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Arthritis Rheum. Author manuscript; available in PMC 2012 Jan 26.
Published in final edited form as:
PMCID: PMC3266664
NIHMSID: NIHMS347693
PMID: 18163497

Estimates of the Prevalence of Arthritis and Other Rheumatic Conditions in the United States, Part II

Reva C. Lawrence, MPH,1 David T. Felson, MD, MPH,2 Charles G. Helmick, MD,3 Lesley M. Arnold, MD,4 Hyon Choi, MD, DrPH,5 Richard A. Deyo, MD, MPH,6 Sherine Gabriel, MD, MSc,7 Rosemarie Hirsch, MD, MPH,8 Marc C. Hochberg, MD, MPH,9 Gene G. Hunder, MD,7 Joanne M. Jordan, MD, MPH,10 Jeffrey N. Katz, MD,11 Hilal Maradit Kremers, MD, MSc,7 and Frederick Wolfe, MD12, for the National Arthritis Data Workgroup

Abstract

Objective

To provide a single source for the best available estimates of the US prevalence of and number of individuals affected by osteoarthritis, polymyalgia rheumatica and giant cell arteritis, gout, fibromyalgia, and carpal tunnel syndrome, as well as the symptoms of neck and back pain. A companion article (part I) addresses additional conditions.

Methods

The National Arthritis Data Workgroup reviewed published analyses from available national surveys, such as the National Health and Nutrition Examination Survey and the National Health Interview Survey. Because data based on national population samples are unavailable for most specific rheumatic conditions, we derived estimates from published studies of smaller, defined populations. For specific conditions, the best available prevalence estimates were applied to the corresponding 2005 US population estimates from the Census Bureau, to estimate the number affected with each condition.

Results

We estimated that among US adults, nearly 27 million have clinical osteoarthritis (up from the estimate of 21 million for 1995), 711,000 have polymyalgia rheumatica, 228,000 have giant cell arteritis, up to 3.0 million have had self-reported gout in the past year (up from the estimate of 2.1 million for 1995), 5.0 million have fibromyalgia, 4–10 million have carpal tunnel syndrome, 59 million have had low back pain in the past 3 months, and 30.1 million have had neck pain in the past 3 months.

Conclusion

Estimates for many specific rheumatic conditions rely on a few, small studies of uncertain generalizability to the US population. This report provides the best available prevalence estimates for the US, but for most specific conditions more studies generalizable to the US or addressing understudied populations are needed.

METHODS

The purpose of this study, definitions of general terminology, and methods used for ascertaining the data and generating the estimates are described in the companion article (1).

RESULTS

Osteoarthritis (OA)

OA is the most common type of arthritis. We estimated prevalence for each of the most commonly affected joints (knees, hips, and hands) as well as for overall OA.

Estimating the prevalence of OA is difficult because the structural changes of the disease occur in most persons as they get older, but these changes may not be accompanied by symptoms. Furthermore, prevalence estimates vary considerably depending on whether only moderate and severe radiographic changes are counted or mild changes are also included.

Clinically defined OA

Study examiners characterize a person as having OA on the basis of symptoms and physical examination findings. The National Health and Nutrition Examination Survey I (NHANES I) (2) showed that 12.1% of the US population ages 25–74 years had clinically defined OA of some joint.

Radiographically defined OA

Generally, researchers grade radiographs according to the Kellgren/Lawrence scale (3), which defines OA on the basis of the presence of osteophytes (outgrowths of bone at the margin of the joint). We summarized prevalence data primarily from 3 recent US population-based studies: the NHANES III, the Framingham Osteoarthritis Study, and the Johnston County Osteoarthritis Project. In these studies, participants had to appear in person to undergo radiographic testing, and the validity of the estimates could be compromised if only individuals who had symptoms (instead of all individuals) attended. High participation rates for radiography (>70%) in all 3 studies make this unlikely.

In phase 2 of the NHANES III (1991–1994), prevalence of knee OA was assessed in adults age ≥60 years; this was the only study to use non–weight-bearing radiographs, a method that minimizes joint space narrowing evident with weight bearing (4). The Framingham Osteoarthritis Study was a survey of knee and hand OA in ~2,400 adults age ≥26 years from suburban Boston, Massachusetts (5,6). The Johnston County Osteoarthritis Project was a study of hip and knee OA in ~3,000 African American and white adults age ≥45 years in a rural county in North Carolina (7). The prevalence of knee OA in adults age ≥45 was 19.2% in Framingham and 27.8% in Johnston County, and the prevalence among adults age ≥60 was 37.4% in the NHANES III (Table 1). The prevalence of hip OA was high (27.0%) in Johnston County adults age ≥45, but in another US community-based study of 4,855 women age ≥65 years, prevalence was found to be only 7.2% (8). In the latter study, hip OA was defined based on individual features, but the discordance among study results leaves uncertainty regarding to the prevalence of hip OA. The prevalence of hand OA in Framingham adults was 27.2% overall and reached ≥80% among older adults, but only a minority of persons with radiographic OA have pain in these joints.

Table 1

Prevalence of radiographic OA in the hands, knees, and hips, by age and sex, from population-based studies*

Anatomic site,
age, years
Source (ref.)% with mild, moderate,
or severe OA
MaleFemaleTotal
Hands, ≥26Framingham OA study (6)25.928.227.2
Knees
    ≥26Framingham OA study (5)14.113.713.8
    ≥45Framingham OA study (5)18.619.319.2
    ≥45Johnston County OA Project (7)24.330.127.8
    ≥60NHANES III (4)31.242.137.4
Hips, ≥45Johnston County OA Project (10)25.726.927.0
*Estimates represent prevalence per 100 persons age-standardized to the projected 2000 Census population (see ref. 63) except for National Health and Nutrition Examination Survey III (NHANES III) estimates, which were adjusted to the 1980 Census population.
All data on radiographic knee osteoarthritis (OA) are based on anteroposterior radiographs and therefore capture only tibiofemoral OA. Inclusion of patellofemoral imaging would probably yield higher prevalence estimates.

