Subjective expectation of reaching age 85: agreement with population statistics and association with behavioral and...

It is not clearly known how well Danes estimate their chances of reaching the average life expectancy and whether identifiable population subgroups misestimate their life expectancy, and potentially also investments and savings in health and pensions. Therefore, in this study, we examined on the individual level whether subjective life expectancy is in line with the statistically calculated chance of reaching age 85, and further explored the psychological and behavioral factors associated with under or overestimation.

We opted for a cross-sectional survey design based on a sample of 5,379 Danish citizens aged 50-70 years, returning a web-based questionnaire with socio-demographic data supplemented from a national registry. Average participant estimates of their chance of reaching age 85 for each age range and sex group were compared with actuarial data. We then performed multiple linear regression analyses to examine factors associated with the subjective expectancy of reaching age 85 years.

We found that 32% of females and 23% of males reported 100% certainty of reaching age 85, and average expected survival chance exceeded the statistically predicted survival chance for 23% of males and 16% for females in age-ranges 50-60 and 61-70. Our multivariable analysis found that health literacy, internal health locus of control, willingness to take health risks, self-rated health, and health and life satisfaction all showed a significant positive association with expectation of reaching age 85. Moreover, those on daily medications, ex- or current smokers, and heavy drinkers were significantly less optimistic about reaching age 85.

Particularly for the population groups with inaccurate life expectancies, the significant associations with psychological and behavioral factors open a way for initiatives based on behavior change theories to reach a better agreement between subjective and statistical life expectancy.