Associations between age at menopause and prevalence of chronic LBP in cross-sectional 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 | 11 332 | 11 332 | 10 054 | ||
| Age at menopause (year) | |||||
| ≤40 | 263 | 90 | 34.2 | 1.10 (0.92 to 1.32) | 1.08 (0.88 to 1.32) |
| 41–43 | 269 | 88 | 32.7 | 1.06 (0.88 to 1.28) | 1.05 (0.86 to 1.27) |
| 44–46 | 743 | 260 | 35.0 | 1.12 (0.98 to 1.27) | 1.06 (0.92 to 1.21) |
| 47–49 | 1170 | 394 | 33.7 | 1.07 (0.96 to 1.20) | 1.05 (0.93 to 1.18) |
| 50–52 | 1859 | 601 | 32.3 | 1.01 (0.90 to 1.13) | 1.03 (0.92 to 1.15) |
| 53–55 | 818 | 290 | 35.5 | 1.09 (0.95 to 1.25) | 1.06 (0.91 to 1.23) |
| ≥56 | 182 | 46 | 25.3 | 0.78 (0.59 to 1.02) | 0.79 (0.59 to 1.06) |
| Premenopausal | 6028 | 1670 | 27.7 | 1.00 (reference) | 1.00 (reference) |
| P for categorical effect | 0.09 | 0.56 | |||
| P for linear trend† | 0.15 | 0.49 |
*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.