OA prevalence increased with age and affected the hands and knees of women more frequently than men, especially in persons age ≥50 years. In Johnston County and in the NHANES III, African Americans were more likely than whites to have radiographic knee OA. A study of perimenopausal women in Michigan also demonstrated that African Americans were more likely than whites to have radiographic knee and hand OA (9). In the NHANES III, the prevalence of radiographic knee OA was significantly higher in non-Hispanic African Americans than in non-Hispanic whites or Mexican Americans (52.4%, 36.2%, and 37.6%, respectively) (4). In Johnston County, the prevalence of radiographic hip OA was comparable in African Americans and whites (10).

Symptomatic OA

Persons are considered to have symptomatic OA if they have frequent pain in a joint and radiographic evidence of OA in that joint, although sometimes this pain may not actually emanate from the arthritis seen on the radiograph. Most prevalence surveys require that a person have pain in a joint on most days of a recent month, to meet the definition for presence of symptoms.

The prevalence of symptomatic knee OA was 4.9% among adults age ≥26 years in the Framingham study, 16.7% among adults age ≥45 in the Johnston County study, and 12.1% among adults aged ≥60 in the NHANES III study (Table 2).

Table 2

Prevalence of symptomatic OA (symptoms and radiographic changes of OA in the symptomatic joint) in the hands, knees, and hips, by age and sex, from population-based studies*

Anatomic site,
age, years
Source (ref.)% with symptomatic OA
MaleFemaleTotal
Hands, ≥26Framingham OA study (6)3.89.26.8
Knees
    ≥26Framingham OA study (5)4.64.94.9
    ≥45Framingham OA study (5)5.97.26.7
    ≥45Johnston County OA Project (7)13.518.716.7
    ≥60NHANES III (4)10.013.612.1
Hips, ≥45Johnston County OA Project (10)8.79.39.2
*Adjusted to the projected 2000 population age ≥18 years (see ref. 63) except for National Health and Nutrition Examination Survey III (NHANES III) estimates, which were adjusted to the 1980 Census population. OA = osteoarthritis.

The prevalence of symptomatic hip OA was 9.2% among adults age ≥45 in the Johnston County study. The prevalence was slightly higher among women than among men for both of these outcomes (Table 2). The prevalence of symptomatic hand OA in the Framingham subjects (6) was 6.8% overall and was especially high in older adults. Among individuals age ≥71 years, prevalence was 26.2% in women and 13.4% in men.

Using the Framingham data on age/sex prevalence among persons age ≥26 years and the corresponding 2005 population estimates from the Census Bureau, we estimated that 9,267,000 adults have symptomatic knee OA and 13,054,000 adults have symptomatic hand OA. The generalizability of the Framingham estimates to the US population has not been determined.

For estimating overall OA, we calculated weighted age/sex-specific prevalence estimates of clinical arthritis for persons ages 25–74 from the NHANES I, the only published national source of data on OA at multiple anatomic sites and the source we used in our 1998 report (11). Using the corresponding 2005 population estimates from the Census Bureau and additionally applying the NHANES I estimate for those ages 65–74 to the Census population age ≥75 years, we estimated that 26.9 million adults age 25 and older have clinical OA of some joint. Whether the 1971–1975 NHANES I estimates reflect the 2005 US population prevalence is uncertain.

Polymyalgia rheumatica (PMR) and giant cell (temporal) arteritis (GCA)

PMR and GCA, two closely related syndromes that occur almost exclusively in persons age ≥50 years, appear to be much more common in whites than in other racial or ethnic groups (12). In the US, prevalence is highest among persons of northern European descent (13,14).

The only population-based study of PMR and GCA in the US is from Olmsted County, Minnesota, where the prevalences of PMR and GCA were derived from cumulative incidence rates. GCA was diagnosed according to the American College of Rheumatology (ACR) criteria (15). Among persons age ≥50 years in 2000, the prevalence of PMR was 739 per 100,000 (95% confidence interval [95% CI] 674–808) (16) and the prevalence of GCA was 278 per 100,000 (95% CI 192–268) (17). For each, the prevalence was higher in women than in men and increased dramatically with age (for PMR, from 21 per 100,000 among persons ages 50–54 years to 4,070 per 100,000 among those age ≥90 years) (Table 3).

Table 3

Prevalence of polymyalgia rheumatica and giant cell arteritis in Olmsted County, Minnesota, by age and sex*

Age,
years
Prevalence of polymyalgia
rheumatica
Prevalence of giant cell arteritis
MaleFemaleTotalMaleFemaleTotal
50–54222121000
55–5912410211304523
60–64294328313377758
65–6953065960192210156
70–741,0151,4011,238214460353
75–791,5552,2671,982298836617
80–842,2393,0552,7374681,196913
85–892,6853,4253,1276371,5001,178
≥904,2394,2134,0701,2402,0251,721
Overall532925739100344228
*Values are cumulative incidence rates per 100,000 persons in each age/sex group through 1999.
Data collected 1970–1999 (16).
Data collected 1950–1999 (17).

In addition to these data, case series of PMR and GCA suggest that these conditions are common throughout the US. In Europe, incidence rates in populations in the northern area of the continent are similar to those of Olmsted County, Minnesota, whereas rates among southern European populations are lower (1821).

