 to 1.23)1.05 (0.94 to 1.18)1.00 (0.89 to 1.12)0.494
Fruits
 Median, g/day†57.47114.79194.87369.31
 Cases/ person-years579/270 253677/278 859762/286 424798/292 317
 Multivariate model 11.001.01 (0.90 to 1.13)1.14 (1.02 to 1.27)1.21 (1.08 to 1.35)<0.001
 Multivariate model 21.000.99 (0.88 to 1.10)1.08 (0.96 to 1.20)1.10 (0.98 to 1.23)0.037
 Multivariate model 31.000.99 (0.88 to 1.11)1.07 (0.96 to 1.20)1.08 (0.96 to 1.21)0.134
Vegetables
 Median, g/day†59.5876.87106.49170.56
 Cases/person-years544/271 912678/280 181761/285 676833/290 085
 Multivariate model 11.001.02 (0.90 to 1.14)1.06 (0.95 to 1.19)1.13 (1.01 to 1.26)0.011
 Multivariate model 21.001.01 (0.90 to 1.13)1.01 (0.91 to 1.14)1.05 (0.94 to 1.17)0.332
 Multivariate model 31.001.01 (0.90 to 1.13)1.00 (0.89 to 1.12)1.02 (0.91 to 1.15)0.738
  • Multivariate model 1: adjusted for age at interview, sex, year of interview, total energy intake, dialect and education level.

  • Multivariate model 2: model 1 plus body mass index, sitting duration, sleep, physical activity, smoking, history of hypertension, diabetes, coronary artery disease and stroke.

  • Multivariate model 3: model 2 plus grain products, legumes, nuts and seeds, soy food, fruits and vegetables (except the exposure of interest).

  • *Linear trend was tested by assigning to participants the median value of the quartile they belonged to and treating this as a continuous variable.

  • †Fibre food sources are shown in energy-adjusted units using the residual method.

  • ‡The grain products included noodles and pasta, rice, bread and pancakes, breakfast cereals, biscuits and crackers.

  • Q, quartile.