Lifestyle and ADL Are Prioritized Factors Influencing All-Cause Mortality Risk Among Oldest Old: A Population-Based Cohort Study.

To identify key factors affecting all-cause mortality in the elderly aged 80 years and above. Data from Chinese Longitudinal Healthy Longevity Survey (2011-2018) were utilized (N = 3993). A healthy lifestyle score was obtained by assigning 8 factors: smoking, drinking, exercise, sleep duration, social activity, waist circumference, BMI, and healthful plant-based diet index. Cox regression and decision tree model were used to identify factors influencing the mortality risk. Lifestyle and activities of daily living (ADL) were 2 of the most important modifiable factors influencing the mortality risk of the oldest seniors. A higher healthy lifestyle score was associated with lower mortality risk. The HR (95% CI) of death risk in Q2, Q3, and Q4 groups were 0.91 (0.81-1.01), 0.78 (0.71-0.86), and 0.64 (0.58-0.71), respectively, when compared with the Q1 group of healthy lifestyle score. Elderly with ADL disability had a higher mortality rate than those without ADL disability. When the elderly already have ADL disability, the healthier the lifestyle, the lower the mortality rate. Among individuals aged 80 to 89 years with ADL disability, the mortality rate was higher in the healthy lifestyle score Q1-Q2 groups (92.1%) than that in the Q3-Q4 groups (71.6%). Similar results were observed among subjects aged 90 to 99 years with ADL disability (Q1-Q2: 97.9%, Q3-Q4: 92.1%). For centenarians without ADL disability, maintaining a healthy lifestyle significantly reduced mortality (Q1-Q3: 90.5%, Q4: 75.5%). Caregivers should prioritize the consideration of lifestyle and ADL in their healthcare practices of the oldest old.