Table 2 Summary of key outcomes, findings, and strength of evidence. Abbreviations: RCT, randomized controlled trial; SMD, standardized mean difference; CI, confidence interval; TXA, tranexamic acid; tTXA, topical use of TXA
| Outcome | Study design: No. studies (N) | Findings and direction (magnitude) of effect | Strength of evidence |
|---|---|---|---|
| Major outcomes | |||
| Postoperative drainage output |
RCT: 9 (569) Non-RCT: 3 (213) | RCTs with sufficient sample sizes and non-RCTs with low risks of study limitations found a consistent effect that tTXA reduced postoperative drainage output more than placebo, with overall SMD − 160.62 (− 302.41, − 117.83). | High |
| Postoperative drainage duration |
RCT: 3 (198) Non-RCT: 3 (213) | RCTs and non-RCTs with medium-level study limitations found a consistent and precise effect that tTXA reduced postoperative drainage duration more than placebo, with overall SMD − 0.75 (− 1.09, − 0.40). | Moderate |
| Hidden blood loss |
RCT: 2 (141) Non-RCT: 1 (100) | Consistent and precise effect was found in studies with medium-level study limitations that tTXA reduced perioperative hidden blood loss more than placebo by SMD − 91.18 (− 121.42, − 60.94). | Moderate |
| Hemoglobin level drop |
RCT: 3 (179) Non-RCT: 1 (40) | Few studies included. Direction of effect in non-RCT conflicted with that in RCTs, yielding an overall SMD − 0.65 (− 1.36, 0.05) with a wide (imprecise) CI. | Insufficient |
| Other patient-centered outcomes | |||
| Length of hospital stay (LOH) |
RCT: 7 (467) Non-RCT: 3 (213) | Studies with medium-level study limitations yielded consistent and precise effect that tTXA reduced LOH more than placebo by SMD − 1.32 (− 1.90, − 0.74). | Moderate |
| Adverse events | |||
| Rod fracture | Non-RCT: 1(40) | Only a single event was reported in one small non-RCT. | Insufficient |
| Wound infection |
RCT: 2 (110) Non-RCT: 1(40) | Three events were reported in a few small RCT and non-RCTs, finding no significant difference in wound infection rate. | Insufficient |
| Myocardial infarction | RCT: 1 (29) | Only a single event was reported in one small RCT. | Insufficient |