Background
With population aging and increased life expectancies in high-income countries, quality of life (QoL) has become important. Since influences of QoL have expanded beyond the personal concerns for health to the society and to policy interest in the potential for reducing public expenditure, several social and health aspects should be considered while addressing QoL in older people [
1‐
4]. Furthermore, unlike the previous dominant paradigm of QoL decline in old age [
5] due to higher risk of cognitive and physical impairments as well as of social losses [
6,
7], some empirical research indicated no age-related decline in QoL and greater satisfaction with life than in younger age groups [
7‐
9]. These observations may reflect a shift of emphasis away from the previously negative construction of old age [
10] and then the question, ‘if contextual factors influence QoL in different older generations at different ages?’ has gained relevance that warrants further investigation into the complex concept of QoL.
QoL is generally viewed as a multidimensional concept reflecting macro-societal and micro-individual influences and arising from the subjective feeling of satisfaction or dissatisfaction in many domains important to people [
4,
11‐
14]. The level of satisfaction with these domains is therefore a function of its perceived importance by the individual [
15]. As a consequence, QoL appears more as a dynamic concept with significant within-subject and between-subjects variations [
16]. Within-subject differences refer to changes in an individual’s QoL over his/her life span [
17]. Between-subjects differences result from variations in QoL among different groups defined by characteristics such as age [
18], gender [
12] or belonging to specific birth cohorts and thus ageing in specific socio-economic contexts [
17].
To get further insight on the dynamic interplay between importance, satisfaction and QoL, we investigated the hypothesis that different social contexts experienced by individuals born at specific times in history may determine cohort effects (also referred to as “generation” effects) [
19] on QoL through variations in satisfaction with, as well as in perceived importance of QoL domains. The specific socio-economic contexts caused by World War II, as a macro-societal influence, even in countries not directly involved in the conflict [
20], offered a unique opportunity to assess variations in older people’s QoL across successive birth cohorts. Thus, this study aimed to measure and compare among community-dwelling older persons born before, during, and after World War II: a) their satisfaction with QoL, overall and per domains; b) the importance they gave to each domain of QoL.
Discussion
This population-based study addressed cohort effects on the overall satisfaction with QoL as well as on satisfaction with, and importance of, seven QoL domains in community-dwelling older people, taking the World War II as a pivotal historical event determining socioeconomic life circumstances. Despite significant differences in cohorts’ profile (improvements in education in later-born cohorts, lower morbidity profile in the war cohort who more frequently lived alone than the previous cohort), no significant change on their respective satisfaction with QoL was observed at the ages of 68–72 years and 73–77 years. This holds true when further analysing subgroups of the population, with only one exception among older persons still living with others at the age of 73–77 years who appeared more satisfied when born during rather than before WWII. An important contribution of this study is thus to question the assumption that stability of the overall QoL across birth cohorts might result from internal compensation of positive and negative changes. Indeed, results from the present study also reveal a significant improvement in satisfaction with QoL only for the “Feeling of safety” domain in the later-born cohorts. No other cohort effect was observed in satisfaction with QoL for any other specific QoL domains.
This study also provides unique information on changes in the importance attributed to QoL domains across cohorts and at different ages. Our initial hypothesis that cohort differences in educational, socio-economic, and health profiles might translate into changes in the importance attributed to QoL domains was not confirmed. Furthermore, we found only very limited evidence that these changes in profiles could modify and compensate possible differences in satisfaction with QoL. Indeed, only the “Health and mobility” domain appeared to have a significantly higher importance in QoL at age 73–77 year among participants from the war cohort who, on the other hand, reported a lower level of medical diagnoses. Overall, these results emphasize the complexity of the relationship between changing life circumstances and QoL. Further longitudinal analyses among the same cohort over time are needed to further disentangle the issue of between and within subject’s change in QoL satisfaction over time. The within subject dynamism of the QoL concept involves a ‘response shift’ phenomenon resulting from an evolution in the respondent’s values (reprioritization of the importance attributed to the component domains) [
27‐
29]. What was once important may seem unimportant and what once ignored may have great importance [
30]. Such response shift may also occur at the population-level [
31].
Results of the current study also challenge those from previous studies. While the observed different socio-economic and health profiles of successive cohorts did not influence their satisfaction with QoL in our analysis, a study on life satisfaction trajectories of older women living in Switzerland reported that the mean life satisfaction score and the prevalence of satisfied women were lower in more recent cohorts of identical ages [
17]. However, in this study, only women were investigated and cohorts were defined with a 10-year interval, irrespective of historical events.
Results from the current study might also be related to previous observations suggesting that satisfaction with QoL is influenced by expectations [
32], resulting in a stability-despite-loss paradox or ‘satisfaction paradox’ [
7,
33]. In other words, on one hand, as the more recent cohorts benefited from better socio-economic contexts, they are expected to better cope with aging and to express higher satisfaction with life. On the other hand, difficulties experienced by earlier cohorts may translate into lowered expectations, resulting in more satisfaction than the next generations would feel in similar circumstances [
34]. Such adaptation can be also described in terms of response shift, by which individuals change their internal standards, values and conceptualizations of QoL to accommodate some hardship or negative circumstance [
27]. Closely allied to adaptation is fostered resilience, the phenomenon of people beating the odds and doing well against expectation [
3,
35] that may be a reason for such favorable perception of QoL; and a study by Seery et al. indicated that people with some prior lifetime adversity were the least affected by recent adverse events [
36]. Finally, satisfaction with QoL is influenced by social comparisons [
32], mainly downward contrast comparisons and the advantage of “counting blessings” and “not complaining” as coping strategies may also play a role in preserving perceived QoL in individuals experiencing a declining situation [
37‐
39].
Strengths and limitations
This study took advantage of an historical event that determined specific socio-economic contexts in which each of the successive cohorts were born (before, during, and end of World War II), grew up and worked. This afforded a unique opportunity to assess variations in both the importance attributed to the multiple facets of QoL and the level of satisfaction with them between the cohorts at a given age.
A limitation of this study could potentially be the difficulty to disentangle cohort and period effects. However, no major event occurred in Switzerland between 2011 and 2016 that would influence responses to the QoL assessments. We also relied on a relatively short time interval (5 years) to define the birth cohorts, which may have limited the ability to observe differences; however, results pointed to significant socio-economic and health differences between cohorts that could have likely had an impact on their QoL in spite of this short interval.
Conclusion
Despite certain differences in socio-economic, educational, and health profiles between cohorts in identical age groups, no difference was observed in the overall satisfaction with QoL as well as in the scores of importance and satisfaction in most QoL domains.