In summary, PMR is common in older adults. GCA, which is approximately one-third as common as PMR, is the most common form of vasculitis in the population over 50 years of age. Using the Olmsted County age/sex prevalence rates and the corresponding 2005 estimates from the Census Bureau, we estimated that 711,000 Americans have PMR and 228,000 have GCA. With the aging of the US population, these estimates are likely to increase in coming years. These Olmsted County estimates are generalizable to the white US population, but their generalizability to other racial/ethnic populations is uncertain.

Gout

Gout is an inflammatory arthritis that results from phagocytosis of monosodium urate monohydrate crystals within the joint and is usually associated with an elevated concentration of uric acid in the blood, i.e., hyperuricemia. Among criteria developed to classify gout, the ACR criteria (22) have been used in recent epidemiologic studies (23,24).

Our previous National Arthritis Data Workgroup (NADW) report (11) reviewed the population-based Tecumseh Community Health Study (25), the Framingham Heart Study (26), and the Sudbury Study (27) (Table 4), all of which were relatively small studies of gout conducted in confined geographic regions. All of these studies took place before the ACR criteria were developed, the age populations included were not consistent among studies.

Table 4

Prevalence of gout in the United States*

Source and year of study/gout
definition (ref.)
Age, yearsPrevalence per 100,000
MaleFemaleTotal
Regional population studies
    Tecumseh Community Health Study, 1960/“Rome” (25)≥20720480ND
    Framingham Heart Study, 1964/arbitrary (26)≥42 (mean 58)2,8503901,480
    Sudbury Study, 1972/Rome and New York (27)≥15660100370
National survey studies
    NHIS, 1988/self-report (1-year prevalence) (64)§≥18NDND850
18–4429090310
45–643,3509502,100
≥654,1101,7002,700
    NHIS, 1992/self-report (1-year prevalence) (65)§≥18NDND840
18–4444030380
45–642,6308101,680
≥654,4101,8202,900
    NHIS, 1996/self-report (1-year prevalence) (30)§≥18NDND940
18–4434020180
45–643,3501,2002,240
≥654,6401,9503,080
    NHANES III, 1988–1994/self-report (lifetime prevalence) (32)≥203,8001,6002,600
≥20–29200500400
30–392,1001001,100
40–492,6009001,700
50–595,6002,3003,900
60–699,4003,2006,100
70–7911,6005,2008,000
≥807,1005,3005,900
*ND = no data; NHIS = National Health Interview Survey; NHANES III = National Health and Nutrition Examination Survey III.
“Rome” = Rome criteria used “insofar as possible.”
Arbitrary = at least 2 of the following 3 features: a typical attack of arthritis, an attack of arthritis with a prompt response to colchicine therapy, and/or hyperuricemia.
§One-year prevalence of gout ascertained by the question, “Have you or any member of your household had gout within the past year?”
Lifetime prevalence of gout ascertained by the question, “Has a doctor ever told you that you had gout?” Interviewers were instructed to emphasize the word “doctor.” If the respondent stated that it was another health professional who gave the diagnosis of gout to him or her, the answer was coded as “no.”

The prevalence of gout also has been estimated using self-reported information from the National Health Interview Survey (NHIS) and the NHANES (Table 4). Because these self-reports were not verified, the data may produce an overestimate of prevalence. For example, investigators in the Sudbury Study (27) could validate only 44% of self-reported cases using Rome (28) or New York (29) criteria, and in a study of health professionals (23), only 70% of cases could be validated by ACR criteria. However, in one study of physicians (24), it was reported that 100% of self-reported cases could be validated by ACR criteria and medical record review. In the most recent NHIS survey on gout (1996), the prevalence for the 1-year period was 940 per 100,000 adults age ≥18 years in the US (30). Prevalence increased with age, was higher in men than in women at all ages, and among those age ≥45 years was higher in African Americans than in whites.

One-year period prevalence estimates derived from the NHIS over time can be compared directly because the instrument has not changed. In this survey, the presence of gout is recorded if a respondent answers “yes” to the question, “Have you or any member of your household had gout within the past year?” From 1969 to 1985 the prevalence more than doubled, with the steepest increase occurring between 1969 and 1976 (30), but the increase later slowed between 1992 and 1996 (840 and 940 per 100,000, respectively) (Table 4). In a recent study from a US managed care population, the overall prevalence of gout or hyperuricemia requiring a gout or urate-lowering medication increased by 80% from 1990 to 1999 (31); however, this increase may reflect treatment change.

The lifetime prevalence estimate from the NHANES III (1988–1994) (32), based on the question, “Has a doctor ever told you that you had gout?,” was 2,600 per 100,000 overall for those age ≥20 years, with a low of 400 per 100,000 in adults ages 20–29 years and a peak of 8,000 per 100,000 in adults ages 70–79 years (Table 4). Gout was reported more often by men than by women overall, but prevalence increased with age for both, especially among women after menopause.

In summary, gout appears to be increasing in frequency. Using 1996 NHIS and NHANES III age/sex prevalence data and the corresponding 2005 population estimates from the Census Bureau, we estimated that 3.0 million adults age ≥18 years had gout in the past year, and 6.1 million adults age ≥20 have ever had gout. Both are likely overestimates because they are based on self-reported data.

Fibromyalgia

The 1990 ACR criteria for the classification of fibromyalgia require the presence of widespread pain for at least 3 months and pain on palpation in at least 11 of 18 anatomic sites (33). Despite its acceptance, a number of problems occur when the ACR criteria set is used to define fibromyalgia in populations, leading to difficulties in estimating prevalence (3436). Also, fibromyalgia may be more common among persons with other medical conditions (37), so prevalence estimates of primary fibromyalgia may be lower than estimates that do not differentiate primary fibromyalgia from fibromyalgia secondary to other disorders.

