Frequently asked questions about the county cancer maps
What do these maps show?
These are maps of the age-adjusted cancer incidence rates by county and by gender for some of the more common types of cancer. The counties are divided into five groups of 12 or 13 counties each based on their rates. Counties with the highest rates have the dark purple color, while counties with the lowest rates have the dark green color. The number inside each county refers to the name of the county found in the bar graph to the left.
These maps can be used to show us the pattern of cancer cases in the state, help health officials to plan services and even suggest ideas for more research. These maps cannot tell us what causes cancer or why the cancer rates in an area are higher than the state as a whole.
What does age-adjusted mean?
The incidence rates used to make these maps are age-adjusted. That means we produced the rates in a way that lets us compare one county to another, by taking into account the ages of the people in each county. Learn more about age-adjustment here.
What does the bar graph show?
The points on the bar graph shows the age-adjusted cancer incidence rate in each county. The rectangles surrounding the points show the 95% confidence intervals around these rates. A confidence interval is similar to a "margin of error". Roughly speaking, the 95% confidence interval means that the true cancer rate for the county falls within the range covered by the rectangle 95% of the time. Learn more about confidence intervals here.
The vertical line near the middle of the graph shows the New York State rate (the number of people per 100,000 individuals in New York State who get this type of cancer).
The line that shows the "New York State Rate" may not fall exactly in the middle of the bar graph. This is because it is not the average of all the county rates. It is the total number of new cases of this kind of cancer in the State, divided by the total number of people in the State (either males or females).
Why do some county rates seem high?
Sometimes the cancer rate in a county is high one year and low the next. This may occur because the number of county residents is small and only a few cases of a particular cancer occur there each year. A change of one or two cases more, or one or two cases less, may have a large effect on the cancer rate for a small county.
Am I more at risk if my county's cancer rate is high?
If you live or lived in a county where the rate is higher than the New York State rate, it does not mean that you are more likely to get cancer than someone who lives in a county with a lower rate. Your risk depends on many things including your lifestyle (smoking, diet), your family history, and contact you have with cancer causing substances (sunlight, x-rays, tobacco smoke, some chemicals).
If my county's rate is high, is the environment to blame?
A map cannot prove that something in the environment causes cancer. Cancers develop slowly in people. They usually appear five to 40 years after exposure to a cancer causing agent. This is called the latency period. This is one of the reasons it is difficult to determine what causes cancer in humans. Also, many people move during this period of time, making it hard to link exposure to a cancer causing agent to where a person lives.