Long Covid Symptom Clusters, Correlates and Predictors in a Highly Vaccinated Australian Population in 2023, 2025, Tawfiq+

[SNT Gatchaman]

Long Covid Symptom Clusters, Correlates and Predictors in a Highly Vaccinated Australian Population in 2023
Essa Tawfiq; Rosalie Chen; Damian Alexander Honeyman; Rebecca Dawson; Mohana Kunasekaran; Adriana Notaras; Deepti Gurdasani; Helen Skouteris; Darshini Ayton; Chandini Raina MacIntyre

BACKGROUND
Limited data exists regarding long Covid burden following Omicron infection in highly vaccinated populations.

OBJECTIVE
To (1) characterise long Covid prevalence and predictors and (2) identify key symptom clusters and their correlates among long Covid patients, during an Omicron-predominant period in a highly vaccinated population.

DESIGN
Anonymous, online, cross-sectional survey.

SETTING
January 2023, Australia.

PARTICIPANTS
Residents aged ≥ 18 years with self-reported history of test-positive Covid-19.

The main variables studied were socio-demographic characteristics, Covid-19 risk factors, vaccination, infection history and experiences with long Covid.

MAIN OUTCOME MEASURES
Long Covid symptoms. Symptom-based clustering was used to identify long Covid symptom clusters and their functional correlates. Predictors of long Covid occurrence and severity were assessed using multivariable logistic regression.

RESULTS
Overall, 240/1205 participants (19.9%) reported long Covid. Long Covid risk was significantly higher for women OR 1.71 (95% CI: 1.17–2.51), people with comorbidities 2.19 (95% CI: 1.56–3.08) and those using steroid inhalers for Covid-19 treatment (2.34 [95% CI: 1.29–4.24]). Long-Covid risk increased with increasing Covid-19 infection severity (moderately severe symptoms: 2.23 [95% CI: 1.50–3.30], extremely severe symptoms: 5.80 [95% CI: 3.48–9.66], presented to ED/hospitalised: 7.22 [95% CI: 3.06–17.03]). We found no significant difference in the likelihood of long Covid between the Omicron and pre-Omicron periods, vaccination status and participant age.

We identified two long Covid clusters (pauci-symptomatic, n = 170, vs. polysymptomatic, n = 66). Polysymptomatic cluster membership was associated with worse functioning (impacts on work, moderate activity, emotions and energy). Severity acute infection was strongly predictive of polysymptomatic cluster membership (5.72 [2.04–17.58]). Monoclonal antibody treatment was strongly associated with pauci-symptomatic cluster membership (0.02 [0.00–0.13]).

DISCUSSION
Our study shows that long Covid is an important health burden in Australia, including during the Omicron era, and identifies several risk factors. We found a subgroup of patients characterised by more symptoms and worse functional outcomes. Our findings can inform policies for protecting vulnerable populations and frameworks for long Covid risk assessment and management.

CONCLUSIONS
One-in-five people may suffer long Covid after acute Covid-19 infection, with similar risk across age groups. Omicron variants appear not to have a lower risk compared to earlier variants in our study. A cumulative number of symptoms can help triage long Covid patients.

PATIENT OR PUBLIC CONTRIBUTION
We did not involve patients or the public in the design of the questionnaire. However, after a soft launch, we revised some survey questions by reviewing early responses from patients and the public.

Link | PDF (Health Expectations) [Open Access]

 

[Utsikt]

We found no significant difference in the likelihood of long Covid between the Omicron and pre-Omicron periods, vaccination status and participant age.

That’s a bit surprising about vaccine and age.

Monoclonal antibody treatment was strongly associated with pauci-symptomatic cluster membership (0.02 [0.00–0.13]).

I wonder what that was. I’ll check the article later.

PATIENT OR PUBLIC CONTRIBUTION
We did not involve patients or the public in the design of the questionnaire. However, after a soft launch, we revised some survey questions by reviewing early responses from patients and the public.

Better late than never - but I hope they learned their lesson!

 

[Utsikt]

In multivariate analysis of predictors of polysymptomatic cluster membership, having Severity of acute infection (extremely severe symptoms in acute infection) was significantly associated with cluster membership (OR = 5.72, 95% CI: 2.04–17.58, p = 0.001), and monoclonal antibody treatment was significantly associated with pauci-symptomatic cluster membership (OR = 0.02, 95% CI: 0.00–0.13, p = 0.0001) (Figure 4).

Monoclonal antibodies were found to be associated with an increased risk of long Covid. This is likely due to residual confounding by the presence of health conditions and acute Covid-19 severity, which was associated both with antiviral use, monoclonal antibody use and a higher probability of long Covid. Stratifying by the number of comorbidities rendered the association between monoclonal antibodies and long Covid non-significant (with effect size reduced), although this may also be partly due to reduced statistical power due to smaller numbers within strata.

Regarding the clustering analysis based on long Covid symptoms experienced, it is possible that the milder symptom profile in the pauci-symptomatic cluster may be a result of treatment received, as we found a strong association with monoclonal antibody treatment. We note that while the pauci-symptomatic cluster is strongly associated with treatment, causality cannot be inferred, given the cross-sectional and observational nature of our survey.

I can’t find any info on what kind of monoclonal antibody that was used.

 

[Arnie Pye]

The main variables studied were socio-demographic characteristics, Covid-19 risk factors, vaccination, infection history and experiences with long Covid.

Why bother looking into socio-demographic characteristics? It reeks of wanting to blame one particular class of people for their own health problems. And the class to be blamed for their own problems is usually the poor and working class. And what are they going to do if it turns out that the majority of people with Long Covid are poor? Are they going to give them more money or better living conditions (sarcasm)? Or just a questionnaire so they can keep blaming the poor without changing their circumstances one iota?

I've never yet seen any research about Long Covid where practical things like triiodothyronine (T3 - the active thyroid hormone that researchers say is not important *rolls eyes* probably because it costs more than they want to spend if it turned out to be relevant) is tested, or iron and ferritin levels before and after infection are tested. It all seems to be geared towards blaming the patient and finding things to investigate that can't be treated.

What about Vitamins and Minerals? Can anyone say for certain that some patient's vitamins or minerals have or haven't been trashed as a result of Covid. Something physical for goodness sake, that can actually be improved if a relationship is found during research.

The amount of wasted time, effort, and money to achieve absolutely nothing is just jaw-dropping. It must have cost billions, only to give some researchers a pension, or some students a degree. It will never amount to anything useful.

 

[Sean]

The real take away message is that the major risk factor is extremely severe acute Covid infection.