Fig. 2

a. Journal articles reporting critical inhaler errors for pMDIs and DPIs. Note: percentages are calculated as a proportion of total mentions (n = 105) of each inhaler type by all inhaler error studies. Individual studies may mention more than one inhaler type. b. Journal articles reporting critical inhaler errors for specific DPI device types, both multi-dose (blue) and single-dose (red). Note: percentages are calculated as a proportion of total mentions (n = 65) of all device types by all inhaler error studies. Individual studies may mention more than one inhaler type. c. Studies stating a definition of a critical error, separated into categories. Details of each study and the exact wording used by each are presented in Additional file 1: Table S4. Note: In this figure the term “critical error” refers to both critical errors and critical steps that, when performed incorrectly, constitute critical errors