This thesis is comprised of four studies and concerns haemodialysis patients’ confidence in being able to manage fluid intake between treatment sessions, and whether the fluid intake is influenced by certain modifiable characteristics of the persons in question. The overall aim was to study aspects of excessive fluid overload and haemodialysis patients’ self-regulation of fluid allotment from a bio-psychosocial and behavioural medicine perspective.

The extent of non-adherence to fluid allotment was described in Study I. National registry data were used. Three out of ten Swedish haemodialysis patients had excessive fluid overload and one out of five was at risk for treatment related complications due to too rapid ultrafiltration rate.

The objective in Study II was to develop and psychometrically evaluate a self-administered scale to measure situation-specific self-efficacy to low fluid intake. The measure (the Fluid Intake Appraisal Inventory) was found to be reliable and valid in haemodialysis settings.

Subgroups based on individual profiles of self-efficacy, attentional style and depressive symptoms were explored in Study III using a cluster analytic approach. Three distinct subgroups were found and the subgroup structure was validated for clinical relevance. The individuals’ profile concerning self-efficacy, attentional style and depressive symptoms has to be taken into account in nursing interventions designed to reduce haemodialysis patients’ fluid intake.

In Study IV, an intervention designed to reduce haemodialysis patients’ fluid intake was introduced and its acceptability, feasibility and efficacy were evaluated and discussed. Acceptability of such an intervention was confirmed. Addressing beliefs, behaviours, emotions and physical feelings is clinically feasible and may reduce haemodialysis patient’s excessive fluid overload.

This thesis indicates that there is a potential for improvement in the fluid management care of haemodialysis patients. Behavioural nursing strategies that aim to assist patients to achieve fluid control should be applied more extensively. Cognitive profiles of the patients should be taken into account when targeted nursing intervention aiming to encourage and maintain the patient’s fluid control is introduced.