Is the Corrected Carotid Flow Time a Clinically Acceptable Surrogate Hemodynamic Parameter for the Left Ventricular Ejection Time?

OBJECTIVE: The corrected left ventricular ejection time (cLVET) comprises the phase from aortic valve opening to aortic valve closure corrected for heart rate. As a surrogate measure for cLVET, the corrected carotid flow time (ccFT) has been proposed in previous research. The aim of this study was to assess the clinical agreement between cLVET and ccFT in a dynamic clinical setting. METHODS: Twenty-five patients with severe aortic valve stenosis (AS) were selected for transcatheter aortic valve replacement (TAVR). The cLVET and ccFT were derived from the left ventricular outflow tract (LVOT) and the common carotid artery (CCA), respectively, using pulsed wave Doppler ultrasound. Bazett's (B) and Wodey's (W) equations were used to calculate cLVET and ccFT. Measurements were performed directly before (T1) and after (T2) TAVR. Correlation, Bland-Altman and concordance analyses were performed. RESULTS: Corrected LVET decreased from T1 to T2 (p < 0.001), with relative reductions of 11% (B) and 9% (W). Corrected carotid flow time decreased (p < 0.001), with relative reductions of 12% (B) and 10% (W). The correlation between cLVET and ccFT was strong for B (ρ = 0.74, p < 0.001) and W (ρ = 0.81, p < 0.001). The bias was -39 ms (B) and -37 ms (W), and the upper and lower levels of agreement were 19 and -98 ms (B) and 5 and -78 ms (W), respectively. Trending ability between cLVET and ccFT was good (concordance 96%) for both B and W. CONCLUSION: In TAVR patients, the clinical agreement between cLVET and ccFT was acceptable, indicating that ccFT could serve as a surrogate measure for cLVET.

User Experience of a Chatbot Questionnaire Versus a Regular Computer Questionnaire: Prospective Comparative Study.

BACKGROUND: Respondent engagement of questionnaires in health care is fundamental to ensure adequate response rates for the evaluation of services and quality of care. Conventional survey designs are often perceived as dull and unengaging, resulting in negative respondent behavior. It is necessary to make completing a questionnaire attractive and motivating. OBJECTIVE: The aim of this study is to compare the user experience of a chatbot questionnaire, which mimics intelligent conversation, with a regular computer questionnaire. METHODS: The research took place at the preoperative outpatient clinic. Patients completed both the standard computer questionnaire and the new chatbot questionnaire. Afterward, patients gave their feedback on both questionnaires by the User Experience Questionnaire, which consists of 26 terms to score. RESULTS: The mean age of the 40 included patients (25 [63%] women) was 49 (SD 18-79) years; 46.73% (486/1040) of all terms were scored positive for the chatbot. Patients preferred the computer for 7.98% (83/1040) of the terms and for 47.88% (498/1040) of the terms there were no differences. Completion (mean time) of the computer questionnaire took 9.00 minutes by men (SD 2.72) and 7.72 minutes by women (SD 2.60; P=.148). For the chatbot, completion by men took 8.33 minutes (SD 2.99) and by women 7.36 minutes (SD 2.61; P=.287). CONCLUSIONS: Patients preferred the chatbot questionnaire over the computer questionnaire. Time to completion of both questionnaires did not differ, though the chatbot questionnaire on a tablet felt more rapid compared to the computer questionnaire. This is an important finding because it could lead to higher response rates and to qualitatively better responses in future questionnaires.