Category: Epidemiology

Demographic and clinical aspects of an Italian patient population with chronic fatigue syndrome

Abstract:

OBJECTIVE: The purpose of this study was to investigate demographic and clinical aspects of a group of Italian patients with Chronic Fatigue Syndrome (CFS) which have not yet been described, in order to compare them with International literature, and to better define certain clinical aspects of the syndrome with respect to the Fukuda et al. case definition.

METHODS: A detailed questionnaire was sent to patients with certified CFS diagnosed in a referral center and the data were collected two weeks later.

RESULTS AND CONCLUSIONS: Besides persistent fatigue, a clinical syndrome with infectious, neurological and rheumatological characteristics is outlined from the data. Demographic characteristics of Italian patients are very similar to those described in international literature. Therapy has yet to be validated with evidence-based studies in Italy. Studies on the prevalence of CFS in Italy are lacking and would be useful to better define the syndrome in this Mediterranean population.

 

Source: Carlo-Stella N, Cuccia M. Demographic and clinical aspects of an Italian patient population with chronic fatigue syndrome. Reumatismo. 2009 Oct-Dec;61(4):285-9. http://www.reumatismo.org/index.php/reuma/article/view/reumatismo.2009.285/440 (Full article)

 

Chronic fatigue syndrome is associated with metabolic syndrome: results from a case-control study in Georgia

Abstract:

We hypothesized that persons with chronic fatigue syndrome (CFS) would have a higher prevalence of metabolic syndrome compared with well controls, and that unwell persons with insufficient symptoms or fatigue for CFS (termed ISF) would have a prevalence of metabolic syndrome intermediate between those with CFS and the controls. We also sought to examine the relationship between metabolic syndrome and measures of functional impairment, fatigue, and other symptoms.

Our analysis was based on a population-based case-control study conducted in metropolitan, urban, and rural areas of Georgia, United States, between September 2004 and July 2005. There were 111 persons with CFS, 259 with ISF, and 123 controls.

Metabolic syndrome was determined based on having at least 3 of 5 standard risk components (abdominal obesity, high triglycerides, high blood pressure, elevated fasting glucose, and decreased high-density lipids) according to the National Cholesterol Education Program Adult Treatment Panel III definition.

Persons with CFS were 2-fold as likely to have metabolic syndrome (odds ratio = 2.12, confidence interval = 1.06, 4.23) compared with the controls. There was a significant graded relationship between the number of metabolic syndrome factors and CFS; each additional factor was associated with a 37% increase in likelihood of having CFS. The association of ISF with metabolic syndrome was weaker (odds ratio = 1.72, confidence interval = 0.94-3.16).

Among persons with CFS, the number of metabolic syndrome factors was significantly correlated with worse fatigue on a standardized summary measure of fatigue (r = 0.20, P = .04). In conclusion, CFS was associated with metabolic syndrome, which further exacerbated fatigue.

 

Source: Maloney EM, Boneva RS, Lin JM, Reeves WC. Chronic fatigue syndrome is associated with metabolic syndrome: results from a case-control study in Georgia. Metabolism. 2010 Sep;59(9):1351-7. doi: 10.1016/j.metabol.2009.12.019. Epub 2010 Jan 27. https://www.ncbi.nlm.nih.gov/pubmed/20102774

 

Fatigue and chronic fatigue syndrome-like complaints in the general population

Abstract:

BACKGROUND: Most knowledge on chronic fatigue (CF) and chronic fatigue syndrome (CFS) is based on clinical studies, not representative of the general population. This study aimed to assess the prevalence of fatigue in an adult general population and to identify associations with lifestyle factors.

METHODS: Total 22,500 residents of Nijmegen were selected at random and interviewed by questionnaire. Data on 9062 respondents (43% response) were analysed, taken into account age, gender and concomitant disease. Subjects were classified into four groups: not fatigued (NF, reference group), short-term fatigue (SF, <6 months), chronic fatigue (CF, >or=6 months) and CFS-like fatigue (in accordance with the Center for Disease Control criteria for CFS, without clinical confirmation).

