Fig. 11

Co-occurrence network of keywords in policy-related publications on medical tourism. Note: The figure shows the relatedness of author designated and auto indexed keywords (with at least three occurrences) based on how frequently they occur in the same publications. Nodes depict keywords and their linkages convey co-occurrence relationships. Larger nodes indicate keywords with more occurrences. Link strengths indicate the frequency with which they co-occur. Keywords that co-occur more frequently are clustered together. Nodes are colored based on the frequency with which the keywords occur in publications in different years. Keywords occurring with greater frequency in recent publications are colored lighter than those frequently occurring in the past