Wolfe et al conducted the only study of the prevalence of primary fibromyalgia in the US, in Wichita, Kansas in 1993 (38). At the time of the study, the population of Wichita was ≥88% white, different from that of the overall US population. From a random sample of 3,006 adults age ≥18 years, 193 individuals with chronic widespread pain were examined and 36 cases of ACR-defined fibromyalgia were confirmed. The overall prevalence among adults was ≥2% (95% CI 1.4–2.7); prevalence was higher among women than among men (3.4% versus 0.5%). In women, the prevalence of fibromyalgia rose sharply in middle age, to a maximum of 7.4% in the 70–79-year age group, and then dropped off. Prevalence in men similarly peaked in the eighth decade of life, but was only slightly more than 1% among men in this age group. Fibromyalgia was associated with depressive and anxiety symptoms, current and past depression, and a history of depression in the family. Other characteristic symptoms, i.e., “pain all over,” subjective swelling, paresthesias, stiffness, sleep disturbance, fatigue, and irritable bowel syndrome, were also associated with fibromyalgia (38). Women experienced more of these associated symptoms than men (34). Other factors associated with fibromyalgia included reduced income and education, higher rates of divorce, and application for disability benefits (38).

Although no recent prevalence studies of fibromyalgia in the US have been published, a population survey of 3,395 randomly selected adults (≥18 years of age) in Ontario, Canada showed 100 cases of fibromyalgia, yielding an even higher overall age/sex-adjusted prevalence of 3.3% (95% CI 3.2–3.4%) (4.9% in women and 1.6% in men) (39). As in the US study, the prevalence of fibromyalgia in women rose with age, to a peak of 7.9% in the 55–64-year age group, and declined thereafter. The prevalence in men also increased with age, and peaked at 2.5% in the 45–54-year age group.

Using the Wichita age/sex prevalence and the corresponding 2005 population estimates from the Census Bureau, we estimated that ~5.0 million adults age ≥18 years have primary fibromyalgia. The generalizability of the Wichita estimates to the US population is uncertain.

Carpal tunnel syndrome (CTS)

Because there is no gold standard for the diagnosis of CTS and no standard definition of the syndrome, and because some cases can be transient, challenges arise in determining the prevalence of this condition. The clinical examination findings associated with CTS have sensitivities and specificities in the range of 45–80% (40). The typical location of symptoms in the median nerve distribution has sensitivity and specificity in the range of 60–70% (41,42). On median nerve conduction testing, >20% of asymptomatic individuals exhibit abnormalities consistent with CTS (42,43).

The most well–accepted definitions of CTS involve combinations of symptom, electrophysiologic, and physical examination findings. Three population-based prevalence studies have been performed in Europe, involving a combination of history, physical examination, and nerve conduction assessments. Atroshi and colleagues (44), in a Swedish study, inquired about symptoms typical of CTS (40,42) and studied symptomatic and asymptomatic subjects further by history-taking, physical examination, and nerve conduction studies. They estimated the prevalence of symptoms typical of CTS, of symptoms accompanied by examination findings indicative of CTS, of symptoms accompanied by positive electrophysiologic results, and of symptoms accompanied by positive findings on all tests. The prevalence of CTS was consistently higher in women than in men, and rose with age. CTS prevalence ranged from 2% to 4% in men and 3% to 5% in women, depending on the stringency of the case definition.

Ferry and colleagues (45) administered a hand symptom diagram (42) to a random population sample in the UK. Persons with and persons without typical symptoms of CTS underwent physical examination and electrophysiologic testing. The prevalence of positive nerve conduction findings did not differ between subjects with typical CTS symptoms and asymptomatic subjects. Thus, although the authors reported a prevalence of electrophysiologic evidence of CTS on the order of 10%, it is difficult to draw conclusions about the prevalence of symptomatic CTS.

In an earlier study, de Krom and colleagues (46) evaluated the prevalence of CTS in 715 persons from The Netherlands. Of the respondents, 1.6% had diagnosed CTS and 9% had nocturnal finger paresthesias. The latter underwent neurologic and electrophysiologic evaluation. The overall prevalence of CTS (either diagnosed or detected via this 2-stage screening process) was 5.8% in women and 0.6% in men.

Studies using a combination of self-report, physical examination, and nerve conduction testing have not been performed in the US. Tanaka et al analyzed data from the 1988 NHIS (47). Respondents were asked if they had CTS. An estimated 1.55% of 170 million adults (2.65 million) self-reported CTS. CTS was twice as common among women as among men (47). The self-report nature of the case definition makes these data difficult to interpret.

In summary, the prevalence of electrophysiologically confirmed, symptomatic CTS, based on studies conducted outside the US, is ~1–4% in men and 3–5% in women, with prevalence increasing with age. Using these adult prevalence estimates and the corresponding 2005 population estimates from the Census Bureau, we estimated that 1–4 million men and 3–6 million women in the US have CTS.

Back and neck pain

Low back pain affects most adults at some time. Because back pain is rarely permanent, terms such as incidence and prevalence may be ambiguous. Although neck pain is less common than low back pain, it shares many similar characteristics. The thoracic spine’s mobility is limited by the rib cage, and is less often a cause of back pain except in osteoporosis. Thus, the prevalence of thoracic spine pain is rarely reported.

Back pain is a symptom, not a disease. For many, a precise pathoanatomic diagnosis is impossible (48,49). There is no definitive imaging or diagnostic test to determine its prevalence. Investigators depend on patient self-report, and many patients have few objective physical findings.

