10 ms·

Attributes and predictors of long Covid

81 points by luu 6y ago

lofi_lory 6y ago
> Long COVID was characterized by symptoms of fatigue, headache, dyspnea and anosmia and was more likely with increasing age and body mass index and female sex. Experiencing more than five symptoms during the first week of illness was associated with long COVID. A bit disappointing information. So, first week severity indicates risk for long covid? Or is it multiorgan involvement independent from severity?
- wvh 6y ago
  It's surprising how long it takes to draw solid conclusions, considering the amount of "live" cases to draw from.
  - jacquesm 6y ago
    Why is that surprising? The whole descriptor 'long Covid' suggests that there is an element of time involved that is rather longer than the initial round of the disease itself. Many diseases take years to run their course, I would expect the real damage toll from long Covid to not be visible for years to come rather than that we would somehow be able to predict the course of the disease before we have real world data showing what it can be like. The number of cases has no effect on that at all.
    - jamesrcole 6y ago
      I think they probably mean that, if there’s lots of cases, then there’s (in principle) lots of available information to study, regarding whatever mechanisms are behind the long covid effects we’ve seen so far.
  - smhg 6y ago
    Indeed, also taking into consideration that the pandemic is the most pressing issue in many countries. It can't be a budgetary issue. Could someone shed some light on why these questions are so hard?
  - entropicdrifter 6y ago
    Ironically, an excessively large amount of raw data can make study harder, at least at first, since it can be difficult to scientifically discern what is a real case of long covid and what is the result of other external factors. Raw data abundance may seem like a good thing for study, but when people have time to build their own lore and superstitions, it can make scientific inquiry that much more difficult.
- tremon 6y ago
  Many severe long covid cases are benign in the acute phase. Multiorgan involvement seems to me like it 1) doesn't occur in the first week 2) doesn't occur in benign cases. Also, from the abstract: This model could be used to identify individuals at risk of long COVID for trials of prevention or treatment and to plan education and rehabilitation services. So this is not about "first week of illness indicates COVID severity" per se, this is about creating a prediction model to triage cases. It makes sense to focus on early symptoms for that.
- regularfry 6y ago
  You could get over the 5-symptom limit in this study just with knackered lungs.
  - mannykannot 6y ago
    If you do, you might have more pressing concerns that Long Covid if you are in the first week of an infection, and yet you might also be at higher risk for that as well.
- IfOnlyYouKnew 6y ago
  It's amount of symptoms, not severity.
vanderZwan 6y ago
Something I've noticed: when people in my surroundings bring up worries of long-term effects of the fast-tracked vaccines, they somehow tend to not consider the unknown long-term effects of covid. Even though the argument that we cannot know the long term effects yet should apply equally. When I bring this up they do seem receptive to this argument though, provided I'm not dismissive of their own skepticism. I'm not trying to convince them to get vaccinated, but I do wish that my friends stay safe until the pandemic is over at least, so I ask them to please be consistent and be worried about the unknown long-term effects of getting covid. Especially given that for the latter we do know that it's an actual disease that has already taken lots of lives and given lots of people long-term symptoms.
- greenwich26 6y ago
  You can't neglect the prior. In most European countries, somewhere around 5% of the population might have been infected with covid. Up to around 10% in the US. Therefore, to have comparable posterior probabilities for long-term side effects, you would need the side effects argument not to merely "apply equally", but to favour the vaccine over the disease by a factor of about 10.
  - vanderZwan 6y ago
