Associations of Preoperative Malnutrition With Disability Levels and Health-Related Quality of Life After Surgery

Objectives: To determine the associations of preoperative malnutrition with disability levels and health-related quality of life (HRQoL) after surgery. Methods: This was a single-center sub-study from a prospective cohort study of patients undergoing major elective cardiothoracic or general surgery. After local research ethics committee approval (CREC 2021.703), a dietitian assessed the patients' nutritional status one day before surgery using the Subjective Global Assessment (SGA). We measured disability levels and HRQoL using the Chinese (Hong Kong) version of the 12- item World Health Organization Disability Assessment Schedule (WHODAS) 2.0 score and the Chinese (Hong Kong) version of the EuroQoL EQ-5D-5L respectively before surgery, Day 30 (POD30), and Day 90 (POD90) after surgery. The WHODAS score range was 0% to 100%; minimal clinically important difference is at 5%. The EQ-5D index assessed patients' HRQoL in 5 domains (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), with higher values representing higher HRQoL. Generalized estimating equations were used to assess the associations between preoperative malnutrition and the changes in WHODAS (%) and EQ-5D scores over time, adjusting for age, frailty, comorbidities, and social support. Results: Of the 531 patients (median [IQR] age 65 [59-71] years; 344 men [65%]), 178 (34%) were moderately or severely malnourished. The mean WHODAS scores at preoperative, POD30, and POD90 were 8% (95% CI 6%-9%), 16% (95% CI 15%-18%), and 7% (95% CI 6%-8%), respectively. Overall, malnourished patients had higher score of disability than well-nourished patients (14% vs 9%; mean difference [MD] 5%, 95% CI 3%-8%) with the largest difference seen at preoperative and POD30. The mean EQ5D Indices at preoperative, POD30, and POD90 were 0.88 (95% CI 0.86-0.89), 0.77 (95% CI 0.74-0.80), and 0.88 (95% CI 0.86-0.90), respectively. Malnourished patients had lower mean HRQoL than well-nourished patients at all time-points (0.80 vs 0.86; MD -0.07, 95% CI -0.10 to -0.03). Conclusions: One in three patients was malnourished before surgery. Preoperative malnutrition was associated with higher, but mild disability levels and lower HRQoL after surgery. Funding Sources: HK PhD Fellowship Award (PF20-46990) and General Research Fund (GRF#14104222).