RESULTS: Our study population showed the following breakdown: NF 64.4% (95% CI 63.6-65.6%), SF 4.9% (95% CI 4.5-5.4%), CF 30.5% (95% CI 29.5-31.4%) and CFS-like fatigue 1.0% (95% CI 0.8-1.2%). Compared with the NF group, more of the CFS respondents were female [odds ratio (OR) = 1.9], obese (OR = 4.1), using analgesics (OR = 7.8), had a low alcohol intake (OR = 0.4), were eating less healthy food (OR = 0.5) and were physically less active (OR = 0.1). These associations largely applied to the SF and CF group. The fatigue could have been due to a concomitant disease in 34 and 55.5% of the SF and CF cases, respectively.

CONCLUSION: The prevalence of CF in the general population appears to be much higher than previously indicated. Even with strict criteria for CFS, it is estimated that approximately 1% of the adult population experiences this condition. Interestingly, a large part of this group remains unrecognized by the general practitioner. A striking similarity in lifestyle pattern between SF, CF and CFS calls for further research.

 

Source: van’t Leven M, Zielhuis GA, van der Meer JW, Verbeek AL, Bleijenberg G. Fatigue and chronic fatigue syndrome-like complaints in the general population. Eur J Public Health. 2010 Jun;20(3):251-7. doi: 10.1093/eurpub/ckp113. Epub 2009 Aug 18. http://eurpub.oxfordjournals.org/content/20/3/251.long (Full article)

 

A comparison of patients with chronic fatigue syndrome in two “ideologically” contrasting clinics

Abstract:

Aim of the present study was to compare chronic fatigue syndrome (CFS) patients, attending 2 “ideologically” contrasting clinics for CFS, on various patient and illness characteristics. Fifty-nine CFS patients of each clinic, located in Leuven and Brussels (Belgium), participated. Patients did not differ with regard to age, levels of fatigue, psychopathology, and self-efficacy. However, patients from the psychosocially-oriented clinic had a lower level of education, reported more progressive illness onset, and attributed their illness more to psychological causes.

Patients in the biologically-oriented clinic reported more pain, and showed higher levels of social functioning, motivation and vitality, as well as fewer limitations related to emotional problems. It is concluded that CFS patients attending the 2 clinics could not be distinguished along dualistic biological/psychosocial lines, but those reporting sudden illness onset and making somatic attributions were more likely to be represented in the biologically-oriented clinic.

 

Source: Van Houdenhove B, Van Hoof E, Becq K, Kempke S, Luyten P, De Meirleir K.A comparison of patients with chronic fatigue syndrome in two “ideologically” contrasting clinics. J Nerv Ment Dis. 2009 May;197(5):348-53. doi: 10.1097/NMD.0b013e3181a2081f. https://www.ncbi.nlm.nih.gov/pubmed/19440108

 

A systematic review of chronic fatigue, its syndromes and ethnicity: prevalence, severity, co-morbidity and coping

Abstract:

BACKGROUND: Chronic Fatigue Syndrome (CFS) is characterized by unexplained fatigue that lasts for at least 6 months alongside a constellation of other symptoms. CFS was historically thought to be most common among White women of higher socio-economic status. However, some recent studies in the USA suggest that the prevalence is actually higher in some minority ethnic groups. If there are convincing differences in prevalence and risk factors across all or some ethnic groups, investigating the causes of these can help unravel the pathophysiology of CFS.

METHODS: A systematic review was conducted to explore the relationship between fatigue, chronic fatigue (CF–fatigue lasting for 6 months), CFS and ethnicity. Studies were population-based and health service-based. Meta-analysis was also conducted to examine the population prevalence of CF and CFS across ethnic groups.

RESULTS: Meta-analysis showed that compared with the White American majority, African Americans and Native Americans have a higher risk of CFS [Odds Ratio (OR) 2.95, 95% confidence interval (CI): 0.69-10.4; OR = 11.5, CI: 1.1-56.4, respectively] and CF (OR = 1.56, CI: 1.03-2.24; OR = 3.28, CI: 1.63-5.88, respectively). Minority ethnic groups with CF and CFS experience more severe symptoms and may be more likely to use religion, denial and behavioural disengagement to cope with their condition compared with the White majority.

CONCLUSIONS: Although available studies and data are limited, it does appear that some ethnic minority groups are more likely to suffer from CF and CFS compared with White people. Ethnic minority status alone is insufficient to explain ethnic variation of prevalence. Psychosocial risk factors found in high-risk groups and ethnicity warrant further investigation to improve our understanding of aetiology and the management of this complex condition.