    You're not wrong, but my priority is to ensure that my friends who rely on emotion-based arguments (fear of the unknown regarding the vaccines, dismissing the risks of covid and taking too few precautions as a result) to be safe and to not contribute to keeping the pandemic going. Going this deep into statistics would just lose them, because I'd come across as trying to intimidate them into taking my viewpoint on how to reason about these things. edit: apparently none of you have ever been accused of being an ivory tower jerk in their lives, explicitly or implicitly, ever? We're not talking about a discussion between people trying to weigh uncertainties based on what they do and do not know and working it out on a paper napkin. We're talking about people being overwhelmed by the complexity of it all and as a result starting from what they're most scared of and reasoning backwards from there. Which is how most people out there function, like it or not.
brb92 6y ago
> For the reduced logistic regression model, the score was given by the following formula: S = 0.259503 × NumberSymptoms + 0.055457 × age − 0.633310 × sex − 3.20 (where sex is encoded as 1 − female/2 − male) Where ‘NumberSymptoms’ corresponds to the sum of different symptoms experienced over the first week among the list of 14 symptoms reported on daily logs. This score was then transformed to a probability using the formula: 1/(1 + exp(−score)) > App users were disproportionately female, and those over 70 years of age were underrepresented, which could increase or decrease our estimate of the prevalence and duration of long COVID. So basically if the patient is a 30 y.o man with 7 symptoms has almost twice more chance of having long covid than a woman on the same conditions ? Hmmmmmmmmmmm
- greenwich26 6y ago
  Not an epidemiologist so don't weigh my opinion too highly, but as a data analyst, my first impression of this "model" is overfitted nonsense.
  - learnstats2 6y ago
    I checked the paper to try and defend it, but I was unable to find a table with significance testing or standard errors for this regression - it is just stated without justification. This seems an unusual style of reporting results, to me. (Happy to be corrected)
    - nharada 6y ago
      I don't see a table but Fig 3 presents 95% confidence intervals for the odds ratios in the logistic model.
- icegreentea2 6y ago
  Gender differences wouldn't be unheard of. Also, in that model, being male reduces your predicted probably of long COVID. This model does seem kinda wacky though. Just throwing in 1 symptom, age of 30, and female gives a probability of 13% which seems high. I'll have to read the paper more carefully to figure out what exactly that probability is supposed to mean.
Glench 6y ago
A related article about the long-term effects of any viral infection, including COVID: [Long Covid isn’t as unique as we thought](https://www.vox.com/22298751/long-term-side-effects-covid-19-hauler-symptoms https://www.vox.com/22298751/long-term-side-effects-covid-19...)
m0llusk 6y ago
One of the biggest risk factors for COVID and especially for poor outcomes is Vitamin D deficiency, but this study apparently didn't even check Vitamin D levels. That seems like a serious oversight.
- airhead969 6y ago
  My new PCP doctor threw shade on why I was taking 5000 IU of Vitamin D3 per day. I asked him why he wasn't considering Fauci and others take it for COVID outcome prophylaxis.
  - yyyk 6y ago
    Note that very high levels of vitamin D supplements are possibly linked to reduction of volumetric bone density[0]. Low levels make sense given most people are more housebound during the pandemic. [0] https://pubmed.ncbi.nlm.nih.gov/31454046/ https://pubmed.ncbi.nlm.nih.gov/31454046/ "Conclusions and relevance: Among healthy adults, treatment with vitamin D for 3 years at a dose of 4000 IU per day or 10 000 IU per day, compared with 400 IU per day, resulted in statistically significant lower radial BMD; tibial BMD was significantly lower only with the 10 000 IU per day dose. There were no significant differences in bone strength at either the radius or tibia. These findings do not support a benefit of high-dose vitamin D supplementation for bone health; further research would be needed to determine whether it is harmful."
- jdjdn827js 6y ago
  > One of the biggest risk factors for COVID and especially for poor outcomes is Vitamin D deficiency. Is it? How exactly is vitamin D deficiency measured and diagnosed? How much variance / tolerance is there between people. Most importantly does COVID impact Vitamin D levels? This may be a serious oversight. Or it may be that the Vitamin D thing is pseudoscience.
  - nradov 6y ago
    I recommend you read through all the studies indexed on this page and then get back to us. https://vitamin-d-covid.shotwell.ca/ https://vitamin-d-covid.shotwell.ca/
jokethrowaway 6y ago
Looking at the symptoms of long covid, I wonder how much of it is depression vs covid?

