Posts Tagged ‘Community Health Analysis Areas’

The Texas Sharpshooter

June 1st, 2012

There’s an old tale about a Texas “Sharpshooter” that pulls his pistol out of his holster and shoots at the broad side of a barn pretty much at random without aiming.  Then he goes up to the barn with a paintbrush and draws a circle around the bullet holes and says: “See, I have perfect aim”.  That’s kinda how a lot of cancer clusters are. 

People generally get cancer at random (with some exceptions like occupational exposures, gross environmental contamination & genetic risk etc.).  But, the laws of statistics state that even when cases of cancer are randomly distributed, there’ll be some groupings that form at random- giving the false appearance that there’s a geographic cluster- when it’s really just random. 

Back in the day, our Arizona Cancer Registry calculated cancer rates etc. on a county by county level- but didn’t have any pre-calculated analyses on a smaller scale. That policy led to tons requests for special analyses for smaller areas (with perceived “cancer clusters”)- creating lots of extra work and with little to no public health payoff.  So, Dr. Bob England (when he was our State Epi) had an idea to revamp our cancer registry so that we constantly calculated rates in smaller areas of the state.  With this uniform approach- we could stop chasing our tail and actually provide some useful public health information.  That’s when the (now famous because of medical marijuana) 126 Community Health Analysis Areas (CHAAs) were born.  Using CHAAs, we can map cancer rates over time in smaller areas. 

Nowadays our Arizona Cancer Registry has a highly interactive website that uses state-of-the-art GIS technology- which lets ordinary folks as well as researchers to access cancer data by CHAA.   The website visualizes cancer data with interactive maps, tables and graphs including a rate distribution graph, a time series chart and a rate classification chart.  All the elements are linked, so a selected community in one chart or map will be selected in all others. Explore this link to explore the website and its many features- have at it.

 

Doctor/Patient Density- Our Online Gap Analysis Map

April 30th, 2012

In public health it’s good to know where the resources are – and where they’re short. Our Health Systems Development team created an excellent online tool to help our partners keep track of resources –  to see where we have enough physicians and where we could use more.  It also shows how much of an area is at the poverty level and where the underinsured and uninsured live in AZ.  You get to choose the geographic break down – Community Health Analysis Areas, Counties and even by census tracts.  

This type of data can be useful in your programs as you determine the best places for interventions.  We’ll update the Designation Mapper quarterly to keep you updated on changes in status.  Also, Health Systems is putting together a webinar to help folks learn to use the new tool.

The ABC’s of our Community Health Analysis Areas

January 28th, 2011

Several years ago, our public health statistics team divided the State into 126 Community Health Analysis Areas to help us analyze data for various disease monitoring programs.  The initial trigger to develop the CHAAs was a 1988 law that directed the ADHS to use the data in the cancer registry to identify areas and populations that need investigation. Until recently, the state-collected cancer data was not complete enough to looks at rates on a relatively small geographic scale, limiting analysis to the county level only.  Once we had enough data to meet the legislative mandate to report on rates across the state we developed CHAAs to present our data at a geographic scale smaller than the county level.

We created CHAAs by modifying the 126 Primary Care Areas used by the ADHS program for Health Systems Development. PCAs have been used to characterize the health needs of communities for many years; however, the PCAs didn’t provide all the coverage and detail that we require for every part of the state, so we developed the CHAAs to more closely align to the growing rural communities and to Phoenix’s villages.

Each CHAA is built from US 2000 Census Block Groups. These Block Groups are relatively small geographic regions of the state. A typical CHAA contains approximately 21,500 residents. But, because of the scattered pattern of development in Arizona they range widely in population, from 5,000 to 190,000 persons. The use of the relatively small Block Groups gives us the ability to aggregate data at a variety of sizes, from the Block Group level up to the CHAA level that we use in analysis. A CHAA in the highly urbanized areas of Maricopa County contains approximately 100,000 persons. The average rural CHAA contains approximately 10,000 persons.

You’ll be hearing alot more about CHAAs in the very near future.

New High-Tech Interactive Arizona Cancer Registry Website

December 1st, 2010

Our Arizona Cancer Center has developed a highly interactive new website using state-of-the-art GIS technology.  This nifty new website lets the public and researchers access cancer data by communities (Community Health Analysis Areas).  It allows easy access to age adjusted incidence rates and counts for 13 cancers that have public health implications.  The website visualizes cancer data with interactive maps, tables and graphs including a rate distribution graph, a time series chart and a rate classification chart.

All the elements are linked, so a selected community in one chart or map will be selected in all others.  Confidence intervals and the Arizona State rate were added to increase understanding of complex statistics and minimize misinterpretation of the data.  All 13 Cancer data tables can be downloaded in an Excel format.   Use this link to explore the website and its many features.  If you have any questions or need any additional information contact our local (but federally-funded) guru Wesley Kortuem at wes.kortuem@azdhs.gov.

Arizona Cancer Registry

May 5th, 2010

The ADHS Arizona Cancer Registry is a population-based surveillance system that collects, manages and analyzes information on the incidence, survival and mortality of persons having been diagnosed with cancer. We began collecting cancer case information in 1981.  The Registry has data available describing cancer in Arizona using a variety of descriptors, including site of origin, age, gender, race, ethnicity, geographic area, and year of diagnosis.  Strict confidentiality safeguards require that data be reported only in aggregate; no individual can be identified from a data.

A few years ago, we calculated cancer rates etc. on a county by county level- but didn’t have any pre-calculated analyses on a smaller scale.  This led to numerous requests for special analyses for smaller areas (with perceived “cancer clusters”) creating lots of extra work.  So, we revamped the program and created 126 pre-designated Community Health Analysis Areas (CHAAs) so that we can track rates over time and have more resolution with the rates.  You can see more in our CHAA Q & A fact sheet.  Using these CHAAs, we can map cancer rates over time in smaller areas.  If you’re interested, you can check out our 2001-2004 Cancer Incidence Reports on our Vital Statistics website.