Round 1 of the interviews evaluated 3 items to evaluate ease of use of inhaler (Items 1a, 1b and 1c), 3 items to assess the ease in evaluating remaining doses (Items 2a, 2b, 2c) and one item to understand if the participants could compare different types of inhalers. Three response options were developed to assess ease of inhaler use and ease of evaluating remaining doses: Item 1a/2a-a verbal response scale with four options (Very easy, easy, hard, very hard); Item 1b/2b-the same four verbal response options accompanied by illustrations of faces for each verbal response; and Item 1c/2c-a verbal response scale with two options (Yes, No). Item 3 consisted of 3 response options (Yes, No, The same). The number of participants who had difficulty in distinguishing item responses has been presented.