Epidemiologic Features of Recovery From SARS-CoV-2 Infection, 2024, Oelsner, Balte et al

[rvallee]

Epidemiologic Features of Recovery From SARS-CoV-2 Infection
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2820087


Findings In this cohort study of 4708 participants in a US meta-cohort, the median self-reported time to recovery from SARS-CoV-2 infection was 20 days, and an estimated 22.5% had not recovered by 90 days. Women and adults with suboptimal prepandemic health, particularly clinical cardiovascular disease, had longer times to recovery, whereas vaccination prior to infection and infection during the Omicron variant wave were associated with shorter times to recovery.

Results Of 4708 participants with self-reported SARS-CoV-2 infection (mean [SD] age, 61.3 [13.8] years; 2952 women [62.7%]), an estimated 22.5% (95% CI, 21.2%-23.7%) did not recover by 90 days post infection. Median (IQR) time to recovery was 20 (8-75) days. By 90 days post infection, there were significant differences in restricted mean recovery time according to sociodemographic, clinical, and lifestyle characteristics, particularly by acute infection severity (outpatient vs critical hospitalization, 32.9 days [95% CI, 31.9-33.9 days] vs 57.6 days [95% CI, 51.9-63.3 days]; log-rank P < .001). Recovery by 90 days post infection was associated with vaccination prior to infection (hazard ratio

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, 1.30; 95% CI, 1.11-1.51) and infection during the sixth (Omicron variant) vs first wave (HR, 1.25; 95% CI, 1.06-1.49). These associations were mediated by reduced severity of acute infection (33.4% and 17.6%, respectively). Recovery was unfavorably associated with female sex (HR, 0.85; 95% CI, 0.79-0.92) and prepandemic clinical cardiovascular disease (HR, 0.84; 95% CI, 0.71-0.99). No significant multivariable-adjusted associations were observed for age, educational attainment, smoking history, obesity, diabetes, chronic kidney disease, asthma, chronic obstructive pulmonary disease, or elevated depressive symptoms. Results were similar for reinfections.

Conclusions and Relevance In this cohort study, more than 1 in 5 adults did not recover within 3 months of SARS-CoV-2 infection. Recovery within 3 months was less likely in women and those with preexisting cardiovascular disease and more likely in those with COVID-19 vaccination or infection during the Omicron variant wave.

 

[rvallee]

"Results were similar for reinfections" suggests that every infection is another roll of the dice / pulling the trigger.

So the only known risk factors would be half the population and common health problems, but only by about 15%.

The main protective factor of vaccines appears to be reducing severity of acute illness, but it's not a sure thing, and their uptake will only go down with time.

 

[Hutan]

No significant multivariable-adjusted associations were observed for age, educational attainment, smoking history, obesity, diabetes, chronic kidney disease, asthma, chronic obstructive pulmonary disease, or elevated depressive symptoms.

Worth noting - obesity didn't increase odds, nor a history of 'elevated depressive symptoms'.

 

[Hutan]

This report describes the epidemiologic features of recovery from SARS-CoV-2 over the first 3 years of the US pandemic period in 14 longstanding cohort studies that included diverse participants from across the US.12Compared with studies leveraging electronic health records,8,13,14 our prospective study design includes infections diagnosed at home, which is currently mainstream and recommended practice,15 and offers reliable prepandemic measures of preinfection health and lifestyle factors. Using these unique longitudinal data, we investigated temporal trends in, and prepandemic and pandemic-era factors associated with, time to recovery from SARS-CoV-2 infection.

This cohort study uses data from the Collaborative Cohort of Cohorts for COVID-19 Research (C4R), a nationwide prospective meta-cohort of adults comprising 14 established prospective, National Institutes of Health–funded cohort studies

This report includes participants with self-reported nonfatal SARS-CoV-2 infection and information on recovery status ascertained by questionnaires administered from April 1, 2020, through February 28, 2023.

Of 53 143 eligible participants, 49 319 (92.8%) responded to at least 1 C4R questionnaire, of whom 6980 (14.2%) reported a history of first nonfatal SARS-CoV-2 infection and 5036 of these (72.1%) provided information on time to recovery. Excluding asymptomatic and fatal cases, there were 4708 participants included in the main analysis

I think this potentially is one of the better studies we have seen - prospective, very large, multiple cohorts. I'm just not sure why the people with reported SARS-CoV-2 infection were such a low percentage (14.2%) of the people who responded to the questionnaire. Given this study was done over the first 3 years, I would have expected a much higher percentage.

