For many people affected by Long COVID, the disease has a substantial impact on their ability to work. Scientific evidence on work ability and occupational changes after a SARS-CoV-2 infection are however limited. Philipp Kerksieck and Co-authors from the Epidemiology, Biostatistics and Prevention Institute (EBPI) at the University of Zurich (UZH) analyzed data from a population-based study to evaluate the association between Long COVID and work-related outcomes. The study was recently published as a preprint.
Work ability was lower in participants with Long COVID than in those without.
The study included individuals from the Canton of Zurich, who had a diagnosed SARS-CoV-2 infection, have not been vaccinated before infection and were in the working age (18-64 years old) at recruitment between August 2020 and January 2021. Participants, who experienced a reinfection during the study and participants who were retired at the beginning of the study were excluded. Overall, 672 participants were included, and the following information was collected using electronic questionnaires:
- Symptoms and severity of the acute primary infection
- Pre-existing conditions
- Pre-infection health status
- Socio-demographic characteristics
- Participants’ health trajectories in regular intervals after infection
- Ability to work and occupational changes at 12 months after the infection
- Pre-existing and new/worsened psychiatric diagnoses
After 12 months, participants were asked to rate their work ability on a scale from 1-10 where 10 equals best ability to work. The reported score for work ability was 0.6 points lower for participants with Long COVID compared to those without. Especially participants with severe health impairment reported an ability to work score that was 5 points lower than the score reported by participants who did not suffer from Long COVID.
Moreover, people affected by Long COVID showed a lower ability to meet physical and mental demands. An extrapolation of the work ability towards 2 years in the future, suggested that participants with moderate to severe health impairment at 12 months might still have reduced work ability after 2 years as compared to participants who were fully recovered at 12 months after infection. The current work ability, work ability related to physical and mental demands, and estimated 528 future work ability in 2 years of participants with and without Long COVID is presented in the Figure.
Work ability at 12 months post-infection. PCC, post COVID-19 condition (Long COVID); WAI, work ability index (Point scale for assessing the ability to work).
The impact of Long COVID on work ability was generally higher in older participants (40-64 years) compared to younger ones (18-39 years). The results were similar for male and female participants as well as for participants with 0-1 comorbidities versus 2 or more. Participants with a past, new or worsened psychiatric diagnosis seemed to experience a stronger reduction in work ability than those without any psychiatric diagnosis.
Within the 12 months follow-up, 26% of participants with Long COVID and 16% of those without Long COVID reported occupational changes.
More participants with Long COVID at 12 months reported occupational changes compared to fully recovered participants.
Previous studies on work ability and occupational changes associated with Long COVID have reported that 10-72% of affected persons do not regain their full work capacity. Compared to that, the number of people, who experienced occupational changes in the Zurich cohort (6%) is rather low. This can for example be explained by differences in the study population and the study duration. Many available studies include more severely ill individuals, which are more likely to experience a strong reduction in work ability and have a shorter follow-up (less than 6 months). Differences between countries can be an additional factor.
Regarding study limitations, participants who are more health literate and more severely impacted by Long COVID might be more likely to join and stay in the study, leading to an overestimation of the impact of Long COVID on work ability. On the contrary, the small proportion of persons hospitalized due to Long COVID might lead to an underestimation. Moreover, the study only included individuals who were infected with wild-type SARS-CoV-2 and not vaccinated, making it difficult to generalize the results for persons who were vaccinated and/or infected with a variant. Of note, vaccination, and infection with e.g., the omicron variant, significantly reduces the risk of developing long COVID. However, since 45% of the global population is estimated to have been infected with the omicron variant, from which a reduced but still existing proportion developed Long COVID, the impact on workforce could still be high in absolute terms.
The reduction of work ability associated with Long COVID can have a significant impact on our economy and society.
Although most participants had no occupational changes within 1 year after infection, work ability was still decreased for many, resulting in reduced productivity and efficiency. This can have an impact on the economy and the society, especially since middle-aged adults between 40 and 64 are more affected than younger people. This age group accounts for a significant proportion of the workforce, tax revenue, and gross domestic product. Moreover, impairment of work ability, even if temporary, increases the odds for early retirement. It is therefore important to find ways to help people affected by Long COVID to regain their work ability and to closely monitor the consequences of the reduction of the work ability on the economy.