Associations between age at menopause and risk of chronic LBP in HUNT3 in prospective analysis, among women at least 40 years old in HUNT2
| Total number of women in category of age at menopause | Number of women with chronic LBP | Crude AR of chronic LBP (%) | RR (95% CI) with adjustment for age only | RR (95 % CI) with additional adjustment* | |
| Number of women included | 5394 | 5394 | 4941 | ||
| Age at menopause (year) | |||||
| ≤40 | 108 | 24 | 22.2 | 1.06 (0.73 to 1.55) | 1.05 (0.70 to 1.57) |
| 41–43 | 102 | 26 | 25.5 | 1.21 (0.85 to 1.73) | 1.10 (0.74 to 1.62) |
| 44–46 | 308 | 67 | 21.8 | 1.03 (0.80 to 1.34) | 1.03 (0.79 to 1.34) |
| 47–49 | 500 | 96 | 19.2 | 0.91 (0.73 to 1.15) | 0.94 (0.74 to 1.19) |
| 50–52 | 841 | 155 | 18.4 | 0.87 (0.70 to 1.09) | 0.86 (0.68 to 1.09) |
| 53–55 | 368 | 83 | 22.6 | 1.07 (0.82 to 1.40) | 1.05 (0.79 to 1.40) |
| ≥56 | 86 | 12 | 14.0 | 0.66 (0.38 to 1.16) | 0.68 (0.37 to 1.26) |
| Premenopausal | 3081 | 637 | 20.7 | 1.00 (reference) | 1.00 (reference) |
| P categorical effect | 0.33 | 0.59 | |||
| P for linear trend† | 0.11 | 0.31 |
*Adjustment for age, BMI, physical activity, education, smoking, nulliparity, age at first delivery and age at menarche.
†Among postmenopausal women.
AR, absolute risk; BMI, body mass index; HUNT, Trøndelag Health Study; LBP, low back pain; RR, relative risk.