Our culture of overtime is costing us dearly



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About 13% of Australian worker are working 50 hours or more a week, putting themselves, and others, at greater risk.
Shutterstock

Joshua Krook, University of Adelaide

The story of Yumiko Kadota, whose gruelling schedule as a Sydney hospital registrar included clocking up more than 100 hours of overtime in her first month, has highlighted the punishing work schedules required in the medical profession.

Research indicates working more than 48 hours a week is associated with significant declines in productivity, more mistakes and more mental health problems. Yet the Royal Australasian College of Surgeons reckons working up to 65 hours a week “is appropriate for trainees to gain the knowledge and experience required”.

It’s an attitude that explains why a 2017 audit found more than 70% of surgeons in public hospitals were working unsafe hours. And it’s symptomatic of many areas where pushing the hours envelope is seen as part of the job.




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Working long and hard? It may do more harm than good


Last month, for example, a study by the Australian Transport Safety Bureau found almost one in four long-haul pilots reported working on less than five hours of sleep in the previous 24 hours – putting them in the risk zone where fatigue leads to impaired performance.

Meanwhile, two of Australia’s largest law firms are being investigated for overworking staff. At King & Wood Mallesons in Melbourne, lawyers working on the banking royal commission were reportedly sleeping in their offices overnight, too tired to go home. At Gilbert + Tobin Lawyers in Sydney, it is alleged lawyers were resorting to drugs and other supplements to cope with fatigue.

Other areas in which long hours are common are in mining, farming and construction. All up about 13% of the workforce – 19% of men and 6% of women – are working 50 hours or more, putting themselves, and others, at risk.

What’s the damage

After a century of “scientific management” you might think that more attention would be paid to the scientific studies on working long hours.

The relationship between work hours and productivity follows the economic law of diminishing returns. Productivity peaks at a certain point and then declines. Work too long and you get to the point where you’re achieving nothing; or are even doing damage.

Diminishing returns: author Mark Manson decided to chart his productivity over hours in the day in this fashion.
The Observer

This is what the research literature tells us:

  • After working 39 hours a week, mental health tends to decline.
  • After 48 hours, job performance begins to rapidly decrease. There are more signs of depression and anxiety, and worse sleep quality associated with long-term health risks such as cardiovascular disease, type 2 diabetes and cancer.
  • Working more than 10 hours a day increases the risk of workplace injury by 40%, and more than 12 hours a day doubles it.
  • Longer working hours harm relationships, erode job satisfaction and contribute to depression, including increased suicidal thoughts.

A rule made to be broken

All of this research shows there’s good sense in Australia’s federal Fair Work Act (s. 62) capping the standard work week at a maximum of 38 hours.

But that maximum is easy to flout. The act also says an employer can require an employee to work “reasonable” extra hours. Determining whether they are unreasonable depends on 10 factors, including a risk to health and safety, family circumstances, the needs of the business, compensation, the usual patterns of work in the industry and “any other relevant matter”.

The law says an employee can refuse to work more than 38 hours a week, but in practice that rarely happens.

You may be happy to put in more hours because you are compensated. You may even do it “voluntarily”, because you see it as a path to promotion, or the way to keep your job. You may be enmeshed in a “first in, last out” culture, where it’s a competition to show your devotion to your job through the number of hours you work.

As a result, Australians work an average six hours of unpaid overtime a week.

Gaming the system

Management practices can promote an overtime culture without explicitly flouting the law.

One way is to scrutinise an employee’s working hours, such as using a billable hours system. This is common in law firms and other professional services. Clients are charged by the hour (or six-minute increments, as is the case in law firms) for the time an employee spends working on a matter. It puts pressure on a conscientious employee to do any work not related to a client in their own time. An employee may also under-report hours so as not look slow or unproductive to a manager.




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Another way is through using casual or contract workers. Such employment can result in workers doing more hours than what they are paid for, either because they have underquoted to get the job, or are working on a fixed contract where the employer has defined how long it should take, or they feel the need to prove their worth to ensure they get more work.

Changing attitudes

State and federal government agencies, including the Fair Work Ombudsman and Safe Work Australia have broad powers to investigate worker health and safety (including overtime).

