Structural and Process Factors Associated with 30-Day Postoperative Complication Severity After Open-Heart Surgery: A Single-Center Observational Study

Background: Open-heart surgery is associated with substantial postoperative morbidity. Guided by the Nursing Role Effectiveness Model, this study focused on the severity of 30-day postoperative complications rather than only the presence or absence of complications. Purpose: The study examined structural factors (health literacy, nutritional status, severity of comorbidities, anemia, and surgical mortality risk) and process factors (perception of patient-centered care, type of surgery, and cardiopulmonary bypass time) associated with complication severity after open-heart surgery. Patients and Methods: A prospective, single-center observational prognostic factor study with medical record review was conducted from June 2022 to July 2023 among 136 adult patients undergoing open-heart surgery at a tertiary hospital in Thailand. Data were collected from patient questionnaires and medical records. The primary outcome was 30-day complication severity measured using the Comprehensive Complication Index. Bivariate analyses and multiple linear regression were performed, with prespecified covariates selected based on clinical relevance. Results: Participants had a mean age of 61.32 years (SD = 13.09), and 61.8% were male. The mean Comprehensive Complication Index score was 37.25 (SD = 14.70). In the adjusted model, surgical mortality risk (standardized beta = 0.345, p < 0.001), anemia (standardized beta = 0.224, p = 0.018), nutritional status (standardized beta = − 0.218, p = 0.011), and cardiopulmonary bypass time (standardized beta = 0.198, p = 0.034) were independently associated with complication severity. Health literacy, comorbidity severity, and perceived patient-centered care were not statistically significant. Conclusion: Surgical mortality risk, anemia, nutritional status, and cardiopulmonary bypass time were key factors associated with 30-day complication severity. These findings support preoperative optimization of hematological and nutritional status and careful intraoperative management to reduce postoperative morbidity; however, interpretation should consider the single-center design and available covariates. Keywords: open-heart surgery, postoperative complications, nutritional status, health literacy, patient-centered care