81 points by luu 6y ago

> Long COVID was characterized by symptoms of fatigue, headache, dyspnea and anosmia and was more likely with increasing age and body mass index and female sex. Experiencing more than five symptoms during the first week of illness was associated with long COVID. A bit disappointing information. So, first week severity indicates risk for long covid? Or is it multiorgan involvement independent from severity?

wvh 6y ago
It's surprising how long it takes to draw solid conclusions, considering the amount of "live" cases to draw from.
- jacquesm 6y ago
  Why is that surprising? The whole descriptor 'long Covid' suggests that there is an element of time involved that is rather longer than the initial round of the disease itself. Many diseases take years to run their course, I would expect the real damage toll from long Covid to not be visible for years to come rather than that we would somehow be able to predict the course of the disease before we have real world data showing what it can be like. The number of cases has no effect on that at all.
  - jamesrcole 6y ago
    I think they probably mean that, if there’s lots of cases, then there’s (in principle) lots of available information to study, regarding whatever mechanisms are behind the long covid effects we’ve seen so far.
- smhg 6y ago
  Indeed, also taking into consideration that the pandemic is the most pressing issue in many countries. It can't be a budgetary issue. Could someone shed some light on why these questions are so hard?
- entropicdrifter 6y ago
  Ironically, an excessively large amount of raw data can make study harder, at least at first, since it can be difficult to scientifically discern what is a real case of long covid and what is the result of other external factors. Raw data abundance may seem like a good thing for study, but when people have time to build their own lore and superstitions, it can make scientific inquiry that much more difficult.
tremon 6y ago
Many severe long covid cases are benign in the acute phase. Multiorgan involvement seems to me like it 1) doesn't occur in the first week 2) doesn't occur in benign cases. Also, from the abstract: This model could be used to identify individuals at risk of long COVID for trials of prevention or treatment and to plan education and rehabilitation services. So this is not about "first week of illness indicates COVID severity" per se, this is about creating a prediction model to triage cases. It makes sense to focus on early symptoms for that.
regularfry 6y ago
You could get over the 5-symptom limit in this study just with knackered lungs.
- mannykannot 6y ago
  If you do, you might have more pressing concerns that Long Covid if you are in the first week of an infection, and yet you might also be at higher risk for that as well.
IfOnlyYouKnew 6y ago
It's amount of symptoms, not severity.

vanderZwan 6y ago

Something I've noticed: when people in my surroundings bring up worries of long-term effects of the fast-tracked vaccines, they somehow tend to not consider the unknown long-term effects of covid. Even though the argument that we cannot know the long term effects yet should apply equally. When I bring this up they do seem receptive to this argument though, provided I'm not dismissive of their own skepticism. I'm not trying to convince them to get vaccinated, but I do wish that my friends stay safe until the pandemic is over at least, so I ask them to please be consistent and be worried about the unknown long-term effects of getting covid. Especially given that for the latter we do know that it's an actual disease that has already taken lots of lives and given lots of people long-term symptoms.

greenwich26 6y ago
You can't neglect the prior. In most European countries, somewhere around 5% of the population might have been infected with covid. Up to around 10% in the US. Therefore, to have comparable posterior probabilities for long-term side effects, you would need the side effects argument not to merely "apply equally", but to favour the vaccine over the disease by a factor of about 10.
- vanderZwan 6y ago
  You're not wrong, but my priority is to ensure that my friends who rely on emotion-based arguments (fear of the unknown regarding the vaccines, dismissing the risks of covid and taking too few precautions as a result) to be safe and to not contribute to keeping the pandemic going. Going this deep into statistics would just lose them, because I'd come across as trying to intimidate them into taking my viewpoint on how to reason about these things. edit: apparently none of you have ever been accused of being an ivory tower jerk in their lives, explicitly or implicitly, ever? We're not talking about a discussion between people trying to weigh uncertainties based on what they do and do not know and working it out on a paper napkin. We're talking about people being overwhelmed by the complexity of it all and as a result starting from what they're most scared of and reasoning backwards from there. Which is how most people out there function, like it or not.

