TABLE 3.
GRADE Evidence Summary of Findings for the Effect of PTED Versus Open Microdiscectomy
| Quality Assessment | No. of Patients | ||||||||||
| No. of Studies | Design | Limitations | Inconsistency | Indirectness | Imprecision | Other | PTED | OM | Effect (95% CI) | Quality of Evidence | |
| Leg pain (intermediate term) | 4 | RCT | Serious limitations∗ | No serious inconsistency | No serious indirectness | No serious imprecision | No serious considerations | 335 | 336 | SMD 0.05 (–0.10 to 0.21) | Moderate |
| Leg pain (long term) | 3 | RCT | No serious limitations | No serious inconsistency | No serious indirectness | Serious imprecision§ | No serious considerations | 100 | 112 | SMD 0.11 (–0.30 to 0.53) | Moderate |
| Functional outcome (intermediate term) | 3 | RCT | Serious limitations∗ | No serious inconsistency | No serious indirectness | No serious imprecision | No serious considerations | 309 | 311 | SMD –0.09 (–0.24 to 0.07) | Moderate |
| Functional outcome (long term) | 2 | RCT | No serious limitations | No serious inconsistency | No serious indirectness | Serious imprecision§ | No serious considerations | 70 | 82 | SMD –0.11 (–0.45 to 0.24) | Moderate |
| Back pain (intermediate term) | 1 | RCT | No serious limitations | Serious inconsistency† | No serious indirectness | Serious imprecision§ | No serious considerations | 61 | 60 | SMD –0.04 (–0.39 to 0.32) | Low |
| Back pain (long term) | 1 | RCT | No serious limitations | Serious inconsistency† | No serious indirectness | Serious imprecision§ | No serious considerations | 52 | 62 | SMD 0 (–0.37 to 0.37) | Low |
| Complications|| | 12 | RCTProsp. | Serious limitations∗ | No serious inconsistency | No serious indirectness | Serious imprecision§ | Serious considerations¶ | 647 | 678 | Not calculated | Very low |
Quality of evidence is downgraded if >50% of the study population origins of studies with a high or unclear risk of bias for allocation concealment.
Quality of evidence is downgraded if the I2 statistic >75% or if only one study reports on the outcome.
3 Quality of evidence is downgraded if study results are not generalizable.
Quality of evidence is downgraded if there are <400 patients in the study sample for continuous outcomes or if there are less than 300 events in the study sample for dichotomous outcomes.
Quality of evidence is downgraded if there are signs of publication bias or conflicts of interest.
Dural tears, (transient) neurological deficits and wound infections were taken into this analysis.