In epidemiologic surveys, back pain has been defined in many ways. These include counting any episode of back pain, counting pain lasting a certain length of time, counting only “severe” pain, or counting only pain that results in work disability. We focused on population-based estimates of self-reported symptoms, separating neck and low back pain, and attempting to distinguish reports of any back pain, frequent or persistent back pain, and pain with symptoms of radiculopathy (nerve root irritation, usually manifesting as sciatica).

In the 2002 NHIS, respondents were asked whether they had low back pain or neck pain during the past 3 months. Respondents were instructed to report pain that lasted a whole day or longer (50). Approximately one-fourth of all adults in the US reported experiencing low back pain in the past 3 months, and the prevalence of neck pain was approximately half that estimate (Table 5). The prevalence was similar among men and women and among most racial groups, with the exception of a high prevalence among American Indians and Alaskan Natives, and a low prevalence among Asian Americans. Prevalence declined with increasing levels of education.

Table 5

Prevalence of neck pain and various categories of low back pain, by race, age, and sex

Low back pain
Neck pain in the
past 3 months, %
(95% CI)*
LBP in the
past 3 months, %
(95% CI)*
Any LBP in the
past year, %
Frequent LBP in the
past year, %
Lifetime occurrence
of LBP lasting
≥2 weeks, %§
Race
    White14.2 (13.7–14.8)27.4 (26.6–28.2)591914
    African American11.7 (10.5–12.9)23.9 (22.2–25.6)461911
    Other489
Age, years
    18–4411.9 (11.3–12.6)23.7 (22.9–24.5)611510
    45–6516.9 (16.0–17.8)29.8 (28.7–30.9)532012
    65–7414.2 (12.7–15.7)28.8 (26.9–29.8)562117
    ≥7514.0 (12.5–15.5)28.7 (26.7–30.7)491816
Sex
    Male11.7 (11.0–12.4)24.3 (23.4–25.2)531514
    Female15.7 (15.0–16.4)28.3 (27.5–29.1)572013
*Data from the 2002 National Health Interview Survey (50); 95% confidence intervals (95% CIs) calculated by the authors from published standard errors.
Data from the Louis Harris Survey Group, 1985 (52,60). Age ranges were slightly different than labeled here.
Data from a citywide population survey (Dayton, OH, 1973) (57). Age ranges were slightly different than labeled here.
§Data from the National Health and Nutrition Examination Survey II, as reported by Deyo and Tsui-Wu (53). The percentages are estimates because the reported age categories differed slightly from the ranges presented here. Although the decline in lifetime occurrence of low back pain (LBP) in the highest age category may be surprising, it has been noted in several surveys. Possible explanations are survey participants’ limited recall for distant past events, selective mortality (persons with LBP have shorter survival, perhaps due to associated health habits or socioeconomic circumstances), or a “cohort” effect, in which persons over age 65, for unexplained reasons, had a lower likelihood of LBP throughout their lives.

From an analysis of the 1997 NHIS, it was estimated that 3.2% of all persons experienced activity limitations due to chronic back conditions (51). Among the poor, activity limitation was nearly 3 times more frequent than in middle- and high-income adults.

Although about half of adults report low back pain during a given year and about two-thirds report low back pain at some time in their lives (5260), only 15–21% of the adult population reported frequent low back pain (56) and only 14% reported an episode of low back pain lasting longer than 2 weeks at any time in their lives. Pain lasting beyond 3–6 months occurs in only 5–10% of patients with back pain. Approximately 1–2% of adults report having received a diagnosis of a herniated disc.

Computed tomography and magnetic resonance imaging studies in small samples indicate that disc degeneration, fractures, herniated discs, and spinal stenosis are all common among asymptomatic persons (61,62). Thus, the prevalence of radiographic findings is substantially different from the prevalence of clinically important symptoms.

In summary, back pain is common. The etiology is often unclear and classification is controversial, but most episodes probably originate in muscles or ligaments, or are the consequences of degenerative changes in the intervertebral discs and adjacent vertebrae. These changes include osteoarthritic changes in the facet joints and similar degenerative changes in and around the intervertebral discs. Back pain remains a leading cause of work disability.

Using 2002 NHIS age-specific prevalence and the corresponding 2005 population estimates from the Census Bureau, we estimated that 59.1 million adults age ≥18 years have had low back pain “in the past 3 months.” Using the 1997 NHIS age-specific prevalence and the corresponding 2005 population estimates from the Census Bureau, we estimated that 7.1 million adults age ≥18 have activity limitation due to chronic back conditions. Using the same sources, we estimated that 30.1 million adults age ≥18 have had neck pain “in the past 3 months.”

DISCUSSION

As discussed in the companion article (1), the burden of a chronic condition can be measured in various ways. The NADW has chosen to focus on national disease prevalence as an important measure of burden.

The prevalence of clinical osteoarthritis has grown to nearly 27 million, up from our estimate for 1995 of 21 million (11), as would be expected for such a strongly age-related disease. Gout appears to be increasing in frequency as well, with a 1-year prevalence of 3.0 million adults, a higher frequency than in the earlier study. These increases in such common conditions suggest they will have a growing impact on the health care and public health systems in the future, one that needs to be anticipated in order to provide the early diagnosis and interventions that can help reduce that impact.

We have provided estimates of prevalence and numbers of persons affected for overall arthritis and for selected rheumatic conditions and given a rough snapshot of current burden. These estimates have been made by recognized disease experts using the best data available, but, as noted in many of the sections, must be interpreted with several limitations in mind, including those detailed in the companion report (1). Given the large and growing burden of arthritis and other rheumatic conditions, we hope this work will inspire studies that better address these gaps and limitations and provide a better understanding of the burden of these conditions.

