Table 2.
Risk of chronic back pain and back-related disability at follow-up in 2017–2019 associated with change in sleep quality from 1995–1997 to 2006–2008.
| Risk of back pain and change in sleep quality from 1995–1997 to 2006–2008 | No. of persons | No. of cases | Age-adjusted, RRa | Multi-adjusted RR (95% CI)b |
|---|---|---|---|---|
| Chronic back pain | ||||
| Remained good sleep | 6636 | 1212 | 1.00 | 1.00 (reference) |
| Poor sleep to good sleep | 433 | 101 | 1.35 | 1.30 (1.08–1.55) |
| Good sleep to poor sleep | 1106 | 275 | 1.35 | 1.31 (1.16–1.48) |
| Remained poor sleep | 426 | 129 | 1.71 | 1.65 (1.42–1.93) |
| Back-related disability | ||||
| Remained good sleep | 6636 | 486 | 1.00 | 1.00 (reference) |
| Poor sleep to good sleep | 433 | 50 | 1.65 | 1.55 (1.17–2.06) |
| Good sleep to poor sleep | 1106 | 138 | 1.66 | 1.59 (1.32–1.92) |
| Remained poor sleep | 426 | 59 | 2.01 | 1.92 (1.48–2.49) |
CI confidence interval, RR risk ratio.
aAdjusted for age (continuous).
bAdjusted for age (continuous), sex (women, men), education (primary school, high school, college ≤ 4 years, college > 4 years), body mass index (continuous), relative change in body weight (continuous), changes in physical activity (remained active, inactive to active, active to inactive, remained inactive), and smoking (never smoked, former smoker, current low-intensity smoker [< 10 cigarettes per day], medium-intensity smoker [10–19 cigarettes per day] and high-intensity smoker [20 or more cigarettes per day]).