Table 2.
Risk of bias in the included studies
| ATTRM-048-13-2000 | IBCSG-23-01 | ACOSOG Z0011 | AMAROS | OTOASOR | |
|---|---|---|---|---|---|
| Random sequence generation (selection bias) | Unclear | Low | Low | Low | Unclear |
| Allocation concealment (selection bias) | Unclear | Low | Low | Low | Unclear |
| Blinding of outcome assessment (detection bias): Disease control in the axilla | Unclear | High—no blinding | Unclear | High—no blinding | Unclear |
| Blinding of outcome assessment (detection bias): Breast cancer recurrence | Unclear | High—no blinding | Unclear | High—no blinding | Unclear |
| Blinding of outcome assessment (detection bias): Short term adverse events | Outcome not reported | High—no blinding | Unclear | Outcome not reported | Unclear |
| Blinding of outcome assessment (detection bias): Long term adverse events | Outcome not reported | High—no blinding | Unclear | High—no blinding | Unclear |
| Incomplete outcome data (attrition bias): Survival | Low | Low | Low | Low | Low |
| Incomplete outcome data (attrition bias): Disease control in the axilla | Low | Low | Low | Low | Unclear—data not reported in sufficient detail to be able to ascertain whether all patients are included |
| Incomplete outcome data (attrition bias): Breast cancer recurrence | Low | Low | Low | Low | Low |
| Incomplete outcome data (attrition bias): Short term adverse events | Outcome not reported | Unclear—denominator not reported | Unclear—data reported at 30 days for 371/411 ALND and 373/399 SLND + ALND | Outcome not reported | Outcome not reported |
| Incomplete outcome data (attrition bias): Long term complications | Outcome not reported | Unclear—14 patients allocated to surgery alone received ALND and 17 patients allocated to ALND did not receive ALND; all excluded from the analyses | High—data missing from progressively larger proportions of patients as follow up progressed; possibly more pronounced in the SLND group. Outcome data reported at 1 year for 242/411 ALND and 226/399 SLND +ALND | High—data available from 655/744 ALND and 586/681 aRT patients at baseline; progressively higher rates of missing data at 1, 3 and 5 years for lympoedema. Unclear how much data were available for shoulder mobility | Outcome not reported |
| Selective reporting (reporting bias) | High—adverse events not reported | Low | Low | High—only lymphedema and should mobility reported as morbidity outcomes | High—morbidity not reported |
SLND sentinel lymph node dissection, ALND axillary lymph node dissection, aRT axillary radiotherapy