Developing and evaluating the patient’s perspective of needling questionnaire for haemodialysis

Cannulation of vascular access for haemodialysis is essential when using arteriovenous access. However, this can be a painful and distressing procedure for patients. There is no current measure that enables inclusion of patients’ experiences of cannulation as an outcome in research comparing interventions to improve cannulation. This study aimed to develop a patient reported outcome measure of cannulation for haemodialysis, focusing on the physical and psychological experiences of patients. This was named the ‘Patient’s Perspective of Needling’ (PPN) questionnaire. The PPN was developed with six patient representatives. Face validity assessed understandability, relevance and comprehensiveness of the PPN. Convergent validity assessed the correlation of the PPN results to the Short-Form Vascular Access Questionnaire (SF-VAQ). Internal consistency and test-retest reliability tested the reliability of the PPN. Floor and ceiling effects were examined and the interpretation of the results of the PPN were explored by: (a) using an item discrimination index; (b) calculating the smallest detectable change. Free text comments were analysed using basic thematic analysis. The first version of the PPN underwent face validity testing with 12 participants from two renal centres, which led to further amendments of the PPN. The final PPN contained three sections with 17 questions, on pain, worry and problems. Internal consistency of the final PPN was 0.937 (n = 98, 95% CI 0.917–0.954, p < 0.0001). For convergent validity, a correlation to Question 3 of SF-VAQ was − 0.347 (95% CI -0.146 - -0.521, p < 0.001) and Question 4–15 of SF-VAQ was 0.613 (95% CI 0.450–0.736, p < 0.001). Test-retest reliability was 0.856 (95% CI 0.788–0.904, p < 0.001). The smallest detectable change was 0.135. The Pain section of the PPN scored the highest, with the Worry and Problems sections scoring lower. Free text comments from the PPN expanded on difficulties with cannulation, showing that cannulation experience varied over time and how patients cope with cannulation. The PPN behaved in a valid and reliable manner for the tests completed, enabling patients’ experiences of cannulation to be included as an outcome in research studies into cannulation for haemodialysis. Haemodialysis is a treatment for people whose kidneys no longer work. It replaces the function of their kidneys and is essential at least 3 times a week. Some people on haemodialysis require the insertion of large needles into artificially enlarged veins in the arm or leg before each treatment, known as needling, which can be painful and distressing. There is no measure to capture people’s experiences of needling for haemodialysis, meaning this cannot be used as an outcome in research studies aimed to improve needling. We developed the ‘Patients’ Perspective of Needling’ questionnaire to measure physical and psychological consequences of needling for haemodialysis in research studies. This was developed with six patient representatives. We tested this questionnaire in two kidney centres and with a varied sample of people on haemodialysis. Twelve people on haemodialysis assessed the questionnaire for understandability, relevance and comprehensiveness, which led to further changes to the questionnaire. Data were then collected from ninety-eight people on haemodialysis to test other properties of the questionnaire. This was to ensure it measured what it intended to measure (validity), that it did this with consistency (reliability) and to understand what the questionnaire scores meant. The results of these tests showed the questionnaire behaved as it should do and provided guidance on how the questionnaire could be used to capture patients’ experiences of needling for haemodialysis as an outcome in research studies.