But for those powers to make a difference, these agencies need more resources to actually do investigations and greater powers to issue fines and corrective measures to companies where overtime is endemic. There’s no reason hours auditing couldn’t be a more routine procedure, much like food health and safety regulators inspect restaurants.

But more than that we need a change in the cultural attitudes that promote long hours as necessary, acceptable or heroic – even when someone doing their job while overtired and fatigued, such as a surgeon or pilot, is downright scary.The Conversation

Joshua Krook, Doctoral Candidate in Law, University of Adelaide

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Health Check: do we really need to take 10,000 steps a day?



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Walking has a variety of health benefits.
From shutterstock.com

Corneel Vandelanotte, CQUniversity Australia; Kerry Mummery, University of Alberta; Mitch Duncan, University of Newcastle, and Wendy Brown, The University of Queensland

Regular walking produces many health benefits, including reducing our risk of heart disease, type 2 diabetes and depression.

Best of all, it’s free, we can do it anywhere and, for most of us, it’s relatively easy to fit into our daily routines.

We often hear 10,000 as the golden number of steps to strive for in a day. But do we really need to take 10,000 steps a day?

Not necessarily. This figure was originally popularised as part of a marketing campaign, and has been subject to some criticism. But if it gets you walking more, it might be a good goal to work towards.




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Where did 10,000 come from?

The 10,000 steps concept was initially formulated in Japan in the lead-up to the 1964 Tokyo Olympics. There was no real evidence to support this target. Rather, it was a marketing strategy to sell step counters.

There was very little interest in the idea until the turn of the century, when the concept was revisited by Australian health promotion researchers in 2001 to encourage people to be more active.

Based on accumulated evidence, many physical activity guidelines around the world – including the Australian guidelines – recommend a minimum of 150 minutes of moderate intensity physical activity a week. This equates to 30 minutes on most days. A half hour of activity corresponds to about 3,000 to 4,000 dedicated steps at a moderate pace.

In Australia, the average adult accumulates about 7,400 steps a day. So an additional 3,000 to 4,000 steps through dedicated walking will get you to the 10,000 steps target.




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One size doesn’t fit all

Of course, some people accumulate a lot fewer steps per day – for example, older people, those with a chronic disease, and office workers. And others do a lot more: children, runners, and some blue-collar workers. So the 10,000 goal is not suitable for everyone.

Setting a lower individual step goal is fine as long as you try to add about 3,000 to 4,000 steps to your day. This means you will have done your 30 minutes of activity.

People measure their daily steps using a variety of activity trackers.
From shutterstock.com

Studies that examine how the number of daily steps relates to health benefits have mainly been cross-sectional. This means they present a snapshot, and don’t look at how changes in steps affect people’s health over time. Therefore, what we call “reverse causality” may occur. So rather than more steps leading to increased health benefits, being healthier may in fact lead to taking more steps.

Nonetheless, most studies do find taking more steps is associated with better health outcomes.

Several studies have shown improved health outcomes even in participants who take less than 10,000 steps. An Australian study, for example, found people who took more than 5,000 steps a day had a much lower risk of heart disease and stroke than those who took less than 5,000 steps.

Another study found that women who did 5,000 steps a day had a significantly lower risk of being overweight or having high blood pressure than those who did not.

The more the better

Many studies do, however, show a greater number of steps leads to increased health benefits.

An American study from 2010 found a 10% reduction in the occurrence of metabolic syndrome (a collection of conditions that increase your risk of diabetes, heart disease and stroke) for each 1,000-step increase per day.

An Australian study from 2015 demonstrated that each 1,000-step increase per day reduced the risk of dying prematurely of any cause by 6%, with those taking 10,000 or more steps having a 46% lower risk of early death.




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Another Australian study from 2017 showed people with increasingly higher step counts spent less time in hospital.

So the bottom line is the more steps, the better.

Step it up

It’s important to recognise that no public health guideline is entirely appropriate for every person; public health messages are aimed at the population at large.

That being said, we shouldn’t underestimate the power of a simple public health message: 10,000 steps is an easily remembered goal and you can readily measure and assess your progress. You can use an activity tracker, or follow your progress through a program such as 10,000 Steps Australia.

Increasing your activity levels, through increasing your daily step count, is worthwhile; even if 10,000 steps is not the right goal for you. The most important thing is being as active as you can. Striving for 10,000 steps is just one way of doing this.The Conversation

Corneel Vandelanotte, Professorial Research Fellow: Physical Activity and Health, CQUniversity Australia; Kerry Mummery, Dean, Faculty of Kinesiology, Sport and Recreation, University of Alberta; Mitch Duncan, , University of Newcastle, and Wendy Brown, Professor of Human Movement Studies, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Five life lessons from your immune system



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Are you exhausted? Your immune cells might be too.
from www.shutterstock.com

Joanna Groom, Walter and Eliza Hall Institute

This article is part of our occasional long read series Zoom Out, where authors explore key ideas in science and technology in the broader context of society and humanity.


Scientists love analogies. We use them continually to communicate our scientific approaches and discoveries.

As an immunologist, it strikes me that many of our recurring analogies for a healthy, functioning immune system promote excellent behaviour traits. In this regard, we should all aim to be a little more like the cells of our immune system and emulate these characteristics in our lives and workplaces.

Here are five life lessons from your immune system.




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1. Build diverse and collaborative teams

Our adaptive immune system works in a very specific way to detect and eradicate infections and cancer. To function, it relies on effective team work.

At the centre of this immune system team sits dendritic cells. These are the sentinels and leaders of the immune system – akin to coaches, CEOs and directors.

They have usually travelled widely and have a lot of “life experience”. For a dendritic cell, this means they have detected a pathogen in the organs of the body. Perhaps they’ve come into contact with influenza virus in the lung, or encountered dengue fever virus in the skin following a mosquito bite.

Dendritic cells form a surveillance network – shown here as reddish stained cells in skin.
Ed Uthman (Houston, TX, USA) via Wikimedia Commons, CC BY

After such an experience, dendritic cells make their way to their local lymph nodes – organs structured to facilitate immune cell collaboration and teamwork.

Here, like the best leaders, dendritic cells share their life experiences and provide vision and direction for their team (multiple other cell types). This gets the immune cell team activated and working together towards a shared goal – the eradication of the pathogen in question.

The most important aspect of the dendritic cell strategy is knowing the strength of combined diverse expertise. It is essential that immune team members come from diverse backgrounds to get the best results.

To do this, dendritic cells secrete small molecules known as chemokines. Chemokines facilitate good conversations between different types of immune cells, helping dendritic cells discuss their plans with the team. In immunology, we call this “recruitment”.

This 3D image of a lymph node shows the cells that produce chemokines in red and blue.
Joanna Groom/WEHI, Author provided

Much like our workplaces, diversity is key here. It’s fair to say, if dendritic cells only recruited more dendritic cells, our immune system would completely fail its job. Dendritic cells instead hire T cells (among others) and share the critical knowledge and strategy to steer effective action of immune cells.

T cells can then pass these plans down the line – either preparing themselves to act directly on the pathogen, or working alongside other cell types, such as B cells that make protective antibodies.

In this way, dendritic cells establish a rich and diverse team that works together to clear infections or cancer.

2. Learn through positive and negative feedback

Immune cells are excellent students.

During development, T cells mature in a way that depends on both positive and negative feedback. This occurs in the thymus, an organ found in the front of your chest and whose function was first discovered by Australian scientist Jacques Miller (awarded the 2018 Japan Prize for his discoveries).




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As they mature, T cells are exposed to a process of trial and error, and take on board criticism and advice in equal measure, to ensure they are “trained” to respond appropriately to what they “see” (for example, molecules from your own body, or from a foreign pathogen) when they leave the thymus.

Importantly, this process is balanced, and T cells must receive both positive and negative feedback to mature appropriately – too much of either on its own is not enough.

In the diverse team of the immune system, cells can be both the student and the teacher. This occurs during immune responses with intense cross-talk between dendritic cells, T cells and B cells.

In this supportive environment, multiple rounds of feedback allow B cells to gain a tighter grip on infections, tailoring antibodies specifically towards each pathogen.

The result of this feedback is so powerful, it can divert cells away from acting against your own body, instead converting them into active participants of the immune system team.

Developing avenues that promote constructive feedback offers potential to correct autoimmune disorders.

The colours in this magnified slice through a lymph node show different cell types interacting as part of an immune response.
Joanna Groom/WEHI, Author provided



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3. A unique response for each situation

Our immune system knows that context is important – it doesn’t rely on a “one-size–fits-all” approach to resolve all infections.

This allows the cells of our immune system to perfectly respond to different types of pathogens: such as viruses, fungi, bacteria and helminths (worms).

In these different scenarios, even though the team members contributing to the response are the same (or similar), our immune system displays emotional intelligence and utilises different tools and strategies depending on the different situations, or pathogens, it encounters.

Importantly, our immune system needs to carefully control attack responses to get rid of danger. Being too heavy handed leaves us with collateral tissue damage, such as is seen allergy and asthma. Conversely, weak responses lead to immunodeficiencies, chronic infection or cancer.

A major research aim for people working in immunology is to learn how to harness balanced and tailored immune responses for therapeutic benefit.




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4. Focus on work/life balance

When we are overworked and poorly rested, we don’t function at our peak. The same is true for our immune cells.

An overworked immune cell is commonly referred to as being “chronically exhausted”. In this state, T cells are no longer effective at attacking tumour or virus-infected cells. They are lethargic and inefficient, much like us when we overdo it.

For T cells, this switch to exhaustion helps ensure a balanced response and avoids collateral damage. However, viruses and cancers exploit this weakness in immune responses by deliberately promoting exhaustion.

The rapidly advancing field of immunotherapy has tackled this limitation in our immune system head-on to create new cancer therapeutics. These therapies release cells of their exhaustion, refresh them, so they become effective once more.

This therapeutic avenue (called “immune checkpoint inhibition”) is like a self-care day spa for your T cells. It revives them, renewing their determination and efficiency.

This has revolutionised the way cancer is treated, leading to the award of the 2018 Nobel prize in Medicine to two of its pioneers, James P. Allison and Tasuku Honjo.




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5. Learn from life experiences

The cornerstone of our adaptive immune system is the ability to remember our past infections. In doing so, it can respond faster and in a more targeted manner when we encounter the same pathogen multiple times.

Quite literally, if it doesn’t kill you, it makes your immune system stronger.

Vaccines exploit this modus operandi, providing immune cells with the memories without the risk of infection.

Work still remains to identify the pathways that optimise formation of memory cells that drive this response. Researchers aim to discover which memories are the most efficient, and how to make them target particularly recalcitrant infections, such as malaria, HIV-AIDS and seasonal influenza.

While life might not have the shortcuts provided by vaccines, certainly taking time to reflect and learn after challenges can allow us to find better, faster solutions to future problems.




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The Conversation


Joanna Groom, Laboratory Head, Walter and Eliza Hall Institute

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Health Check: how do I tell if I’m dehydrated?



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Our bodies are pretty good at telling us when we need to drink water.
from www.shutterstock.com

Karen Dwyer, Deakin University

It’s a message that’s been drummed into us since childhood. Drink water, especially when it’s hot, otherwise you’ll get dehydrated.

But how do you know if you’re dehydrated? Who’s more at risk? And what can you do about it?




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What’s dehydration and why does it matter?

When people use the term dehydration, they usually refer to what doctors call “volume depletion” or hypovolaemia.

Volume depletion is a reduction in the volume of water in the blood vessels. But dehydration is quite different and is less common. It’s the loss of water from both blood vessels and the body’s cells.

Doctors are concerned about volume depletion and dehydration because adequate hydration is required for the body to function normally. Water maintains our body temperature and lubricates our joints. Our body’s cells rely on water as does our circulatory, respiratory, gastrointestinal and neurological systems.

Severe cases of volume depletion can lead to shock and collapse. Without resuscitation with fluid, the consequences may be devastating.

Water, water everywhere

A 70kg person is made up of 40L (40kg) is water. Two-thirds of that water is in the cells (intracellular), one-third outside the cells (extracellular).

Outside the cells, 20% of body water is in plasma (around 3L), which together with red bloods cells (2L) gives a total 5L of blood. It’s the movement of water between compartments that maintains each one’s biochemical composition, allowing your cells and body to work normally.

The total body water volume (water in both the blood vessels and the body’s cells) is remarkably constant given the large variation in how much an individual might take in and lose each day.

Water intake is accounted for mostly by how much and what you drink and eat, and the daily variation is regulated by the kidney, which alters your urine output.

The main function of the kidney is to regulate the volume and composition of body fluids within narrow limits by altering output.




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When you drink large volumes of fluid, your body can afford to get rid of increased amounts of dilute urine. But when you drink a minimal amount of fluid, your urine is concentrated and you pass only a small volume.

If you’re urinating less often than normal, or urinating small volumes of darker coloured urine, it may be time to drink more water.




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Other small losses of water include through stool, sweat and lungs.

So if you have diarrhoea or are exercising in the heat, for instance, you will need to drink more fluids.




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As fluid is lost from the extracellular compartment such as in cases of diarrhoea and vomiting or bleeding, you can develop symptoms of volume depletion including:

  • thirst, including a dry mouth
  • dizziness, particularly when standing due to the low blood pressure (a consequence of volume loss)
  • and when very severe, confusion (a consequence of inadequate oxygenation of the brain).

Doctors might also note:

  • that it takes longer for your skin to bounce back when pinched (known as reduced skin turgor)
  • low blood pressure as a reduction in volume directly affects blood pressure
  • an increased heart rate, in an attempt by the body to maintain blood pressure
  • reduced weight as fluid makes up two-thirds of body weight. A loss of 1L of fluid will read as a drop in 1kg on the scales.

Blood testing will often reveal a degree of kidney impairment. That’s because the kidneys require a large blood flow to work normally.

In cases of volume depletion and reduction in blood pressure, blood flow to the kidneys is compromised and they go into a state of “shock”. Mostly this is reversible when volume and blood pressure is restored.

As there’s no single test for volume depletion, doctors will make a diagnosis after taking a note of your history, examining you and a combination of blood and urine tests.

Here’s what happened to Tom

I was on call at the hospital recently when, at 9.45pm on a Sunday, I received a call from the emergency department.

Tom, a 78 year old man, had come in by ambulance after neighbours had found him on his bedroom floor. Tom’s cognition was not great at the best of times, and that night he couldn’t tell us how long he had been on the floor.

There were no obvious injuries, his blood pressure was low (100/60mmHg), pulse rate high (98 beats per minute) and his temperature was normal. Blood tests showed he had low sodium salt levels and kidney impairment.

Tom had been in the emergency department for six hours by the time the call came to me; in that time he had not passed urine. It all pointed to volume depletion.

Elderly people are at increased risk, so keep an eye on relatives and neighbours this summer.
from www.shutterstock.com

We treated Tom with intravenous fluid. He needed 5L over 48 hours, after which he was passing urine again. His blood pressure was back to normal 140/70mmHg, his kidney function had normalised and his weight was up from 46kg on admission to 50kg.

Tom told us he had fallen while getting up at night. He had been on the floor for most of the next day and had not eaten or drunk anything for hours.

Who’s most at risk and why?

Some groups are more susceptible to volume depletion, including:

  • elderly people like Tom, as our total body water reduces with age and the elderly often have a reduced sensation of thirst. Many older people also have other health problems including chronic kidney disease, which may impact the ability to concentrate urine when the volume is depleted
  • babies, because they aren’t able to articulate when they’re thirsty. They have a higher metabolic rate than adults meaning they require more fluid
  • people with impaired thirst mechanisms such as the elderly or people with certain brain injuries
  • people losing large volumes of fluid via the bowel (from diarrhoea or through a colostomy)
  • people taking medications that promote water loss, in particular diuretics, often referred to as water tablets.

These vulnerable groups need to be aware of the increased risk of volume depletion, minimise their risk by maintaining fluid levels, recognise the symptoms of volume depletion early, and seek prompt treatment, including going to hospital if necessary.

If you experience the symptoms of volume depletion it’s important to take heed. At home, start with water if you’re thirsty. Once dizziness is present, significant volume loss has ensued and a trip to the doctor is in order. Confusion mandates emergency treatment.

How about physiological dehydration?

Physiological dehydration, which occurs when water is lost from both the blood vessels and from the body’s cells compartment, is distinct from volume depletion. But there are many overlapping symptoms, such as thirst, a drop in blood pressure and when severe, confusion.

Dehydration can happen with prolonged and sustained high blood sugar levels as can occur in someone with diabetes. This is because the high sugar levels in the blood pull water out of the cells in an attempt to lower the levels. High sugar levels also make you pass more urine. So in this instance there is loss of fluid from both the intracellular and extracellular compartments.




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So for those with diabetes, monitoring blood sugar levels is important. If the blood sugar is persistently high it’s important to seek medical advice to reduce the level safely and prevent dehydration.

In a nutshell

Water is vitally important to the normal function of the body. Volume depletion can occur during anytime of the year, but people are particularly prone over the summer months. The key is prevention and knowing what the signs and symptoms are. So in summer keep your fluids up; talk to your doctor about any medications that may need adjusting (such as diuretics) and keep an eye out for friends, family and neighbours.The Conversation

Karen Dwyer, Deputy Head, School of Medicine, Deakin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Trust Me, I’m An Expert: the science of sleep and the economics of sleeplessness


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You know you’re not supposed to do this – but you do.
Shutterstock

Dilpreet Kaur, The Conversation and Sunanda Creagh, The Conversation

How did you sleep last night? If you had anything other than eight interrupted hours of peaceful, restful sleep then guess what? It’s not that bad – it’s actually pretty normal.

We recently asked five sleep researchers if everyone needs eight hours of sleep a night and they all said no, you don’t.




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We asked five experts: does everyone need eight hours of sleep?


In fact, only about one quarter of us report getting eight or more hours of sleep. That’s according to the huge annual Household, Income and Labour Dynamics in Australia (HILDA) survey which now tracks more than 17,500 people in 9500 households.

We’ll hear today from Roger Wilkins, who runs the HILDA survey at University of Melbourne, on what exactly the survey found about how much and how well Australians sleep.

But first, you’ll hear from sleep expert Melinda Jackson, Senior Research Fellow in the School of Health and Biomedical Sciences, RMIT University, about what the evidence shows about how we used to sleep in pre-industrial times, and what promising research is on the horizon. Here’s a taste:

Listen.

Trust Me, I’m An Expert is a podcast where we ask academics to surprise, delight and inform us with their research. You can download previous episodes here.

And please, do check out other podcasts from The Conversation – including The Conversation US’ Heat and Light, about 1968 in the US, and The Anthill from The Conversation UK, as well as Media Files, a podcast all about the media. You can find all our podcasts over here.

The two segments in today’s podcast were recorded and edited by Dilpreet Kaur Taggar. Additional editing by Sunanda Creagh.




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Additional audio and credits

Kindergarten by Unkle Ho, from Elefant Traks

Morning Two by David Szesztay, Free Music Archive.The Conversation

Dilpreet Kaur, Editorial Intern, The Conversation and Sunanda Creagh, Head of Digital Storytelling, The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

We asked five experts: does everyone need eight hours of sleep?



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How much sleep we need depends on us as individuals and varies by age.
from http://www.shutterstock.com

Alexandra Hansen, The Conversation

Many of us try to live by the mantra eight hours of work, eight hours of leisure, eight hours of rest. Conventional wisdom has long told us we need eight hours of sleep per day, but some swear they need more, and some (politicians, mostly) say they function fine on four or five.

So is the human brain wired to require eight hours, or is it different for everyone? We asked five experts if everyone needs eight hours of sleep per day.

Five out of five experts said no

Here are their detailed responses:

https://cdn.theconversation.com/infographics/300/de319186cdafd9c3ab8c28724f96e5322c67f0c5/site/index.html


If you have a “yes or no” health question you’d like posed to Five Experts, email your suggestion to: alexandra.hansen@theconversation.edu.au


Disclosures: Hailey Meaklim is the recipient of an Australian Government Research Training Program Scholarship.The Conversation

Alexandra Hansen, Chief of Staff, The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Most people don’t benefit from vaccination, but we still need it to prevent infections



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Everyone has to be vaccinated for immunisation programs to work.
from http://www.shutterstock.com

Allen Cheng, Monash University

A recent article in The Conversation questioned whether we should all get flu vaccinations, given 99 people would have to go through vaccination for one case of flu to be prevented.

But this position ignores the purpose of immunisation programs: whole populations of people need to take part for just a small number to benefit. So how do we decide what’s worth it and what’s not?




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Decision-making in public health

When we consider a treatment for a patient, such as antibiotics for an infection, we first consider the evidence on the benefits and potential harms of treatment. Ideally, this is based on clinical trials, where we assume the proportion of people in the trial who respond represents the chance an individual patient will respond to treatment.

This evidence is then weighed up with the individual patient. What are the treatment options? What do they prefer? Are there factors that might make this patient more likely to respond or have side effects? Is there a treatment alternative they would be more likely to take?

In public health, the framework is the same but the “patient” is different – we are delivering an intervention for a whole population or group rather than a single individual.

We first consider the efficacy of the intervention as demonstrated in clinical trials or other types of studies. We then look at which groups in the population might benefit the most (such as the zoster vaccine, given routinely to adults over 70 years as this group has a high rate of shingles), and for whom the harms will be the least (such as the rotavirus vaccine, which is given before the age of six months to reduce the risk of intussusception, a serious bowel complication).

Compared to many other public health programs, immunisation is a targeted intervention and clinical trials tell us they work. But programs still need to target broad groups, defined by age or other broad risk factors, such as chronic medical conditions or pregnancy.




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Risks and benefits of interventions

When considering vaccination programs, safety is very important, as a vaccine is being given to a generally healthy population to prevent a disease that may be uncommon, even if serious.

For example, the lifetime risk of cervical cancer is one in 166 women, meaning one woman in 166 is diagnosed with this cancer. So even if the human papillomavirus (HPV) vaccine was completely effective at preventing cancer, 165 of 166 women vaccinated would not benefit. Clearly, if we could work out who that one woman was who would get cancer, we could just vaccinate her, but unfortunately we can’t.

It’s only acceptable to vaccinate large groups if clinically important side effects are low. For the HPV vaccine, anaphylaxis (a serious allergic reaction) has been reported, but occurs at a rate of approximately one in 380,000 doses.

An even more extreme case is meningococcal vaccination. Before vaccination, the incidence of meningococcal serogroup C (a particular type of this bacterium) infection in children aged one to four years old was around 2.5 per 100,000 children, or 7.5 cases for 100,000 children over three years.

Vaccination has almost eliminated infection with this strain (although other serotypes still cause meningococcal disease). But this means 13,332 of 13,333 children didn’t benefit from vaccination. Again, this is only acceptable if the rate of important side effects is low. Studies in the US have not found any significant side effects following routine use of meningococcal vaccines.

This is not to say there are no side effects from vaccines, but that the potential side effects of vaccines need to be weighed up against the benefit.

For example, Guillain Barre syndrome is a serious neurological complication of influenza vaccination as well as a number of different infections.

But studies have estimated the risk of this complication as being around one per million vaccination doses, which is much smaller than the risk of Guillain Barre syndrome following influenza infection (roughly one in 60,000 infections). And that’s before taking into account the benefit of preventing other complications of influenza.




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High schools are bigger, so immunisation is easier than at primary schools.
from http://www.shutterstock.com

What other factors need to be considered?

We also need to consider access, uptake and how a health intervention will be delivered, whether through general practices, council programs, pharmacies or school-based programs.

Equity issues must also be kept in mind: will this close the gap in Indigenous health or other disadvantaged populations? Will immunisation benefit more than the individual? What is the likely future incidence (the “epidemic curve”) of the infection in the absence of vaccination?

A current example is meningococcal W disease, which is a new strain of this bacteria in Australia. Although this currently affects individuals in all age groups, many state governments have implemented vaccination programs in adolescents.

This is because young adults in their late teens and early 20s carry the bacteria more than any other group, so vaccinating them will reduce transmission of this strain more generally.

But it’s difficult to get large cohorts of this age group together to deliver the vaccine. It’s much easier if the program targets slightly younger children who are still at school (who, of course, will soon enter the higher risk age group).

In rolling out this vaccine program, even factors such as the size of schools (it is easier to vaccinate children at high schools rather than primary schools, as they are larger), the timing of exams, holidays and religious considerations (such as Ramadan) are also taken into account.




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For government, cost effectiveness is an important consideration when making decisions on the use of taxpayer dollars. This has been an issue when considering meningococcal B vaccine. As this is a relatively expensive vaccine, the Pharmaceutical Benefits Advisory Committee has found this not to be cost effective.

This is not to say that meningococcal B disease isn’t serious, or that the vaccine isn’t effective. It’s simply that the cost of the vaccine is so high, it’s felt there are better uses for the funding that could save lives elsewhere.

While this might seem to be a rather hard-headed decision, this approach frees up funding for other interventions such as expensive cancer treatments, primary care programs or other public health interventions.

Why is this important?

When we treat a disease, we expect most people will benefit from the treatment. As an example, without antibiotics, the death rate of pneumonia was more than 80%; with antibiotics, less than 20%.

The ConversationHowever, vaccination programs aim to prevent disease in whole populations. So even if it seems as though many people are having to take part to prevent disease in a small proportion, this small proportion may represent hundreds or thousands of cases of disease in the community.

Allen Cheng, Professor in Infectious Diseases Epidemiology, Monash University

This article was originally published on The Conversation. Read the original article.

The faster you walk, the better for long term health – especially as you age



File 20180530 120484 1r92o7l.jpg?ixlib=rb 1.1
OK, you don’t need the poles. But you should pick up the pace.
from http://www.shutterstock.com

Emmanuel Stamatakis, University of Sydney

Some of us like to stroll along and smell the roses, while others march to their destination as quickly as their feet will carry them. A new study out today has found those who report faster walking have lower risk of premature death.

We studied just over 50,000 walkers over 30 years of age who lived in Britain between 1994 and 2008. We collected data on these walkers, including how quickly they think they walk, and we then looked at their health outcomes (after controlling to make sure the results weren’t due to poor health or other habits such as smoking and exercise).

We found any pace above slow reduced the risk of dying from cardiovascular disease, such as heart disease or stroke. Compared to slow walkers, average pace walkers had a 20% lower risk of early death from any cause, and a 24% lower risk of death from heart disease or stroke.

Australian Science Media Centre.



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Those who reported walking at a brisk or fast pace had a 24% lower risk of early death from any cause and a 21% lower risk of death from cardiovascular causes.

We also found the beneficial effects of fast walking were more pronounced in older age groups. For example, average pace walkers aged 60 years or over experienced a 46% reduction in risk of death from cardiovascular causes, and fast walkers experienced a 53% reduction. Compared to slow walkers, brisk or fast walkers aged 45-59 had 36% lower risk of early death from any cause.

In these older age groups (but not in the whole sample or the younger age groups), we also found there was a linearly higher reduction in the risk of early death the higher the pace.

What it all means

Our results suggest walking at an average, brisk or fast pace may be beneficial for long term health and longevity compared to slow walking, particularly for older people.

But we also need to be mindful our study was observational, and we did not have full control of all likely influences to be able to establish it was the walking alone causing the beneficial health effects. For example, it could be that the least healthy people reported slow walking pace as a result of their poor health, and also ended up dying earlier for the same reason.

Fast walking for some might not seem it for others.
from http://www.shutterstock.com

To minimise the chances of this reverse causality, we excluded all those who had heart disease, had experienced a stroke, or had cancer when the study started, as well as those who died in the first two years of follow up.




Read more:
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Another important point is that participants in our study self-reported their usual pace, which means the responses were about perceived pace. There are no established standards for what “slow”, “average” or “brisk” walking means in terms of speed. What is perceived as “fast” walking pace by a very sedentary and physically unfit 70-year-old will be very different from a sporty and fit 45-year-old.

For this reason, our results could be interpreted as reflecting relative (to one’s physical capacity) intensity of walking. That is, the higher the physical exertion while walking, the better health results.

For the general relatively healthy middle-aged population, a walking speed between 6 and 7.5 km/h will be fast and if sustained, will make most people slightly out of breath. A walking pace of 100 steps per minute is considered roughly equivalent to moderate intensity physical activity.

We know walking is an excellent activity for health, accessible by most people of all ages. Our findings suggest it’s a good idea to step up to a pace that will challenge our physiology and may even make walking more of a workout.

The ConversationLong term-health benefits aside, a faster pace will get us to our destination faster and free up time for all those other things that can make our daily routines special, such as spending time with loved ones or reading a good book.

Emmanuel Stamatakis, Professor of Physical Activity, Lifestyle, and Population Health, University of Sydney

This article was originally published on The Conversation. Read the original article.