Characteristic | IRR and 95% CI | |||
Crude IRR | A* | B† | C‡ | |
Past-year GAD | ||||
Yes | 1.18 (1.02 to 1.36) | 1.25 (1.09 to 1.43) | 1.10 (0.96 to 1.27) | 1.04 (0.90 to 1.20) |
No | 1.00 | 1.00 | 1.00 | 1.00 |
Sociodemographics | ||||
Age | ||||
Per 10 years | 1.36 (1.33 to 1.40) | 1.19 (1.16 to 1.23) | 1.20 (1.17 to 1.24) | 1.21 (1.18 to 1.25) |
Sex | ||||
Women | 0.80 (0.76 to 0.83) | 0.76 (0.73 to 0.79) | 0.76 (0.72 to 0.79) | 0.78 (0.74 to 0.81) |
Men | 1.00 | 1.00 | 1.00 | 1.00 |
Education§ | ||||
Low | 1.30 (1.24 to 1.36) | 1.13 (1.08 to 1.18) | 1.13 (1.08 to 1.19) | 1.11 (1.06 to 1.16) |
High | 1.00 | 1.00 | 1.00 | 1.00 |
Marital status | ||||
Single | 0.88 (0.79 to 0.99) | 0.85 (0.77 to 0.95) | 0.85 (0.76 to 0.95) | 0.84 (0.76 to 0.94) |
Married | 1.00 | 1.00 | 1.00 | 1.00 |
Other¶ | 1.21 (1.14 to 1.28) | 1.17 (1.11 to 1.24) | 1.14 (1.07 to 1.21) | 1.09 (1.03 to 1.16) |
Social class | ||||
Manual | 1.29 (1.23 to 1.34) | 1.24 (1.19 to 1.30) | 1.24 (1.19 to 1.30) | 1.21 (1.16 to 1.26) |
Non-manual | 1.00 | 1.00 | 1.00 | 1.00 |
Employment | ||||
Yes | 1.00 | 1.00 | 1.00 | 1.00 |
No | 1.64 (1.57 to 1.71) | 1.18 (1.12 to 1.25) | 1.18 (1.12 to 1.24) | 1.15 (1.09 to 1.21) |
Health status | ||||
Physical conditions** | ||||
Yes | 1.32 (1.26 to 1.37) | 1.18 (1.13 to 1.23) | 1.17 (1.12 to 1.22) | 1.18 (1.13 to 1.23) |
No | 1.00 | 1.00 | 1.00 | 1.00 |
Disability level | ||||
High†† | 1.78 (1.71 to 1.86) | 1.52 (1.45 to 1.59) | 1.51 (1.44 to 1.57) | 1.48 (1.42 to 1.55) |
Low | 1.00 | 1.00 | 1.00 | 1.00 |
Psychiatric conditions | ||||
Past-year MDD | ||||
Yes | 1.34 (1.22 to 1.48) | 1.34 (1.22 to 1.48) | 1.33 (1.21 to 1.46) | |
No | 1.00 | 1.00 | 1.00 | |
Lifestyle | ||||
Physical activity | ||||
Active‡‡ | 1.00 | 1.00 | ||
Inactive | 1.27 (1.21 to 1.33) | 1.04 (1.00 to 1.09) | ||
Smoking status | ||||
Current smoker | 1.60 (1.49 to 1.72) | 1.51 (1.41 to 1.62) | ||
Former smoker | 1.33 (1.27 to 1.39) | 1.13 (1.08 to 1.18) | ||
Never-smoker | 1.00 | 1.00 | ||
Alcohol intake | ||||
High§§ | 0.88 (0.85 to 0.92) | 0.92 (0.88 to 0.96) | ||
Low | 1.00 | 1.00 |
*Model A: adjusted for sociodemographics (age, sex, education, marital status, social class, employment), physical conditions, disability.
†Model B: adjusted for sociodemographics, physical conditions, disability, MDD.
‡Model C: adjusted for sociodemographics, physical conditions, disability, MDD, physical activity, smoking, alcohol.
§High education: O-level, A-level, degree; low education: refers to no education.
¶Other: divorced, separated, widowed.
**Physical conditions: respiratory disease (asthma and bronchitis), allergies and hay fever, stroke, heart attack, cancer, diabetes, thyroid conditions, arthritis.
††Below the physical component summary score value of 50.6.
‡‡Moderately inactive, moderately active, active.
§§3+units of alcohol/week (one pint beer=two units, one glass wine=one unit, one glass sherry=one unit, one glass spirits=one unit).
IRR, incidence rate ratio; MDD, major depressive disorder.