science

Preventable years of life lost

Preventable years of life lost is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Preventable years of life lost rather than just read about it. In short: Preventable years of life lost (PrYLL) is an epidemiological measure. It is an estimate of the average years a person would have lived if s/he had not died prematurely due to a preventable cause of death.

Key takeaways

Preventable years of life lost belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Preventable years of life lost to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Preventable years of life lost from memory before moving on to harder problems.

Reference excerpt

Preventable years of life lost (PrYLL) is an epidemiological measure. It is an estimate of the average years a person would have lived if s/he had not died prematurely due to a preventable cause of death. PrYLL is closely related to potential years of life lost (PYLL) and like PYLL, it gives more weight than mortality rates to deaths that occur among younger people. Unlike PYLL, PrYLL excludes causes of death that aren't deemed to be preventable. Premature deaths are those that could be avoided through public health interventions such as getting people to take more exercise or stop smoking, or in tackling the wider social determinants of health. Causes of death can be classified using the International Classification of Diseases (ICD) codes. The United Kingdom’s Office for National Statistics (ONS) has published lists of ICD codes that are deemed to be avoidable, amenable and preventable. Within this publication, the ONS proposes the following definition for preventable causes of death: “A death is preventable if, in the light of current understanding of the determinants of health, all or most deaths from that cause (subject to age limits if appropriate) could be avoided by public health interventions in the broadest sense”.

History PrYLL was developed in 2012 by Errol Taylor at The Royal Society for the Prevention of Accidents (RoSPA) to highlight the burden to society of accidental injury. PrYLL features prominently in RoSPA’s Big Book of Accident Prevention and RoSPA’s guidance for local government decision-makers, which was supported by Public Health England(PHE) and funded by the UK Department of Health.

Calculation To calculate the preventable years of life lost, the analyst has to set an upper reference age. This is essentially arbitrary and can be set, for example, to 65 to capture the whole population up to retirement, or 75 which, in developed countries, corresponds roughly to the life expectancy of the population being studied. The analyst must then select the ICD codes for causes of death that are deemed by the ONS to be preventable. The calculation can then proceed in the same way as for years of potential life lost (PYLL).

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. Since PrYLL excludes causes that aren't deemed to be preventable and it gives more weight to deaths among young individuals, it is a powerful metric for those who want to draw attention to the premature and preventable loss of human potential. Some might argue that causes of death with the highest PrYLL should attract the greatest share of research and funding for prevention campaigns. Graph showing percentage of total preventable years of life lost (PrYLL) in 2010, to people in England & Wales up to age 60.

Comparison This table which contrasts the leading causes of death when measured first by PrYLL and then by the total number of deaths. The rankings are completely different, depending on which epidemiological measure is chosen. Accidental injuries rise from being the fifth cause of death in terms of mortality to the leading cause in terms of PrYLL, while cancers drop from being the leading cause of death to be being second when measured in terms of PrYLL.

References

Worked examples

Example 1 — a first encounter with Preventable years of life lost

Start with the simplest possible case. Write down what Preventable years of life lost claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Preventable years of life lost before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Preventable years of life lost ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Preventable years of life lost

In research: Preventable years of life lost appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Preventable years of life lost in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Preventable years of life lost is common in secondary-school and first-year university syllabi. It links to neighbouring topics Actuarial science, Death, Epidemiology, so understanding it makes those chapters shorter.
In everyday life: Look for Preventable years of life lost outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Preventable years of life lost in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Preventable years of life lost means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Preventable years of life lost out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Preventable years of life lost in simple terms?

Why does Preventable years of life lost matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Preventable years of life lost?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Preventable years of life lost.