Risk stratification for post-operative pulmonary complications following major cardiothoracic or abdominal surgery: Validation of the PPC Risk Prediction Score for physiotherapist's clinical decision-making

IntroductionPatients undergoing major cardiothoracic or abdominal surgery are at increased risk of developing post-operative pulmonary complications (PPC), but respiratory physiotherapy can prevent PPC. We have previously developed the PPC Risk Prediction Score to allocate physiotherapists' resources and stratify patients into three risk groups. In this study, we performed a temporal external validation of the PPC Risk Prediction Score. Such validation is rare and adds to the originality of this study. MethodsA cohort of 360 patients, admitted to undergo elective cardiothoracic or abdominal surgery, were included. Performance and clinical usefulness of the PPC Risk Prediction Score were estimated through discrimination, calibration and clinical usefulness, and the score was updated. ResultsThe score showed c-statistics of 0.62. Related to clinical usefulness, a cut point at 8 gave a sensitivity of 0.49 and a specificity of 0.70, whereas a cut point at 12 gave a sensitivity of 0.13 and a specificity of 0.95. Two predictors included in the development sample score, thoraco-abdominal incision odds ratio (OR) 2.74 (1.12;6.71) and sternotomy OR 2.09 (1.18;3.72), were statistically significantly associated to PPC in the validation sample. ConclusionsThe score was not able to discriminate between patients with and without PPC; neither was the updated score, but the study identified clinically relevant risk factors for developing PPC.