Background: Percutaneous lung biopsy (PLB) is a minimally invasive method for workup of suspicious lung nodules with nearly 30,000 biopsies performed by interventional radiologists in the VHA between FY 2017- 2022. Up to 30% of patients develop a pneumothorax after PLB, and while many pneumothoraces are managed conservatively, pneumothoraces requiring chest tube placement occur in 5-15% of PLBs. Severe pneumothoraces are associated with prolonged hospitalization and on rare occasions mortality. In prior work on an HSR&D Merit Award by the Principal Investigator, Dr. Mull (IIR 18-034), we found significant hospital- level variation in risk-adjusted rates of pneumothorax requiring chest tube placement from 6% to 43% of PLBs, highlighting the urgent need to identify best practices and develop interventions to improve PLB safety. Significance: This study will close an important gap in the clinical management of suspicious lung nodules. While a pneumothorax is an unwelcome outcome, if the PLB results in an early cancer diagnosis, the benefit may exceed the risk. There is little information about balancing these goals with PLB evidence-based practices. Our work directly contributes to two of the HSR&D 2024 Areas of Scientific Inquiry, Data Science and Systems Science. We will employ informatics tools and investigate novel data sources to study PLB outcomes, and we will assess systems-level practices to optimize management of suspicious lung nodules. Innovation & Impact: This pilot proposal breaks new scientific ground by assessing decision-making by interventional radiologists and examining practices that maximize detection of lung cancer and minimize adverse lung biopsy outcomes, e.g., pneumothorax requiring chest tube placement. Given the expansion of Veteran participation in the Lung Cancer Screening program, the results and subsequent HSR&D IIR to test implementation of best practices may substantively improve care for Veterans at risk of lung cancer. Specific Aims: Guided by the QUERI implementation roadmap, we propose the following specific aims: (1) Assess interventional radiologist's practices and experience with PLB and pneumothorax prevention, (2) Identify trends in patient selection, intraprocedural care, and PLB outcomes to further characterize facility/ provider variation, (3) Integrate results from Aims 1 and 2 to identify which facility and provider-level practices are associated with lower rates of severe pneumothorax and higher rates of meaningful diagnostic findings. Methodology: This study uses both qualitative and quantitative methods: interviews with interventional radiologists and VHA Corporate Data Warehouse (CDW) data mining of text and structured data. Aim 1) We will interview interventional radiologists about patient selection, referral behavior and pneumothorax prevention in facilities with high (n=20) and low (n=20) pneumothorax rates from preliminary data. Aim 2) Our quantitative analysis includes reviewing community care a...