Table 2.
Low back pain in the last 30 days among high school students from Pelotas (Brazil) and its distribution according to demographic, socioeconomic and behavioral variables, 2009
| Variables | Acute low back pain prevalence | Crude analysis prevalence ratios (95%CI) | p | |
|---|---|---|---|---|
| N | % | |||
| Gender (n = 1,233) | 0.1* | |||
| Boys | 69 | 12.2 | 1.0 | |
| Girls | 100 | 15.2 | 1.2 (0.9–1.6) | |
| Schooling (n = 1,233) | ||||
| First year | 69 | 14.7 | 1.0 | 0.7* |
| Second year | 54 | 13.6 | 1.0 (0.7–1.3) | |
| Third year | 46 | 12.6 | 0.9 (0.6–1.2) | |
| Economic level (n = 1,036) | ||||
| A | 19 | 23.2 | 0.7 (0.3–1.9) | 0.2** |
| B | 69 | 12.3 | 0.7 (0.3–1.8) | |
| C | 47 | 12.8 | 0.7 (0.6–0.9) | |
| D | 4 | 17.4 | 1.0 | |
| Age (n = 1,233) | 0.01* | |||
| 13/14 | 27 | 17.3 | 1.0 | |
| 15 | 25 | 9.0 | 0.5 (0.3–0.9) | |
| 16 | 60 | 15.0 | 0.9 (0.6–1.3) | |
| 17 | 35 | 12.0 | 0.7 (0.4–1.1) | |
| 18/19 | 22 | 20.0 | 1.2 (0.7–2.0) | |
| Skin color (n = 1,201) | 0.05* | |||
| White | 120 | 12.6 | 1.00 | |
| Non-white | 44 | 17.5 | 1.4 (1.0–1.9) | |
| Physical activity (n = 1,233) | 0.3* | |||
| Inactive | 114 | 14.5 | 1.0 | |
| Active | 55 | 12.4 | 0.9 (0.6–1.2) | |
| BMI (kg/m2) (n = 1,191) | 0.6** | |||
| Normal | 122 | 13.7 | 1.0 | |
| Overweight | 32 | 13.6 | 1.0 (0.7–1.4) | |
| Obese | 7 | 10.5 | 0.8 (0.4–1.6) | |
| Smoking (n = 1,221) | 0.4* | |||
| Former smoker/never smoked | 156 | 13.6 | 1.0 | |
| Smoker | 12 | 16.9 | 1.2 (0.7–2.1) | |
* Chi-square test for heterogeneity
** Wald’s test for linear trend