Quality of the evidence and reasons for downgrading (in bold)
| Prognostic factor | Follow-up | Population | Study | Risk of bias | Imprecision | Quality |
| Demographic factors | ||||||
| Age | 2 years | Mixed | Grøvle et al 25 | Low | OR 0.97 (0.93 to 1.00); NS | Low |
| Age | 4 years | Mixed | Atlas et al 23 | Low | OR 0.7 (0.6 to 0.8) | Moderate |
| Age | 10 years | Mixed | Atlas et al 24 | Moderate | OR 0.42 (0.3 to 0.58); CI crosses 0.5 | Very low |
| Age | 3 months | Surgical | Than et al 28 | Moderate | OR 0.92 (0.85 to 0.99) | Low |
| Female sex | 2 years | Mixed | Grøvle et al 25 | Low | OR 0.61 (0.31 to 1.22); NS | Low |
| Male sex | 10 years | Mixed | Atlas et al 24 | Moderate | OR 0.33 (0.09 to 1.0); NS | Very low |
| Male sex | 3 months | Surgical | Than et al 28 | Moderate | OR 0.22 (0.04 to 1.09); NS | Very low |
| General health | ||||||
| General health | 2 years | Mixed | Grøvle et al 25 | Low | OR 1.03 (1.01 to 1.05) | Moderate |
| General health | 6 years | Mixed | Atlas et al 23 | Low | OR 1.1 (1.0 to 1.2) | Moderate |
| General health | 3 months | Surgical | Than et al 28 | Moderate | OR 1.03 (0.98 to 1.08); NS | Very low |
| Pain and disability | ||||||
| Low back pain intensity | 4 years | Mixed | Atlas et al 23 | Low | OR 0.8 (0.6 to 0.9) | Moderate |
| Low back pain frequency | 10 years | Mixed | Atlas et al 24 | Moderate | No data; NS | Very low |
| Bothersomeness | 2 years | Mixed | Grøvle et al 25 | Low | OR 0.89 (0.82 to 0.97) | Moderate |
| Opioid use within 1 month postoperative | 3 years | Surgical | O’Donnell et al 27 | Low | OR 0.44 (0.26 to 0.75); CI crosses 0.5 | Low |
| Physical function | 10 years | Mixed | Atlas et al 24 | Moderate | OR 1.4 (1.1 to 1.8) | Low |
| Physical function | 3 months | Surgical | Than et al 28 | Moderate | OR 1.06 (0.997 to 1.13); NS | Very low |
| Pain/disability presurgery | 2 years | Surgical | Schade et al 22 | Moderate | No CI presented; NS; <10 participants/PF | Very low |
| Psychological factors | ||||||
| Fear avoidance | 2 years | Mixed | Grovle et al 25 | Low | OR 0.93 (0.90 to 0.97) | Moderate |
| Fear avoidance* | 6 months | Surgical | den Boer et al 26 | Low | OR 1.09 (1.01 to 1.17) | Moderate |
| Mental health | 10 years | Mixed | Atlas et al 24 | Moderate | No data; NS | Very low |
| Depression* | 2 years | Surgical | Schade et al 22 | Moderate | <10 participants/PF | Very low |
| Psychiatric comorbidity | 3 years | Surgical | O’Donnell et al 27 | Low | OR 0.19 (0.05 to 0.68); CI crosses 0.5 | Low |
| Occupational mental stress* | 2 years | Surgical | Schade et al 22 | Moderate | <10 participants/PF | Very low |
| Passive pain coping* | 6 months | Surgical | den Boer et al 26 | Low | OR 1.08 (1.0 to 1.16) | Moderate |
| Other health-related factors | ||||||
| Smoking status | 3 months | Surgical | Than et al 28 | Moderate | OR 4.37 (0.82 to 23.27), NS | Very low |
| Clinical examination | ||||||
| Positive SLR-test | 2 years | Mixed | Grøvle et al 25 | Low | OR 0.44 (0.20 to 0.95) | Moderate |
| Quebec classification | 10 years | Mixed | Atlas et al 24 | Moderate | No data; NS | Very low |
| Care related factors | ||||||
| Physician expected benefit of surgery | 10 years | Mixed | Atlas et al 24 | Moderate | OR 5.0 (1.65 to 17.7); CI crosses 2.0 | Very low |
| Initial treatment: surgery | 10 years | Mixed | Atlas et al 24 | Moderate | OR 1.4 (0.46 to 4.6); NS | Very low |
| Revision surgery with fusion | 3 years | Surgical | O’Donnell et al 27 | Low | OR 0.56 (0.33 to 0.97) | Moderate |
| Work-related factors | ||||||
| Receiving workers’ compensation | 4 years | Mixed | Atlas et al 23 | Low | OR 0.6 (0.3 to 1.2); NS | Low |
| Physical work load* | 6 months | Surgical | den Boer et al 26 | Low | OR 1.19 (1.07 to 1.31) | Moderate |
| Job satisfaction | 6 months | Surgical | den Boer et al 26 | Low | No CI presented; NS | Low |
| Duration sick leave | 6 months | Surgical | den Boer et al 26 | Low | No CI presented; NS | Low |
*Prognostic factor for reduced return to work; CI, 95% CI; NS, non-significant; PF, prognostic factor.