Predictors of on-going fatigue after acute infection: a systematic review

Abstract

Background Fatigue is a prevalent and debilitating symptom, preceded by an acute infectious episode in some patients. This systematic review aimed to identify factors which predict lasting fatigue after an acute infection, to inform the development of a working model of post-viral fatigue. Methods Electronic databases (Medline, PsycINFO and EMBASE) were searched from inception to July 2015, for studies which investigated biopsychosocial predictors of on-going fatigue after an acute infection. Inclusion criteria were: prospective design; biological, psychological or social predictors; valid and reliably measured post-infectious fatigue. Studies were excluded if participants had a pre-existing medical condition (including chronic fatigue at baseline), infection was conceptualised as ‘vaccination’ or they were intervention trials. Findings Seventy-eight full texts were screened, of which seventeen met inclusion criteria. Over half included glandular fever populations. Other infections included dengue, ‘general’/’viral’ and Q-fever. A wide range of predictive factors were investigated, grouped under sub-themes: Biological; Social; Behavioural; Cognitive; Emotional Well-being. Conceptualisation of fatigue varied– some studies used criteria definitions, others used questionnaires. Despite this heterogeneity, certain variables were associated with the development of chronic fatigue in multiple studies and/or across time-points, including bed rest, total symptoms reported, distress and attribution style. Subsequently, a working model was developed. Discussion Core aspects of the model are related to patients’ illness response (e.g. behaviours engaged in, attributions and perceptions held, and emotional well-being) which are likely to be relevant in understanding the progression from acute to chronic fatigue. Thus, the model lends itself to informing a chronic fatigue prevention intervention.