Question

Please no copy paste. Kindly don't attempt if you will copy. Answer in minimum 300 words please.

Discussion Topic 2: Measuring population risk What do we mean by relative risk as opposed to population attributable risk? Efforts have been made to standardize methods of measurement of risk factors at the global level, including the WHO MONICA Project in the 1980s and 1990s. More recently, the WHO STEPS approach to the measurement of population levels of risk factors provides methods and materials to encourage countries to collect data in a standardized manner' (Bonita, Beaglehole & Kjellström 2006). What are some of the things that need to be taken into consideration in collecting global health statistics related to disease risk?

Answer 1

Health and wellbeing are affected by many factors – those linked to poor health, disability, disease or death, are known as risk factors. A risk factor is a characteristic, condition, or behaviour that increases the likelihood of getting a disease or injury. Risk factors are often presented individually, however in practice they do not occur alone. They often coexist and interact with one another. For example, physical inactivity will, over time, cause weight gain, high blood pressure and high cholesterol levels. Together, these significantly increase the chance of developing chronic heart diseases and other health related problems. Ageing populations and longer life expectancy have led to an increase in long-term (chronic), expensive-to-treat diseases and disabilities. There is a rising demand for healthcare, placing the sector under increasing budget pressure which is not always met. It is important that we, as a society and users of healthcare systems, understand the causes and risk factors behind diseases, so that we can actively take part in available cost effective prevention and treatment programmes.

Risk

Risk is the proportion of individuals in a population (initially free of disease) who develop the disease within a specified time interval. Incidence risk is expressed as a percentage (or if small as per 1000 persons).

Attributable risk

Disease rate in exposed persons minus that in unexposed persons. It is the measure of association that is most relevant when making decisions for individuals. For example, in deciding whether or not to indulge in a dangerous sport such as rock climbing, it is the attributable risk of injury which must be weighed against the pleasures of participation.

Relative risk

Ratio of the disease rate in exposed persons to that in people who are unexposed. It is related to attributable risk by the formula: Attributable risk= rate of disease in unexposed persons x ( relative risk- 1)

In general, risk factors can be categorised into the following group

• Behavioural
• Physiological
• Demographic
• Environmental
• Genetic

Behavioural risk factors

• smoking tobacco
• drinking too much alcohol
• nutritional choices
• physical inactivity
• spending too much time in the sun without proper protection
• not having certain vaccinations
• unprotected sex.

Physiological risk factors

Physiological risk factors are those relating to an individual’s body or biology. They may be influenced by a combination of genetic, lifestyle and other broad factors. Examples are

• being overweight or obese
• high blood pressure
• high blood cholesterol
• high blood sugar (glucose

Demographic risk factors

Demographic risk factors are those that relate to the overall population. Examples include:

• age
• gender
• population subgroups, such as occupation, religion, or income.

Environmental risk factors

Environmental risk factors cover a wide range of topics such as social, economic, cultural and political factors as well as physical, chemical and biological factors. Examples include:

• access to clean water and sanitation
• risks in the workplace
• air pollution
• social settings.

Genetic risk factors

Genetic risk factors are based on an individual’s genes. Some diseases, such as cystic fibrosis and muscular dystrophy, come entirely from an individual’s ‘genetic make-up’. Many other diseases, such as asthma or diabetes, reflect the interaction between the genes of the individual and environmental factors. Other diseases, like sickle cell anaemia, are more prevalent in certain population subgroups.

Global risks for mortality and demographic factors

Income

For high and middle-income countries, the most important risk factors are those related to long-term diseases, whereas in low-income countries, factors such as childhood malnutrition and unprotected sex are much more widespread.

Age

Risk factors also change with age. Some risk factors almost exclusively affect children such as malnutrition and indoor smoke from solid fuels. For adults, there are considerable differences depending on age: Unprotected sex and addictive substances (e.g. tobacco and alcohol) account for most of the health problems in younger adults Risk factors for long-term diseases and cancers mainly affect older adults.

Gender

Gender differences also exist. For example, men are much more likely to be at risk of factors associated with addictive substances. Women are prone to suffer from iron deficiency during pregnancy

Reducing exposure to risk factors

Reducing contact (exposure) to risk factors would greatly improve global health and life expectancy by many years. This would therefore reduce healthcare costs. See also the SCORE Project fact sheet as an example of how risk factors would greatly influence health and life expectancy.