Acknowledgments

The National Arthritis Data Workgroup is a consortium of experts in epidemiology organized to provide a single source of national data on the prevalence and impact of rheumatic diseases. It is supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH; the National Center for Chronic Disease Prevention and Health Promotion and National Center for Health Statistics, CDC; the American College of Rheumatology; and the Arthritis Foundation.

Footnotes

The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention, the National Institutes of Health, or the Department of Veterans Affairs.

AUTHOR CONTRIBUTIONS

Dr. Helmick had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study design. Lawrence, Felson, Helmick, Choi, Gabriel, Hunder.

Acquisition of data. Felson, Helmick, Choi, Hochberg, Hunder, Jordan, Katz, Maradit Kremers, Wolfe.

Analysis and interpretation of data. Felson, Helmick, Arnold, Choi, Deyo, Gabriel, Hunder, Jordan, Katz, Maradit Kremers, Wolfe.

Manuscript preparation. Lawrence, Felson, Helmick, Arnold, Choi, Deyo, Gabriel, Hirsch, Hochberg, Hunder, Jordan, Katz, Maradit Kremers, Wolfe.

Statistical analysis. Helmick, Choi.

Project initiation and organization. Lawrence.

REFERENCES

1. Helmick CG, Felson DT, Lawrence RC, Gabriel S, Hirsch R, Maradit Kremers H, et al. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Part I. Arthritis Rheum. 2008;58:15–25. [PubMed] [Google Scholar]
2. Cunningham LS, Kelsey JL. Epidemiology of musculoskeletal impairments and associated disability. Am J Public Health. 1984;74:574–579. [PMC free article] [PubMed] [Google Scholar]
3. Kellgren JH, Lawrence JS. Radiological assessment of osteoarthrosis. Ann Rheum Dis. 1957;16:494–501. [PMC free article] [PubMed] [Google Scholar]
4. Dillon CF, Rasch EK, Gu Q, Hirsch R. Prevalence of knee osteoarthritis in the United States: arthritis data from the third National Health and Nutrition Examination Survey 1991–1994. J Rheumatol. 2006;33:2271–2279. [PubMed] [Google Scholar]
5. Felson DT, Naimark A, Anderson J, Kazis L, Castelli W, Meenan RF. The prevalence of knee osteoarthritis in the elderly: the Framingham Osteoarthritis Study. Arthritis Rheum. 1987;30:914–918. [PubMed] [Google Scholar]
6. Zhang Y, Niu J, Kelly-Hayes M, Chaisson CE, Aliabadi P, Felson DT. Prevalence of symptomatic hand osteoarthritis and its impact on functional status among elderly: the Framingham Study. Am J Epidemiol. 2002;156:1021–1027. [PubMed] [Google Scholar]
7. Jordan JM, Helmick CG, Renner JB, Luta G, Woodard J, Dragomir AD, et al. Prevalence of knee symptoms and radiographic and symptomatic knee osteoarthritis in African-Americans and Caucasians: the Johnston County Osteoarthritis Project. J Rheumatol. 2007;34:172–180. [PubMed] [Google Scholar]
8. Nevitt MC, Lane NE, Scott JC, Hochberg MC, Pressman AR, Genant HK, et al. and the Study of Osteoporotic Fractures Research Group. Radiographic osteoarthritis of the hip and bone mineral density. Arthritis Rheum. 1995;38:907–916. [PubMed] [Google Scholar]
9. Sowers M, Lachance L, Hochberg M, Jamadar D. Radiographically defined osteoarthritis of the hand and knee in young and middle-aged African-American and Caucasian women. Osteoarthritis Cartilage. 2000;8:69–77. [PubMed] [Google Scholar]
10. Helmick C, Renner JB, Luta G, Dragomir AD, Kalsbeek W, Abbate L, et al. Prevalence of hip pain, radiographic hip osteoarthritis (OA), severe radiographic hip OA, symptomatic hip OA: the Johnson County Osteoarthritis Project [abstract] Arthritis Rheum. 2003;48 Suppl 9:S212. [Google Scholar]
11. Lawrence RC, Helmick CG, Arnett FC, Deyo RA, Felson DT, Giannini EH, et al. Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States. Arthritis Rheum. 1998;41:778–799. [PubMed] [Google Scholar]
12. Smith CA, Fidler WJ, Pinals RS. The epidemiology of giant cell arteritis: report of a ten-year study in Shelby County, Tennessee. Arthritis Rheum. 1983;26:1214–1219. [PubMed] [Google Scholar]
13. Salvarani C, Cantini F, Boiardi L, Hunder GG. Polymyalgia rheumatica and giant-cell arteritis. N Engl J Med. 2002;347:261–271. [PubMed] [Google Scholar]
14. Weyand CM, Goronzy JJ. Giant-cell arteritis and polymyalgia rheumatica. Ann Intern Med. 2003;139:505–515. [PubMed] [Google Scholar]
15. Hunder GG, Bloch DA, Michel BA, Stevens MB, Arend WP, Calabrese LH, et al. The American College of Rheumatology 1990 criteria for the classification of giant cell arteritis. Arthritis Rheum. 1990;33:1122–1128. [PubMed] [Google Scholar]
16. Doran MF, Crowson CS, O’Fallon WM, Hunder GG, Gabriel SE. Trends in the incidence of polymyalgia rheumatica over a 30 year period in Olmsted County, Minnesota, USA. J Rheumatol. 2002;29:1694–1697. [PubMed] [Google Scholar]
