Data & Lifestyle Factors (AQA GCSE Biology): Revision Note

Sampling, translating & interpreting data

• Sampling allows researchers to infer (deduce/conclude) information about a population without having to investigate every individual, which would be time-consuming and essentially impossible to do accurately

• Data from a study is more valid when the sample is large, the study runs for a long time and other factors that could affect the disease (control variables, e.g. smoking, diet, BMI, medication, family history) are kept the same between the groups

• Self-reported data (e.g. how much alcohol people say they drink) can reduce validity, because people may under- or over-estimate

• Scientists sample populations to determine risk factors for different diseases and inform public health policy

  • For example: sampling individuals with type 2 diabetes and identifying patterns or similarities in their lifestyle and health condition allows scientists to deduce that obesity and a diet high in sugar and fat are risk factors for developing this condition (as these factors are found in most individuals who develop type 2 diabetes)

• Scientists present their findings in graphical and numerical forms to identify if there are relationships between risk factors and certain diseases

• Scatter diagrams are used to identify correlations between two variables to see whether a factor (such as obesity) is linked to a disease (such as type 2 diabetes). A correlation shows that the two are associated; on its own it does not prove that the factor causes the disease

Lifestyle factors & non-communicable disease

• Lifestyle factors such as diet, alcohol consumption and choosing to smoke have a big impact on the incidence of non-communicable diseases at all levels in society, from the individual to the national and global level

• Some lifestyle factors are associated with increased likelihood of individuals within a population suffering from non-communicable disease

  • A non-communicable disease is not caused by a pathogen and tends to have longer-lasting effects on the health of an individual (usually they get progressively worse over time)

• A causal mechanism has been proven for some risk factors, but not in others

Smoking as an example

• An individual who smokes cigarettes is far more likely to suffer lung cancer than an individual who does not

• Treatment for cancer includes surgery, radiotherapy and chemotherapy – all of these require hospitalisation and access to the right medication

• Hospitalisation utilises healthcare capacity and medicinal drugs – costing time and money at both a local and national level (and a personal level if healthcare is self-funded)

• The individual with lung cancer may not be able to work whilst receiving treatment, and this reduces their income, and loss of work can have a profound effect on mental health

• Nationally, more people with non-communicable diseases means the health service (NHS) spends more money on surgery, medication and hospital stays, and more people unable to work means lower productivity and more financial support from employers or the government