Subjective life expectancy and subjective age
Contact: Dorly Deeg
Whereas the societal consequences of increasing longevity are widely discussed, much less attention is paid to the individual experiences of prolonged ageing. More insight in individual perspectives may be obtained by studying how older people experience ageing. Questions are: how old do people feel, and how do they experience their remaining life expectancy? The former is commonly referred to as subjective age, and the latter as subjective life expectancy. Both concepts have been found to affect behaviour such as retirement from work, volunteering, health habits, functioning, and well-being (Mirowsky, 1999; van Solinge & Henkens, 2010; Lee et al., 2019; Ziegelmann, Lippke, & Schwarzer, 2006;Stephan, Sutin, & Terracciano, 2015; Demiray & Bluck, 2014; Boehmer, 2007).
LASA includes a “graphical” instrument to measure subjective age and subjective life expectancy, based on the ‘life-line’, and “numerical” instruments asking directly for an age or expected number of years left to live.
Measurement 1: LASA life-line †
In the Longitudinal Aging Study Amsterdam main interview, subjective age and subjective life expectancy are combined in the ‘life-line’. This is a line of 25 cm in length representing the life course from beginning to end (see figure 1), on which the respondent is asked to position himself or herself prompted by the question: ‘Can you please indicate with a cross where on your life-line you feel you are at the present moment?’
Figure 1. The LASA life-line as presented to the respondent. The cross represents a sample response (score calculated as 0.66).During the data processing, the place of the cross is measured in centimeters and rescaled to a score between 0 and 1. The life-line score can be interpreted as the self-perceived life stage. From the same life-line, subjective age and the subjective life expectancy can be derived.
Age can be defined as the distance in years from birth. Likewise, subjective age can be defined as the experienced distance from birth to the present. To calculate subjective age, it is assumed that the total life span is the sum of the chronological age and the remaining actuarial life expectancy (derived from life expectancy tables) based on that chronological age. For example, for a man aged 61 in 1998, the remaining actuarial life expectancy was 18 years, and his total life span is calculated as:61+18=79 years.The subjective age is then calculated by multiplying the life-line score with the estimated total life span. If the example in Figure 1 would have been filled out by this man, his subjective age would be:79*0.66=52 years.
Subjective life expectancy
Remaining life expectancy can be defined as the distance in years from the chronological age to the actuarial age at death. Subjective (remaining) life expectancy can be defined as the experienced distance to death. Two steps are taken to calculate subjective life expectancy using the life-line. First, the chronological age is divided by the life-line score in order to obtain the subjective total life span. In the example, this is:61 / 0.66=93 years.Second, the chronological age is subtracted from the total subjective life span, which results in the subjective remaining life expectancy. In the example, this is:93 – 61 = 32 years.
Measurement 2: Subjective age and subjective life expectancy explicit questions
From 2008-09 (wave LASA-G) onwards, in the main interview following the administration of the ‘life-line’, explicit questions were asked about participants’ perceived age, desired remaining life years, expected remaining life years, and their preference for a longer or shorter life in the presence of health problems (Ziegelmann et al 2006).
Lifeline: LASAD094 / LASAE094 / LASAF094 / LASAG094 / LASAH094 / LASAI094 / LASAJ094 / lASAK094;
Subjective age and Life expectancy: LASAG094 / LASAH094 / LASAI094 / LASAJ094 / LASAK094 (main interview, in Dutch)
Life-line: LASAD094 / LASAE094 / LASAF094 / LASAG094 / LASAH094 / LASAI094 / LASAJ094 / LASAK094 (K not available yet);
Subjective age and Life expectancy: LASAG094 / LASAH094 / LASAI094 / LASAJ094 / LASAK094 (K not available yet)
Availability of information per wave ¹
|Subjective life |
¹ More information about the LASA data collection waves is available here.* 2B=baseline second cohort;
3B=baseline third cohort;
MB=migrants: baseline first cohort;
K=not available yet
Ma=data collected in main interview
Previous use in LASA
The explicit question on subjective life expectancy proved to be associated with attitude towards euthanasia (Buiting et al 2012). The relations of the life-line score with chronological age and actuarial life expectancy are described by Thijsen and colleagues (2014). Over a period in which life expectancy sharply increased (1999-2016), it was shown that lifeline-derived subjective life expectancy did not increase in men, but did so in women (Deeg et al., 2019).
- Buiting HM, Deeg DJ, Knol DL, Ziegelmann JP, Pasman HR, Widdershoven GA, Onwuteaka-Philipsen BD. Older peoples’ attitudes towards euthanasia and an end-of-life pill in The Netherlands: 2001-2009. J Med Ethics 2012; 38(5): 267-273.
- Deeg D, van der Noordt M, Sant N, Galenkamp H, Janssen F, Huisman M. The rise in life expectancy – corresponding rise in subjective life expectancy? Changes over the period 1999-2016. Netspar Design Paper 122, May 2019. https://www.netspar.nl/en/publication/the-rise-in-life-expectancy-corresponding-rise-in-subjective-life-expectancy.
- Thijsen A, Wiegersma SB, Deeg DJH, Janssen F. Leeftijd is meer dan een getal: subjectieve levensverwachting onder Nederlandse ouderen [Age is more than a number: subjective life expectancy in Dutch older people]. CBS Bevolkingstrends, January 2014: 3-13. In Dutch
- Boehmer S. Relationships between felt age and perceived dis-ability, satisfaction with recovery, self-efficacy beliefs and coping strategies. Journal of Health Psychology 2007; 12: 895–906. doi:10.1177/1359105307082453
- Demiray B, Bluck S. Time since birth and time left to live: opposing forces in constructing psychological wellbeing. Ageing & Society 2014; 34: 1193-1218. doi: 10.1017/S0144686X13000032
- Lee K, Kim D, Gilligan M, Martin P. The effects of subjective life expectancy on volunteerinsm in older adults. International Journal of Behavioral Development 2019; 43(4): 342-350. doi: 10.1177/0165025419830238
- Mirowsky J. Subjective life expectancy in the US: Correspondence to actuarial estimates by age, sex and race. Social Science and Medicine 1999; 49(7): 967–979.
- Stephan Y, Sutin AR, Terracciano A. “Feeling younger, walking faster”: subjective age and walking speed in older adults. Age (Dordrecht, Netherlands) 2015; 37(5): 6. doi: 10.1007/s11357-015-9830-9
- Van Solinge H, Henkens K. Living longer, working longer? The impact of subjective life expectancy on retirement intentions and behaviour. European Journal of Public Health 2009; 20(1): 47–51.
- Ziegelmann JP, Lippke S, Schwarzer R. Subjective residual life expectancy in health self-regulation. Journals of Gerontology 2006; 61B(4): P195–P201.
† In LASAD094 at wave D a ‘happiness-line’ was added similar to the life-line. For the description of this subject see the documentation on Satisfaction with life and happiness.
Date of last update: November 11, 2020