17. Salvarani C, Crowson CS, O’Fallon WM, Hunder GG, Gabriel SE. Reappraisal of the epidemiology of giant cell arteritis in Olmsted County, Minnesota, over a 50-year period. Arthritis Rheum. 2004;51:264–268. [PubMed] [Google Scholar]
18. Petursdottir V, Johansson H, Nordborg E, Nordborg C. The epidemiology of biopsy-positive giant cell arteritis: special reference to cyclic fluctuations. Rheumatology (Oxford) 1999;38:1208–1212. [PubMed] [Google Scholar]
19. Gran JT, Myklebust G. The incidence of polymyalgia rheumatica and temporal arteritis in the county of Aust Agder, south Norway: a prospective study 1987–94. J Rheumatol. 1997;24:1739–1743. [PubMed] [Google Scholar]
20. Baldursson O, Steinsson K, Bjornsson J, Lie JT. Giant cell arteritis in Iceland: an epidemiologic and histopathologic analysis. Arthritis Rheum. 1994;37:1007–1012. [PubMed] [Google Scholar]
21. Gonzalez-Gay MA, Garcia-Porrua C, Rivas MJ, Rodriguez-Ledo P, Llorca J. Epidemiology of biopsy proven giant cell arteritis in northwestern Spain: trend over an 18 year period. Ann Rheum Dis. 2001;60:367–371. [PMC free article] [PubMed] [Google Scholar]
22. Wallace SL, Robinson H, Masi AT, Decker JL, McCarty DJ, Yu TF. Preliminary criteria for the classification of the acute arthritis of primary gout. Arthritis Rheum. 1977;20:895–900. [PubMed] [Google Scholar]
23. Choi HK, Atkinson K, Karlson EW, Willett WC, Curhan G. Purine-rich foods, dairy and protein intake, and the risk of gout in men. N Engl J Med. 2004;350:1093–1103. [PubMed] [Google Scholar]
24. Roubenoff R. Gout and hyperuricemia. Rheum Dis Clin North Am. 1990;16:539–550. [PubMed] [Google Scholar]
25. Mikkelsen WM, Dodge HJ, Duff IF, Kato H. Estimates of the prevalence of rheumatic diseases in the population of Tecumseh, Michigan, 1959–60. J Chronic Dis. 1967;20:351–369. [PubMed] [Google Scholar]
26. Hall AP, Barry PE, Dawber TR, McNamara PM. Epidemiology of gout and hyperuricemia: a long-term population study. Am J Med. 1967;42:27–37. [PubMed] [Google Scholar]
27. O’Sullivan JB. Gout in a New England town: a prevalence study in Sudbury, Massachusetts. Ann Rheum Dis. 1972;31:166–169. [PMC free article] [PubMed] [Google Scholar]
28. Brochner-Mortensen K, Cobb S, Rose BS. Report of sub-committee on criteria for the diagnosis of gout in surveys. In: Kellgren JH, Jeffrey MR, Ball JF, editors. The epidemiology of chronic rheumatism. Vol. I. Philadelphia: FA Davis; 1963. pp. 295–297. [Google Scholar]
29. Bennett PH, Wood PH, editors. Population studies of the rheumatic diseases. Amsterdam: Excerpta Medica; 1968. [Google Scholar]
30. Adams PF, Hendershot GE, Marano MA. Current estimates from the National Health Interview Survey, 1996. National Center for Health Statistics. URL: www.cdc.gov/nchs/data/series/sr_10/sr10_200.pdf. [PubMed]
31. Wallace KL, Riedel AA, Joseph-Ridge N, Wortmann R. Increasing prevalence of gout and hyperuricemia over 10 years among older adults in a managed care population. J Rheumatol. 2004;31:1582–1587. [PubMed] [Google Scholar]
32. Kramer HM, Curhan G. The association between gout and nephrolithiasis: the National Health and Nutrition Examination Survey III, 1988–1994. Am J Kidney Dis. 2002;40:37–42. [PubMed] [Google Scholar]
33. Wolfe F, Smythe HA, Yunus MB, Bennett RM, Bombardier C, Goldenberg DL, et al. The American College of Rheumatology 1990 criteria for the classification of fibromyalgia: report of the multicenter criteria committee. Arthritis Rheum. 1990;33:160–172. [PubMed] [Google Scholar]
34. Wolfe F, Ross K, Anderson J, Russell IJ. Aspects of fibromyalgia in the general population: sex, pain threshold, and fibromyalgia symptoms. J Rheumatol. 1995;22:151–156. [PubMed] [Google Scholar]
35. Gracely RH, Grant MA, Giesecke T. Evoked pain measures in fibromyalgia. Best Pract Res Clin Rheumatol. 2003;17:593–609. [PubMed] [Google Scholar]
36. MacFarlane GJ, Croft PR, Schollum J, Silman AJ. Widespread pain: is an improved classification possible? J Rheumatol. 1996;23:1628–1632. [PubMed] [Google Scholar]
37. Buskila D, Press J, Abu-Shakra M. Fibromyalgia in systemic lupus erythematosus: prevalence and clinical implications. Clin Rev Allergy Immunol. 2003;25:25–28. [PubMed] [Google Scholar]
38. Wolfe F, Ross K, Anderson J, Russell IJ, Hebert L. The prevalence and characteristics of fibromyalgia in the general population. Arthritis Rheum. 1995;38:19–28. [PubMed] [Google Scholar]
39. White KP, Speechley M, Harth M, Ostbye T. The London Fibromyalgia Epidemiology Study: the prevalence of fibromyalgia syndrome in London, Ontario. J Rheumatol. 1999;26:1570–1576. [PubMed] [Google Scholar]
40. Katz JN, Larson MG, Sabra A, Krarup C, Stirrat CR, Sethi R, et al. The carpal tunnel syndrome: diagnostic utility of the history and physical examination findings. Ann Intern Med. 1990;112:321–327. [PubMed] [Google Scholar]
