Should psychological distress be listed as a surgical indication for indeterminate pulmonary nodules: protocol for a prospective cohort study in real-world settings.

Background: Pulmonary nodules (PNs) are documented in up to 30% of computed tomography (CT) reports. PNs of indeterminate nature (IPN) have been reported to be associated with increased psychological distress and deterioration of the quality of life. Despite lack of solid evidence, severe anxiety or depression has been proposed to be one of the surgical indications in expert consensus for IPN management. So far, there is no established criterion to guide the decision-making process, or to ensure evidence-based management. This study aims to evaluate whether psychological distress could be a surgical indication for IPN, and to establish an evidence-based distress threshold for necessary surgical intervention. Methods: This prospective observational study in real-world setting will involve an expected sample size of 1,253 IPN patients from the thoracic clinic of Guangdong Provincial People's Hospital. Web-based questionnaires powered by Wen Juan Xing (WJX) platform will be delivered to the patients for baseline data collection and psychological screening. Based on our pilot study, a total of 376 IPN patients with abnormal or borderline abnormal psychological states, as assessed by the Hospital Anxiety and Depression Scale (HADS), will be followed for 1 year before proceeding to the final analysis. The planned study period is from Jan 1, 2021, to Sept 30, 2022, and will entail two HADS assessments at baseline and follow-up. Sleep quality and indicators of healthcare-seeking behavior, such as the number of unplanned clinic visits or CT scans per year, will be used as anchors of psychological state. Patients who undergo surgical resection against the follow-up plan will be enrolled into a surgical group (expected n=94), while those who adhere to their plan will be automatically classified as a follow-up group after 1-year follow-up (expected n=282). Statistical measures such as independent-samples t-test and receiver operating characteristics (ROC) analysis will be used to assess the difference in psychological changes between the groups, and to generate an optimal threshold alerting surgical need. A Chi-square test or nonparametric test will be used to compare the baseline characteristics. Contributors to psychological burden and their effect sizes will be evaluated using general linear regression. Discussion: To date, data on the psychological benefits of surgical resection of IPN remains scanty. Evidence-based procedure of patient selection using appropriate psychological screening tools is crucial in improving the quality of care and preventing overtreatment. This protocol describes the rationale and methodology to address this unmet clinical need using real-world data, aiming to bridge the gap between clinical guidelines and real-world practice. Trial Registration: ClinicalTrials.gov Identifier: NCT04857333. Registered April 23, 2021.