Whole of population-based cohort study of recovery time from COVID-19 in New South Wales Australia

Abstract

Background: COVID-19 results in persisting symptoms but there is little systematically collected data estimating recovery time following infection. Methods:We followed 94% of all COVID-19 cases diagnosed in the Australian state of New South Wales between January and May 2020 using 3-4 weekly telephone interviews and linkage to hospitalisation and death data to determine if they had recovered from COVID-19 based on symptom resolution. Proportional hazards models with competing risks were used to estimate time to recovery adjusted for age and gender.Findings: In analyses 2904 cases were followed for recovery (median follow-up time 16 days, range 1-122, IQR 11-24).There were 2572 (88.6%) who reported resolution of symptoms (262/2572 were also hospitalised), 224 (7.8%) had not recovered at last contact (28/224 were also hospitalised), 51 (1.8%) died of COVID-19, and 57 (2.0%) were hospitalised without a documented recovery date. Of those followed, 20% recovered by 10 days, 60% at 20, 80% at 30, 91% at 60, 93% at 90 and 96% at 120 days. Compared to those aged 30-49 years, those 0-29 years were more likely to recover (aHR 1.22, 95%CI 1.10-1.34) while those aged 50-69 and 70 + years were less likely to recover (aHR respectively 0.74, 95%CI 0.67-0.81 and 0.63, 95%CI 0.56-0.71). Men were faster to recover than women (aHR 1.20, 95%CI 1.11-1.29) and those with pre-existing co-morbidities took longer to recover than those without (aHR 0.90, 95%CI 0.83-0.98).Interpretation: In a setting where most cases of COVID-19 were ascertained and followed, 80% of those with COVID-19 recover within a month, but about 5% will continue to experience symptoms 3 months later.

Modelling the potential acute and post-acute burden of COVID-19 under the Australian border re-opening plan

“… 14 days [ 17 ] 0.655 (0.579 – 0.727) a [ 10 , 11 ] Post-acute consequences (ONS) Start at 25.91% (23.2 to 29.0%) 2 weeks after initial COVID infection [ 18 ] a See notes below on how we compute for the COVID-19 survivors noted in this calculation. 14 days to 2 years (assumed) 0.219 (0.148-0.308) [ 10 , 11 ] Post-acute consequences (NSW) Start at 33.60% (33.0 to 34.0%) 2 weeks after initial COVID infection [ 19 ] See notes below on how we compute for the COVID-19 survivors noted in this calculation. 14 days to 2 years (assumed) 0.219 (0.148-0.308) [ 10 , 11 ] Post-Intensive Care Syndrome (PICS) 90.6% of ICU survivors [ 20 ] See notes below on how we compute for the COVID-19 survivors noted in this calculation.…”

“…Our model assumed that Long COVID symptoms start directly after the symptomatic phase. Briefly, Long COVID refers to those patients experiencing any of the following symptoms: persistent fever, headache, muscle ache, weakness/tiredness/fatigue, nausea/vomiting, abdominal pain, diarrhoea, sore throat, cough, shortness of breath, loss or change of taste, loss or change of smell runny nose and chest pain post COVID-19 infection to reflect the symptoms observed in the studies of Liu et al [ 19 ] and UK ONS cohort study [ 18 ]. Given the United Kingdom (UK) evidence that some patients still report Long COVID over 12 months after infection [ 18 ], our model assumed that Long COVID could potentially last up to 2 years.…”

“…Given the United Kingdom (UK) evidence that some patients still report Long COVID over 12 months after infection [ 18 ], our model assumed that Long COVID could potentially last up to 2 years. Due to the lack of longitudinal data regarding the length of Long COVID, we extrapolated available data on numbers of Long COVID cases over time from the UK Office of National Statistics (ONS) [ 18 ] and a population-based cohort study in New South Wales (NSW) [ 19 ] until it reached 0% using a fitted decay function [ 27 ]. This estimate was only applied to COVID-19 survivors.…”

SARS-CoV-2 and HIV-1: Should HIV-1-Infected Individuals in Sub-Saharan Africa Be Considered a Priority Group for the COVID-19 Vaccines?

“…While it is clear that the majority of unvaccinated individuals survive primary infection without the need for hospitalization (91) what remains to be fully elucidated are the specific immune correlates of protection against SARS-CoV-2 (92)(93)(94). The pandemic will continue until further studies reveal the veritable correlates of protection against SARS-CoV-2 and/or the whole world is immunized, including those most vulnerable to severe COVID-19 such as those living with HIV-1.…”

Long covid clinics should be run as research hubs

“…The April 2021 survey by the Office for National Statistics shows 21% of people with confirmed covid-19 still have symptoms at 5 weeks and 13.7% at 12 weeks 4. A recent population based longitudinal study from Australia reported high rates of recovery among adults with confirmed covid-19 (20%, 80%, 93%, and 96% at 10, 30, 90, and 120 days respectively) 5. This indicates that, however distressing the symptoms, most people meeting NICE criteria for long covid are on a path, albeit often fluctuating, to natural recovery.…”