Measuring health and disease

Question 1

Incidence

Answer 1

Considers how many new cases of a disease occur over a defined period of time.

Question 2

Incidence rate

Answer 2

Number of new cases of a disease arising over a time period/ person-years at risk

Question 3

Prevalence

Answer 3

Measures how many people have a disease at one point in time.

Question 4

Point prevalence equation

Answer 4

number of people with a disease at a point in time/ total population at risk of the disease at the time point

Question 5

Types of birth and fertility rates

Answer 5

Birth rate= number of live births per 1000 population
General fertility rate= number of live births per 1000 women aged 15-44
Total fertility rate= the average number of children that a woman would bear if she experienced the age-specific fertility rates at that point in time

Question 6

Infant mortality rate (per 1000)

Answer 6

(number of deaths in children aged >1year/ all live births) x1000

Question 7

Crude mortality rate

Answer 7

total number of deaths in 1 year/ total mid-year population

Question 8

Disease specific death rate (per 1000)

Answer 8

(number of deaths from disease/total mid-year population) x1000

Question 9

Purpose of measuring health

Answer 9

• find out incidence and prevalence
• identify longitudinal trends
• investigate whether interventions/policies are effective
• identify disease patterns
• service planning

Question 10

Sources of health information

Answer 10

• Office for National Statistics
• NHS Digital
• World Health Organisation

Question 11

Types of health data sources

Answer 11

• Death Certification
• Census
• Health Survey for England (HSE)
• General Lifestyle Survey
• Hospital Episode Statistics
• General Practice Research databases (CPRD and THIN)
• Health protection reports of notifiable infectious diseases
• Cancer registration
• National/regional/local audits or surveys

Question 12

Key methods of measuring health and disease

Answer 12

• Birth and fertility rates
• Incidence
• Prevalence
• Mortality rate (crude and standardised)

Question 13

Standardisation

Answer 13

Enables us to compare rates of disease or death in populations with different structures ie. age/sex/ethnicity. Specific death rates are applied to a standard population structure. Can be expressed directly or as a ratio of observed/expected number of deaths (indirect).