I'm also not sure why they would exclude asymptomatic cases from the main analysis.

 

[Hutan]

The mean (SD) age of the analytic sample was 61.3 (13.8) years in 2020;

Note the high mean age of the sample.

Infections occurred across 6 pandemic waves (Figure 1). Hospitalized participants numbered 597 (12.6%), and 148 (3.1%) required critical care. There were 3825 confirmed infections (81.2%) (eTable 5 in Supplement 1). Vaccination prior to infection was reported by 966 participants (20.5%), of whom 57 (5.9%) had received only 1 mRNA vaccine dose.

Vaccination prior to infection was also very low (20.5%) - making me think that most of the surveys must have been sent out earlier rather than later. I think that low level of vaccination makes it more likely that the vaccinated people are different to the full sample - probably more concerned about their health, maybe better able to take steps to look after their health, maybe more able and more likely to convalesce when the got Covid-19. That may (partly) explain their lower risk of Long Covid.

Restricted mean recovery time was 35.4 days (95% CI, 34.4-36.4 days) and was associated with sociodemographic, clinical, lifestyle, and infection-related factors (Figure 2). Pertinent negatives included lack of significant differences by age group, educational attainment, or prepandemic chronic kidney disease or asthma. Mean recovery time was 57.6 days (95% CI, 51.9-63.3 days) after critical hospitalization vs 32.9 days (95% CI, 31.9-33.9 days) for outpatient infection.

Interesting that neither asthma and smoking increased the chance of Long Covid.

Lesser recovery was associated with female vs male sex (HR, 0.85; 95% CI, 0.79-0.92) and clinical CVD vs no CVD (HR, 0.84; 95% CI, 0.71-0.99).

CVD is cardiovascular disease. That result of CVD increasing the risk of poorer recovery might be confounded by a more severe infection.

 

[Hutan]

When added to the multivariable model, infection severity was strongly associated with recovery (eTable 8 in Supplement 1). Compared with outpatient infection, HRs for recovery were 0.59 for noncritical hospitalization (95% CI, 0.52-0.67) and 0.46 for critical illness hospitalization (95% CI, 0.36-0.57). Other effect estimates were comparable to the main model.

Yeah, we've still got this problem of Long Covid being a whole heap of things. It's not surprising that people who have been through a traumatic hospitalisation will take longer to recover, and might not ever recover their pre-illness health. That's going to really blur identification of risk factors for ME/CFS-like Long Covid.

The unfavorable association of recovery with clinical CVD was partially mediated by its association with greater severity (20.0%; P = .047). There was significant negative mediation of sex effects (−24.3%; P = .006): Compared with women, the greater risk of severe acute illness observed in men offset the shorter time to recovery in men.

It's possible that the inclusion of people with lasting effects of a severe illness that aren't ME/CFS-like is serving to reduce the higher risk from being female. That is, if we had a purer ME/CFS-like sample, being female would be a higher risk of Long Covid.

Results were similar with inclusion of fatal and asymptomatic COVID-19 cases (eTable 10 in Supplement 1) and with exclusion of nonconfirmed infections (eTable 11 in Supplement 1). In models that included cohort as a factor rather than a stratum term, there were significant associations observed for the 2 cohorts with the highest restricted mean recovery times (Genetic Epidemiology of COPD study, 61.9 days; Strong Heart Study, 52.1 days) (eTable 12 and eFigure 3 in Supplement 1). Models excluding these cohorts yielded similar results to the main model, as did models excluding the 4 cohorts with lung disease (eTable 13 in Supplement 1).

 

[Hutan]

In models that did not account for cohort effects (eTable 12 in Supplement 1), American Indian or Alaska Native participants showed adverse associations with recovery compared with non-Hispanic White participants (HR, 0.64; 95% CI, 0.53-0.78). This association was not mediated by infection severity, although the sample size was limited (371 participants). In these models, significant associations were also observed for smoking vs never smoking (former smoking: HR, 0.89 [95% CI, 0.82-0.96]; current smoking: HR, 0.82 [95% CI, 0.74-0.92]) and COPD vs no COPD (HR, 0.71; 95% CI, 0.61-0.83).

That is, higher risks of poor recovery for American Indian and Alaska Native participants