Cultural and linguistic testing of the Handling Questionnaire: a specific instrument for assessing the patient's acceptability of dry powder inhalers.

The testing and checking phases of a questionnaire are briefly described in this paper, identifying the common errors due to incorrect formulation of questions and the main issues. The theoretical methods for "testing" a questionnaire has been examined in the first section, in the second section the testing process for a specific questionnaire for assessing the patient's acceptability of a dry powder device (the Handling Questionnaire) has been described, together with the grading of improvement achieved.