(P08-003-23) Association of Frailty With Preoperative Malnutrition on Quality of Recovery After Surgery

Objectives: To estimate the prevalence of preoperative malnutrition and determine the extent of its association with frailty on affecting the quality of recovery (QoR) after surgery.

Methods: This was a single-center sub-study of a prospective cohort study of patients undergoing major elective cardiothoracic or general surgery. After written informed consent, a registered dietitian assessed the patients’ nutritional status one day before surgery using the Subjective Global Assessment. Frailty levels were assessed by the Clinical Frailty Scale (CFS) with pre-frail/frailty defined as CFS⩾4. We measured the QoR levels using the Chinese version of the 15-item QoR (QoR-15) on the third day after surgery. The QoR-15 score (0 to 150, higher scores for better recovery) has a minimal clinical important difference of 6.0. A four-way decomposition model was used to assess the associations between preoperative malnutrition, frailty, and poor recovery after adjusting for age, comorbidity, and social support. The 4-way model helped explained “how” (mediation) and “for whom” (interaction) preoperative malnutrition caused poorer QoR-15 scores.

Results: Of the 305 patients, 108 (35.4%) were moderately or severely malnourished. Sixty-two (20.3%) patients were prefrail or frail. The median [IQR] QoR-15 was 106 [92-188]. Malnourished patients were more likely to be frail (OR 3.53, 95%CI: 1.91-6.53, P< 0.001). Preoperative malnutrition was associated with poorer QoR-15 scores (total effect [TE]: -7.6, 95% CI: -12.7 to -2.5, P< 0.01). The direct effect of preoperative malnutrition on QoR-15 was -4.5 (95% CI: -9.6 to 0.6, P=0.08); proportion of TE was 59%. The total indirect effect of preoperative malnutrition on QoR-15 through frailty was -3.1 (95% CI: -5.3 to -0.8, P< 0.01); proportion of TE was 41%. There was weak evidence of a combined (mediation and interaction) effect of preoperative malnutrition and frailty on QoR-15 scores (-2.1, 95% CI: -4.4 to 0.2, P=0.07); proportion of TE was 28%.

Conclusions: One-third of patients were malnourished before surgery. Frail and malnourished patients may be more likely to have clinically important poorer QoR levels than robust well-nourished patients.

Funding Sources: Department funding from the Chinese University of Hong Kong