The effectiveness of visual-based interventions on health literacy in health care: a systematic review and meta-analysis

Background: Limited Health Literacy (HL) is an obstacle to accessing and receiving optimal health care and negatively impacts patients’ quality of life, thus making it an urgent issue in the health care system. Visual-based interventions are a promising strategy to improve HL through the use of visual aids and pictorial materials to explain health-related concepts. However, a comprehensive summary of the literature on the topic is still scarce. Methods: To fill this gap, we carried out a systematic review and meta-analysis with the aim to determine the effectiveness of visual-based interventions in improving comprehension of health related material in the clinical population. Independent studies evaluating the effectiveness of visual-based interventions on adults (> 18 years) and whose primary outcome was either health literacy (HL) or comprehension were eligible for the review. After a systematic literature search was carried out in five databases, 28 studies met the inclusion criteria and thus were included. Most of the studies were randomized controlled trials and they focused on HL and health knowledge as outcomes. Results: The review and meta-analysis showed that visual-based interventions were most effective in enhancing the comprehension of health-related material compared to traditional methods. According to meta-analytic results, videos are more effective than traditional methods (Z = 5.45, 95% CI [0.35, 0.75], p < 0.00001) and than the employment of written material (Z = 7.59, 95% CI [0.48, 0.82], p < 0.00001). Despite this, no significant difference was found between video and oral discussion (Z = 1.70, 95% CI [-0.46, 0.53], p = 0.09). Conclusions: We conclude that visual-based interventions, particularly the ones using videos, are effective for improving HL and the comprehension of health-related material.