Role of illness perception and self-efficacy in lifestyle modification among non-alcoholic fatty liver disease patients

AIM: To describe the relationships between non-alcoholic fatty-liver disease (NAFLD) patient’s disease consequences and treatment perceptions, self-efficacy, and healthy lifestyle maintenance. METHODS: A cross-sectional study among 146 ultrasound diagnosed NAFLD patients who visited the fatty liver clinic at the Tel-Aviv Medical Center. Eighty-seven of these individuals, participated in a clinical trial of physical activity and underwent fasting blood tests, analyzed at the same lab. Exclusion criteria included positivity for serum HBsAg or anti-HCV antibodies; fatty liver suspected to be secondary to hepatotoxic drugs; excessive alcohol consumption (≥ 30 g/d in men or ≥ 20 g/d in women) and positive markers of genetic or immune-mediated liver diseases. Patients were asked to complete a self-report structured questionnaire, assembled by the Israeli Center for Disease Control. Nutrition habits were measured using six yes/no questions (0 = no, 1 = yes) adopted from the national survey questionnaire. Participants in the clinical trial completed a detailed semi-quantitative food frequency questionnaire (FFQ) reporting their habitual nutritional intake during the past year. Self-efficacy was assessed by the Self-Efficacy Scale questionnaire, emotional representation, degree of illness understanding, timeline perception, treatment perception and symptoms were measured by the Brief Illness Perception questionnaire. Illness consequences were measured by the Personal Models of Diabetes Interview questionnaire. A path analysis was performed to describe the interrelationships between the patients’ illness perceptions, and assess the extent to which the data fit a prediction of nutritional habits. RESULTS: The study sample included 54.1% men, with a mean age of 47.76 ± 11.68 years (range: 20-60) and mean body mass index of 31.56 ± 4.6. The average perceived nutrition habits score was 4.73 ± 1.45 on a scale between 0-6, where 6 represents the healthiest eating habits. Most of the study participants (57.2%) did not feel they fully understood what NAFLD is. Better nutritional habits were positively predicted by the degree of illness understanding (β = 0.26; P = 0.002) and self-efficacy (β = 0.25; P = 0.003). Perceptions of more severe illness consequences were related with higher emotional representation (β = 0.55; P < 0.001), which was related with lower self-efficacy (β = -0.17; P = 0.034). The perception of treatment effectiveness was positively related with self-efficacy (β = 0.32; P < 0.001). In accordance with the correlation between self-efficacy and the perceived nutrition habits score, self-efficacy was also correlated with nutrient intake evaluated by the FFQ; negatively with saturated fat (percent of saturated fat calories from total calories) (r = -0.28, P = 0.010) and positively with fiber (r = 0.22, P = 0.047) and vitamin C intake (r = 0.34, P = 0.002). In a sub analysis of the clinical trial participants, objectively measured compliance to physical activity regimen was positively correlated with the self-efficacy level (r = 0.34, P = 0.046). CONCLUSION: Self-efficacy and illness understanding are major determinants of lifestyle-modification among NAFLD patients. This information can assist clinicians in improving compliance with lifestyle changes among these patients.