Table 3.
Associations of caffeine intake with severe headache or migraine.
| Variables | Crude model | Model 1a | Model 2b | Model 3c | Model 4d | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| OR (95% CI) | P value | OR (95% CI) | P value | OR (95% CI) | P value | OR (95% CI) | P value | OR (95% CI) | P value | |
| Totals | ||||||||||
| Per 100 mg/day caffeine intake | 1.01 (0.98,1.03) | 0.546 | 1.03 (1.01,1.05) | 0.016 | 1.03 (1.01,1.06) | 0.006 | 1.04 (1.01,1.06) | 0.003 | 1.05 (1.02,1.07) | < 0.001 |
| Group 1 (Caffeine:(≥ 0 to < 40 mg/day) | Reference1 | Reference1 | Reference1 | Reference1 | Reference1 | |||||
| Group 2 (Caffeine: ≥ 40 to < 200 mg/day) | 1.00 (0.89,1.13) | 0.979 | 1.08 (0.95,1.22) | 0.223 | 1.11 (0.98,1.26) | 0.110 | 1.10 (0.97,1.25) | 0.123 | 1.12 (0.98,1.27) | 0.090 |
| Group 3 (≥ 200to < 400 mg/day) | 0.95 (0.82,1.10) | 0.497 | 1.09 (0.93,1.28) | 0.268 | 1.18 (1.00,1.38) | 0.048 | 1.18 (1.01,1.39) | 0.040 | 1.24 (1.05,1.46) | 0.011 |
| Group 4 (≥ 400 mg/day) | 1.02 (0.85,1.23) | 0.838 | 1.23 (1.01,1.49) | 0.040 | 1.28 (1.05,1.57) | 0.016 | 1.30 (1.06,1.60) | 0.011 | 1.42 (1.16,1.75) | < 0.001 |
| P value for trend | 0.857 | 0.047 | 0.005 | 0.003 | < 0.001 | |||||
| Males | ||||||||||
| Per 100 mg/day caffeine intake | 1.04 (1.01,1.07) | 0.019 | 1.04 (1.01,1.07) | 0.008 | 1.04 (1.01,1.07) | 0.012 | 1.04 (1.01,1.08) | 0.007 | 1.05 (1.01,1.08) | 0.006 |
| Group 1 (Caffeine:(≥ 0 to < 40 mg/day) | Reference1 | Reference1 | Reference1 | Reference1 | Reference1 | |||||
| Group 2 (Caffeine: ≥ 40 to < 200 mg/day) | 1.07 (0.86,1.33) | 0.548 | 1.10 (0.88,1.38) | 0.399 | 1.11 (0.88,1.39) | 0.380 | 1.12 (0.89,1.40) | 0.342 | 1.11 (0.88,1.40) | 0.378 |
| Group 3 (≥ 200 to < 400 mg/day) | 1.08 (0.84,1.39) | 0.545 | 1.15 (0.89,1.50) | 0.286 | 1.22 (0.93,1.59) | 0.152 | 1.23 (0.94,1.61) | 0.126 | 1.23 (0.94,1.62) | 0.131 |
| Group 4 (≥ 400 mg/day) | 1.37 (1.03,1.81) | 0.028 | 1.48 (1.11,1.99) | 0.009 | 1.51 (1.11,2.06) | 0.009 | 1.54 (1.13,2.10) | 0.006 | 1.56 (1.14,2.14) | 0.005 |
| P value for trend | 0.033 | 0.007 | 0.004 | 0.002 | 0.002 | |||||
| Females | ||||||||||
| Per 100 mg/day caffeine intake | 1.02 (0.99,1.06) | 0.184 | 1.07 (1.03,1.11) | < 0.001 | 1.06 (1.02,1.10) | 0.005 | 1.06 (1.02,1.10) | 0.003 | 1.07 (1.02,1.11) | 0.002 |
| Group 1 (Caffeine: ≥ 0 to < 40 mg/day) | Reference1 | Reference1 | Reference1 | Reference1 | Reference1 | |||||
| Group 2 (Caffeine: ≥ 40 to < 200 mg/day) | 1.04 (0.89,1.20) | 0.630 | 1.17 (1.00,1.36) | 0.045 | 1.17 (1.00,1.36) | 0.048 | 1.16 (0.99,1.36) | 0.059 | 1.15 (0.99,1.35) | 0.071 |
| Group 3 (≥ 200to < 400 mg/day) | 1.04 (0.86,1.26) | 0.710 | 1.28 (1.05,1.56) | 0.016 | 1.28 (1.04,1.58) | 0.018 | 1.29 (1.05,1.59) | 0.017 | 1.30 (1.05,1.60) | 0.015 |
| Group 4 (≥ 400 mg/day) | 1.10 (0.84,1.43) | 0.489 | 1.43 (1.08,1.88) | 0.011 | 1.34 (1.00,1.79) | 0.046 | 1.36 (1.02,1.81) | 0.038 | 1.40 (1.04,1.87) | 0.026 |
| P value for trend | 0.593 | 0.003 | 0.007 | 0.007 | 0.006 | |||||
CI confidence interval, OR odds ratio.
aModel 1: Adjust for age and race/ethnicity.
bModel 2: Adjusted for the variables in Model 1 plus body mass index, poverty-income ratio, educational level, marital status, alcohol status, and smoking status.
cModel 3: Adjusted for the variables in Model 2 plus hypertension, cancer, and triglycerides.
dModel 4: Adjusted for the variables in Model 3 plus energy intake, protein intake, calcium intake, magnesium intake, iron intake, and sodium intake.