Table 3.
Correlation matrix between the eight constructed variables of low back pain (LBP) in Dphacto, N = 842 (p < 0.001)
| Accumulated LBP | Mean LBP | Median LBP | LBP >2 | LBP >4 | LBP =0 | Standard Deviation | Variation span | |
|---|---|---|---|---|---|---|---|---|
| Accumulated LBP | 1 | - | - | - | - | - | - | - |
| Mean LBP | 0.99 | 1 | - | - | - | - | - | - |
| Median LBP | 0.97 | 0.98 | 1 | - | - | - | - | - |
| LBP > 2 | 0.94 | 0.93 | 0.91 | 1 | - | - | - | - |
| LBP > 4 | 0.92 | 0.92 | 0.89 | 0.81 | 1 | - | - | - |
| LBP = 0 | −0.81 | −0.81 | −0.79 | −0.80 | −0.57 | 1 | - | - |
| Standard deviation | 0.42 | 0.42 | 0.31 | 0.38 | 0.32 | −0.42 | 1 | - |
| Variation span | 0.43 | 0.43 | 0.33 | 0.40 | 0.32 | −0.46 | 0.96 | 1 |
Analysed with Pearson correlation. LBP = low back pain. The eight LBP variables are constructed for all blue- and white-collar workers included from the DPhacto study. Accumulated LBP: summation of all LBP intensity scores for each worker, mean LBP: the mean of all LBP intensity scores, median LBP: the median of all LBP intensity scores, LBP > 2: number of months with LBP assessments higher than 2, LBP > 4: number of months with LBP assessments higher than 4, LBP = 0: number of months with LBP assessments equal to 0, standard deviation of all LBP intensity scores, and the variation span: numeric difference between the workers highest and lowest pain intensity scores. Coefficients are shown between all eight LBP variables with p < 0.001