 

Source: Dinos S, Khoshaba B, Ashby D, White PD, Nazroo J, Wessely S, Bhui KS. A systematic review of chronic fatigue, its syndromes and ethnicity: prevalence, severity, co-morbidity and coping. Int J Epidemiol. 2009 Dec;38(6):1554-70. doi: 10.1093/ije/dyp147. Epub 2009 Apr 6. http://ije.oxfordjournals.org/content/38/6/1554.long (Full article)

 

Comparative epidemiology of chronic fatigue syndrome in Brazilian and British primary care: prevalence and recognition

Abstract:

BACKGROUND: Although fatigue is a ubiquitous symptom across countries, clinical descriptions of chronic fatigue syndrome have arisen from a limited number of high-income countries. This might reflect differences in true prevalence or clinical recognition influenced by sociocultural factors.

AIMS: To compare the prevalence, physician recognition and diagnosis of chronic fatigue syndrome in London and São Paulo.

METHOD: Primary care patients in London (n=2459) and São Paulo (n=3914) were surveyed for the prevalence of chronic fatigue syndrome. Medical records were reviewed for the physician recognition and diagnosis.

RESULTS: The prevalence of chronic fatigue syndrome according to Centers for Disease Control 1994 criteria was comparable in Britain and Brazil: 2.1% v. 1.6% (P=0.20). Medical records review identified 11 diagnosed cases of chronic fatigue syndrome in Britain, but none in Brazil (P<0.001).

CONCLUSIONS: The primary care prevalence of chronic fatigue syndrome was similar in two culturally and economically distinct nations. However, doctors are unlikely to recognise and label chronic fatigue syndrome as a discrete disorder in Brazil. The recognition of this illness rather than the illness itself may be culturally induced.

Comment in: Diagnosing chronic fatigue syndrome. [Br J Psychiatry. 2009]

 

Source: Cho HJ, Menezes PR, Hotopf M, Bhugra D, Wessely S. Comparative epidemiology of chronic fatigue syndrome in Brazilian and British primary care: prevalence and recognition. Br J Psychiatry. 2009 Feb;194(2):117-22. doi: 10.1192/bjp.bp.108.051813. http://bjp.rcpsych.org/content/194/2/117.long (Full article)

 

CFS: A Review of Epidemiology and Natural History Studies

Abstract:

Almost all studies with samples of patients who have chronic fatigue syndrome (CFS) have relied on referrals from physicians or health facilities. Under-served minorities, who not only tend to manifest higher levels of chronic illness, but are also less likely to seek and receive adequate medical care, have not been represented in these studies (1). This may have contributed to an under-estimation of CFS among minority groups (2). Few studies have derived their samples from socioeconomically and ethnically diverse community-based populations. A technical report issued by the Agency for Healthcare Research and Quality (3) concluded that estimating rates of recovery/improvement or relapse from CFS are not possible because there are so few natural history studies and those that are available have involved selected referral populations.

This paper provides a review of epidemiologic studies of CFS followed by a discussion of diagnostic issues and risk factors for the illness. Findings from Jason et al.’s (4) epidemiologic study in a multi-ethnic, economically diverse urban area are highlighted as this research group is now examining the natural course of CFS over the past 10 years with this community-based sample. The current study will add to current epidemiologic and risk factors research by assessing the course, progression, and risk factors of CFS among a demographically diverse sample of participants who are unbiased by illness, help-seeking behaviors, or differential access to the health care system.

 

Source: Jason LA, Porter N, Brown M, Anderson V, Brown A, Hunnell J, Lerch A. CFS: A Review of Epidemiology and Natural History Studies. Bull IACFS ME. 2009;17(3):88-106. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3021257/ (Full article)

 

The awareness of chronic fatigue syndrome: a comparative study in Brazil and the United Kingdom

Abstract:

OBJECTIVE: While in many Western affluent countries there is widespread awareness of chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME), little is known about the awareness of CFS/ME in low- and middle-income countries. We compared the awareness of CFS in Brazil and the United Kingdom.

