 |
 |
National Center for Chronic Disease Prevention and Health Promotion
Arthritis
Home | About Us | Contact Us
|
||||||||
|
|
|
|
|
|
|
||
National Center for Chronic Disease Prevention and Health Promotion Arthritis Home | About Us | Contact Us |
|
|
||||||
|
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Note: These questions refer to both NHIS and BRFSS surveys, unless otherwise indicated.
What is the current case definition for self-reported arthritis?
Since 2002, CDC, partners, and outside experts have agreed on a case definition of simply “doctor-diagnosed arthritis.”
Both the Behavioral Risk Factor Surveillance System and the National Health Interview Survey use the following question to identify adults with arthritis “Have you ever been told by a doctor or other health professional that you have some form of arthritis, rheumatoid arthritis, gout, lupus, or fibromyalgia?
For more information on the evolution of the case definition read more.
Why does CDC include the four types of arthritis to the end of the survey question addressing doctor-diagnosed arthritis: “Have you ever been told by a doctor or other health professional you have some form of arthritis, rheumatoid arthritis, gout, lupus, or fibromyalgia?”
For public health surveillance, we are trying to capture more than 100 diseases that are considered “arthritis or other rheumatic conditions.” Some of these conditions may not be readily recognized as arthritis by survey respondents. Experts recommended adding these conditions.
Are self-reports for arthritis valid?
Self-reports have been shown to be valid for surveillance purposes. Sacks JJ, Harrold LR, Helmick CG, Gurwitz JH, Emani S, Yood RA. Validation of a surveillance case definition for arthritis. J Rheumatol 2005;32:340–347.
Which estimate best indicates the prevalence of arthritis for the nation?
National estimates should come from a national survey; CDC uses the National Health Interview Survey (NHIS) for such estimates. Healthy People 2010 also recommends using NHIS data for national estimates.
Using NHIS data (2003-2005), we estimate that 46.4 million (21.6%) adults had doctor-diagnosed arthritis.
Is self-reported information on the type of arthritis valid?
The CDC Arthritis Program strongly discourages the collection and reporting of self-reported data on arthritis type (e.g., osteoarthritis, rheumatoid arthritis, lupus) because self-reported condition data have been shown to be inaccurate based on studies done by the program and other researchers. For example, the CDC Arthritis Program compared how frequently the arthritis condition type reported by participants in the Medical Expenditure Panel Survey1 (MEPS) agreed with each of the participants’ doctor’s diagnosis. This study found that among persons whose doctor had diagnosed them with osteoarthritis, only 9% of survey participants reported that they had osteoarthritis. Since self-reported information on type of arthritis is not valid, the CDC arthritis program discourages states and researchers from measuring and using data on self-reported arthritis condition type. (Click here for references.)
The Medical Expenditure Panel Survey is a nationally representative survey of the U.S. civilian non-institutionalized population.
What changes are expected for future BRFSS surveys?
We expect the BRFSS Arthritis Burden Questions will continue to be asked in all states in odd number years. New Arthritis Burden Questions are being added to the survey in 2009. A list of BRFSS Arthritis Core (Arthritis Burden Questions) by year is available.
How often are the Arthritis Burden Questions on the BRFSS survey?
Starting in 2003, the BRFSS Arthritis Core (Arthritis Burden Questions) are offered on the core survey in odd numbered years. State programs are encouraged to add the optional module known as the BRFSS Arthritis Optional Module (Arthritis Management Questions) in the same odd-numbered year. Although states may be interested in using the questions every year, CDC will NOT financially or analytically support the use of any arthritis questions in even numbered years. States may add them as state-added questions.
What does the CDC Arthritis Program recommend state arthritis programs do regarding the BRFSS survey in even years?
CDC is not supporting the use of arthritis questions in even years. This means we are not funding the BRFSS to put the questions on the survey nor are we providing our standard analytic tables, as we do for all states using odd number year data. Any use of these questions in even years would have to be as state-added questions. We do not feel it is necessary to have the data each year, as the prevalence is unlikely to change rapidly and with lots of programs competing for space on the questionnaire, one can quickly wear their welcome out with the BRFSS coordinator. In infrequent instances, when a state feels it is imperative for its program to make substate prevalence estimates (e.g., for large cities), it may choose to use the arthritis questions in even years. CDC is unable to provide any support for doing this and we don’t recommend it.
Is there more than one way to define a “case” of arthritis?
