Table 1

Secondary objectives and associated end points in the pre-EDIT study

Secondary objectives	Secondary end points
To determine the feasibility of P_EL computation using the novel DPM	The time taken to perform the EDIT large volume aspiration, including measurement of ΔIPP using the DPM, recording of ΔV and computation of P_EL The failure rate of the procedure, defined as the proportion of patients in whom P_EL cannot be computed
To determine the safety and tolerability of P_EL computation using the novel DPM	The occurrence of chest pain, cough or breathlessness during the procedure AEs) and SAEs associated with use of the DPM
To assess the pleural fluid aspiration volume required to detect abnormal P_EL (where present)	The pleural fluid aspiration volume at which the rolling average pleural elastance over the preceding 250 mL (P_EL250) first exceeds the upper limit of normal (14.5 cm H₂O/L)
To determine the proportion of patients allocated to EDIT management who require pneumothorax induction to facilitate safe ICD/IPC insertion following DPM	The proportion of patients in whom pneumothorax induction is required to facilitate safe ICD/IPC insertion in the EDIT arm
To test the assumption that pleural cavity ΔV is equivalent to the volume of pleural fluid removed during aspiration	Pleural fluid aspiration volume (ΔV_OUT) Pleural cavity volume change, as measured directly using volumetric MRI (ΔV_MRI; defined as pre-aspiration minus post-aspiration pleural cavity volume)
To test the accuracy of a predictive model of pleural effusion volume (V_TUS) based on TUS measurements, which is a proposed inclusion criterion for the EDIT study	TUS estimated total pleural effusion volume (V_TUS) Pre-pleural fluid aspiration pleural cavity volume (V_MRI)

AE, adverse events; DPM, digital pleural manometer; EDIT, elastance-direct intrapleural catheter or talc pleurodesis; ICD, intercostal drain; IPC, indwelling pleural catheter; IPP, intrapleural pressure; P_EL, pleural elastance; SAE, serious adverse event; TUS, thoracic ultrasound; V, pleural fluid volume.