Epid 503 Class 6 Standardization Exam is Feb

Epid 503: Class 6 Standardization

Exam is Feb 8: One more class after today with new content February 1 – meet in auditorium February 6 – go over practice problems/exam GSI office hours

3 Comparing Mortality Across Populations Age is the strongest predictor of mortality Population age structures differ at different time points and between populations

US Mortality Curve 4

5 Example from Gordis tables 4. 7 &4. 8 Crude Mortality Rates by Race, Baltimore City, 1965 Race Mortality per 1, 000 population White 14. 3 Black 10. 2 Death Rates by Age and Race, Baltimore City, 1965 Death Rates by Age per 1, 000 population Race All ages <1 yr 1 -4 yr 5 -17 yr 18 -44 yr 45 -64 yr >65 yr White 14. 3 23. 9 0. 7 0. 4 2. 5 15. 2 69. 3 Black 10. 2 31. 3 1. 6 0. 6 4. 8 22. 6 75. 9

Direct Age Adjustment 6 Uses a standard population structure to adjust for population age structure differences Hypothetical “standard” population age structure used Age-specific mortality rates from populations of interest are applied to the “standard” age structure

Steps in Direct Age Adjustment 7 Step 1 – Calculate the crude and age-specific mortality rates for each population of interest Step 2 - Create (or choose) a “standard” population Step 3 - Apply population of interest agespecific death rates to the standard population Step 4 - Calculate age-adjusted death rates

8 Step 1: Calculate the Crude and Age-specific Mortality Rates Crude Death Rates in Two Communities Community A Age (yrs) Populatio Deaths Death n Rate (per 1000) Community B Populatio n Deaths Under 1 1, 000 15 5, 000 1 -14 3, 000 3 20, 000 10 15 -34 6, 000 6 35, 000 35 35 -54 13, 000 52 17, 000 85 55 -64 7, 000 105 8, 000 160 Over 64 20, 000 1, 600 15, 000 1, 350 Totals 1, 781 100, 000 1, 740 50, 000 Death Rate (per 1000) Example from Klienbaum

9 Step 1: Calculate the Crude and Age-specific Mortality Rates Crude Death Rates in Two Communities Community A Age (yrs) Populatio Deaths Death n Rate (per 1000) Community B Populatio n Deaths Death Rate (per 1000) Under 1 1, 000 15 15. 0 5, 000 100 20. 0 1 -14 3, 000 3 1. 0 20, 000 10 0. 5 15 -34 6, 000 6 1. 0 35, 000 35 1. 0 35 -54 13, 000 52 4. 0 17, 000 85 5. 0 55 -64 7, 000 105 15. 0 8, 000 160 20. 0 Over 64 20, 000 1, 600 80. 0 15, 000 1, 350 90. 0 Totals 1, 781 35. 6 100, 000 1, 740 17. 4 50, 000

10 Step 2: Create (or Choose or Use Provided) a Standard Population Many choices here Could be: Either community A or B Sum of community A & B External community such as US population or another country

11 Step 2: Create (or Choose) a Standard Population In this case we will add the populations of Community A & B Community A Community B Standard Population Under 1 1 -14 15 -34 35 -54 55 -64 Over 64

12 Step 2: Create (or Choose) a Standard Population In this case we will add the populations of Community A & B Community A Community B Standard Population Under 1 1, 000 5, 000 6, 000 1 -14 3, 000 20, 000 23, 000 15 -34 6, 000 35, 000 41, 000 35 -54 13, 000 17, 000 30, 000 55 -64 7, 000 8, 000 15, 000 Over 64 20, 000 15, 000 35, 000 Total 50, 000 100, 000 150, 000

13 Step 3: Apply the age-specific death rates to the standard population Standard Comm. A Population Death Rate (per 1000) Expected Comm. B Deaths at Death A’s rates Rate (per 1000) Under 1 6, 000 15. 0 20. 0 1 -14 23, 000 1. 0 0. 5 15 -34 41, 000 1. 0 35 -54 30, 000 4. 0 55 -64 15, 000 15. 0 20. 0 Over 64 35, 000 80. 0 90. 0 Total 150, 000 Expected Deaths at B’s rates

14 Step 3: Apply the age-specific death rates to the standard population Standard Comm. A Population Death Rate (per 1000) Expected Comm. B Deaths at Death A’s rates Rate (per 1000) Expected Deaths at B’s rates Under 1 6, 000 15. 0 90 20. 0 120 1 -14 23, 000 1. 0 23 0. 5 11. 5 15 -34 41, 000 1. 0 41 35 -54 30, 000 4. 0 120 5. 0 150 55 -64 15, 000 15. 0 225 20. 0 300 Over 64 35, 000 80. 0 2, 800 90. 0 3, 150 Total 150, 000 3, 299 3, 772. 5

