Recovery from chronic fatigue syndrome: a systematic review—heterogeneity of definition limits study comparison

Abstract

BackgroundPaediatric chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME) is a common illness with a major impact on quality of life. Recovery is poorly understood. Our aim was to describe definitions of recovery in paediatric CFS/ME, the rate of recovery and the time to recovery.MethodsThis systematic review included a detailed search of MEDLINE, EMBASE, PsycInfo and Cochrane Library between 1994 and July 2018. Inclusion criteria were (1) clinical trials and observational studies, (2) participants aged <19 years with CFS/ME, (3) conducted in Western Healthcare systems and (4) studies including a measure of recovery and time taken to recover.ResultsTwelve papers (10 studies) were identified, involving 826 patients (range 23–135). Recovery rates were highly varied, ranging between 4.5% and 83%.Eleven distinct definitions of recovery were used; six were composite outcomes while five used unidimensional outcomes. Outcome measures used to define recovery were highly heterogeneous. School attendance (n=8), fatigue (n=6) and physical functioning (n=4) were the most common outcomes included in definition of recovery. Only five definitions included a personal measure of recovery.ImplicationsDefinitions of recovery are highly variable, likely secondary to differences in study design, outcomes used, follow-up and study populations. Heterogeneous definitions of recovery limit meaningful comparison between studies, highlighting the need for a consensus definition going forward. Recovery is probably best defined from the child’s own perspective with a single self-reported measure. If composite measures are used for research, there should be agreement on the core outcome set used.

Health, Wellbeing, and Prognosis of Australian Adolescents with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Case-Controlled Follow-Up Study

“…The remaining third (35%) were not classified as meeting criteria and more likely reflected a sub-clinical sample of individuals that had improved considerably since diagnosis, given that none reported unexplained, persistent fatigue that represented a substantial reduction in previous functioning. This 35% of participants could be interpreted as having improved clinical status since diagnosis, which would fall within the observed 'recovery' range in Moore et al's [30] systematic review of paediatric ME/CFS longitudinal studies (ranging from 5% to 83% recovery). However, there are obvious limitations in inferring recovery and when comparing results across these follow-up studies, given the variability in case definition, inclusion criteria, and definitions of recovery used.…”

“…Importantly, the group disparity in these features of health and psychological wellbeing became less pronounced from diagnosis to follow-up, due to the significant improvement observed over time in the ME/CFS group, and the relative stability of the control group over time. Indeed, improvement in ME/CFS patient-reported outcomes have previously been shown in the domain of fatigue [12,65], with a recent systematic review showing recovery rates for paediatric ME/CFS of between 15% and 85% based on outcome measures of fatigue severity [30]. Fatigue and HRQOL have also been shown to co-vary in paediatric ME/CFS [43], which may account for the relative improvement being observed in both these domains over the follow-up period.…”

“…While there are relatively few longitudinal studies assessing follow-up of adolescent patients with ME/CFS, the limited evidence available suggests that improvement and recovery are more likely in paediatric ME/CFS compared with adult ME/CFS [1]. To date, paediatric ME/CFS follow-up studies (ranging from 1 to 21 years follow-up) have reported recovery rates of between 5% and 83% [11,12,[22][23][24][25][26][27][28][29][30], although there is variability in how recovery is defined across studies. Research has tended to use individuals' selfdefined recovery in the common domains of fatigue, physical functioning, and school attendance [30].…”

“…To date, paediatric ME/CFS follow-up studies (ranging from 1 to 21 years follow-up) have reported recovery rates of between 5% and 83% [11,12,[22][23][24][25][26][27][28][29][30], although there is variability in how recovery is defined across studies. Research has tended to use individuals' selfdefined recovery in the common domains of fatigue, physical functioning, and school attendance [30]. The latter measure may be problematic, however, for older adolescents who had already finished schooling at the follow-up time point, or for younger adolescents who are attending school but not functioning well due to ongoing cognitive disturbances.…”

The fragile process of Homecoming - Young women in recovery from severe ME/CFS

“…From a health care perspective, children and adolescents are generally considered to have a better prognosis for recovery from ME/CFS than adults (Moore et al, 2021 ; Rowe et al, 2017 ). However, while for adults there are multiple ways of defining and measuring recovery from ME/CFS (Adamowicz et al, 2014 ), recovery rates among children and adolescents vary considerably, and there is no international consensus on how to measure and define recovery (Moore et al, 2021 ). The most common outcome parameters for children and adolescents relate to school attendance, fatigue, and improvement in physical functioning (Moore et al, 2021 ).…”