The International Study of Asthma and Allergies in Children (ISAAC) questionnaire was developed in the 1990s and has been used throughout the world to assess the prevalence of asthma, eczema and hay fever. Archivist was particularly impressed by the size and participation rate of the study published by Oyenuga VO et al [The Lancet Child & Adolescent Health 2024;8: 859–871. https://doi.org/10.1016/ S2352-4642(24)00232-3]. They caried out a cross sectional, two-phase, multi-country (Malawi, South Africa, Zimbabwe, Ghana and Nigeria) study in 149 secondary schools involving 27, 407 adolescents who were screened with the ISAAC questionnaire with a 99·5% (27 272) participation …