Demography and populations

Question 1

Define demography

Answer 1

The study of the size, structure, dispersement and development of human populations

Question 2

What is a census?

Answer 2

The simultaneous recording of demographic data by the government at a particular time pertaining to all the persons who live in a particular territory

Question 3

Uses of the census

Answer 3

Projections and estimates of population size
Trends In population characteristics
Highlights regional differences
Provides data for planning services
Material deprivation (ome ownership, car access, amenities)
Some health information

Question 4

Uses of mortality data

Answer 4

Planning
Public health monitoring
Outcome indicator of healthcare

Question 5

Define morbidity

Answer 5

Any departure, subjective or objective from a state of physiological or psychological well-being. In this sense, sickness, illness and morbid condition are similarly defined (synonymous)

Question 6

Uses for cancer registration

Answer 6

Epidemiological studies
Management planning of services for prevention and care
Healthcare research
Evaluation of screening programmes
Survival studies from malignant disease

Question 7

What is the Health Survey for England

Answer 7

Annual survey using a random sample of 16000 adults 16+ and 4000 children in private households.

Includes health and socio-economic questionnaire
physical measurements (height, weight bp)
blood sample tested for Hb, Ferritin, cholesterol.

Question 8

Hospital episode statistics (HES)

Answer 8

Contains details of all admissions to NHS hospitals in England

Question 9

Use of demography

Answer 9

To establish reliable statistics on

• birth and death rates
• marriages and divorces
• life expectancy
• migration

Question 10

Framework for assessing quality of Health Information

Answer 10

Completeness: how much of the data is missing
Accuracy: is it correct? Has there been adequate coverage
Representativeness: is it relevant to the question, is it representative of the population
Timeliness: completed within the required time
Accessibility: who has access

Question 11

Value of census to health

Answer 11

Knowledge of population size & structure are strong determinants for needs in healthcare

Base population used to evaluate disease in a population

Measures of material deprivation used to identify and target inequalities

Question 12

Measures of fertility

Answer 12

Crude birth rate: live births/1000 population (includes men, infertile women)
General fertility rate: live births/1000 women aged 15-44
Total fertility rate: average number of live children that a group of women would have if they experienced the age-specific fertility rates of the calendar year in question throughout their child-bearing lifespan.

Question 13

Birth registration

Answer 13

Birth attendant ( midwife) notifies health authority within 36hrs
Birth registration by parents to local registrar within 42 days

Both submitted to ONS

Question 14

Death registration

Answer 14

Death certificate issued by doctor (certifies age, place and cause of death)
Death registration by informant within 5 days to local registrar
Submitted to ONS

Question 15

Population estimates

Answer 15

Estimate of population size and structure between census

Census baseline+ births - deaths +/- migration

Question 16

Strengths of making population estimates

Answer 16

More up to date than census

More accurate than projections

Question 17

Weaknesses of population estimates

Answer 17

Less reliable with time from census
Poor information on migration
Says nothing about future

Question 18

Population projections

Answer 18

Forecast future population size and structure, based on assumptions about mortality, fertility and migration

Question 19

Strengths of population projections

Answer 19

Can be used for longer term planning

Question 20

Weaknesses of population projections

Answer 20

Less accurate the further ahead

Unforeseen changes of past trends can invalidate projections

Question 21

Why is notification of communicable disease important?

Answer 21

Uses:
To prevent further infection
Identify outbreaks
Surveillance to monitor trends

Question 22

Main disadvantages of surveys

Answer 22

Responder bias: non-responders likely to be those who are have the poorest health (eg. Obese, poor glucose management)

Reporting bias: values can be over or under estimates e.g. Self-reporting of weight tends to be lower than true value

Question 23

Causes of a change in trend over time

Answer 23

Chance
Artefact (change in population size/structure, accuracy or completeness)
Real change (natural change in disease or medical care effects

Question 24

3 examples of low enumerated groups in the census

Answer 24

Students (unsure whether residence is term-time or parents)

Travellers

Babies (left off the form)

Elderly (living alone, accessing form)

Young people (20-29) (lifestyle and multi-occupied housing)

Ethnic minorities (language barrier, suspicion)

Question 25

Strengths and weaknesses of mortaility data

Answer 25

Complete coverage
Gives important information of health of the population

Underlying CoD subject to errors such as incorrect diagnosis, omissions in recording
Doesnt give reliable picture of morbidity
Ethnicity not collected

Question 26

3 sources of morbidity data

Answer 26

Cancer register
Notifications of communicable disease
NHS activity data

Question 27

Strengths and weaknesses of notification of communicable disease

Answer 27

Timeliness - weekly return to HPA
Representative - routine national data
Linked to other data to improve accuracy

Poor variable completeness for some diseases (e.g. food poisoning, colds)
Low accuracy, asked to notify suspected cases.

Question 28

Two main clinical classifications used in HES

Answer 28

ICD-10: international classification of diseases. Describes conditions treated or investigated

OPCS-4: classification of surgical operations and procedures. Records details of operations

Question 29

Strengths and weaknesses of QoF data

Answer 29

Almost 100% response from GPs
Representative of all the population
Updated annually
Accessible online

Excludes practices who do not participate
Unsure how complete disease registers are for individual practices
Aggregated data (no age, sex breakdown)

Question 30

QoF

Answer 30

Requires GPs to record information on number and clinical management of patients with chronic diseases and the care they receive.

Information collected is used to produce a set of quality scores which are linked to payments. Data can be used to estimate the incidence and prevalence of different diseases and assess the quality of care in general practice.

Question 31

How do population pyramids help in the design of services?

Answer 31

Age and sex are strong determinants for the need of health services. Knowledge of the breakdown is essential to plan which services are needed. Population pyramids also allow forecasting of future service needs.

Question 32

What things to do you need to consider when interpreting trends over time?

Answer 32

Need to consider whether the change is due to:

1. Chance
2. Artefact: change in numerator (completeness of data or accuracy varies over time), change in denominator (change in population size or structure)
3. Real change: natural change in disease or effects of medical care.