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Compare Outcomes: 

Compare Outcomes Using all the above specific categories, we could compare 0-4 year-old male Asian mortality rates for asthma with 0-4 Asian female rates for asthma 0-4 other than Asian male rates for asthma 0-4 Asian male rates for diseases other than asthma

Slide2: 

Calculation Practice Calculate cause-specific and age-specific lung cancer death rates What information will you need?

Lung Cancer Deaths by Age Group, United States, 1995: 

Lung Cancer Deaths by Age Group, United States, 1995 15,420 188,500,741 Total 12,356 31,078,760 45-54 2,709 42,467,719 35-44 303 40,873,139 25-34 41 35,946,635 15-24 11 38,134,488 5-14 Lung Cancer Deaths Population Age (years) How would you calculate the cause-specific lung cancer death rate? How would you calculate age-specific lung cancer death rates?

Lung Cancer Deaths by Age Group, United States, 1995: 

Lung Cancer Deaths by Age Group, United States, 1995 15,420 xxx 188,500,741 Total 12,356 2,709 303 41 11 Lung Cancer Deaths 12,356 / 31,078,760 = 39.76 2,709 / 42,467,719 = 6.38 303 / 40,873,139 = 0.74 41 / 35,946,635 = 0.11 11 / 38,134,488 = 0.03 Age-Specific Lung Cancer Death Rate 31,078,760 45-54 42,467,719 35-44 40,873,139 25-34 35,946,635 15-24 38,134,488 5-14 Population Age (years) What inferences can you make from these age-specific rates? Cause Specific Rate = (15,420/188,500,741) x 100,000 = 8.18 / 100,000

Mortality Outcomes (cont.): 

Mortality Outcomes (cont.) Adjusted rate: Used to compare rates for entire populations, taking into account differences in variables we consider as influencing outcomes (age, gender, race)

Two methods to adjust rates:: 

Two methods to adjust rates: Direct Method: AAR (age-adjusted rate) Indirect Method: SMR (standardized mortality ratio)

Standardization for Age (Age Adjustment): 

Standardization for Age (Age Adjustment) Direct method Requires Age-specific rates for the sample Age-structure of a standard population Yields a summary figure: AGE-ADJUSTED RATE

Standardization: Age Adjustment (cont.): 

Standardization: Age Adjustment (cont.) Indirect method Requires Age structure of the sample population at risk Total cases in the sample population (not ages of cases) Age-specific rates for a standard population Yields a summary figure: STANDARDIZED MORTALITY RATIO (SMR)

Creating a cause-specific, age-adjusted death rate using direct standardization: 

Creating a cause-specific, age-adjusted death rate using direct standardization (3) x (4) = (5) (4) (1) / (2) = (3) (2) (1) 226,500,000 xxx 45,000 115 Total 25,700,000 15,000 100 65+ 140,300,000 25,000 10 19-64 60,500,000 5,000 5 0-18 Expected 1980 U.S. Standard Population Age Specific Rate (per 1000) Population at risk Cancer Deaths Age

Creating a cause-specific, age-adjusted death rate using direct standardization: 

Creating a cause-specific, age-adjusted death rate using direct standardization (3) x (4) = (5) (4) (1) / (2) = (3) (2) (1) 288,039,000 226,500,000 xxx 45,000 115 Total 171,419,000 25,700,000 6.67 15,000 100 65+ 56,120,000 140,300,000 0.40 25,000 10 19-64 60,500,000 60,500,000 1.00 5,000 5 0-18 Expected 1980 U.S. Standard Population ASR / 1000 Population at risk Cancer Deaths Age Age-Adjusted Rate (288,039,000 / 226,500,000) x 1000 1.27 per 1,000 > Crude Rate (115 / 45,000) x 1000 2.56 per 1,000

Comparing crude and age-adjusted rates: 

Comparing crude and age-adjusted rates If crude rate decreases after adjustment, the study population is older than the standard population (Crude rate > age-adjusted rate  study population is older) If crude rate increases after adjustment, the study population is younger than the standard population (Crude rate < age-adjusted rate  study population is younger)

The adjusted rate tells you what the rate would be if the sample population had a similar age structure to that of the United States in 1980: 

The adjusted rate tells you what the rate would be if the sample population had a similar age structure to that of the United States in 1980

Comparing Crude and Age-Adjusted Rates: 

