2 Epidemiology Module - Camp Crisis

Alison Grant 28/8/18

Descriptive epidemiology and survey design

Epidemiology is a tool box, to ansqer q’s:

How much disease? Who gets it? What happens to people with disease? What causes disease? Does this intervention prevent this disease?

2.1 Camp Death Rate

What do you want to know when invesigating deaths?

Total Population Size, WHAT IS THE DENOMINATOR (most important thing) Some Average Mortality Rate Comparison against that But is it a fair comparison? (are you comparing like for like)

Comparisons between groups, use a rate/1000 to allow comparison, but take into account the overall size of a group, think about how much random chance will change a rate/1000 (it will affect a rate/1000 in a smaller group)

2.1.1 What will affect reported rates?

ACCESS Distance Physical Barriers to transport - river Affordability Security of camps

HEALTH SEEKING BEHAVIOUR Beliefs about what requires medical help Cultural persecution of affected group Other medical support elsewhere/Self medicating Reputation of hospital

SEVERITY OF ILLNESS Comorbidity

PRIMARY CARE Nursing support in camps

Disease seen in hospital may not be representative of the disease in the community

What additional information?

COnfirm diagnosis Breakdown cases age and sex Place of residence of cases Is this all the cases?

2.1.2 Surveying a community

through selecting on a map:

The sample needs to be representative. Each house has to have an equal chance of getting picked.

Simple random sampling (number houses, then randomly select numbers)

Systematic sampling (some prefefined characteristic, that every 10th house is picked), fine providing theres nothing abnormal about the system

You can cluster areas, but this is not a good idea in an infectious disease outbreak as you might miss a focal outbreak. So clustering may work for something like malnutrition/NCDs. Not a good idear when areas are different.

If your sample is not representative, you cannot say anything more about the population as a whole.