Fatigue: Biomedicine, Health & Behavior - Volume 5, Issue 4, 2017

Volume 5, Issue 4, 2017

 * Fatigue experiences in competitive soccer: development during matches and the impact of general performance capacity"Abstract - Background: Fatigue as a result of prolonged activity may increase injury risk and decrease performance. Purpose: To provide insight in the development of fatigue experiences during soccer matches and the extent to which general performance capacity (i.e. overall physical fitness, psychological fitness, and recovery) contributes to these fatigue experiences. Methods: 450 Soccer players from the highest divisions in the Netherlands completed a questionnaire to assess (a) fatigue experiences (feeling tired, physically exhausted, not fit, weak, and mentally exhausted: not at all [1] – very much [7]) during a typical match; and (b) subjective indices of general performance capacity (i.e. general capacity to handle workload). Results: On average, fatigue levels were reported to be moderate. Fatigue increased primarily during the second half of the match and only a small decrease in fatigue was observed during half time. Generally, higher intensity fatigue experiences were reported by attackers than defenders. Regression analyses showed that players’ general performance capacity explained a substantial part of fatigue at the start of a match and also predicted the development of fatigue experiences during a match, with low performance capacity being associated with higher baseline levels of fatigue and a steeper increase in fatigue over time. Conclusions: The observed association between players’ general performance capacity and their fatigue levels during matches suggests that periodic screening of general performance capacity can be informative with regard to the employability of players across different stages of match-play and as such, aid in reducing injury risk and increasing performance."
 * Cost-utility of home-based fatigue self-management versus usual care for the treatment of chronic fatigue syndrome"Abstract - Background: Chronic fatigue syndrome (CFS) is a complex chronic condition with large negative impact on patients’ function and quality of life. Efficacy and cost-effectiveness of cognitive behavioral intervention remain inconclusive. Objective: To evaluate the cost-utility of a home-based fatigue self-management (FSM) intervention as compared to usual care among primary care patients with severe CFS. Methods: An economic evaluation alongside of a randomized controlled study design was used. Cost and utility data were collected from 137 patients with severe CFS at baseline and 1-year follow-up. The FSM group (n = 89) received self-delivered cognitive behavioral self-management intervention and the usual care group (n = 48) received regular medical care. Cost was measured by total costs (direct, indirect, and intervention costs) during the follow-up period. Quality-adjusted life years (QALY), as the utility measure, were derived from the Medical Outcomes Survey Short Form-36. A societal perspective was adopted. Bootstrapped incremental cost-utility ratios (ICURs) and net monetary benefit (NMB) were calculated as measures of cost-effectiveness. Results: Baseline individual characteristics were similar between the two groups. The intervention was well received by the participants with only minimum attrition. At the end of one-year post-intervention, FSM dominated usual care in terms of ICUR in both the intention-to-treat analysis and the complete-cases-only analysis. Net monetary benefit analysis showed that FSM has higher probability of achieving positive net monetary across the entire range of possible societal willingness to pay for fatigue symptom management. Conclusions: In primary care patients with severe CFS, the low-cost FSM appears to be a cost-effective treatment."
 * Chronic fatigue syndrome prevalence is grossly overestimated using Oxford criteria compared to Centers for Disease Control (Fukuda) criteria in a U.S. population study"Abstract - Background: Results from treatment studies using the low-threshold Oxford criteria for recruitment may have been overgeneralized to patients diagnosed by more stringent chronic fatigue syndrome (CFS) criteria. Purpose: To compare the selectivity of Oxford and Fukuda criteria in a U.S. population. Methods: Fukuda (Center for Disease Control (CDC)) criteria, as operationalized with the CFS Severity Questionnaire (CFSQ), were included in the nationwide rc2004 HealthStyles survey mailed to 6175 participants who were representative of the U.S. 2003 Census population. The 9 questionnaire items (CFS symptoms) were crafted into proxies for Oxford criteria (mild fatigue, minimal exclusions) and Fukuda criteria (fatigue plus ≥4 of 8 ancillary criteria at moderate or severe levels with exclusions). The comparative prevalence estimates of CFS were then determined. Severity scores for fatigue were plotted against the sum of severities for the eight ancillary criteria. The four quadrants of scatter diagrams assessed putative healthy controls, CFS, chronic idiopathic fatigue (CIF), and CFS-like with insufficient fatigue subjects. Results: The Oxford criteria designated CFS in 25.5% of 2004 males and 19.9% of 1954 females. Based on quadrant analysis, 85% of Oxford-defined cases were inappropriately classified as CFS. Fukuda criteria identified CFS in 2.3% of males and 1.8% of females. Discussion: CFS prevalence using Fukuda criteria and quadrant analysis was near the upper limits of previous epidemiology studies. The CFSQ may have utility for on-line and outpatient screening. The Oxford criteria were untenable because they inappropriately selected healthy subjects with mild fatigue and CIF and mislabeled them as CFS."
 * Article commentary - Mistaken conclusions about systemic exercise intolerance disease being comparable to research case definitions of CFS: A rebuttal to Chu et al."Abstract - The recent article by Chu et al. contrasted different case definitions that have been used to describe chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME). In particular, their study compared the new Institute of Medicine (IOM) criteria for systemic exertion intolerance disease (SEID) with three other ME and CFS case definitions. We appreciate these investigators attempting to use and operationalize the new IOM criteria; however, we disagree with their main conclusion that the percentage of patients selected by the IOM criteria is comparable to the percentage selected by other research case definitions. This conclusion could potentially encourage investigators to use the IOM criteria for research purposes. In this commentary, we discuss our observations of the Chu et al. article with respect to their methodology, illustrating how the conclusions of an investigation can be influenced by the manner in which case definitions are operationalized."
 * Article commentary - Differences of opinion on systemic exercise intolerance disease are not ‘mistakes’: a rejoinder to Jason Sunnquist, Gleason and Fox"Abstract -Differences of opinion about how case definitions are operationalized should not be characterized as ‘mistaken.’ Despite limitations, our study provides insight into how systemic exertion intolerance disease (SEID) criteria perform early in the course of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) compared to other case definitions. To facilitate early, accurate diagnosis, research needs to be performed, ideally, prospectively with subjects who have not been ill for years. In addition, results of past treatment studies may not be applicable to many ME/CFS patients because criteria used for research differed from patients’ clinical presentations. To avoid this potential mismatch between research employing the new clinically-focused SEID criteria should be promoted, rather than discouraged."