We administered the MDP several times over the course of the ED visit, with questions referring to how breathing felt at

that particular time (“now” wording) or how breathing felt at the time the participant decided to come to the ED (“recall” wording). Apart from the difference in time frame, the instructions and questions were identical. Support for the potential independence of MDP ratings of intensity from unpleasantness and work/effort from air hunger have been reported in controlled physiological experiments in a laboratory setting [26]. However, principal components analysis Inhibitors,research,lifescience,medical of “now” ratings using the MDP in ED patients showed two components (domains) that jointly accounted for 66% to 74% of Inhibitors,research,lifescience,medical item variance [28]. The first domain comprised the single-item ratings of intensity and unpleasantness together with the five sensory quality ratings and was labeled Immediate Perception (7 items; Cronbach’s

α>.90). The second domain consisted of the ratings of breathing-related emotional distress and was labeled Emotional Response (5 items; Cronbach’s α≥.84). Protocol ED phase Patients were triaged according to established departmental procedures. The initial contact for study participation took place after they had been evaluated and treatment was under Inhibitors,research,lifescience,medical way. Potentially eligible participants were identified by study staff, and the visit record was screened for excluding conditions. After ascertaining from the physician or registered nurse staff that the patient was sufficiently stable to be approached, potential participants were informed by ED personnel that a study was Inhibitors,research,lifescience,medical ongoing for which they

might be eligible and given a brochure about the study prior to the initial contact by study staff. After the initial contact, those who expressed interest in participating were given a copy of the consent form and given time to read and consider it. After answering any questions, signed consent and full HIPAA authorization forms were obtained from all who agreed to participate. As soon as possible after Inhibitors,research,lifescience,medical enrollment Bay 11-7085 (Time 1), the study questionnaire was administered to assess how breathing felt at that time (“now” wording) and in a separate administration that asked participants to recall and rate how their breathing felt when they decided to come to the ED (“recall” learn more wording: Time 0). In the initial protocol, there was only a single administration of the Time 0 questionnaire (i.e., using the recall wording), but there were two subsequent administrations of the questionnaire using the “now” wording: an hour after the initial administration (Time 2) and, if possible, a third administration prior to leaving the department (Time 3). After 27 participants had been enrolled, a protocol amendment added a second recall administration immediately following the Time 2 administration of the “now” questionnaire.