Identification des facteurs sociocognitifs liés à l’adhésion au traitement des jeunes atteints d’hémophilie : une étude pour guider l’intervention en milieu hospitalier

Hemophilia is an incurable bleeding disorder that slows the blood clotting process. The treatment plan aims to prevent bleeding episodes that occur in the joints, since repeated bleeding episodes can cause long-term damage to internal structures. The treatment plan consists of regular infusions of the missing clotting factor and specific recommendations as to which physical activities are safe and which are to be avoided. The objective of this thesis, composed of 5 articles, was to determine the socio-cognitive factors likely to influence the adherence of children and adolescents to the recommendations of the treatment plan, and to suggest avenues for intervention. To do this, we relied on three theoretical models which, together, shed light on the central aspects of adherence: the perspective of young patients on the medical recommendations, their perceptions of the illness and, finally, avenues of intervention to promote better adherence in those young patients in the long-term. In the first article, we translated to French an instrument that measured adherence to the infusion therapy, and we provided the preliminary psychometric data of the instrument. The data supported the use of the instrument with young patients, which allowed us to use it in the thesis. In the second article, we used the theory of planned behavior to understand how young people perceive the recommendations concerning infusion treatment and physical activity. For this, we measured their attitude towards the behavior, their perception of behavioral control, the subjective social norm and past behavior. We assessed whether these factors were related to the intention to follow the recommendations. The results indicated that these factors explain a large proportion of the variance in intention to follow physical activity recommendations, especially for those at risk of causing bleeding. As adherence to injection therapy was high in our sample while adherence to physical activity recommendations was lower and more variable among participants, we decided to focus on the latter for the next articles. In the third article, we wanted to understand how patients view their illness and whether illness perceptions could have an impact on their physical activity practice. For this we used the common-sense model. Perceptions were more negative for the following areas: the consequences of hemophilia, the number of symptoms and the emotional impact. When we ranked participants according to their physical activity profile, the subgroup that followed the recommendations less iv closely and had a lower intention of following the recommendations had significantly more concerns and perceived more symptoms. The fourth article highlights the interest of the autonomy support model in hemophilia intervention and consists of a practical adaptation of this model to the specific challenges of the illness. The fifth article is about the development of an information booklet that we created using the concepts of this theory. We used quantitative and qualitative methods to assess the parents’ acceptability of the booklet and modified the booklet according to their suggestions.

Keyphrases: hemophilia, adherence to treatment, physical activity, health behaviors, theory of planned behavior, self-determination theory, self-regulation, perceptions of illness, autonomy support, health psychology, pediatrics, common-sense model