1. Postgraduate Course Feedback DATA ON POPULATION AND MORTALITY INTRODUCTION TO BASIC CONCEPTS IN DEMOGRAPHY workshop Dr Carmen Aceijas, PhD c.aceijas@mdx.ac.uk BIO4503 APPLIED EPIDEMIOLOGY

2. WORKSHOP OUTLINE Building from lecture contents: Population pyramids transformation. Video watching Some key indicators to describe populations: 2. BIRTH RATE, 3. FERTILITY RATE, 4. MORTALITY RATE, AND 5. DISEASE RATE

3. POPULATION PYRAMIDS http://www.youtube.com/watch?fea ture=player_embedded&v=OpOEH jndywkhttp://www.youtube.com/watch?fea ture=player_embedded&v=OpOEH jndywk

4. Are measures of frequency Used when the aim is to know how frequently an event happens within a given period of time in a given population. Most used in PH epidemiology: –Birth Rate –Fertility Rate –Mortality [Death] Rate –Disease Rate Take into account –The number of events (e.g. No of deaths, births, cases of a disease) – The number of people to whom it could potentially happen (Population at risk) – Time period within which it happened (often year) Reported as “x” [evens/cases] per 1,000 or 100,000 population WHAT ARE RATES? WHAT ARE THEY USED FOR? WHAT ARE THOSE MOST USED IN EPIDEMIOLOGY?

5. Birth rate: –Measures number of births within a given period of time (e.g. Year) –The denominator is the whole population –Reported as per 1,000 population BIRTH RATE Birth rate = Number of births in year x 1000 (crude) (mid-year) population

6. Measures number of births within a given period of time (e.g. Year) The denominator is the female population 15-44 Reported as “no. of children per woman” FERTILITY RATE Fertility rate = Number of births in year x 1000 (crude) (mid-year) female population 15-44 Adjusted FR is calculated based on current fertility rates in different age groups

7. Mortality (death) rate: –Measures number of deaths per 1,000 within a given period of time (e.g. Year) –The denominator is the whole population –Reported as per 1,000 population MORTALITY RATE Crude Mortality Rate (CMR) = Number of deaths in year x 1000 mid-year population

8. OTHER MORTALITY RATES. INFANT MORTALITY RATE, UNDER 5 MORTALITY RATE, MATERNAL MORTALITY RATE Infant mortality rate= No. of deaths in children under 1 year of age x 1000 No. of live births in year Under 5 mortality rate= No. of deaths in children under 5 years of age x 1000 No. of live births in year Maternal mortality = Number of deaths related to childbearing x 1000 No. of live births in year

9. Measures number of event [people getting the disease = cases] within a given period of time (e.g. Year) The denominator is the population at risk [might or might no be the whole population] Reported as per 100,000 population but might vary depending on extent of disease [often multiplies used 1,000 or 10,000 too] DISEASE RATE Disease rate= Number of cases x 100,000 pop at risk *or other multiplier

10. Exercise: Calculate the natural increase, the birth and the mortality rates in a “x” country in 2012: –Population: 25,000,000 –Number of births in 2008: 3,500 –Number of deaths in 2008: 47,500 BIRTH RATE and MORTALITY RATE [exercise]

11. CMR = 47,500/25,000,000x1,000= 1.9 deaths per 1,000 population NATURAL INCREASE, BIRTH RATE and MORTALITY RATE [exercise] BR = 3,500/ 25,000,000x1,000= 0.14 births per 1,000 population NI = 3,500 – 47,500 / 25,000,000 x 100 = - 0.176% [-0.18%] Answers:

12. Exercise: Calculate the disease rate of HIV in a “x” country in 2010 excluding vertical transmission. Population: 25,000,000 Population at risk: Calculate it taking into account the percentage of 0-12 years old = 15% Cases: 3,000 DISEASE RATE [exercise]

13. Answer: Population: 25,000,000 Population at risk: 21,250,000 [85% of whole pop] Cases: 3,000 3,000/21,250,000x1,000 = 0.14 cases per 1,000 population 3,000/21,250,000x100,000 = 14.11 cases per 100,000 pop DISEASE RATE [exercise]

14. When presenting data Always specify Year Always specify Source of data Make sure you compare data from the same year and the same source Always use units of measurement (years, people, percentages etc.) When presenting rates check multiplier (per 1000, per 10,000 or 100,000 etc).