Impact of Quality of Life on Survival and Mortality of Physically Independent Older Adults: Findings From Seven Years of Data.

INTRODUCTION

Healthy aging emphasizes not only the extension of life expectancy but also the preservation of physical, mental, and social well-being, along with quality of life. However, several factors, such as the prevalence of chronic diseases and low educational and economic levels, may negatively affect the quality of life among older adults. This study aimed to identify the factors associated with a negative perception of quality of life and to evaluate the impact of negative quality of life on mortality over a seven-year follow-up period.

METHODS

The research involved 419 older adults, 60 years or older, physically independent (levels 3 or 4 on the Spirduso Functional Status) and with mental status >17 points according to the Mini-Mental State Examination questionnaire. Variables assessed included sex, age group, education, economic class, quality of life index (QLI), race, marital status, falls in the last 12 months, body mass index (BMI), regular physical activity, and presence of comorbidities. Data on quality of life were collected using the Short Form Health Survey (SF-36), classifying in absolute binary threshold (positive/negative) into three variables: Health-Related Quality of Life (HRQoL), Quality of Life - Components of Physical Health (QL-CPH), and Quality of Life - Components of Mental Health (QL-CMH). Mortality information and causes of death from 2009 to 2016 were obtained from the Municipal Health Department. The association between negative perception of HRQoL with sociodemographic aspects, BMI, and comorbidities was analyzed using multivariate logistic regression analysis. To assess the association between quality of life variable and all-cause mortality, the Cox regression model was used, including crude and adjusted models. Kaplan-Meier curves and Mantel-Cox analysis were performed to compare survival curves between those subjects with positive and negative perceptions of quality of life.

RESULTS

Older adults with negative HRQoL were characterized by lower educational levels, economic status, QLI scores, overweight status, and the presence of more than three comorbidities (p<0.01 for all). Negative HRQoL was associated with gender (male), low QLI, the presence of more than three comorbidities, and specific conditions, including hypertension, diabetes, neurological disorders, and rheumatic diseases (odds ratio (OR) ranging from 1.81 to 9.05). The adjusted Cox regression analysis showed that negative HRQoL (hazard ratio (HR) = 1.852; 95% confidence interval (CI): 1.05 to 3.27; p=0.034) and negative QL-CPH (HR = 1.83; 95% CI: 1.06 to 3.15; p=0.031) increased the risk of mortality in older adults. Kaplan-Meier survival curves indicated that older adults with a negative HRQoL index had a 21.3% probability of death over a seven-year period (p<0.01).

CONCLUSION

Sociodemographic factors, as well as the number and type of comorbidities, are associated with negative HRQoL in community-dwelling older adults. Furthermore, individuals with a negative perception of their quality of life face an increased risk of mortality.