Estimates of Incidence and Predictors of Fatiguing Illness after SARS-CoV-2 Infection, 2023, Vu, Unger et al

Abstract

This study aimed to estimate the incidence rates of post–COVID-19 fatigue and chronic fatigue and to quantify the additional incident fatigue caused by COVID-19. We analyzed electronic health records data of 4,589 patients with confirmed COVID-19 during February 2020–February 2021 who were followed for a median of 11.4 (interquartile range 7.8–15.5) months and compared them to data from 9,022 propensity score–matched non–COVID-19 controls.

Among COVID-19 patients (15% hospitalized for acute COVID-19), the incidence rate of fatigue was 10.2/100 person-years and the rate of chronic fatigue was 1.8/100 person-years. Compared with non–COVID-19 controls, the hazard ratios were 1.68 (95% CI 1.48–1.92) for fatigue and 4.32 (95% CI 2.90–6.43) for chronic fatigue. The observed association between COVID-19 and the significant increase in the incidence of fatigue and chronic fatigue reinforces the need for public health actions to prevent SARS-CoV-2 infections.

Open access: https://wwwnc.cdc.gov/eid/article/30/3/23-1194_article

 

CDC study, mentions of ME/CFS:

A substantial percentage of patients with fatigue remain ill for many months with an illness similar to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) (5), an unexplained syndrome sometimes seen after infections that is characterized by functional limitations that impair patients’ ability to maintain daily activities and is associated with profound fatigue (6).

(...)

This study also provides new estimates of incidence rate of chronic fatigue, including ME/CFS after COVID-19 illness. The incidence rate of 1.8/100 person-years is notable, as is the observation that chronic fatigue diagnoses continued in the 18 months of follow-up after COVID-19 detection. The extended period of incident chronic fatigue occurrences suggests a persistent effect but could also indicate a delay in diagnosing fatigue as a separate symptom or diagnosis. The hazard ratio for chronic fatigue (4.32, 95% CI 2.90–6.43) indicates that COVID-19 illness results in 4.3 times the risk for chronic fatigue compared with non–COVID-19 group.

That increase is similar to findings from a study of chronic fatigue syndrome in Germany (IRR 3.04, 95% CI 2.66–3.48) (19). Although chronic fatigue is not the same as chronic fatigue syndrome or ME/CFS, which requires additional symptoms for diagnosis, including activity limitation, postexertional malaise, unrefreshing sleep, and either cognitive impairment or orthostatic intolerance (20), the ICD-9 and ICD-10 codes used for the diagnosis of ME/CFS were included in the diagnostic codes used to define the chronic fatigue diagnosis. The recently implemented diagnostic code G93.32 for ME/CFS when used in conjunction with code U09.9, post COVID-19 condition, will be instrumental in identifying COVID-19–related ME/CFS in future research (21).​

 

Whoops, forgot to add the link, it is added now!

 

"In this study, chronic fatigue is a subset of fatigue, defined as having any of the following 3 ICD-10-CM or ICD-9-CM codes recorded in the EHR during the postacute period: G93.3, postviral fatigue syndrome; R53.82, chronic fatigue, unspecified; and 780.71, chronic fatigue syndrome/postviral fatigue syndrome. We defined incident chronic fatigue as a patient who had >1 diagnostic code for chronic fatigue during the postacute period."

 

"This study also provides new estimates of incidence rate of chronic fatigue, including ME/CFS after COVID-19 illness. The incidence rate of 1.8/100 person-years is notable, as is the observation that chronic fatigue diagnoses continued in the 18 months of follow-up after COVID-19 detection. The extended period of incident chronic fatigue occurrences suggests a persistent effect but could also indicate a delay in diagnosing fatigue as a separate symptom or diagnosis. The hazard ratio for chronic fatigue (4.32, 95% CI 2.90–6.43) indicates that COVID-19 illness results in 4.3 times the risk for chronic fatigue compared with non–COVID-19 group. That increase is similar to findings from a study of chronic fatigue syndrome in Germany (IRR 3.04, 95% CI 2.66–3.48) (19). Although chronic fatigue is not the same as chronic fatigue syndrome or ME/CFS, which requires additional symptoms for diagnosis, including activity limitation, postexertional malaise, unrefreshing sleep, and either cognitive impairment or orthostatic intolerance (20), the ICD-9 and ICD-10 codes used for the diagnosis of ME/CFS were included in the diagnostic codes used to define the chronic fatigue diagnosis. The recently implemented diagnostic code G93.32 for ME/CFS when used in conjunction with code U09.9, post COVID-19 condition, will be instrumental in identifying COVID-19–related ME/CFS in future research (21)."

So if chronic fatigue is not the same as ME/CFS why include ME/CFS in the chronic fatigue group?

"We found many diseases and conditions to be associated with post–COVID-19 fatigue. Those associations might provide useful prognostic information for the assessment of patients with COVID-19. Patients with mood disorders were previously reported to be at higher risk for illness and death during acute COVID-19 and increased risk of needing postacute care (22). Our findings indicate that patients with a history of mood disorders are also at increased risk for post–COVID-19 fatigue. The association of post–COVID-19 fatigue with pain syndromes and sleep disorders is supported by previous research in non–COVID-19 populations (23)."

And while they "found many diseases and conditions to be associated with post–COVID-19 fatigue" they didn't include them in the fatigue group....

 

I guess they may be thinking that, though ‘chronic fatigue’ does not necessitate ME/CFS, ME/CFS does imply the presence of ongoing ‘chronic fatigue’. That they make this distinction is a step forward, but by the same logic, as @Andy says, they should then also include in their ‘chronic fatigue group’ those with other chronic conditions following on from the acute infection such as lung damage or cardiac issues as these are also likely to cause ongoing fatigue issues.

Even when it is grasped that the symptom of chronic fatigue is distinct from the condition of ME/CFS unfortunately it is not recognised that this is a nonspecific symptom linked to a large number other medical conditions too. The issue is deciding when it is useful to group patients by symptom and when that is misleading or unhelpful, would you lump chronic headaches associated with brain tumours together with chronic migraine or food intolerances and send them all to general pain clinic or would you send them to a service aimed at treating the underlying condition?

 

That hasn't copied across correctly. This is what it says:

i.e. 1 or more

 

LA Times newspaper article:
"Risk for chronic fatigue soars among those who had #COVID19, study says"
https://www.latimes.com/california/...igue-soars-among-covid-19-patients-study-says

 

I think this is the crux. The report was about "fatiguing illness", not post-viral fatigue syndrome or MECFS, presumably to warn clinicians and policy makers about patients with post-covid fatigues. But it doesn't tell them much about what to do since it lumps them all into one. In fact, it is more likely to cause them to treat all fatigues the same way, which could prove to be detrimental for those with post-COVID MECFS.

 

A PDF version of the paper is now available:
https://wwwnc.cdc.gov/eid/article/30/3/pdfs/23-1194.pdf

[That's the way I like to save papers rather than trying to save webpages]