Table 2

HRs (95% CIs) for associations between BMF and multiple vascular and non-vascular diseases

DiseasesMore than once a dayOnce a dayOnce every 2 to 3 daysLess than three times a weekP value for trend*
Vascular diseases
 IHD
 No. of cases466830 47034481761
 Cases/PYs (1/1000)10.438.457.608.59
 Multivariable adjusted1.12 (1.09 to 1.16)1.001.00 (0.96 to 1.03)1.07 (1.02 to 1.12)0.008
 MCEs
 No. of cases8715960765376
 Cases/PYs (1/1000)1.881.611.641.78
 Multivariable adjusted1.03 (0.96 to 1.11)1.001.10 (1.02 to 1.19)1.22 (1.10 to 1.36)0.002
 Haemorrhagic stroke
 No. of cases10286856723336
 Cases/PYs (1/1000)2.221.851.561.60
 Multivariable adjusted0.97 (0.90 to 1.03)1.000.98 (0.91 to 1.06)1.07 (0.95 to 1.19)0.256
 Ischaemic stroke
 No. of cases404428 59432911650
 Cases/PYs (1/1000)9.007.917.248.03
 Multivariable adjusted1.01 (0.98 to 1.05)1.001.04 (1.00 to 1.08)1.10 (1.05 to 1.16)0.002
 Heart failure
 No. of cases5353068398203
 Cases/PYs (1/1000)1.160.830.860.96
 Multivariable adjusted1.33 (1.22 to 1.46)1.000.96 (0.86 to 1.06)0.99 (0.86 to 1.15)<0.001
Non-vascular diseases
 COPD
 No. of cases15188167926443
 Cases/PYs (1/1000)3.632.372.142.29
 Multivariable adjusted1.28 (1.22 to 1.36)1.000.89 (0.83 to 0.95)0.92 (0.84 to 1.02)<0.001
 T2DM
 No. of cases220711 5141077483
 Cases/PYs (1/1000)5.143.302.462.46
 Multivariable adjusted1.20 (1.15 to 1.26)1.000.86 (0.81 to 0.92)0.84 (0.77 to 0.92)<0.001
 CKD
 No. of cases8214786605314
 Cases/PYs (1/1000)1.811.311.331.52
 Multivariable adjusted1.15 (1.07 to 1.24)1.001.07 (0.98 to 1.17)1.20 (1.07 to 1.35)0.577
  • Cox regression models were stratified by 5 year groups and 10 survey sites, with age as the underlying time scale.

  • Multivariable models were adjusted for sex (men or women); level of education (no formal school, primary school, middle school, high school, college or university or higher); occupation (agricultural, industrial, administrative or managerial, professional or technical, sales or service, retired, house wife or husband, self-employed, unemployed, other); household income (<2500, 2500 to 4999, 5000 to 9999, 10 000 to 19 999, 20 000 to 34 999, ≥35 000 RMB per year); marital status (married, widowed, divorced or separated or never married); family history of certain diseases (presence, absence or unclear; for corresponding disease only; no adjustment for heart failure, COPD and CKD); smoking status (non-smoker, former smoker, current smoker who smoked <15, 15 to 24 or ≥25 cigarettes or equivalents per day; those who had stopped smoking because of ill health were included in current smokers to avoid bias); total physical activity level (MET-hours/day); alcohol consumption (non-drinker, former weekly drinker, weekly drinker, daily drinker with an intake of <15, 15 to 29, 30 to 59 or ≥60 g/day of pure alcohol); intake frequency of fresh vegetables, fresh fruit and red meat (daily, 4 to 6 days/week, 1 to 3 days/week, monthly or rarely or never); BMI (kg/m2); waist circumference (cm); prevalent hypertension and diabetes at baseline (presence or absence, no adjustment for T2DM).

  • *Assessed by assigning consecutive integers to four BMF categories in a separate model. A Bonferroni corrected threshold was used, α=0.00625.

  • BMF, bowel movement frequency;BMI, body mass index; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; IHD, ischaemic heart disease; MCEs, major coronary events;PYs, person-years; T2DM, type 2 diabetes mellitus.