Illness perception and treatment adherence in haemodialysis: a systematic review

Patients with kidney failure need lifelong renal replacement therapy to survive and, worldwide, in-centre haemodialysis is the most common modality. The efficacy of this treatment largely depends on the patients' adherence to several health behaviours. According to Leventhal's self-regulation model, patients' illness perceptions can be a key factor for treatment adherence. Therefore, it is of utmost importance to better understand this relationship to further fine-tune the effectiveness of renal rehabilitation programs. This study aimed to systematically review the literature on the association between illness perceptions and treatment adherence in adults undergoing in-centre haemodialysis. The search was performed on PubMed, Scopus, CINAHL, Web of Science (all databases included), and ProQuest (all databases included), from the 17(th) to the 21(st) of December 2020. The last update was performed on the 9(th) of June of 2022. Articles were critically appraised using the Joanna Briggs Institute (JBI) Critical Appraisal Checklists for Analytical Cross-Sectional Studies. Nine studies were included comprising a total of 1161 patients undergoing in-centre haemodialysis. Associations between illness perceptions and treatment adherence were found in six studies. Adherence to dietary restrictions was the type of adherence with more significant associations with illness perceptions, followed by fluid control and medication intake. Two studies combining several types of adherences into an overall score also showed significant associations with illness perceptions. No significant associations were found between illness perceptions and adherence to dialysis sessions. These findings suggest that illness perceptions in patients undergoing in-centre haemodialysis should continue to receive research attention. Future interventions should acknowledge the importance of modifying maladaptive illness perceptions to improve treatment adherence in kidney failure. The protocol for this systematic review was registered on PROSPERO (CRD42021231929).