METHODS: Recognition and knowledge of CFS were assessed among 120 Brazilian specialist doctors in two major university hospitals using a typical case vignette of CFS. We also surveyed 3914 and 2435 consecutive attenders in Brazilian and British primary care clinics, respectively, concerning their awareness of CFS.

RESULTS: When given a typical case vignette of CFS, only 30.8% [95% confidence interval (CI), 22.7-39.9%] of Brazilian specialist doctors mentioned chronic fatigue or CFS as a possible diagnosis, a proportion substantially lower than that observed in Western affluent countries. Similarly, only 16.2% (95% CI, 15.1-17.4%) of Brazilian primary care attenders were aware of CFS, in contrast to 55.1% (95% CI, 53.1-57.1%) of their British counterparts (P<.001). This difference remained highly significant after controlling for patients’ sociodemographic and socioeconomic characteristics (P<.001).

CONCLUSIONS: The awareness of CFS was substantially lower in Brazil than the United Kingdom. The observed difference may influence patients’ help-seeking behavior and both doctors’ and patients’ beliefs and attitudes in relation to fatigue-related syndromes. Attempts to promote the awareness of CFS should be considered in Brazil, but careful plans are required to ensure the delivery of sound evidence-based information.

 

Source: Cho HJ, Menezes PR, Bhugra D, Wessely S. The awareness of chronic fatigue syndrome: a comparative study in Brazil and the United Kingdom. J Psychosom Res. 2008 Apr;64(4):351-5. doi: 10.1016/j.jpsychores.2007.12.006. https://www.ncbi.nlm.nih.gov/pubmed/18374733

 

Fatigue among Spanish- and English-speaking Latinos

Abstract:

The present study investigated sociodemographic differences, fatigue severity, and the occurrence of prolonged or chronic fatigue reported by Spanish-speaking and English-speaking Latinos. The sample included 2,102 English-speaking Latinos and 1,348 Spanish-speaking Latinos interviewed as part of an epidemiological study of persons with chronic fatigue syndrome in the Chicago area. Results indicated that English-speaking Latinos scored higher on measure of fatigue than Spanish-speaking Latinos. Further, language status continued to be a predictor of fatigue level even when controlling for other sociodemographic differences found between the groups. Findings suggest that language spoken in Latino populations is important in predicting fatigue, and point to the potential importance of cultural factors such as acculturation or acculturative stresses.

 

Source: Torres-Harding SR, Mason-Shutter J, Jason LA. Fatigue among Spanish- and English-speaking Latinos. Soc Work Public Health. 2008;23(5):55-72. doi: 10.1080/19371910802053232. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2913726/ (Full article)

Risk factors for chronic fatigue syndrome/myalgic encephalomyelitis: a systematic scoping review of multiple predictor studies

Abstract:

BACKGROUND: The aetiology of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is still unknown. The identification of risk factors for CFS/ME is of great importance to practitioners.

METHOD: A systematic scoping review was conducted to locate studies that analysed risk factors for CFS/ME using multiple predictors. We searched for published and unpublished literature in 11 electronic databases, reference lists of retrieved articles and guideline stakeholder submissions in conjunction with the development of a forthcoming national UK guideline. Risk factors and findings were extracted in a concise tabular overview and studies synthesized narratively.

RESULTS: Eleven studies were identified that met inclusion criteria: two case-control studies, four cohort studies, three studies combining a cohort with a case-control study design, one case-control and twin study and one cross-sectional survey. The studies looked at a variety of demographic, medical, psychological, social and environmental factors to predict the development of CFS/ME. The existing body of evidence is characterized by factors that were analysed in several studies but without replication of a significant association in more than two studies, and by studies demonstrating significant associations of specific factors that were not assessed in other studies. None of the identified factors appear suitable for the timely identification of patients at risk of developing CFS/ME within clinical practice.

CONCLUSIONS: Various potential risk factors for the development of CFS/ME have been assessed but definitive evidence that appears meaningful for clinicians is lacking.

 

Source: Hempel S, Chambers D, Bagnall AM, Forbes C. Risk factors for chronic fatigue syndrome/myalgic encephalomyelitis: a systematic scoping review of multiple predictor studies. Psychol Med. 2008 Jul;38(7):915-26. Epub 2007 Sep 25. https://www.ncbi.nlm.nih.gov/pubmed/17892624