Yes, the purpose (e.g., estimating prevalence or assessing burden) and source of the data determine the arthritis case definition to be used. In general, data used in arthritis surveillance falls into two broad categories, self-reported data and health care system data.
For the purpose of estimating the population prevalence of arthritis, we recommend using self-reported data as the data source and using doctor-diagnosed arthritis as the case definition. Both the state-based Behavioral Risk Factor Surveillance System (BRFSS) and National Health Interview Survey (NHIS) are self-reported data surveys, and use doctor-diagnosed arthritis as the case definition. A “case” of doctor-diagnosed arthritis in these surveys is defined as a “yes” answer to the following question: “Have you EVER been told by a doctor or other health professional that you have some form of arthritis, rheumatoid arthritis, gout, lupus, or fibromyalgia?” Further information on the CDC arthritis case definition is available.
For assessing the burden of arthritis using health care system data
(e.g. hospital discharge data, ambulatory care, death.) a “case” of
arthritis is defined by the National Arthritis Data Workgroup definition
using
arthritis related ICD–9–CM codes
(PDF-73K) and is labeled “arthritis and other rheumatic conditions”.
The CDC discourages states from pursuing these assessments unless there is a
direct link to program activity that is consistent with the state arthritis
plan.
Be aware that other studies (e.g., clinical trials) including some statistics and studies cited elsewhere on this Website, have different data sources and use different arthritis case definitions.
Why did CDC decide to drop questions on chronic joint symptoms and cease surveillance of “possible arthritis”?
The state-based Behavioral Risk Factor Surveillance System (BRFSS) included 2 questions on joint symptoms between the years of 2002 and 2007. “Possible arthritis” is defined as a person without doctor-diagnosed arthritis who answers “yes” to both of the following questions: “During the past 30 days, have you had any symptoms of pain, aching or stiffness in or around a joint?” and “Did your joint symptoms first begin more than 3 months ago?” CDC conducted an expanded data collection in 4 states in 2005 to learn more about people with “possible arthritis.” Results indicate that over 90% of persons with possible arthritis who had seen a doctor did not appear to have arthritis and that the majority of those who had not seen a doctor did not deem their symptoms serious enough for medical intervention. The CDC arthritis program reasons that persons with possible arthritis would not be amenable to public health programmatic interventions for arthritis and that maintaining surveillance of this group is currently not necessary.
Further analysis of BRFSS data on “possible arthritis” indicated the group has a different profile than those with doctor diagnosed arthritis. Unlike doctor-diagnosed arthritis, “possible arthritis” decreases with age and is more common in men than women. A smaller proportion of people with possible arthritis report activity limitation due to joint symptoms compared to those with doctor-diagnosed arthritis. In 2009 the 2 joint symptoms questions were dropped from the BRFSS. These questions continue to be collected through the National Health Interview Survey (NHIS).
Some documents on this page are available in Portable Document Format (PDF). Learn more
about viewing and printing PDF documents with
Acrobat Reader.
A note about “possible arthritis”
“Possible arthritis” is another variant of self-reported data. It is defined
as a person without doctor-diagnosed arthritis who answers “yes” to both
of the following questions: “During the past 30 days, have you had any symptoms
of pain, aching or stiffness in or around a joint?” and “Did your joint symptoms
first begin more than 3 months ago?” The state-based Behavioral Risk Factor
Surveillance System (BRFSS) and National Health Interview Survey (NHIS) can
identify persons with “possible arthritis.” Analysis of BRFSS data on
“possible arthritis” indicates
the group has a different demographic profile than those with doctor
diagnosed arthritis. Unlike doctor-diagnosed arthritis,
“possible arthritis” decreases
with age and is more common in men than women. A smaller proportion of
people with possible arthritis report activity limitation due to joint
symptoms compared to those with doctor-diagnosed arthritis. CDC is currently
analyzing data from 4 states collected in 2005 to learn more about people
with “possible arthritis.” Additionally, CDC will be analyzing data for people
with possible arthritis from a national sample collected in 2005 through the
Arthritis Conditions Health Effects Survey (ACHES). We are still learning
who these people are and whether or not they fit into the larger arthritis
picture.
Page last reviewed: June 8, 2008
Page last modified: September 9, 2008
Content Source: Division of
Adult and Community Health,
National Center for Chronic Disease Prevention and Health Promotion
|
|
Privacy
Policy | Accessibility United
States Department of Health and Human Services |
|
