Development of a measure for patients preparing to start dialysis and their partners: The Starting Dialysis Questionnaire (SDQ)

BACKGROUND: The transition onto dialysis is a stressful time that affects both patients and their partners. Research suggests that psychological and interpersonal characteristics within the couple are related to how well they adapt to dialysis. The aim of this multi-phase, mixed methods study was to develop a measure, the Starting Dialysis Questionnaire (SDQ), that is applicable to both patients and their partners and assesses their own thoughts and feelings about these constructs. METHODS: Data from semi-structured interviews with patients and their partners (n = 22 couples) were analysed using theoretical thematic analysis to identify and define constructs related to quality of life (QOL). Next, items addressing these constructs were derived from the interviews. Then, cognitive interviews were conducted with patients with chronic kidney disease and their partners (n = 5 couples) to assess the face validity and comprehensibility of the items. Lastly, preliminary psychometric properties were evaluated in a sample of patients preparing to start dialysis and their partners (n = 83 couples). RESULTS: Three themes related to QOL were identified, namely dialysis expectations, accepting dialysis and dyadic relationship characteristics. The cognitive interviews refined the SDQ and established its face validity. Psychometric assessments indicated that overall the items performed well and did not show significant floor or ceiling effects. Good internal consistency was found within the three domains, and items correlated within the domains. CONCLUSIONS: The SDQ is a measure (34 items) that assesses key psychological and interpersonal factors in patients and their partners as they start dialysis. It shows good preliminary psychometric properties; however, a large-scale field trial is needed to establish its validity. Once validated, it could offer a clinically useful tool to assist clinicians in preparing patients and partners for dialysis.