Arthritis and other rheumatic conditions are among the most common chronic diseases, according to the new report "Public Health and Aging: Projected Prevalence of Self-Reported Arthritis or Chronic Joint Symptoms Among Persons Aged >65 Years - United States, 2005-2030". Affecting approximately 70 million U.S. adults in 2001, they comprise the leading cause of disability among U.S. adults. A whopping 60% of the U.S. population aged 65 years or older has arthritis.

People are living longer as a result of different factors (such as better identification and treatment of chronic diseases and lower mortality from infectious diseases), so the number of people living with a nonfatal but disabling condition like arthritis or chronic joint symptoms (CJS) may be increasing.

The Centers for Disease Control and Prevention (CDC) used data from the 2001 Behavioral Risk Factor Surveillance System (BRFSS) to estimate the burden of arthritis or CJS among people aged 65 years or older for 2005-2030 (national population data) and 2025 (state population data). BRFSS is a state-based, random-digit-dialed telephone survey of U.S. citizens aged 18 years or older.

Response Criteria
Respondents were classified as having CJS if they answered "yes" to two questions: 1. "In the past 12 months, have you had pain, aching, stiffness, or swelling in or around a joint?"

2. "Were these symptoms present on most days for at least a month?"

Respondents were classified as having physician-diagnosed arthritis if they answered "yes" to the question:
1. "Have you ever been told by a doctor that you have arthritis?"

Respondents who reported CJS or physician-diagnosed arthritis were classified as having arthritis or CJS. Those who did not know, were unsure, or refused to answer were classified as not having either condition.

Results
During 2005 - 2030, the percentage of the U.S. population aged 65 years or older is expected to increase from 12.9% to 20%. Based on current prevalence rates, the number of people aged 65 years or older projected to have arthritis or CJS will double, from 21.4 million in 2005 to 41.1 million in 2030, with the average state prevalence projected at 56.5% by 2025. This takes into consideration that the prevalence of arthritis or CJS varies by state (highest in Alabama -- 70.3% of the population; lowest in Hawaii -- 34.8%).

The authors suggest that the aging of the population is a huge issue facing the U.S. public health, medical, and economic systems. Arthritis contributes to disability, poor health-related quality of life, and increased medical costs, so decreasing this impact will require public health interventions. Currently, less than 1% of people with arthritis who could benefit from such interventions (like exercise and aquatic programs, self-management education classes, etc.) receive them.

Report Limitations - Potential Problems with the Study
1. Estimates were based on self-reported data, not physician confirmation.

2. It excluded military personnel living on bases, institutionalized populations, and people without telephones.

3. The response rate in this survey was low (51.1% of people who were contacted actually participated), but BRFSS demographics mirror U.S. Census distributions.

4. The BRFSS disease criteria may actually have included some people with acute, self-limiting musculoskeletal injuries rather than arthritis. New BRFSS disease criteria questions were changed to help alleviate this potential problem.

5. The projected prevalence numbers may be too low because the authors used steady age- and sex-specific rates of arthritis, while other factors potentially affecting the prevalence of arthritis (like therapy and the obesity epidemic) were not considered.