Number of subjects according to their specification of LBP within the preceding 12 months in 1992 and follow up in 1999 (n=728)
| 1992 | |||||
|---|---|---|---|---|---|
| 1999 | 0 days | 1–7 days | 8–30 days | 30–90 days | >90 days |
| 0 days | 110 | 72 | 33 | 6 | 1 |
| 1–7 days | 49 | 107 | 67 | 13 | 1 |
| 8–30 days | 22 | 55 | 68 | 21 | 2 |
| 30–90 days | 13 | 22 | 24 | 17 | 6 |
| >90 days | 0 | 4 | 10 | 1 | 4 |