Years of potential life lost

Years of potential life lost (YPLL) or potential years of life lost (PYLL), is an estimate of the average years a person would have lived if they had not died prematurely.[1] It is, therefore, a measure of premature mortality. As an alternative to death rates, it is a method that gives more weight to deaths that occur among younger people. An alternative is to consider the effects of both disability and premature death using disability adjusted life years.

Calculation

To calculate the years of potential life lost, the analyst has to set an upper reference age. The reference age should correspond roughly to the life expectancy of the population under study. In the developed world, this is commonly set at age 75, but it is essentially arbitrary. Thus, PYLL should be written with respect to the reference age used in the calculation: e.g., PYLL[75].

PYLL can be calculated using individual level data or using age grouped data.[2]

Briefly, for the individual method, each person's PYLL is calculated by subtracting the person's age at death from the reference age. If a person is older than the reference age when they die, that person's PYLL is set to zero (i.e., there are no "negative" PYLLs). In effect, only those who die before the reference age are included in the calculation. Some examples:

  1. Reference age = 75; Age at death = 60; PYLL[75] = 75 − 60 = 15
  2. Reference age = 75; Age at death = 6 months; PYLL[75] = 75 − 0.5 = 74.5
  3. Reference age = 75; Age at death = 80; PYLL[75] = 0 (age at death greater than reference age)

To calculate the PYLL for a particular population in a particular year, the analyst sums the individual PYLLs for all individuals in that population who died in that year. This can be done for all-cause mortality or for cause-specific mortality.

Significance

In the developed world, mortality counts and rates tend to emphasise the most common causes of death in older people because the risk of death increases with age. Because YPLL gives more weight to deaths among younger people, it is the favoured metric among those who wish to draw attention to those causes of death that are more common in younger people. Some researchers say that this measurement should be considered by governments when they decide how best to divide up scarce resources for research.[3]

For example, in most of the developed world, heart disease and cancer are the leading causes of death, as measured by the number (or rate) of deaths. For this reason, heart disease and cancer tend to get a lot of attention (and research funding). However, one might argue that everyone has to die of something eventually, and so public health efforts should be more explicitly directed at preventing premature death. When PYLL is used as an explicit measure of premature death, then injuries and infectious diseases, become more important. While the most common cause of death of young people aged 5 to 40 is injury and poisoning in the developed world, because relatively few young people die, the principal causes of lost years remain cardiovascular disease and cancer.[4]

Person-years of potential life lost in the United States in 2006[5]
Cause of premature death Person-years lost
Cancer8,628,000 person-years
Heart disease and strokes8,760,000 person-years
Accidents and other injuries5,873,000 person-years
All other causes13,649,000 person-years

By country

Here is a table of YPLL for all causes (ages 0–69, per 100,000) with the most recent available data from the OECD:

Rank Country Female YPLL Male YPLL Date
1 Latvia4831132252015
2 Mexico6120114272016
3 Lithuania4460123722017
4 Hungary458995472017
5 Estonia386396262016
6 United States486282652016
7 Poland372992902016
8 Turkey413172622016
9 Chile366065092016
10 Czech Republic308365552017
11 Greece277657802016
12 Slovenia263057232015
13 United Kingdom329250962016
14 France277556212015
15 Germany297253122016
16 Portugal260757612016
17 Canada319750022015
18 Belgium296351972016
19 Finland255854512016
20 Denmark307547762015
21 Austria260647362017
22 Ireland280045252015
23 Netherlands301940752016
24 Australia263444602016
25 South Korea220747092016
26 Israel247341902016
27 Spain219843912016
28 Italy236441902015
29 Sweden250839752016
30 Iceland223541912017
31 Norway247638952016
32 Luxembourg223139572016
33 Japan214440152016
34  Switzerland236936142016

Australia

The report of the NSW Chief Medical Officer in 2002 indicates that cardiovascular disease (32.7% (of total Males Years of Life Lost due to premature mortality) and 36.6% of females YLL) and malignant neoplasms (27.5% of Males YLL and 31.2% of Females YLL) are the main causes of lost years [6]

When disability adjusted life years are considered, cancer (25.1/1,000), cardiovascular disease (23.8/1,000), mental health issues (17.6/1,000), neurological disorders (15.7/1,000), chronic respiratory disease (9.4/1,000) and diabetes (7.2/1,000) are the main causes of good years of expected life lost to disease or premature death.[7] The dramatic difference is in the greater number of years of disability caused mental illness and neurological issues and by diabetes.

See also

References

  1. ↑ Gardner JW; Sanborn JS (1976). "Years of potential life lost (YPLL)—what does it measure?". Comparative Biochemistry and Physiology. A, Comparative Physiology. 53 (4): 323–6. doi:10.1016/s0300-9629(76)80148-x. PMID 3312.
  2. ↑ Association of Public Health Epidemiologists in Ontario. "Calculating Potential Years of Life Lost (PYLL)". Archived from the original on July 6, 2011. Retrieved 2008-05-13.
  3. ↑ Burnet NG, Jefferies SJ, Benson RJ, Hunt DP, Treasure FP (January 2005). "Years of life lost (YLL) from cancer is an important measure of population burden—and should be considered when allocating research funds". Br. J. Cancer. 92 (2): 241–5. doi:10.1038/sj.bjc.6602321. PMC 2361853. PMID 15655548.
  4. ↑ "Archived copy" (PDF). Archived from the original (PDF) on 2009-01-21. Retrieved 2009-01-17.{{cite web}}: CS1 maint: archived copy as title (link)Page 54 Retrieved 17 January 2009.
  5. ↑ National Cancer Institute. "Person-Years of Life Lost". Cancer Trends Progress Report, 2009/2010 Update. Archived from the original on July 1, 2011.
  6. ↑ "Archived copy". Archived from the original on 13 June 2007. Retrieved 2009-01-17.{{cite web}}: CS1 maint: archived copy as title (link) Retrieved=17 January 2009
  7. ↑ "Archived copy" (PDF). Archived from the original (PDF) on 2009-01-21. Retrieved 2009-01-17.{{cite web}}: CS1 maint: archived copy as title (link)Retrieved=17 January 2009 Page 53
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