Despite the upheaval of COVID-19, French participants reported higher well-being scores during the pandemic, while researchers found that everyday illness symptoms had a far greater association with how people felt than seasonal or demographic factors.
Study: Evolution and determinants of subjective well-being in the French general population between 2014 and 2023. Image credit: sommart sombutwanitkul/Shutterstock.com
A recent BMC Public Health study assessed longitudinal trends in subjective well-being and identified key associated factors, including health status, sociodemographic variables, acute symptom burden, seasonality, and the COVID-19 pandemic period, in a French participatory surveillance cohort from 2014 to 2023.
Evolution and current gaps in subjective well-being research
Much more than physical health shapes how people feel about their lives. Subjective well-being (SWB), which encompasses emotions, life satisfaction, and a sense of purpose, is influenced by social, economic, and environmental conditions. Researchers increasingly view it as an important indicator of individual well-being and broader societal health.
Once largely a topic of philosophical debate, well-being has become a major focus of scientific research and public policy. Since the mid-20th century, advances in measurement have helped researchers explore how happiness and life satisfaction relate to health, finances, and social circumstances. More recently, growing recognition that economic growth alone cannot capture quality of life has placed well-being at the center of wider discussions about public health and sustainability.
Yet important questions remain about how well-being changes when people become ill. Although the relationship between general health and well-being is well established, less is known about the effects of short-term infectious illnesses, particularly during seasonal outbreaks. Researchers also face the challenge of separating the effects of winter itself from those of the increased illness burden that typically accompanies it.
The COVID-19 pandemic has added another layer of uncertainty. While numerous studies have examined its immediate effects on well-being, fewer have tracked how people's perceptions of their health and well-being changed over longer periods, including before, during, and after the pandemic emergency.
Assessing subjective well-being in the French population between 2014 and 2023
The current study used data from Grippenet/Covidnet, a French online influenza surveillance system within the European Influenzanet platform. Participants registered voluntarily and anonymously and completed a baseline survey on sociodemographic characteristics, medical history, and lifestyle habits.
Each influenza season (November–May), participants received weekly reminders to self-report health status and symptoms and rate their overall well-being in response to the question, “Overall, how are you feeling?” on a 0–100 scale. This single-item measure primarily captured perceived health-related well-being.
Symptomatic individuals reported new symptoms unrelated to chronic conditions. Reporting was flexible, and participants could submit data at any frequency. The study spanned nine winter seasons (2014–2015 to 2022–2023) and included adults (≥18 years) residing in mainland France who completed at least one intake and one weekly survey per season.
Sociodemographic variables included gender, age group, education (≤high school, >high school), household composition, occupational status, residence (urban/rural), transport, smoking status, contact patterns, chronic medication, and the French Deprivation Index. Weekly surveys recorded symptom count (0, 1–2, 3–5, >5), but symptom cause was excluded from the adjusted analysis. Seasons were grouped as pre-pandemic (2014–2015 to week 10, 2019–2020), pandemic (week 11, 2019–2020 to 2021–2022), and post-emergency (2022–2023). Participants missing age, gender, or education data were excluded.
Participants' demographics and trends in influenza-like illness and COVID-19
Over nine seasons, 16,065 individuals contributed a total of 54,861 registrations. Participation peaked in 2019–2020 during the COVID-19 pandemic, when 10,448 participants were active, then gradually declined in subsequent years.
Demographic weighting aligned the sample with the 2022 French population in age, gender, and education, but these variables reflect statistical adjustments rather than real shifts in the cohort and should not be compared across seasons. Most participants, 78% to 81% depending on the year, lived in urban areas. The proportion reporting regular medication for a chronic condition ranged from 26% to 41% across seasons.
Weekly symptom surveys showed that 78–92% of responses reported no symptoms. Reports of 1–2 symptoms ranged from 5–12%, 3–5 symptoms from 2–7%, and more than 5 symptoms from 1–4%. Most symptoms were attributed to "other causes" (57–74%).
Reports of influenza-like illness (ILI) declined from 17% of symptomatic questionnaires in 2014–2015 to 2% in 2020–2021, before rising to 12% in 2022–2023. COVID-19 was cited as the cause in 8% (2019–2020), 6% (2020–2021), 23% (2021–2022), and 9% (2022–2023) of symptomatic surveys.
Seasonal variation and subjective well-being trends and influences
Self-reported well-being rose over the study period, with median scores increasing from 86 in 2014–2015 to 93 in 2020–2021. Health status appeared to play a major role in how participants felt. Those reporting no symptoms consistently had higher well-being scores, with medians ranging from 90 to 94, compared with 59 to 75 among those experiencing symptoms.
Among participants with laboratory-confirmed infections, those with influenza reported particularly low well-being scores, with medians of 44–48, compared with 50–60 among those with COVID-19. However, the difference was statistically significant only in 2021–2022. The researchers cautioned that the small number of confirmed influenza cases and differences in testing practices limited these comparisons. Looking at trends over time, well-being scores remained relatively stable from 2014–2015 through 2019–2020 before rising sharply in 2020–2021. Scores remained elevated in 2021–2022, although the increase was less pronounced. A recurring winter dip was also observed between mid-December and mid-March, largely reflecting the greater number of participants reporting illness symptoms during these months.
The researchers also identified several demographic and lifestyle factors associated with well-being. Higher scores were linked to being male, aged 65 or older, living with others, having higher education, and having contact with patients. Students, retirees, unemployed individuals, and those on sick leave or staying at home also reported higher scores after adjustment for other factors. However, the researchers cautioned that some of these unexpected occupational associations could reflect selection effects or other unmeasured differences rather than benefits associated with those circumstances.
Well-being was also higher during the pandemic and post-emergency periods. After accounting for other factors, scores averaged approximately two points higher on the 0–100 scale in both periods compared with before the pandemic. In contrast, contact with children, smoking, regular medication for chronic conditions, and winter were associated with lower scores.
Of all the factors examined, symptom burden showed by far the strongest negative association with well-being. Compared with participants reporting no symptoms, those with one or two symptoms scored approximately 15 points lower, those with three to five symptoms scored 26 points lower, and those with more than five symptoms scored 40 points lower after adjustment.
The French Deprivation Index showed mixed associations with well-being, without a consistent pattern across deprivation levels. Meanwhile, no statistically significant associations were observed for middle-aged adults, urban residents, public transport users, or participants reporting contact with older people or groups of at least 10 individuals.
Conclusion
This study analyzed subjective well-being in a French participatory surveillance cohort from 2014 to 2023. Acute symptom burden, particularly during winter, was strongly associated with most short-term declines in self-rated well-being. An increase in well-being scores during the COVID-19 pandemic may reflect reduced respiratory virus circulation, selective participation, or other unmeasured factors, though these could not be directly assessed. Sociodemographic differences, including a persistent gender gap, shaped baseline well-being.
However, the voluntary online cohort was not fully representative of the French population, and demographic weighting could not eliminate selection bias. The observational design, reliance on a single-item measure that predominantly reflected perceived health-related well-being, and lack of detailed psychological and social data also limit causal interpretation and generalizability.
These results highlight the promise and challenges of participatory surveillance for monitoring population well-being and emphasize the importance of addressing measurement and selection biases in future research.
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