Data review and validation comprised a year-long process involving multiple researchers vetting scores, data and justifications in stages to ensure consistency across countries. The model’s default ‘expert’ weights were derived from extensive deliberation and input from the GHS Index International Panel of Experts, a group of 21 subject matter experts in health security representing organizations in 13 countries.16 However, recognising that no single weighting scheme can reflect every country’s priorities, we also built flexibilities into the GHS Index model: users can customise weights based on context-specific considerations, priorities or other criteria, and country scores and rankings adjust accordingly.