Compliance with preoperative oral nutritional supplements in patients at nutritional risk--only a question of will?

Preoperative nutrition has been shown to reduce morbidity after major gastrointestinal (GI) surgery in selected patients at risk. In a randomized trial performed recently (NCT00512213), almost half of the patients, however, did not consume the recommended dose of nutritional intervention. The present study aimed to identify the risk factors for noncompliance.

Demographic (n = 5) and nutritional (n = 21) parameters for this retrospective analysis were obtained from a prospectively maintained database. The outcome of interest was compliance with the allocated intervention (ingestion of ⩾ 11/15 preoperative oral nutritional supplement units). Uni- and multivariate analyses of potential risk factors for noncompliance were performed.

The final analysis included 141 patients with complete data sets for the purpose of the study. Fifty-nine patients (42%) were considered noncompliant. Univariate analysis identified low C-reactive protein levels (P = 0.015), decreased recent food intake (P = 0.032) and, as a trend, low hemoglobin (P = 0.065) and low pre-albumin (P = 0.056) levels as risk factors for decreased compliance. However, none of them was retained as an independent risk factor after multivariate analysis. Interestingly, 17 potential explanatory parameters, such as upper GI cancer, weight loss, reduced appetite or co-morbidities, did not show any significant correlation with reduced intake of nutritional supplements.

Reduced compliance with preoperative nutritional interventions remains a major issue because the expected benefit depends on the actual intake. Seemingly, obvious reasons could not be retained as valid explanations. Compliance seems thus to be primarily a question of will and information; the importance of nutritional supplementation needs to be emphasized by specific patients' education.