The Influence of Health Literacy and Health Numeracy on Weight Loss Outcomes Following Bariatric Surgery
Miller-Matero L, Hecht L, Martens K, Hamann A, and Carlin A. The Influence of Health Literacy and Health Numeracy on Weight Loss Outcomes Following Bariatric Surgery. Surg Obes Relat Dis 2019; 15(10):S94.
Surg Obes Relat Dis
Background: Guidelines for pre-surgical psychosocial evaluations for bariatric surgery recommend that evaluators understand patients’ cognitive abilities. However, existing research has focused on global cognitive functioning. The purpose of this study was to examine whether health literacy and health numeracy influence weight loss outcomes. Patients (N=527) who underwent bariatric surgery from 2014-2017 completed a survey reporting current weight in March-April 2018. Pre-surgical weight/BMI and levels of health literacy (REALM) and health numeracy (Brief Medical Numbers Test) were collected from the pre-surgical psychosocial evaluation. Participants were categorized in the weight loss period (<2 years post-surgery) or weight maintenance period (2-4 years post-surgery). Weight loss outcomes included change in BMI (ΔBMI), percent total weight loss (%TWL), and percent excess weight loss (%EWL). Participants were predominantly female (83.3%), middle-aged (M=45.5 years), and Caucasian (62.3%) or African American (36.0%), with an average pre-surgical BMI of 48.06. For participants in the weight loss period, there were no significant relationships between weight loss outcomes and health literacy or health numeracy (p>.05). However, for participants in the weight maintenance period, better health numeracy was related to greater ΔBMI (p=.01), %TWL (p=.01), and %EWL (p=.047). Additionally, there was a trend suggesting those with better health literacy had greater %EWL (p=.07). Findings suggest that patients with lower health literacy and numeracy may be less likely to maintain weight loss following bariatric surgery. Clinicians conducting pre-surgical psychosocial evaluations could consider assessing health literacy and health numeracy. Patients with low health numeracy may benefit from additional support, especially during the weight maintenance period.