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Title: Understanding adherence to ankle-foot orthoses : an application of the theory of planned behaviour
Author: McMonagle, Christine
ISNI:       0000 0004 8509 923X
Awarding Body: University of Strathclyde
Current Institution: University of Strathclyde
Date of Award: 2019
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Ankle-foot orthoses (AFOs) are used to manage mobility disability in a wide range of conditions such as stroke, multiple sclerosis, arthritis, and trauma. However, sub-optimal adherence has been identified as a major concern. Poor adherence to AFOs may result in diminished physical and mental health outcomes, and is also an inefficient use of scarce resource. In addition, little is known about the extent of use of AFOs in the longer term. Therefore, this thesis set out to initially understand the prevalence of adherence to AFOs, and the relationship between adherence to AFOs and health and functioning outcomes. The International Classification of Functioning Disability and Health (ICF, WHO, 2001) was used as a framework to define health outcomes. The first investigation was a cross-sectional survey, conducted with 157 participants from NHS Greater Glasgow and Clyde, who had been prescribed an AFO for a range of conditions. The adherence rate to use of AFOs as recommended was 56%. This study demonstrated that AFO use as recommended was associated with better physical and mental health outcomes. Therefore, an understanding of potentially modifiable factors, which can improve adherence to AFOs, offers an alternative method of optimising outcomes of AFO use. The Medical Research Council's framework for complex interventions (Craig et al., 2013) identifies the need for theory-driven research to inform interventions. Consequently, this thesis used a theoretical approach to attempt to understand adherence to orthoses. Firstly, the Theory of Planned Behaviour (TPB, Ajzen, 1991) was identified as a potentially appropriate model. Then, a meta-analysis was conducted, which drew on the wider health adherence literature, to review the efficacy of the TPB in understanding health adherence behaviours in conditions, which may give rise to an orthotic intervention. This found that the TPB accounted for 28.3% of the variance in intentions and 14% of the variance in adherence behaviours. Attitudes and Perceived Behavioural Control (PBC) were significant predictors of intention, and intention was a significant predictor of behaviour. In line with the TPB, intention mediated the effects of attitude and PBC on behaviour. This suggested the TPB might offer a useful model to investigate adherence to AFOs. This thesis then applied the TPB to modelling AFO use in people with stroke. Stroke was selected as the focus of this investigation, as it is the leading cause of acquired adult disability worldwide (McGrath, Canavan, & O'Donnell, 2018), and, in the first study, was identified as the most common condition for which an AFO is prescribed. In addition, Scotland has a high incidence of stroke, compared to other UK nations, and improving the treatment and care of stroke is a clinical priority (Scottish Government, 2014a). In order to conduct a TPB investigation, firstly, a beliefs elicitation study was conducted with 13 participants who had been prescribed an AFO by NHS Lanarkshire following stroke. This study enabled elicitation of attitudinal, normative and control beliefs, in line with the TPB model. Participants reported more advantages compared to disadvantages of using AFOs, suggesting that they had a generally positive attitude towards AFO use. The most commonly stated advantages were '€˜increased mobility'™ and 'supports the position of the leg or foot'€™. The most common disadvantage detailed was 'discomfort', followed by 'problems with footwear size' and 'problems with footwear style'. Participants also identified a far greater number of people who would approve of AFO use, compared to people who would disapprove of AFO use suggesting that support for use of AFOs from a wide range of normative groups is high. Family and health professionals were the most frequently elicited supporting normative referents. However, participants identified far fewer enabling factors compared to factors which made AFO use difficult, suggesting that perceived control of AFO use may be low in people with stroke. The main barriers to AFO use highlighted by participants were: obstacles in the environment, needing help to put the AFO on and off, the AFO causing pain or discomfort, and low mood or tiredness. Then, the efficacy of the TPB model in explaining adherence to use of AFOs in people with stroke was investigated. Attitude, subjective norm and PBC were measured at Time 1 and behaviour was measured one month later, at Time 2, using a prospective questionnaire design in 49 participants from NHS Lanarkshire. In this investigation, 63% of people used their AFO as recommended. The TPB accounted for 57% variance in intentions and 43% variance in use of AFOs as recommended. The significant amount of variance accounted for indicates the TPB is a useful model for understanding adherence to AFOs in people with stroke. Attitude was the only significant predictor of intention, and intention was the only significant predictor of behaviour. These findings were broadly in line with the meta-analysis conducted, albeit, with a greater amount of variance explained. The higher level of variance found in the TPB study could potentially be explained by careful design of the questionnaire, and use of an elicitation investigation using participants with the same inclusion criteria, which ensured compatibility of measures. The relationship between the underlying beliefs, the direct TPB constructs, and intention and behaviour, were analysed, enabling potential targets of a future intervention to be identified. Attitudinal beliefs, normative beliefs and control beliefs were significantly correlated with the direct constructs, demonstrating that the beliefs measured provided a good understanding of the cognitive foundations of attitude, subjective norms and PBC. Analysis of correlations between belief-based measures, intention, and behaviour enabled the identification of beliefs that could be targeted in a future intervention to increase adherence to AFO use. These were positive attitudinal beliefs that AFOs can increase mobility, improve balance, and help a person to improve during rehabilitation, and also negative beliefs that AFOs may cause pain or discomfort, are heavy, and are effortful to use. This thesis is the first body of work, which has applied a psychological model of behaviour to understanding AFO use in stroke, and therefore makes a significant contribution to the emerging cross-disciplinary field of psychology and physical rehabilitation for mobility disabilities. In addition, this work provides evidence of the efficacy of the TPB as a theoretical model for investigating other health behaviours, and specifically adherence behaviours in stroke. Finally, this investigation has identified potential beliefs, which could be utilised in a future intervention to increase adherence to use of AFOs, by targeting the significant underlying attitudinal beliefs. More research is required to corroborate these findings, and important areas for future research have also been highlighted: there is the need for a stronger evidence base for recommendations for use of AFOs, and researchers should consider a broader range of outcome measures, which are more reflective of the patient experience of using an AFO in a real-world setting.
Supervisor: Elliott, Mark ; Rasmussen, Susan Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral