Why more people die in winter

As we move towards the colder months of the year it is timely to consider the ‘preventable winter deaths’ and to question our ability in practice to be a part of their prevention

Increased winter mortality is well evidenced and, according to Public Health England (PHE),1 there are approximately 24,000 avoidable deaths in England and Wales during cold weather each year. Historically, there has been a gradual reduction in excess winter mortality since the 1950s, when in excess of 80,000 deaths were recorded, but it has been a fluctuating picture. As recently as 2012-13, there was a 29% increase on the previous winter, totalling an astonishing 31,100 excess deaths in England and Wales, with 25,600 being attributed to the over 75 age group alone.² Winter is defined as the period of December to March, and mortality rates for these months are compared with those for the previous three months of August to November and the following three months of April to July.

Any preventable deaths are of concern and there has recently been mounting interest in trying to reduce the figures through strategic planning and multi-agency involvement. Since the Health and Social Care Act 2012 was passed, many public health service responsibilities have been transferred to local authorities.³ Taking these reforms into account, the Cold Weather Plan for England 20131 has been updated and calls on social care and community services – working in partnership with the NHS – to protect vulnerable individuals from avoidable harm during the cold weather. The plan provides guidance on activities for the relevant services to consider, either individually or as part of a local network. In addition, NICE is developing guidance on excess winter mortality and morbidity, with publication due in 2015.⁴

Practice nurses are in an excellent position to be a part of the implementation of aspects of the Cold Weather Plan, and it is hoped that by sharing what is currently known about contributory factors to preventable winter deaths, they may feel better placed to do so.

Related physiology

According to PHE, cold weather increases the risk from heart attacks, strokes, lung diseases, flu and other diseases.¹ Relatively few deaths are recorded with hypothermia as the underlying cause in the UK,⁵ but this may be misleading as it is often the related disease that is recorded on death certificates rather than hypothermia.⁶

In order to maintain metabolic activity within the cells, the body requires a stable core temperature of 36-37.5°C.⁷ When a cool external environment is detected, behavioural changes may occur such as putting on extra clothing or turning up the heating,⁸ or internal physiological mechanisms, such as shivering and constriction of the peripheral blood vessels, may be triggered by the thermoregulatory centre in the hypothalamus.⁹ Hypothermia occurs when the body temperature falls to 35°C or below, although there is some evidence that some people may experience harm before this body temperature is reached.¹⁰

Several physiological changes occur as part of the ageing process that put the older person at particular risk of hypothermia. Older people tend to have reduced subcutaneous tissue (they are thinner), a reduced metabolic rate (they are slower and less active), and an impaired ability to regulate blood flow through vasoconstriction, and even an altered perception of cold.¹¹ Higher blood pressure and increases in blood viscosity directly related to cold temperatures increase the risk of cardiovascular events in the older person.¹²

Influenza is a seasonal respiratory infection, typically occurring between October and March in the northern hemisphere.¹³ Approximately 3,000 - 4,000 deaths are attributable to influenza in the UK during a season of low incidence, with the under-2s and over-60s being most vulnerable, but this figure can rise significantly during an epidemic.¹⁴ The most effective preventative measure is vaccination,¹⁵ and practices are required to identify and compile a register of individuals in the at-risk groups so that they may be invited to receive an annual vaccination.¹⁶ As readers will be only too aware, much of the responsibility of implementing the annual flu vaccination programme falls on practice nurses.¹³

There are, however, additional factors that make people susceptible to preventable winter death. See Table 1

Many of the individuals at risk will be known to, or access health and social care services and local authority housing departments. A systematic approach to identifying those at greater risk is helpful when planning for pro-active prevention.

LEARNING FROM OTHER COUNTRIES

There are wide variations in winter mortality rates between countries, and in an analysis of excess winter mortality in 14 European countries between 1988 and 1997, the UK compared poorly with most other countries.¹⁷ (Figure 1)

It can be seen that countries with milder winter climates, where mean temperatures remain above 5°C, were generally linked with higher mortality rates, prompting the term ‘the paradox of excess winter mortality’.¹⁷

Healy’s seminal study,¹⁷ now published over a decade ago, suggested that making improvements to the energy efficiency of the housing stock and tackling poverty and inequality through social policy could close the gap in mortality rates across the European countries. However, subsequent studies have revealed that causative factors are in fact more complex.

BEHAVIOURAL FACTORS

Donaldson and colleagues¹⁸ found that there was no increase in mortality in western Siberia in Russia where temperatures regularly fall to 0°C, whereas the same conditions resulted in large increases in excess winter deaths in Western Europe. In Russia, it seems, people are better prepared for low temperatures – by maintaining warmer homes (typically 21.9°C), keeping physically active and wearing hats, gloves and several layers of clothing to prevent cold stress when going outdoors. However, in warmer climates people are less likely to wear hats, gloves and insulated outer clothing, leading to a loss of body heat.

So why, when wearing appropriate winter clothing would be a sensible precaution, particularly for the vulnerable and those with pre-existing cardiovascular disease, are UK residents not so prepared to maintain comfort in similar temperatures?

One simple explanation may be that people are resistant to advice targeted at an older age group than they perceive themselves to be, and in particular may resist wearing clothes which they think are old-fashioned or ‘unbecoming’.²⁰

Lack of outdoor activity may result in reduced tolerance to the cold, but conversely, strenuous outdoor activity (such as shovelling snow) at a time when immune function is lower can also contribute to winter mortality and morbidity.¹⁹ This is an area where evidence in the literature is limited and further research is needed.

INDOOR TEMPERATURE

There is a plethora of evidence to demonstrate that cold homes are a significant factor in excess winter deaths and, of equal concern, cold homes contribute to childhood asthma, and have a negative impact on

• learning abilities of older children
• mental health problems
• dementia, and
• exacerbations of arthritis and chronic lung conditions.²¹

Studies have shown that there is an increased risk to health when living room temperatures fall below 18°C, particularly for the very elderly and the very young, compounded by the fact that some elderly people feel comfortable at low temperatures and the young have under developed thermo-regulatory systems and/or undeveloped communication abilities.²²

It is recommended that living room temperatures should be heated to 21°C and bedrooms to 18°C.²³

However, fear of high energy bills, energy-inefficient homes and low incomes mean that these recommendations may remain out of reach for many of our patients.

RECOMMENDATIONS FOR PRACTICE

The Cold Weather Plan¹ sets out specific instructions for GPs and practice staff. (Box 1) A key activity is to identify the resources and services that vulnerable people can be directed to, and this means that good communication between agencies is essential. Information regarding local and national winter warmth schemes, eligibility criteria and referral pathways must be accessible to all frontline staff and clinicians, especially when undertaking home visits.

Health promotion is important part of reducing excess mortality, and practice nurses should use risk stratification tools with the practice database to identify those individuals most at risk.

Excellent communication skills and negotiation techniques are needed when challenging long held values and beliefs, and it is important to be sensitive when discussing subjects such as financial difficulties or clothing to respect your patient’s dignity.

A creative and perhaps imaginative display in the waiting room could be considered, providing a range of information, advice and contact numbers. Your practice could consider getting involved in Age UK’s ‘Big Knit Campaign’ to break down stereotyping about hats.²⁴

If practice nurses are to truly be able to ‘go upstream’ in terms of prevention, promotion and protection,²⁵ a lead within each practice must exist in order to ensure that all practice staff are aware of what their roles and responsibilities are in the reduction of the preventable winter death. Practice nurses are well placed to make a real difference.

REFERENCES

1. Public Heath England. Cold Weather Plan for England 2013. London: PHE Publications; 2013.

2. Office for National Statistics. Excess Winter Mortality in England and Wales, 2012/13 (Provisional) and 2011/12 (Final). http://www.ons.gov.uk/ons/rel/subnational-health2/excess-winter-mortality-in-england-and-wales/2012-13--provisional--and-2011-12--final-/index.htm

3. Aylett L, Donovan H. Consequences of radical public health reform in England. Primary Health Care 2013; 23 (3): 6-7.

4. NICE PHG 70. Excess winter deaths and illnesses. 2014. http://guidance.nice.org.uk/PHG/70#projectTeam

5. Office for National Statistics. Hypothermia deaths in England and Wales, 2001-2010. 2013. http://www.ons.gov.uk/ons/about-ons/business-transparency/freedom-of-information/what-can-i-request/published-ad-hoc-data/health/june-2013/hypothermia-deaths-in-e-w--2001---2010.xls

6. Neno R. Hypothermia: assessment, treatment and prevention. Nursing Standard 2005;19(20):47-52

7. Trim J. Monitoring temperature. Nursing Times 2005; 101 (20): 30.

8. Kemp P. Hypothermia: causes and management. British Journal of Healthcare Assistants 2008;2(12):586-588

9. Jevons P, Ewan B. Monitoring the Critically Ill Patient. 2nd ed. Oxford: Blackwell Publishing Ltd. 2007.

10. Neno R. Hypothermia: assessment, treatment and prevention. Nursing Standard 2005;19(20):47-52

11. Farley, McLafferty E, Hendry C. The Physiological Effects of Ageing. US: Wiley-Blackwell. 2011.

12. Peate I. Keeping warm: health risks to vulnerable people Nursing & Residential Care 2008;10(12):606-610

13. Willcox A. Influenza epidemiology and prevention. Practice Nurse 2011;22(10): 538-543

14. Shaw K. Knowledge: Seasonal, avian and pandemic influenza. Nursing Times 2008; http://www.nursingtimes.net/knowledge-seasonal-avian-and-pandemic-influenza/524015.article

15. Nicoll A, Sprenger M. Low effectiveness undermines promotion of seasonal influenza vaccine. The Lancet Infectious Diseases 2013;13(1):7

16. Department of Health. Influenza: the Green Book, chapter 19. 2013. https://www.gov.uk/government/publications/influenza the-green-book-chapter-19

17. Healy J.D. Excess winter mortality in Europe: a cross country analysis identifying key risk factors. Journal of Epidemiology and Community Health 2003; 57(10):784-789

18. Donaldson G, Tchernjavskii V, Ermakov S, et al. Winter mortality and cold stress in Yekaterinburg, Russia: interview survey 1. BMJ 1998;316 (7130):514-518

19. Conlon K, Rajkovich N, White-Newsome J, et al. Preventing cold-related morbidity and mortality in a changing climate. Maturitas 2011;69(3):197-202

20. Day R, Hitchings R. ‘Only old ladies would do that’: Age stigma and older people’s strategies for dealing with winter cold. Health and Place 2011;17(4): 885-894

21. Marmot Review Team. The Health Impacts of Cold Homes and Fuel Poverty. London: Friends of the Earth & the Marmot Review Team. 2011.

22. Ormandy D, and Ezratty V. (Health and thermal comfort: From WHO guidance to housing strategies. Energy Policy 2011;49:116.

23. Public Health England. Keep warm, keep well. London: PHE Publications. 2013.

24. Age UK. The Big Knit Campaign 2014 http://www.ageuk.org.uk/get-involved/events-and-challenges/the-big-knit/

25. Royal College of Nursing. Going upstream: nursing’s contribution to public health; Prevent, promote and protect, 2012 RCN Publishing, Cavendish Square, London

26. Cutler LR, Cutler J. Critical care nursing made incredibly easy. London: Lippincott Williams & Wilkins. 2010