This is the historical control arm. 24 hours removed from their last dose (time period from the last dose of treatment dose Enoxaparin to the blood sampling for anti-Xa testing)

Analyze and determine the best-fit function (beta and standard error) for anti-Xa activity level activity (IU/mL) to determine if there is a significant association between anti-Xa activity at the time of presentation and (gender= male or female).

Individual patient characteristics were assessed to determine their impact on the odds of success, defined as an anti-Xa level of <0.2IU/mL. Patient characteristics assessed included age, sex, renal function (calculated by Cockcroft-Gault and modified Cockcroft-Gault formulae), and body mass index (BMI), the latter of which was assessed post-hoc.

Odds ratios were calculated with both groups combined, as time from last dose varied and even overlapped between groups, which was expected/anticipated as part of the study design. All patient characteristics were analyzed using three separate time intervals from last dose (<24-hours, 24-hours through 35.9-hours, and >36-hours).

Group 2 will be instructed to administer their last dose of enoxaparin at 19:00 in the evening two days prior to their scheduled surgery date. Patients presenting for surgery at 07:00 two days later will be 36-hours removed from their last dose. Patients presenting for surgery later in the day would be slightly farther removed from their last dose, but again this mimics normal clinical practice in which the timing of the last dose of self-administered enoxaparin is not routinely adjusted based on the scheduled surgical start time.

Enoxaparin: The intervention is the implementation of a 36-hour time period from the last dose of treatment dose Enoxaparin to the blood sampling for anti-Xa testing.

Total of all reporting groups

Race and Ethnicity were not collected from any participant.

Group 2 will be instructed to administer their last dose of enoxaparin at 19:00 in the evening two days prior to their scheduled surgery date. Patients presenting for surgery at 07:00 two days later will be 36-hours removed from their last dose. Patients presenting for surgery later in the day would be slightly farther removed from their last dose, but again this mimics normal clinical practice in which the timing of the last dose of self-administered enoxaparin is not routinely adjusted based on the scheduled surgical start time.

Enoxaparin: The intervention is the implementation of a 36-hour time period from the last dose of treatment dose Enoxaparin to the blood sampling for anti-Xa testing.

The randomization of patients to either the 24-hour group or the 36-hour group will allow for modeling, which will generate a prediction of the time point at which the level of anti-Xa activity can reliably be assumed to be lower than 0.2 IU/mL.

On note: Arms/Groups were combined together for analysis purposes and results are reported in this same fashion. The approach was planned apriori. A comparison between the two groups in regard to this primary outcome was neither planned nor performed. Including both arms/groups in a single data set allowed for logistical regression, which was utilized to determine the overall estimate of time until residual anti-Xa level activity reliably fell below 0.2IU/mL).

Analyze and determine the best-fit function (beta and standard error) for anti-Xa activity level activity (IU/mL) to determine if there is a significant association between anti-Xa activity at the time of presentation and patient age (years).

Individual patient characteristics were assessed to determine their impact on the odds of success, defined as an anti-Xa level of <0.2IU/mL. Patient characteristics assessed included age, sex, renal function (calculated by Cockcroft-Gault and modified Cockcroft-Gault formulae), and body mass index (BMI), the latter of which was assessed post-hoc.

Odds ratios were calculated with both groups combined, as time from last dose varied and even overlapped between groups, which was expected/anticipated as part of the study design. All patient characteristics were analyzed using three separate time intervals from last dose (<24-hours, 24-hours through 35.9-hours, and >36-hours).

All patients were included in a single analysis (planned priori) to assess the association between age and residual anti-Xa level activity at the time of presentation, which reflects time from last dose. Data for the association between anti-Xa level activity and age is shown below. Note "number" represents Odds Ratio (OR) with corresponding 95% CI. This outcome was planned to be analyzed as one arm per protocol.

Analyze and determine the best-fit function (beta and standard error) for anti-Xa activity level activity (IU/mL) to determine if there is a significant association between anti-Xa activity at the time of presentation and (gender= male or female).

Individual patient characteristics were assessed to determine their impact on the odds of success, defined as an anti-Xa level of <0.2IU/mL. Patient characteristics assessed included age, sex, renal function (calculated by Cockcroft-Gault and modified Cockcroft-Gault formulae), and body mass index (BMI), the latter of which was assessed post-hoc.

Odds ratios were calculated with both groups combined, as time from last dose varied and even overlapped between groups, which was expected/anticipated as part of the study design. All patient characteristics were analyzed using three separate time intervals from last dose (<24-hours, 24-hours through 35.9-hours, and >36-hours).

All patients were included in a single analysis (planned priori) to assess the association between gender (sex) and residual anti-Xa level activity at the time of presentation, which reflects time from last dose. Data for the association between anti-Xa level activity and gender (sex) is shown below. Note "number" represents Odds Ratio (OR) with corresponding 95% CI. This outcome was planned to be analyzed as one arm per protocol.

Analyze and determine the best-fit function (beta and standard error) for anti-Xa activity level activity (IU/mL) to determine if there is a significant association between anti-Xa activity at the time of presentation and renal function.

Individual patient characteristics were assessed to determine their impact on the odds of success, defined as an anti-Xa level of <0.2IU/mL. Patient characteristics assessed included age, sex, renal function (calculated by Cockcroft-Gault and modified Cockcroft-Gault formulae), and body mass index (BMI), the latter of which was assessed post-hoc.

Odds ratios were calculated with both groups combined, as time from last dose varied and even overlapped between groups, which was expected/anticipated as part of the study design. All patient characteristics were analyzed using three separate time intervals from last dose (<24-hours, 24-hours through 35.9-hours, and >36-hours).

All patients were included in a single analysis (planned priori) to assess the association between renal function and residual anti-Xa level activity at the time of presentation, which reflects time from last dose. Data for the association between anti-Xa level activity and renal function are shown below. Note "number" represents Odds Ratio (OR) with corresponding 95% CI. This outcome was planned to be analyzed as one arm per protocol.

Group 2 will be instructed to administer their last dose of enoxaparin at 19:00 in the evening two days prior to their scheduled surgery date. Patients presenting for surgery at 07:00 two days later will be 36-hours removed from their last dose. Patients presenting for surgery later in the day would be slightly farther removed from their last dose, but again this mimics normal clinical practice in which the timing of the last dose of self-administered enoxaparin is not routinely adjusted based on the scheduled surgical start time.

Enoxaparin: The intervention is the implementation of a 36-hour time period from the last dose of treatment dose Enoxaparin to the blood sampling for anti-Xa testing.