brb92 6y ago

> For the reduced logistic regression model, the score was given by the following formula: S = 0.259503 × NumberSymptoms + 0.055457 × age − 0.633310 × sex − 3.20 (where sex is encoded as 1 − female/2 − male) Where ‘NumberSymptoms’ corresponds to the sum of different symptoms experienced over the first week among the list of 14 symptoms reported on daily logs. This score was then transformed to a probability using the formula: 1/(1 + exp(−score)) > App users were disproportionately female, and those over 70 years of age were underrepresented, which could increase or decrease our estimate of the prevalence and duration of long COVID. So basically if the patient is a 30 y.o man with 7 symptoms has almost twice more chance of having long covid than a woman on the same conditions ? Hmmmmmmmmmmm

greenwich26 6y ago
Not an epidemiologist so don't weigh my opinion too highly, but as a data analyst, my first impression of this "model" is overfitted nonsense.
- learnstats2 6y ago
  I checked the paper to try and defend it, but I was unable to find a table with significance testing or standard errors for this regression - it is just stated without justification. This seems an unusual style of reporting results, to me. (Happy to be corrected)
  - nharada 6y ago
    I don't see a table but Fig 3 presents 95% confidence intervals for the odds ratios in the logistic model.
icegreentea2 6y ago
Gender differences wouldn't be unheard of. Also, in that model, being male reduces your predicted probably of long COVID. This model does seem kinda wacky though. Just throwing in 1 symptom, age of 30, and female gives a probability of 13% which seems high. I'll have to read the paper more carefully to figure out what exactly that probability is supposed to mean.

Glench 6y ago

A related article about the long-term effects of any viral infection, including COVID: [Long Covid isn’t as unique as we thought](https://www.vox.com/22298751/long-term-side-effects-covid-19-hauler-symptoms https://www.vox.com/22298751/long-term-side-effects-covid-19...)

m0llusk 6y ago

One of the biggest risk factors for COVID and especially for poor outcomes is Vitamin D deficiency, but this study apparently didn't even check Vitamin D levels. That seems like a serious oversight.

airhead969 6y ago
My new PCP doctor threw shade on why I was taking 5000 IU of Vitamin D3 per day. I asked him why he wasn't considering Fauci and others take it for COVID outcome prophylaxis.
- yyyk 6y ago
  Note that very high levels of vitamin D supplements are possibly linked to reduction of volumetric bone density[0]. Low levels make sense given most people are more housebound during the pandemic. [0] https://pubmed.ncbi.nlm.nih.gov/31454046/ https://pubmed.ncbi.nlm.nih.gov/31454046/ "Conclusions and relevance: Among healthy adults, treatment with vitamin D for 3 years at a dose of 4000 IU per day or 10 000 IU per day, compared with 400 IU per day, resulted in statistically significant lower radial BMD; tibial BMD was significantly lower only with the 10 000 IU per day dose. There were no significant differences in bone strength at either the radius or tibia. These findings do not support a benefit of high-dose vitamin D supplementation for bone health; further research would be needed to determine whether it is harmful."
jdjdn827js 6y ago
> One of the biggest risk factors for COVID and especially for poor outcomes is Vitamin D deficiency. Is it? How exactly is vitamin D deficiency measured and diagnosed? How much variance / tolerance is there between people. Most importantly does COVID impact Vitamin D levels? This may be a serious oversight. Or it may be that the Vitamin D thing is pseudoscience.
- nradov 6y ago
  I recommend you read through all the studies indexed on this page and then get back to us. https://vitamin-d-covid.shotwell.ca/ https://vitamin-d-covid.shotwell.ca/

jokethrowaway 6y ago

Looking at the symptoms of long covid, I wonder how much of it is depression vs covid?