Comparing Crude and Age-Adjusted Rates

Comparing Crude and Age-Adjusted Rates (cont.): 

Comparing Crude and Age-Adjusted Rates (cont.) San Francisco males and females had crude rates double those for their counterparts in San Jose San Francisco may have had an older population than San Jose and therefore higher crude rates NEVER assume from crude rates that one place is less healthy than another

Comparing Crude and Age-Adjusted Rates (cont.): 

Comparing Crude and Age-Adjusted Rates (cont.) When age structure was controlled through age-adjustment, San Francisco no longer stood out as having higher rates San Jose’s age-adjusted rates were slightly higher than those for San Francisco Public health as measured by age-adjusted rates is not significantly different between the two cities Note: Failure to take differences in population structures into account may lead to inappropriate conclusions Adjustment aids in preventing CONFOUNDING

Comparing Crude and Age-Adjusted Rates (cont.): 

Comparing Crude and Age-Adjusted Rates (cont.) One type of rate is not necessarily more important than another Which you choose depends on the information sought To estimate the economic burden of high rates on a community, it is usual to start with crude rates Crude rates are often used for health services planning

Comparing Crude and Age-Adjusted Rates (cont.): 

To compare rates among subpopulations or for various causes, specific rates are preferred infant mortality maternal mortality rates To compare the health of entire populations, adjusted rates are preferred as they allow for comparison of populations with different demographic structures Comparing Crude and Age-Adjusted Rates (cont.)

New 2000 Standard for Age-Adjustment: 

Historically, a 1940 base-year has been used for age-adjustment Also, other standards have been used which created confusion among data users Starting September 1, 1998, HHS agencies and programs were required to use the year 2000 standard New 2000 Standard for Age-Adjustment

New 2000 Standard for Age-Adjustment (cont.): 

New 2000 Standard for Age-Adjustment (cont.) What are the implications? When describing disparities in mortality between racial and ethnic groups, the size of the disparity between Blacks and Whites and between Hispanics and Non-Hispanics will be affected

New 2000 Standard for Age-Adjustment (cont.): 

New 2000 Standard for Age-Adjustment (cont.) Example: The mortality ratio for Black and White total populations in 1995 is reduced from 1.6 (1940 standard) to 1.4 (2000 standard) The Blacks population tends to be younger than the White population

New 2000 Standard for Age-Adjustment (cont.): 

New 2000 Standard for Age-Adjustment (cont.) NCHS recommends that researchers present age-specific rates, not just AARs If an AAR is used to describe racial and ethnic disparities, explain the impact of the change in the standard and provide age-specific rates When comparing AARs over time, make sure the same standard is used throughout

Alternate Method of Direct Adjustment: 

Alternate Method of Direct Adjustment Some calculators cannot handle large numbers To overcome this limitation, you can convert your standard population into a standard vector

Slide23: 

Calculate a STANDARD VECTOR (1980 US Census) 0.072 16,348,254 0-4 1.000 226,545,805 Total 0.010 2,240,067 85+ 0.034 7,728,755 75-84 0.069 15,580,605 65-74 0.096 21,702,875 55-64 0.101 22,799,787 45-54 0.113 25,634,710 35-44 0.164 37,081,839 25-34 0.188 42,486,828 15-24 0.154 34,942,085 5-14 Vector (%) Population Age

Slide24: 

Create a STANDARDIZATION TABLE and calculate rates Crude Rate = 15.283 per 1000 Age-Adjusted Rate = 6.58 per 1000 5,726 2,259 1,901 829 320 124 47 26 30 30 160 Deaths 6.581 0.825 0.983 1.100 0.737 0.301 0.157 0.131 0.109 0.208 2.030 Expected XXXXX 82.508 28.898 15.947 7.679 2.978 1.387 0.798 0.578 1.353 28.199 ASR per 1000 0.072 5,674 0-4 1.000 374,665 Total 0.010 27,379 85+ 0.034 65,783 75-84 0.069 51,985 65-74 0.096 41,670 55-64 0.101 41,633 45-54 0.113 33,877 35-44 0.164 32,565 25-34 0.188 51,932 15-24 0.154 22,167 5-14 Std Vector (%) Population at Risk Age

Sometimes there are COHORT EFFECTS that need to be considered as specific groups may vary in exposures or treatments as they move together through time.: 

Sometimes there are COHORT EFFECTS that need to be considered as specific groups may vary in exposures or treatments as they move together through time.