A biopsychosocial model of diabetes self-management: mediators and moderators

Diabetes mellitus (diabetes), an endocrine disorder, is in epidemic proportions globally, threatening the well being of people affected and challenging health care systems. In the main, diabetes warrants adjustments to lifestyle and therapeutic interventions simply to self-manage the condition. Research in self-management of diabetes has targeted socio-cognitive theory and espoused self-efficacy as the main driver of self-management. More recently, self-regulatory theory has focused on illness representations and argued they are the force underpinning goal directed behaviours. Research to-date has tended to adopt one or other of the prevailing theoretical models to the exclusion of key concepts in other explanatory health behaviour models. Studies are lacking in demonstrating a comprehensive exploration of the interrelationships between self-regulatory skills inherent in self-management, illness representations and self-efficacy with other potential health behaviour determinants. In this thesis, it was postulated that an integrated biopsychosocial model of self-management was warranted to account for the complexities of human understanding and interactions within a naturalistic setting. The purpose of this dissertation was to develop and substantiate a conceptual model of diabetes self-management integrating key concepts from health behaviour theories within a structure of four broad determinants of health behaviour, which were: personal traits, diabetes traits, socio-environmental factors and health contextual factors. Specifically, determinants associated with diabetes self-management behaviours and the predictors for its success for those with type 1 and type 2 diabetes was sought. In order to substantiate the proposed integrated model a cross-sectional design, using quantitative survey methodology, was undertaken. Structural equation modelling allowed interrelationships in the integrated model to be explored simultaneously and advanced model testing thus far in the field. The study involved males (n = 504) and females (n = 519), aged over 18 years (M = 63.90, SD = 13.89) who had a diagnosis of either type 1 or type 2 diabetes and who resided in Western Australia. Model testing substantiated the integrated biopsychosocial model proposed and was relatively parsimonious, making the application of the findings to a clinical setting possible. Key predictors for both types of diabetes were: self-efficacy, diabetes distress, diabetes traits, self-determination support by health care professionals and to some extent age of the person with diabetes. In addition, locus of control by doctors was important for type 2 diabetes and marital status and socio-economic status for type 1 diabetes. The presence of emotional distress had a negative effect on interrelated factors, emphasising the criticality of its assessment and management by health professionals if self-management is to be achieved. Illness representations had low or minimal predictive power, refuting claims that it is responsible for the initiation of goal directed behaviours. The integrated model, a first of its kind in the Australian context, contributes to existing knowledge in diabetes self-management through its attention to contextualising the self-regulatory individual within their personal, social and health environment. In particular it makes explicit the distinguishing integrated predictors for type 1 and type 2 diabetes previously unknown in the adult population. Through the understanding of predictors, the health sector is better placed to target predictors in supporting self-management