The table below is from a study of the association between Chronic Obstructive Pulmonary Disease (COPD) and dietary fiber intake (Kaluza et al., 2018). The authors used Cox regression models. Interpret the hazard ratios for the age- and smoking-adjusted Cox model.a) After adjusting for age and smoking status, men with higher dietary fiber intake were significantly less likely to develop COPD with a reduction of 19%, 23%, 40% and 39% for quintiles 2 to 5 of dietary fiber intake, respectively, compared to quintile 1. b) After adjusting for age and smoking status, men with higher dietary fiber intake were significantly more likely to develop COPD (19%, 23%, 40% and 39% for quintiles 2 to 5 of dietary fiber intake, respectively, compared to quintile 1). c) Men with higher dietary fiber intake were significantly less likely to develop COPD with a reduction of 19%, 23%, 40% and 39% for quintiles 2 to 5 of dietary fiber intake, respectively, compared to quintile 1. d) Men with higher dietary fiber intake were significantly more likely to develop COPD (19%, 23%, 40% and 39% for quintiles 2 to 5 of dietary fiber intake, respectively, compared to quintile 1).
TABLE 2.Hazard Ratios (95% CIs) of Chronic Obstructive Pulmonary Disease by Quintiles of Energy-Adjusted Total Dietary Fiber in 45,058 Swedish Men,1998-2012
Quintiles of Total Dietary Fiber (g/day),(Median
Time of COPD Diagnose (years)
<23.7 (20.5)
23.727.8 (26.0)
27.931.7 (29.9)
31.836.7 (34.1)
36.8 (40.9)
P Trend
Follow-up 19982012 (15 years) No. cases/Person-years Age and smoking-adjusted HR Multivariable HRa
604/115,364 1.00 1.00
437/118,110 0.81(0.72,0.92 0.84 (0.74, 0.95)
384/118,864 0.77 (0.68, 0.88) 0.80 (0.70, 0.91)
285/119,689 0.60 (0.52, 0.69) 0.63 (0.54, 0.72)
272/119,917
0.61 (0.52, 0.70) 0.62 (0.53, 0.71)
<0.0001 <0.0001
Adjusted for age (continuous), education (less than high school, high school, or university), body mass index (<18.5, 18.524.9, 2529.9, or 30 kg/m), total physical activity (metabolic equivalent-hours/day, quintiles), smoking status and pack-years of smoking (never; past <20, 2039, or 40 pack-years; or current <20, 2039, or 40 pack-years), intake of energy (kcal/day, quintiles), and alcohol consumption (g/day, quintiles); missing values included in the models as a separate category.