Updated Estimates Suggest a Much Higher Prevalence of Arthritis in United States Adults Than Previous Ones

Abstract

Objective. National estimates of arthritis prevalence rely on a single survey question about doctor-diagnosed arthritis without using survey information on joint symptoms, even though some subjects with only the latter have been shown to have arthritis. The sensitivity of the current surveillance definition is only 53% and 69% in subjects ages 45-64 years and ages ≥65 years, respectively, resulting in misclassification of nearly one-half and one-third of subjects in those age groups. This study was undertaken to estimate arthritis prevalence based on an expansive surveillance definition that is adjusted for the measurement errors in the current definition.Methods. Using the 2015 National Health Interview Survey, we developed a Bayesian multinomial latent class model for arthritis surveillance based on doctordiagnosed arthritis, joint symptoms, and whether symptom duration exceeded 3 months.Results. Of 33,672 participants, 19.3% of men and 16.7% of women ages 18-64 years and 15.7% of men and 13.5% of women ages ≥65 years affirmed joint symptoms without doctor-diagnosed arthritis. The measurement error-adjusted prevalence of arthritis was 29.9% (95% Bayesian probability interval [95% PI] 23.4-42.3) in men ages 18-64 years, 31.2% (95% PI 25.8-44.1) in women ages 18-64 years, 55.8% (95% PI 49.9-70.4) in men ages ≥65 years, and 68.7% (95% PI 62.1-79.9) in women ages ≥65 years. Arthritis affected 91.2 million adults (of 247.7 million; 36.8%) in the US in 2015, which included 61.1 million persons between 18 and 64 years of age (of 199.9 million; 30.6%). Our arthritis prevalence estimate was 68% higher than the previously reported national estimate.Conclusion. Arthritis prevalence in the US population has been substantially underestimated, especially among adults younger than 65 years of age.

Reply

“…Unfortunately, the survey question (self-reported recall of doctor-diagnosed arthritis) used by the CDC to derive national estimates of arthritis prevalence has consistently been shown (2,3) to have poor Se and Sp , as exemplified by the validation study of Sacks et al (4) in which these questions were administered to a mixed group of patients who were then examined by trained rheumatology nurses asked to identify patients with treatable arthritis. Further, while this study reported that the Se for doctor-diagnosed arthritis question was merely 53% for persons ages 45–64, our own estimates (Table 3 in our paper) suggested Se of 22% and 34% in men and women (5), respectively, implying that using this single question for arthritis surveillance would miss nearly 65–80% of persons this age with arthritis.…”

Phospholipid Vesicles in Media for Tribological Studies against Live Cartilage

“…[1]. A dramatic increase in the demand for orthopedic care is projected as the baby-boomer generation approaches retirement age [2].…”

Arthritis Prevalence: Which Case Definition Should Be Used for Surveillance? Comment on the Article by Jafarzadeh and Felson

“…When the sensitivity and specificity of an imperfect instrument such as a single question to estimate arthritis prevalence are known, an unbiased estimate for prevalence can be calculated from apparent prevalence (i.e., the proportion who tested positive) by summing true-and false-positive fractions, i.e., Pr(T+) = Prev Se + ([1 -Prev] × [1 -Sp]), where Pr(T+) = proportion tested positive, Prev = true prevalence, