Table 2.
Association of comorbidities with function, symptoms and satisfaction.
| Comorbidity | Function | Evidence strength | Symptoms | Evidence strength | Satisfaction | Evidence strength | |||
|---|---|---|---|---|---|---|---|---|---|
| sign.:n | n.s.:n | for/against association | sign.:n | n.s.:n | for/against association | sign.:n | n.s.: n | for/against association | |
| Comorbidities, comorbidity measures (CM) | 3 | 5 | weak against | 4 | 2 | weak for | 1 | 3 | weak against |
| Previous spine surgery | 3 | 3 | conflicting | 1 | 3 | weak against | 1 | 0 | weak for |
| Symptom duration | 3 | 4 | weak against | 0 | 4 | strong against | 1 | 2 | weak against |
| Body weight | 1 | 4 | strong against | 0 | 1 | weak against | 0 | 2 | weak against |
| Obesity | 1 | 2 | weak against | 0 | 2 | weak against | 1 | 3 | weak against |
| Hypertension | 0 | 0 | no evidence | 0 | 0 | no evidence | 0 | 0 | no evidence |
| Diabetes | 1 | 3 | weak against | 1 | 2 | weak against | 1 | 1 | conflicting |
| Smoking | 2 | 5 | strong against | 0 | 2 | weak against | 2 | 2 | conflicting |
| Cardiovascular disease | 1 | 1 | conflicting | 2 | 0 | weak for | 1 | 1 | conflicting |
| Lung disease | 0 | 1 | weak against | 0 | 1 | weak against | 0 | 0 | no evidence |
| Neurologic disease | 0 | 1 | weak against | 0 | 1 | weak against | 1 | 0 | weak for |
| Rheumatologic disease | 1 | 2 | weak against | 0 | 1 | weak against | 0 | 2 | weak against |
| Depression | 4 | 3 | weak for | 4 | 2 | weak for | 1 | 1 | conflicting |
| Anxiety, fear avoidance beliefs (FAB) | 0 | 2 | weak against | 1 | 0 | weak for | 0 | 0 | no evidence |
| Cancer | 0 | 0 | no evidence | 0 | 0 | no evidence | 1 | 0 | weak for |
| Kidney disease | 0 | 0 | no evidence | 0 | 0 | no evidence | 0 | 0 | no evidence |
| Age | |||||||||
| Continuous | 1 | 10 | strong against | 0 | 8 | strong against | 1 | 4 | strong against |
| Categorical | 1 | 5 | strong against | 1 | 3 | weak against | 1 | 1 | conflicting |
Abbreviations: n, number of studies; sign., significant; n.s., not significant.
#Evidence strength defined as follows; strong: 3 or more studies difference (no effect vs. significant effect), weak: difference of 1-2 studies, conflicting: equal number of studies with or without an effect.