In a recent study published in JAMA Network Open, researchers assessed the long-term effects of coronavirus disease 2019 (COVID-19) infection on every day life activities amongst veterans 18 months post-infection, comparing those with and without COVID-19 histories.

Study: Self-Reported On a regular basis Functioning After COVID-19 Infection. Image Credit: Lightspring / Shutterstock

Background 

The World Health Organisation (WHO) defines post-COVID-19 conditions by its significant effect on every day functioning, yet many studies specializing in post-COVID symptoms and recent diagnoses have ignored functional impacts. Surveys in the final population that compare individuals with and without prior COVID-19 infections often mix the disease’s effects with predisposing risk aspects. While recent studies have concluded substantial long-term disabilities from recent post-COVID diagnoses, direct measures of disability remain scarce. Further research is required to validate the estimated associations and understand the long-term functional impact of COVID-19.

Concerning the study 

In the current study, verbal informed consent was obtained from participants involved in a prospective survey conducted via telephone and mail, targeting veterans 18 months post-COVID-19 infection from October 2020 to April 2021. This timeframe was chosen to be certain that health systems had adapted to the initial pandemic shock, and the reliance on health facility-based testing over home testing minimized classification errors of COVID-19 cases.

The study population comprised veterans engaged with the Veterans Affairs (VA) healthcare system, matched on several criteria, including the month of COVID-19 infection or non-infection, demographic variables, and other health-related aspects. The choice process aimed to discover veterans with documented COVID-19 infections and match them with uninfected comparators based on a comprehensive set of variables to attenuate confounding effects in assessing post-COVID conditions.

For this research, veterans were stratified and randomly sampled across different months and United States (U.S.) regions, emphasizing a methodological approach to represent the national veteran population accurately. A complicated matching process ensured that every COVID-19 case was paired with comparators who had no documented infection, emphasizing the study’s robustness and the precision of its comparisons.

The study’s design aimed to explore COVID-19’s potential as a disabling event, comparing its impact on every day living to that of sepsis or pneumonia. It necessitated significant resources for accurate matching and maintaining internal validity. Precisely planned survey operations encouraged participation by offering incentives and utilizing validated tools to evaluate U.S. veterans’ health and functioning, ensuring comprehensive data collection.

Statistical analyses included assessing covariate balance and examining associations between COVID-19 infection and various health outcomes using regression models. The analyses accounted for potential biases and applied weights to accurately reflect the complex sampling and response rates. 

Study results 

In the current study involving 186 pairs of veterans, one group having recovered from COVID-19 and their counterparts without infection, participants’ mean age across the early 60s, with a predominantly male demographic. When examining fatigue and pain, the findings indicated that each cohorts reported similar fatigue levels, with no statistically significant difference within the scores. Interestingly, a rather lower percentage of veterans within the COVID-19 group reported experiencing moderate to severe pain in comparison with their non-infected peers, though this difference didn’t reach statistical significance.

The research further delved into how every day living activities were impacted. Each groups reported similar numbers of limitations in activities of every day living and instrumental activities, with no significant disparity found between them within the mean variety of reported limitations or the chances of reporting multiple limitations.

One other aspect explored was life-space mobility, which measures a person’s geographical movement and independence. Results showed that mobility levels were comparable between those that had COVID-19 and people who didn’t, with a good portion of each groups experiencing severely restricted mobility. Employment rates also didn’t significantly differ between the groups 18 months after the COVID-19 infection.

Quality of life assessments revealed a subjective sense of recovery amongst participants. A rather higher percentage of the COVID-19 group felt they’d not regained their early 2020 levels of physical and mental capabilities in comparison with the non-infected group, though the difference was not statistically significant. Health-related quality of life, as measured by the EuroQol 5-Dimension 5-Level

(EQ-5D-5L) health utility scales also showed negligible differences between the 2 cohorts.

The study conducted sensitivity analyses to validate its findings, including assessments without excluding certain participants and examining the potential enduring impacts of COVID-19 amongst those hospitalized. Some indications of lasting effects, resembling increased fatigue and functional limitations, were noted in hospitalized individuals. 

Moreover, healthcare utilization amongst participants was scrutinized, revealing barely higher rates of primary care engagement within the COVID-19 group but no significant differences in inpatient admissions, specialty care, or mental health services.