Age (Years) Influenza / Pneumonia Deaths (Di) 2007-2011 Population (Pi) from 2007-2011 (2009 used as mid-year)
<1 year 7 53,267
1-4 years 4 207,832
5-14 years 5 468,548
15-24 years 14 447,580
25-34 years 27 440,646
35-44 years 40 325,022
45-54 years 92 305,929
55-64 years 109 231,203
65-74 years 186 134,247
75-84 years 424 78,997
85+ years 772 30,150
Total 1,680 2,723,421
• Crude Rate:
• Age Adjusted Rate:
Is there a difference? What value will you report to the public and why?:
To determine if there is a difference between the crude rate and age-adjusted rate for influenza/pneumonia deaths, we first need to calculate these rates.
1. Crude Rate:
The crude rate is calculated by dividing the number of deaths (Di) by the population (Pi) and multiplying by a constant (usually 100,000) to express the rate per 100,000 population.
To calculate the crude rate:
Crude Rate = (Di / Pi) * 100,000
For example, for the age group <1 year:
Crude Rate (0-1 year) = (7 / 53,267) * 100,000
Now, you need to perform this calculation for each age group and add up the crude rates to get the overall crude rate.
2. Age-Adjusted Rate:
The age-adjusted rate is a standardized rate that accounts for differences in age distributions between populations. It allows for comparison between populations with different age structures by using a common standard population.
To calculate the age-adjusted rate, you need to follow these steps:
1. Determine the age-specific death rates (ASDR) for each age group. It is calculated by dividing the number of deaths in each age group (Di) by the mid-year population (Pi) of each age group.
ASDR = Di / Pi
2. Determine the standard population distribution. This is a hypothetical population distribution used to standardize rates. You can use a standard population distribution from a reliable source, such as the World Health Organization (WHO), or you can create your own.
3. Calculate the weighted age-specific death rate. Multiply the age-specific death rate (ASDR) of each age group by the percentage distribution of that age group in the standard population.
4. Sum up the weighted age-specific death rates to get the age-adjusted rate.
Now that you have both the crude rate and age-adjusted rate, you can compare them to see if there is a difference.
If the crude rate and age-adjusted rate are similar, it suggests that age is not a major factor in influencing the death rates. If there is a significant difference, it indicates that age plays a role in the observed rates.
As for which value to report to the public, it depends on the purpose and context of the report. If age is an important factor to consider, then the age-adjusted rate might provide a more accurate representation. However, if age is not a significant factor or if a straightforward comparison is desired, the crude rate can be reported.
Ultimately, the decision on which value to report should be based on the specific requirements, target audience, and objectives of the report or study.