Developing a patient information tool for pregnant individuals requiring urgent imaging to rule out pulmonary embolism: a needs' assessment from a patients' perspective

Computed tomography pulmonary angiogram (CTPA) and lung scintigraphy with ventilation/perfusion scan (V/Q scan) are the main diagnostic imaging modalities for pulmonary embolism (PE) in pregnancy. While being associated with ionizing radiation, they are considered safe and well below the radiation threshold associated with fetal toxicities. Counselling on urgent diagnostic imaging to rule out PE in pregnancy may be improved with use of a standardized tool. Thus, we conducted a needs assessment from patients’ perspective to inform the future creation of an information tool. We sought to address the following questions: 1) what do patients want to know before undergoing these tests? 2) how do they want the information to be provided to them? We used a qualitative description methodology. We used purposive and consecutive sampling strategies to recruit pregnant participants at the antenatal clinics of the McGill University Health Center in Montreal, Canada. Structured interviews explored current knowledge about PE, CTPA and V/Q scan, and information needs about diagnostic imaging. We conducted a thematic analysis of the interview transcripts using a mixed deductive and inductive approach. Of 21 individuals approached, 20 consented to participate, including 4 with a prior history of suspected or confirmed PE. Participants wanted to be informed about the risks of untreated PE and those associated with ionizing radiation on maternal and fetal health, and they expressed the need for counselling about potential radiation-related risks of malignancy for them and their infant. Interviewees preferred for radiation doses to be presented in comparison with common medical examinations or known threshold for fetal harm, as opposed to numeric values. They perceived a written tool as useful. While some wished for succinct information to be presented, others requested for detailed information to be available. Participants wished for the tool to be comprehensible, using an accessible language. In addition, pregnant individuals specified that the tool would be integrated in their decision-making according to their values and preferences, which often included a lower risk tolerance for their fetus than for themselves. We identified that patients undergoing diagnostic imaging to rule out PE in pregnancy wished to be informed about the potential risks associated with these tests. A written tool was deemed useful, especially if using an accessible language and comparisons were used to put information into context. The tool was perceived as potentially helpful in their own decision-making. In a next step, we will design the tool.