Does communicating the costs associated with a diagnostic test influence the test ordering behaviour of ICU (intensive care unit) medical professionals?

In this study, two interventions are being evaluated: type of cost information (two levels, financial vs environmental) and way of presenting the cost information (two levels, all doctors in the unit (collective action) vs individual doctor (no collective action)). Participants will be randomised 1:1:1:1:1 to receive one of five hypothetical scenarios that contain these different types of information about the costs associated with diagnostic tests in the ICU. The different types of information presented in the five scenarios are: 1. financial costs incurred by an individual doctor 2. financial costs incurred by all doctors in the unit (collective action) 3. environmental costs incurred by an individual doctor 4. environmental costs incurred by all doctors in the unit (collective action) 5. no cost information (control group) Financial costs are presented as either the indicative dollar amount that would be saved if an individual doctor did not perform a set of routine tests (full blood count, electrolytes/urea/creatinine and chest x-ray) on three patients each day for one week (no collective action) or the indicative dollar amount that would be saved if all doctors working in the ICU did not perform a set of routine tests on three patients each day for one year (collective action). Environmental costs are presented as either the indicative amount of carbon emissions that would be saved if an individual doctor did not perform a set of routine tests (full blood count, electrolytes/urea/creatinine and chest x-ray) on three patients each day for one week (no collective action) or the indicative amount of carbon emissions that would be saved if all doctors working in the ICU did not perform a set of routine tests on three patients each day for one year (collective action). Participants will then be presented with the same hypothetical clinical scenario describing a patient in the ICU and asked which tests (if any) they would order for that patient. All information is provided as text via the survey platform REDCap and participants can access the survey on any device connected to the internet. Reading the study information and scenario and responding to the online questionnaire will take approximately 10 minutes.