Lecture 15: Demographic Measures and Population Health

Question 1

what are the main population data sources for epidemiology?

Answer 1

census
- estimated resident population (erp)
- vital events (births, deaths and marriages)
- HSU: health service utilisation and outcome
- IDI; integrated data infrastrucutre
- nationally representative surveys
- adhoc surveys

Question 2

what is the idi?

Answer 2

routinely collected information from many government and some other agencies
info is de-identified + strict rules are in place to preserve confidentiality
to be counted, you have to have interaction with one or more of these agencies (health, education, tax, police, social development, acc)

Question 3

what are the benefits and potential risks for idi?

Answer 3

de-identified, linkable and acced in a data safe haven
resident population definitions can vary from study to study (compare this to the census or health contact populations as a denominator)

• resource is only as good as the data it contains (what are the concerns about data quality, selection biases inherent?)

Question 4

why do denominators and age-structure matter?

Answer 4

the hsu, idi and census all have different numbers. because they reperesent parts of the population that are more motivated to preform each survey

Question 5

how do events determine population structure?

Answer 5

age-sex structure= function of previous patterns, ternds of fertility, migration and mortality events

vital events:
- changes in fertility/infant mortality rates (dramatic but has time lag)
- adult mortality rates: (less dramatic/less variable overtime bc its spread over a wider age range)
- migration: dramatic effect (esp if trend is age/sex specific)

Question 6

how does populatio nstructure affect events?

Answer 6

fertility: women only, concentrated in young adult ages
mortality: highest among the very young and the elderly
migration: varies with sex/stage in the life cycle

Question 7

what are the advantages + disadvantages of prioritised output?

Answer 7

+ensures that ethnic groups of small size are not swamped by the nz european ethnic group
+ produces data that is easy to work with as each individual appears only once. data = sum of population

-places ppl in specific ethnic group (simplifies yet biases. overrepresents some groups at the expense of others in ethnic groups
- externally applied single ethnicity,, inconsistent with the concept of self-identification

Question 8

what are the advantages + disadvantages of total response output

Answer 8

+ potential to repserent ppl who do not identify with any given ethnic group

• create complexiities in the idistburtion of funding based on population mumbers or in monitoring changes in the ethnic composition
• create issues in interpretations of data reported by ethnic groups. comparisions = overlappign data.

Question 9

what are the types of aging?

Answer 9

1. numerical: the absolute increase in the population that is elderly
   - reflects previous demogrpahic patterns
   - improvements in life expectancy
2. strucutral aging: increase in proportion of population that is elderly
   - driven by decreases in fertility rates
   - began occurring in the 1800s

Question 10

what are the populatio nimpacts of ageing?

Answer 10

1. natural decline of the population: occurs when more deaths than births
   - combo of absolute + structural
   - more eldery = more deaths
2. absolute decline of the popualtion: insufficient migration to replace lost births + increased deaths
   - not expected to happen in nz for 70+ years
   - happening in someeuropean/asians