Limitations of this study include the potential reverse causality due to the cross-sectional design; however, a number of variables identified to be significantly associated with AI preventive behavior (e.g., region of residence and education) are likely to precede temporally the outcome measure, thereby lending additional support to our explanations discussed earlier. Also, combining wearing face masks and handwashing as the outcome variable without assessing them separately could be a limitation of this study because determinants of these two practices could be different. On the other hand, however, in view of the modes of AI transmission through contact and air particles, practicing both face mask wearing and handwashing behaviors could provide better protection against AI infection. Another potential limitation is that this study was not based on national data but on data from northeastern and central Taiwan; yet, regional differences were uncovered. Therefore, future studies should consider drawing a national sample to explore other possible cross-regional differences in Taiwan. In addition, cross-national comparisons may also reveal interesting differences across various countries and cultures in preventive behaviors associated with such emerging infectious diseases. Lastly, while self-efficacy (a construct borrowed from Bandura's Social Learning Theory) was not added to the HBM until 1988 [30] , it has increasingly become an important construct in the HBM but was not included in our study. Hence, future research should consider measuring all other HBM constructs, including self-efficacy, when examining AI preventive behavior. 