Intraoperative Parathyroid Hormone Monitoring to Guide Surgery in Renal hyperparathyroIdism

Randomization rate

Defined as the number of patients agreeing to participate in the trial and being randomized to any of the allocation groups, divided by the number of eligible patients. We will review this data every two weeks during the pilot trial. A randomization percentage of 70% or greater will support the feasibility of a fully powered RCT. We will utilize the traffic light system introduced by Avery and colleagues, whereby if randomization of 70% or greater is achieved, we will proceed with fully powered trial. If a randomization rate of 50-69% is achieved, we will consider proceeding with modifications to the fully powered trial. If randomization rate is \<50%, we will not proceed with fully powered trial. We selected this as a primary feasibility outcome because we are sampling from a relatively rare population, and so gathering an accurate estimate of randomization rate will allow us to determine the ideal number of participating sites for the final trial.

Blinding effectiveness

The Bang Blindness Inventory (BBI) will be administered to patients, outcome assessors, and statisticians at the end of study follow-up and the time of trial completion (for statisticians). The BBI will then be calculated for each of these blinded parties and reported on a scale of -1 (unblinding) to 0 (perfect blinding) to +1 (lack of blinding).

Surgeon compliance and crossover

Surgeon compliance and crossover: The number of patients who undergo surgery with a different IOPTH monitoring criteria from which they were randomized. All surgeons will complete a postoperative de-brief form that will capture their rationale for changing groups. We will consider any percentage of group crossover to hinder consideration of a fully powered trial and based on the direction and number of groups crossovers. If any crossovers are detected, then we will consider to the number and organization of allocation arms for the fully powered trial.

Follow-up completion

Defined as completion of all questionnaires and study bloodwork from randomization to final study follow-up.

Trial costs

We will estimate the study and hospital costs required for this multi-centre initiative for each recruited patient during the study period. This will provide an estimate of the costs for performing the fully powered trial.

Surgeon-dictated changes to intraoperative plan

Any changes to the surgical plan will be documented by surgeons in a postoperative de-brief form.

Operating time

The length of the surgery from skin incision to skin closure, as measured in minutes

Revision surgery rate and indication for revision surgery

Number of patients who either undergo or are consented and scheduled to undergo revision parathyroidectomy within 6 months of randomization. This will be measured as a dichotomous outcome. We will also evaluate the surgical indication for revision surgery. This will be measured as a categorical outcome.

Chronic kidney disease progression, cardiovascular death, or renal death (composite outcome)

Number of patients who meet the criteria of this composite outcome (sustained decline in eGFR of at least 50%, end-stage kidney disease, or kidney-related or cardiovascular death).