Felicidade and perception of health influence the longevity of the elderly

Population monitoring in Campinas indicates that emotional well-being acts as a "buffer" against mortality.

What determines how long a person will live? Beyond clinical exams and diagnoses of chronic diseases, the answer may lie in how the individual perceives their own life and health. “Between living and surviving,” the title of the doctoral thesis by physiotherapist Donatila Barbieri de Oliveira Souza, defended at the Faculty of Medical Sciences (FCM) of Unicamp, summarizes this distinction: the biological act of being alive is one thing; the felt and meaningful experience of life, lived with intensity, purpose, and affection, is another. Both impact the time that remains.

Analyzing longitudinal data collected over a period of time, Souza demonstrated that what the elderly feel and think about themselves has real epidemiological value. Feeling happy, positively evaluating one's own health, and maintaining a good quality of life are factors scientifically associated with increased life expectancy in old age. “Epidemiology has a very strong characteristic of measuring, of working with numbers. Our challenge was precisely to measure what is subjective. It's not common, but the research results show how important this is,” corroborates researcher and FCM professor Margareth Guimarães Lima, thesis advisor.

The research was based on a retrospective population cohort study, in which a group of elderly individuals was identified from past data and followed over the years. It analyzed three central subjective dimensions as predictors of mortality in the elderly: health-related quality of life (HRQoL), subjective well-being (happiness), and self-rated health (SAR). The physiotherapist analyzed responses and data from 1.520 individuals aged 60 or older, originally interviewed in the Campinas Municipal Health Survey (ISACamp 2008/2009), a survey that uses representative samples to collect information on the health of the city's population every five years.

After matching data with the Mortality Information System (SIM) of the Municipal Health Department of Campinas and conducting active searches, by telephone and in home visits, to confirm the vital status of the participants, the final sample comprised 1.311 individuals.

In interviews conducted in 2008 and 2009 for ISACamp, older adults answered a comprehensive set of questions about living conditions, health, income, education, and well-being, in addition to direct self-assessment questions about health and happiness. A quality of life questionnaire was also used. SF-36 (acronym for 36-item short form health survey)The Health-Related Quality of Life (HRQoL) is a multidimensional instrument used to assess health-related quality of life. It allows for the quantitative measurement of the impact of health conditions and diseases on people's lives, considering physical, psychological, emotional, and social dimensions.

Ten years later, in 2018, the cohort was followed up, allowing for the construction of survival curves over the period. Among the results, the research showed that older adults with poorer physical capacity had twice the risk of death compared to those with better mobility. Average survival decreased from 5,9 to 5,1 years among participants with the worst physical function indices. Furthermore, lower levels of emotional and mental health increased the risk of death by up to 36%.

Analyzing reports on feelings of happiness, the thesis showed that older adults who felt happy less frequently had a 60% higher risk of death compared to those who experienced this feeling more often. In practice, the happier older adults lived, on average, one year longer than the less happy ones, even when both had chronic diseases. Happiness acted as a "buffer," reducing the negative effect of physical limitations on the risk of death by 14%.

“People who reported lower frequency of happiness lived, on average, one year less than those who reported higher frequency. We provoked this reflection by asking: what do you do in a year? How many birthday celebrations, how many moments with family are missed?” asks Souza. For the researcher, the results show that happiness cannot be seen merely as a subjective feeling, but as a fundamental indicator of health.

“We also observed that some elderly people without illness had a shorter life expectancy than those with some kind of illness. This shows that there are other factors, besides diseases, that are causing these people to live less,” says the author.

In analyzing self-rated health (SRH), Souza identified that the mortality risk in the group of elderly people who considered their health poor was 4,3 times higher—approximately 300% greater—than in the group with a perception of excellent health, even without a diagnosis of chronic diseases. Conversely, reporting feeling healthier than other people significantly reduced the risk of death. The results suggest that SRH can capture frailties, lack of social support, or initial symptoms that traditional clinical examinations may not detect. “Longevity is the art of living meaningfully,” summarizes the physiotherapist, referring to the way she measures subjective aspects of health and transforms them into robust numbers.

Impact on public health

According to the researchers, the thesis fills a global scientific gap: 98% of studies on quality of life and mortality are conducted in high-income countries, leaving a silence about the reality of low- and middle-income nations, such as Brazil, classified as an upper-middle-income country, in addition to challenging epidemiological tradition by converting feelings into mathematical indicators of survival.

For Souza, the robustness of the numbers serves to validate what is often ignored in the clinical rush: the subject's own perception. She recalls hearing from colleagues that her objectives bordered on the obvious. However, her research demonstrates the need for statistical rigor to corroborate perceptions: “It's something treated as obvious, but which hadn't been demonstrated in numbers. Often the professional focuses on physical findings, but doesn't listen to what the elderly person is saying. A key point is to give voice and listen to this population, because there is a lot of potential in what they say about their own health.”

The results offer a practical application for the Brazilian Unified Health System (SUS). The researchers propose that simple questions about happiness and self-assessment be incorporated or maintained as screening tools in Primary Health Care (PHC). "These are sensitive indicators of vulnerability to guide more timely and early interventions, integrated into the daily practices of PHC, along with strengthening qualified listening," adds Souza.