Objective | Outcome | Hypothesis | Method of analysis | |
---|---|---|---|---|
Name | Variable type | |||
Primary objective | ||||
To compare the surgical site infection rates at 1 year | Surgical site infection | Binary | A longer duration (5 days) of post-operative antibiotics will reduce the risk of surgical site infection compared to a shorter duration (1 day) of post-operative antibiotics. | Cox proportional hazards |
Secondary objectives | ||||
To compare the risk of antibiotic-related complications at 1 year | Antibiotic-related complications | Binary | A longer duration (5 days) of post-operative antibiotics will result in more antibiotic-related complications compared to a shorter duration (1 day) of post-operative antibiotics. | Cox proportional hazards |
To compare the risk of unplanned re-operations at 1 year | Unplanned re-operations | Binary | A longer duration (5 days) of post-operative antibiotics will result in fewer unplanned re-operations compared to a shorter duration (1 day) of post-operative antibiotics. | Cox proportional hazards |
To compare the risk of oncologic events at 1 year | Oncologic events | Binary | There will be no difference in the number of oncologic events irrespective of post-operative antibiotic duration. | Cox proportional hazards |
To compare the mortality at 1 year | Mortality | Binary | There will be no difference in the risk of death irrespective of post-operative antibiotic duration. | Cox proportional hazards |
To compare the patient functional outcomes at 1 year | MSTS-87, MSTS-93 | Continuous | A longer duration (5 days) of post-operative antibiotics will result in better patient functional outcomes compared to a shorter duration (1 day) of post-operative antibiotics. | Multiple linear regression |
To compare the patient quality-of-life outcomes at 1 year | TESS | Continuous | A longer duration (5 days) of post-operative antibiotics will result in better patient quality-of-life outcomes compared to a shorter duration (1 day) of post-operative antibiotics. | Multiple linear regression |
Sub-group analyses | ||||
Tumor type (bone sarcoma, soft tissue sarcoma, and oligometastatic bone disease) | Surgical site infection | Binary | There will be no difference between the tumor types in the association between surgical site infection and post-operative antibiotic duration. | Cox proportional hazards |
Tumor location (femur or tibia) | Surgical site infection | Binary | A longer duration (5 days) of post-operative antibiotics will be more effective at reducing surgical site infections relative to a shorter duration (1 day) of post-operative antibiotics in tibial reconstructions than in femoral reconstructions. | Cox proportional hazards |
Sex (male or female) | Surgical site infection | Binary | There will be no difference between the sexes in the association between surgical site infection and post-operative antibiotic duration. | Cox proportional hazards |
Age (pediatric and young adults [12–30 years of age] or older adults [≥ 31 years of age]) | Surgical site infection | Binary | A longer duration (5 days) of post-operative antibiotics will be more effective at reducing surgical site infections relative to a shorter duration (1 day) of post-operative antibiotics in the older adult population than in the pediatric and young adult population. | Cox proportional hazards |
Peri-operative chemotherapy | Surgical site infection | Binary | A longer duration (5 days) of post-operative antibiotics will be more effective at reducing surgical site infections relative to a shorter duration (1 day) of post-operative antibiotics in patients who received chemotherapy than in those who did not receive chemotherapy. | Cox proportional hazards |
Sensitivity analyses | ||||
Competing risks (death and amputation) | Surgical site infection | Binary | We do not expect the association between post-operative antibiotic duration and surgical site infections to change substantially once we take into account the competing risk of death. | Competing risks analysis |
Trial site (center-effects) | Surgical site infection | Binary | We do not expect the results to change substantially when center-effects are removed from the primary analysis. | Cox proportional hazards (with center-effects removed) |
Potential prognostic imbalances at baseline | Surgical site infection | Binary | Results will remain robust after adjusting for the following prognostic baseline imbalances: total operative time, tumor location, diabetes status, chemotherapy regimen, and radiation treatment. | Cox proportional hazards |