| Total number of cases | 146 patients with lumbar disc degeneration |
| Ethnicity | Norwegian |
| Gender (Males/Females) | 68/78 |
| Age (8 year follow up), years | Range: 30-76, Mean [SD]: 53.2 [8.8] |
| Age of Onset, years | Range: 10-61, Mean [SD]: 32.9 [10.3] |
| Duration of pain (baseline), months | Range: 10-480, Mean [SD]: 128.8 [103.04] |
| Smokers/non-smokers/unknown | 68/69/9 |
| Surgical status (None/discectomy/lumbar fusion) | 27/46/73 |
| History of back pain in first degree relatives, with no treatment/conservative treatment/surgery/unknown | 19/82/40/5 |