41. Tanaka S, Wild DK, Cameron LL, Freund E. Association of occupational and non-occupational risk factors with the self-reported carpal tunnel syndrome in a national survey of the working population. Am J Ind Med. 1997;32:550–556. [PubMed] [Google Scholar]
42. Katz JN, Stirrat CR, Larson MG, Fossel AH, Eaton HM, Liang MH. A self-administered hand symptom diagram for the diagnosis and epidemiologic study of carpal tunnel syndrome. J Rheumatol. 1990;17:1495–1498. [PubMed] [Google Scholar]
43. Ferry S, Silman AJ, Pritchard T, Keenan J, Croft P. The association between different patterns of hand symptoms and objective evidence of median nerve compression: a community-based survey. Arthritis Rheum. 1998;41:720–724. [PubMed] [Google Scholar]
44. Atroshi I, Gummesson C, Johnsson R, Ornstein E, Ranstam J, Rosen I. Prevalence of carpal tunnel syndrome in a general population. JAMA. 1999;282:153–158. [PubMed] [Google Scholar]
45. Ferry S, Pritchard T, Keenan J, Croft P, Silman AJ. Estimating the prevalence of delayed median nerve conduction in the general population. Br J Rheumatol. 1998;37:630–635. [PubMed] [Google Scholar]
46. De Krom MC, Knipschild PG, Kester AD, Thijs CT, Boekkooi PF, Spaans F. Carpal tunnel syndrome: prevalence in the general population. J Clin Epidemiol. 1992;45:373–376. [PubMed] [Google Scholar]
47. Tanaka S, Wild DK, Seligman PJ, Behrens V, Cameron L, Putz-Anderson V. The US prevalence of self-reported carpal 1988 National Health Interview Survey data. Am J Public Health. 1994;84:1846–1848. [PMC free article] [PubMed] [Google Scholar]
48. Deyo RA, Weinstein JN. Low back pain. N Engl J Med. 2001;344:363–370. [PubMed] [Google Scholar]
49. White AA, Gordon SL. Synopsis: workshop on idiopathic low back pain. Spine. 1982;7:141–149. [PubMed] [Google Scholar]
50. Lethbridge-Cejku M, Schiller JS, Bernadel L. Summary health statistics for United States adults: National Health Interview Survey 2002. National Center for Health Statistics. 2004 DHHS publication (PHS) 2004-1550. [PubMed]
51. US Department of Health and Human Services. Healthy people 2010. 2nd ed. With: Understanding and improving health and objectives for improving health. 2 vols. Washington, DC: US Government Printing Office; 2000. [Google Scholar]
52. Sternbach RA. Survey of pain in the United States: the Nuprin pain report. Clin J Pain. 1986;2:49–53. [PubMed] [Google Scholar]
53. Deyo RA, Tsui-Wu YJ. Descriptive epidemiology of low back pain and its related medical care in the United States. Spine. 1987;12:264–268. [PubMed] [Google Scholar]
54. Frymoyer JW, Pope MH, Clements JH, Wilder DG, MacPherson B, Ashikaga T. Risk factors in low-back pain: an epidemiological survey. J Bone Joint Surg Am. 1983;65:213–218. [PubMed] [Google Scholar]
55. Olsen TL, Anderson RL, Dearwater SR, Kriska AM, Cauley JA, Aaron DJ, et al. The epidemiology of low back pain in an adolescent population. Am J Public Health. 1992;82:606–608. [PMC free article] [PubMed] [Google Scholar]
56. Nagi SZ, Riley LE, Newby LG. A social epidemiology of back pain in a general population. J Chronic Dis. 1973;26:769–779. [Google Scholar]
57. Reisbord LS, Greenland S. Factors associated with self-reported back pain prevalence: a population-based study. J Chronic Dis. 1985;38:691–702. [PubMed] [Google Scholar]
58. Kelsey JL, Golder AL, Mundt DJ. Low back pain/prolapsed lumbar intervertebral disc. Rheum Dis Clin North Am. 1990;163:699–715. [PubMed] [Google Scholar]
59. Kelsey JL, White AA. Epidemiology and impact of low back pain. Spine. 1980;5:133–142. [PubMed] [Google Scholar]
60. Taylor H, Curran NM. The Nuprin report. New York: Louis Harris & Associates; 1985. [Google Scholar]
61. Boden SD, Davis DO, Dina TS, Patronas NJ, Wiesel SW. Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects: a prospective study. J Bone Joint Surg Am. 1990;72:403–408. [PubMed] [Google Scholar]
62. Jarvik J, Hollingworth W, Heagerty P, Haynor DR, Deyo RA. The Longitudinal Assessment of Imaging and Disability of the Back (LAIDBack) Study: baseline data. Spine. 2001;26:1158–1166. [PubMed] [Google Scholar]
63. Klein RJ, Schoenborn CA. Age adjustment using the 2000 projected US population. National Center for Health Statistics. 2001 January; Healthy people statistical notes, no. 20. URL: http://www.cdc.gov/nchs/data/statnt/statnt20.pdf. [PubMed]
64. Adams PF, Hardy AM. Current estimates from the National Health Interview Survey 1998. Vital Health Stat 10. 1989;173:1–250. [PubMed] [Google Scholar]
65. Benson V, Marano MA. Current estimates from the National Health Interview Survey, 1992. Vital Health Stat 10. 1994;189:1–269. [PubMed] [Google Scholar]