Illness perceptions and outcome in multiple sclerosis: A systematic review of the literature.

According to Leventhal's self-regulation model, ill people construct personal representations of their disease, namely illness perceptions, which impact their coping strategies and the emotional response to their condition. Since these representations develop in the social environment, the individuals' perceptions may also be related to the opinions of their caregivers. This systematic review aims at synthesising and critically appraising literature pertaining the relationship between illness perceptions and outcome in persons with multiple sclerosis and their caregivers. A literature search was conducted in MEDLINE, PsycINFO, and CINAHL. Only papers with the following characteristics were included: quantitative studies; written in English or Italian; published from 1992; investigating the relationship between illness perceptions and any outcome in persons with multiple sclerosis and/or their caregivers; using validated scales assessing illness perceptions. Twenty papers were included and appraised through the 16-item Quality Assessment Tool for Studies with Diverse Designs. The quality of the papers was acceptable. Eighteen out of 20 papers reported the existence of a moderate effect size when analysing the relationship between illness perceptions and outcome, whereby "positive" perceptions (e.g. stronger beliefs of control) related to better outcomes, while "negative" ones (e.g. attribution of negative consequences to the disease) related to worse outcome.