15 Step 4: Calculate the age-adjusted death rates Divide sum of expected deaths by the total population to calculate the age-adjusted death rates Standar d Populati on Comm. A Death Rate (per 1000) Expected Deaths at A’s rates Comm. B Expected Death Rate Deaths at (per 1000) B’s rates Under 1 6, 000 15. 0 90 20. 0 120 1 -14 23, 000 1. 0 23 0. 5 11. 5 15 -34 41, 000 1. 0 41 35 -54 30, 000 4. 0 120 5. 0 150 55 -64 15, 000 15. 0 225 20. 0 300 Over 64 35, 000 80. 0 2, 800 90. 0 3, 150 Total 150, 000 Age-Adjusted Death Rates 3, 299 3, 772. 5

16 Step 4: Calculate the age-adjusted death rates Divide sum of expected deaths by the total population to calculate the age-adjusted death rates Standar d Populati on Comm. A Death Rate (per 1000) Expected Deaths at A’s rates Comm. B Expected Death Rate Deaths at (per 1000) B’s rates Under 1 6, 000 15. 0 90 20. 0 120 1 -14 23, 000 1. 0 23 0. 5 11. 5 15 -34 41, 000 1. 0 41 35 -54 30, 000 4. 0 120 5. 0 150 55 -64 15, 000 15. 0 225 20. 0 300 Over 64 35, 000 80. 0 2, 800 90. 0 3, 150 Total 150, 000 Age-Adjusted Death Rates 3, 299 22 3, 772. 5 25

Steps in Direct Age Adjustment 17 Step 1 – Calculate the crude and age-specific mortality rates for each population of interest � Divide deaths by population in each category Step 2 - Create (or choose) a “standard” population Step 3 - Apply population of interest age-specific death rates to the standard population � Multiply population of interest age-specific death rates by standard population Step 4 - Calculate age-adjusted death rates � Sum expected deaths of population of interest and divide by total “standard” population

Indirect Age Adjustment 18 Uses a “standard” mortality rate and applies it to the population Expected and observed mortality rates are compared Used to calculate the standardized mortality ratio (SMR) SMR= Observed # deaths Expected # deaths

19 Steps in Indirect Age Adjustment Step 1: Apply “standard” rates to the population structure Step 2: Sum the expected number of deaths over each stratum Step 3: Calculate the standardized mortality ratio (SMR) SMR=observed deaths expected deaths

20 Community B crude death rates as a standard Crude Death Rates in Two Communities Community A Age (yrs) Populatio Deaths Death n Rate (per 1000) Community B Populatio n Deaths Death Rate (per 1000) Under 1 1, 000 15 15. 0 5, 000 100 20. 0 1 -14 3, 000 3 1. 0 20, 000 10 0. 5 15 -34 6, 000 6 1. 0 35, 000 35 1. 0 35 -54 13, 000 52 4. 0 17, 000 85 5. 0 55 -64 7, 000 105 15. 0 8, 000 160 20. 0 Over 64 20, 000 1, 600 80. 0 15, 000 1, 350 90. 0 Totals 1, 781 35. 6 100, 000 1, 740 17. 4 50, 000

21 Step 1: Apply “standard” rates to the population structure Age Population Community A Standard Expected Death Rates Deaths (per 1000) Under 1 1, 000 20. 0 1 -14 3, 000 0. 5 15 -34 6, 000 1. 0 35 -54 13, 000 5. 0 55 -64 7, 000 20. 0 Over 64 20, 000 90. 0 Total 50, 000

22 Step 1: Apply “standard” rates to the population structure Age Population Community A Standard Expected Death Rates Deaths (per 1000) Under 1 1, 000 20 1 -14 3, 000 0. 5 15 -34 6, 000 1. 0 6 35 -54 13, 000 5. 0 65 55 -64 7, 000 20. 0 140 Over 64 20, 000 90. 0 1, 800 Total 50, 000

23 Step 2: Sum the expected deaths over each stratum Age Population Community A Standard Expected Death Rates Deaths (per 1000) Under 1 1, 000 20 1 -14 3, 000 0. 5 15 -34 6, 000 1. 0 6 35 -54 13, 000 5. 0 65 55 -64 7, 000 20. 0 140 Over 64 20, 000 90. 0 1, 800 Total 50, 000

24 Step 2: Sum the expected deaths over each stratum Age Population Community A Standard Expected Death Rates Deaths (per 1000) Under 1 1, 000 20 1 -14 3, 000 0. 5 15 -34 6, 000 1. 0 6 35 -54 13, 000 5. 0 65 55 -64 7, 000 20. 0 140 Over 64 20, 000 90. 0 1, 800 Total 50, 000 2032. 5

Observed deaths 25 Crude Death Rates in Two Communities Community A Age (yrs) Populatio Deaths Death n Rate (per 1000) Community B Populatio n Deaths Death Rate (per 1000) Under 1 1, 000 15 15. 0 5, 000 100 20. 0 1 -14 3, 000 3 1. 0 20, 000 10 0. 5 15 -34 6, 000 6 1. 0 35, 000 35 1. 0 35 -54 13, 000 52 4. 0 17, 000 85 5. 0 55 -64 7, 000 105 15. 0 8, 000 160 20. 0 Over 64 20, 000 1, 600 80. 0 15, 000 1, 350 90. 0 Totals 1, 781 35. 6 100, 000 1, 740 17. 4 50, 000