Healthcare use attributable to COVID-19: a propensity-matched national electronic health records cohort study of 249,390 people in Wales 2023 Parker

Background

To determine the extent and nature of changes associated with COVID-19 infection in terms of healthcare utilisation, this study observed healthcare contact 1 to 4 and 5 to 24 weeks following a COVID-19 diagnosis compared to propensity-matched controls.

Methods
Two hundred forty nine thousand three hundred ninety Welsh individuals with a positive reverse transcription–polymerase chain reaction (RT-PCR) test were identified from data from national PCR test results. After elimination criteria, 98,600 positive individuals were matched to test negative and never tested controls using propensity matching. Cohorts were split on test location. Tests could be taken in either the hospital or community. Controls were those who had tested negative in their respective environments. Survival analysis was utilised for first clinical outcomes which are grouped into primary and secondary. Primary outcomes include post-viral-illness and fatigue as an indication of long-COVID. Secondary outcomes include clinical terminology concepts for embolism, respiratory conditions, mental health conditions, fit notes, or hospital attendance. Increased instantaneous risk for positive individuals was quantified using hazard ratios (HR) from Cox regression, while absolute risk (AR) and relative risk were quantified using life table analysis.

Results
Analysis was conducted using all individuals and stratified by test location. Cases are compared to controls from the same test location. Fatigue (HR: 1.77, 95% CI: 1.34–2.25, p =  < 0.001) and embolism (HR: 1.50, 95% CI: 1.15–1.97, p = 0.003) were more likely to occur in all positive individuals in the first 4 weeks; however, anxiety and depression (HR: 0.83, 95% CI: 0.73–0.95, p = 0.007) were less likely. Positive individuals continued to be more at risk of fatigue (HR: 1.47, 95% CI: 1.24–1.75, p =  < 0.001) and embolism (HR: 1.51, 95% CI: 1.13–2.02, p = 0.005) after 4 weeks. All positive individuals are also at greater risk of post-viral illness (HR: 4.57, 95% CI: 1.77–11.80, p = 0.002). Despite statistical association between testing positive and several conditions, life table analysis shows that only a small minority of the study population were affected.

Conclusions
Community COVID-19 disease is associated with increased risks of post-viral-illness, fatigue, embolism, and respiratory conditions. Despite elevated risks, the absolute healthcare burden is low. Subsequently, either very small proportions of people experience adverse outcomes following COVID-19 or they are not presenting to healthcare.

Open access, https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-023-02897-5

 

This looks significant though I can't attest the soundness of the statistics. One limitation is that the qualifying date ended August 2021 so it is possible that the peaks in Covid in late 2021 and the first half of 2022 may have produced different figures. The following three excerpts seem relevant:

"Principle findings
This study examines the healthcare use 1 to 4 and 5 to 24 weeks following COVID-19 using propensity-matched controls. Propensity matching was selected for simplicity of interpretation as it provides one score for matching as opposed to controlling for multiple confounders in a regression analysis. The sample size was of sufficient size to enable high match rates. Figures 3, 4, 5, and 6 and 7, 8, 9, and 10 show hazard ratios for outcomes 1 to 4 and 5 to 24 weeks respectively. It compares individuals who test positive for SARS-CoV-2 with controls who are propensity matched to account for deprivation, comorbidities, numbers in the households, number of previous SARS-CoV-2 tests (i.e. propensity to test positive), gender, age, and local authority area.

These findings relate to testing prior to the identification of the Omicron variant and therefore include all variants except Omicron. The cohorts were stratified by individuals testing in the community or hospital and their matches also needed to have been tested in the same stratification. Experiencing COVID-19, even if not accompanied by hospital admission, was associated with an increased risk of fatigue, post-viral illness, and a higher risk of embolism in the community cohort (e.g. code for Venous thromboembolism).

The risk of death was greater for COVID-19 positive individuals in the first 4 weeks, but no excess mortality risk was observed after that. Overall, positive individuals were less likely to receive codes for anxiety, depression, or self-harm. However, after 4 weeks, there is an indication that positive individuals tested in hospital may have an increased risk of anxiety, depression, and self-harm. Unfortunately, this finding does not quite meet the threshold for statistical significance (p < 0.05), and the confidence interval encompasses the null so evidence cannot confidently be provided for the association and more work would need to be conducted."


"Implications and future research
The absolute numbers of contacting their healthcare professional with long-term effects of COVID-19 are low, and there was no increased need for sick notes compared to a matched comparison group after 4 weeks. Therefore, the findings are reassuring that post-COVID adverse consequences do arise but the overall number of people seeking healthcare for this are low. It must be noted though that some adverse events such as embolism are serious and so clinicians should be aware of higher rates for a prolonged period in those who have had COVID-19. It is also important that healthcare professionals consider mental health post-COVID as this may be masked or diagnosed as long-COVID and patients may not receive the appropriate care. In addition, more research is needed to examine the burden to patients who are not seeking healthcare."


"Conclusions
This used a national cohort of people with COVID-19. Cox regression showed that COVID-19 positive individuals were at a significantly increased risk of death, embolism, fatigue, influenza, respiratory conditions, and sick notes in the first 4 weeks after a test. Between 5 to 24 weeks, the risk of embolism and fatigue persisted; they were also at an increased risk from post viral syndrome if tested in the community but not in hospital. However, these individuals were at reduced risk from attending healthcare for mental health conditions. If individuals tested positive in hospital, they were at increased risk from death after 5 to 24 weeks but were at a reduced risk if they tested positive in the community. Life table analysis demonstrates that the absolute risk of these outcomes is very low but some of the burden may be undiagnosed due to sufferers not presenting to a healthcare setting."


The overall impression seems to be that, in the Wales population at least, the headline health problem post COVID is cardiovascular disease, plus increased risks for fatigue and post viral syndrome but with the available data for PVS not allowing propensity matching (Table 3).

 

The first part is a nightmare. The risks and disability are real, but healthcare aren't concerned so they keep doing nothing. And the last part is missing an explanation made very obvious by their choice of outcomes: of course they're presenting to healthcare, just not hospitals, and they're pretty much universally brushed off with barely any records.

Healthcare concerned only by what goes on at their workplace, from which they dismiss a whole of actual problems, is seriously a dystopian nightmare.

And given that they note low rates of mental illness despite this being the standard brush off for post-infectious chronic illness, this means that they aren't even coded, which likely suggests that most doctors don't even believe in it, instead likely believe it's just whining and malingering. Just as they're taught. That's just great, a system blind, deaf and mute all at the same time.