232DEVELOPMENT AND VALIDATION OF A CLINICAL PREDICTION RULE FOR CHEST WALL SYNDROME: INSIGHTS FROM A MULTICENTER PROSPECTIVE STUDYChest wall syndrome (CWS) stands out as a prevalent cause of chest pain in primary care settings. This study aimed to develop and validate a clinical prediction rule for identifying chronic wasting disease (CWS) among patients experiencing chest pain. A multicenter clinical cohort was established, comprising individuals with chest pain, who underwent a 12-month follow-up for diagnostic confirmation. Candidate predictors of CWS were identified through thorough literature reviews and bivariate analyses. External validation was performed using cohort data from Germany. Six variables were identified as characteristic of CWS: chest pain, stab pain, well-localized pain, absence of prior coronary heart disease, and palpable pain. These variables were incorporated into the clinical prediction rule, with palpable pain weighted more heavily (two points) than the others (one point each). Receiver operating characteristic curves (ROC curves) were employed to assess the predictive performance of the derived cohorts. Palpable pain accurately diagnosed CWS in 45% of cases. Additional investigations were conducted for 130 correctly classified CWS patients, leading to the identification of false positives in three cases of stable angina. External validation revealed a ROC curve sensitivity of 22% and specificity of 93%. The CWS score effectively complemented standard diagnostic procedures, aiding in the exclusion of patients with CWS. Specifically, 254 patients correctly classified by the clinical prediction rule avoided unnecessary tests and exams, underscoring its clinical utility. The study findings emphasize that reproduction of chest pain through palpation, a primary characteristic of CWS, is not pathognomonic.Manish@gmail.comResearch1122021Pain in the Chest, Thoracic Wall, Muscle Skeletal System, Diagnosis, Decision Support Techniques.Dr Manish RanjanAssistant professor, Department of General medicine, Gouri Devi Institute of Medical Sciences and Hospital, Durgapur, India