A preliminary path analysis: Effect of psychopathological symptoms, mental and physical dysfunctions related to quality of life and body mass index on fatigue severity of Iranian patients with multiple sclerosis

BACKGROUND Multiple sclerosis (MS) is a neurological disease with fatigue as most prevalent symptom. Psychopathological symptoms, physical and mental dysfunctions and body mass abnormalities potentially could deteriorate fatigue. Thus, in this study, we aimed at evaluating the effect of these factors on fatigue severity of MS patients. METHODS In this cross-sectional study, 162 patients with mean age of 34.1 ± 9.4 (16-58 years) were recruited by consecutive sampling. All the patients, after completing demographic information were evaluated using Persian versions of Fatigue Severity Scale (FSS), depression, anxiety and stress scale (DASS-21), and short form Health Survey Questionnaire (SF-36). RESULTS Correlation analysis showed a significant relationship between fatigue severity and depression, anxiety, stress, physical component summary (PCS) and mental component summary (MCS) (P < 0.01). Findings of path analysis demonstrated that PCS is the only variable which has a direct effect on fatigue severity (β = -0.278, P < 0.05). Moreover, the strongest standard coefficient (β) belonged to cause and effect relationship between MCS and depression (β = -0.691, P < 0.0001). CONCLUSION Present study made the role of psychopathological symptoms and physical and mental dysfunctions prominent in exacerbation of fatigue severity. Moreover, we can refer to more sensible effect of physical dysfunction related to life on fatigue.