Table 2.
Narrative GRADE evidence summary table for markers of unfavorable postoperative outcomes.
| Number of Studies | Certainty Assessment | Impact | Certainty | Importance | |||||
|---|---|---|---|---|---|---|---|---|---|
| Study Design | Risk of Bias | Inconsistency | Indirectness | Imprecision | Other Considerations | ||||
| (1) Worse preoperative status | |||||||||
| 12 | Observational studies | Not serious | Serious a | Serious b | Not serious | Strong association | There seems to be evidence linking worse preoperative status to unfavorable outcomes, knowing that most of the studies taking part in this analysis had low risks of bias and showed statistically significant results. | ⨁⨁⨁◯ Moderate | CRITICAL |
| (2) Older age | |||||||||
| 11 | Observational studies | Not serious | Very serious c | Not serious | Not serious | None | The body of evidence supporting older age as a marker of unfavorable outcomes is mostly relying on studies with statistically insignificant results, hence the low certainty level. | ⨁⨁◯◯ Low | NOT IMPORTANT |
| (3) Male sex | |||||||||
| 10 | Observational studies | Not serious | Very serious c | Not serious | Serious d | None | The evidence suggesting male sex as an indicator of poor outcome is backed by a majority of studies showing insignificant results, which is reflected by very low certainty levels. | ⨁◯◯◯ Very low | NOT IMPORTANT |
| (4) Higher WHO grade | |||||||||
| 10 | Observational studies | Not serious | Serious a | Not serious | Serious d | None | There seems to be weak evidence linking tumors with higher WHO grades to unfavorable postoperative outcomes, especially that most studies studying this association revealed insignificant results. | ⨁⨁◯◯ Low | IMPORTANT |
| (5) Longer duration of symptoms or longer waiting time before surgery | |||||||||
| 9 | Observational studies | Not serious | Serious a | Serious b | Not serious | Strong association | The evidence supporting longer timespans before surgery as a marker for poor postoperative outcomes seems to be of moderate strength. Studies that supported this claim were unbiased, and most of them had initially concluded significant results. | ⨁⨁⨁◯ Moderate | CRITICAL |
| (6) Craniocaudal tumor location | |||||||||
| 8 | Observational studies | Not serious | Very serious c | Not serious | Not serious | None | The claim that spinal meningiomas of specific spinal levels may be associated to worse postoperative outcomes is based on studies revealing statistically insignificant results, hence justifying the low level of certainty towards the evidence. | ⨁⨁◯◯ Low | NOT IMPORTANT |
| (7) Ventral attachment | |||||||||
| 8 | Observational studies | Not serious | Very serious c | Not serious | Not serious | None | There is low-certainty evidence backing up the association between tumors of ventral origin and unfavorable postoperative outcomes, mainly stemming from the insignificant results found by most studies included in the synthesis. | ⨁⨁◯◯ Low | NOT IMPORTANT |
| (8) Higher Simpson grade | |||||||||
| 8 | Observational studies | Not serious | Very serious c | Not serious | Not serious | None | There is low-certainty evidence backing up the association between a higher Simpson resection grade and unfavorable postoperative outcomes, mainly stemming from the insignificant results found by most studies included in the synthesis. | ⨁⨁◯◯ Low | NOT IMPORTANT |
| (9) Larger tumor size and spinal cord compression | |||||||||
| 5 | Observational studies | Not serious | Very serious c | Very serious b | Not serious | None | The evidence suggesting larger tumor sizes as an indicator of poor outcome is backed by a majority of studies showing insignificant results, which is reflected by very low certainty levels. | ⨁◯◯◯ Very low | NOT IMPORTANT |
| (10) Surgery for recurrent tumor | |||||||||
| 3 | Observational studies | Not serious | Not serious | Not serious | Serious e | Strong association | There seems to be strong evidence suggesting that the reoperation of tumors may be associated with unfavorable postoperative outcomes. | ⨁⨁⨁⨁ High | CRITICAL |
| (11) Presence of calcification | |||||||||
| 2 | Observational studies | Not serious | Very serious c | Not serious | Very serious d,e | None | There seems to be poor evidence suggesting an association between tumor calcification and worse postoperative outcomes, as there were only two studies that addressed this aspect with mixed-significance results. | ⨁◯◯◯ Very low | NOT IMPORTANT |
a: Moderately conflicting significance levels across studies, b: different surrogates were used throughout the studies, c: severely conflicting significance levels across studies, d: relatively few patients and few events were considered in the analysis, e: few studies were considered in the analysis.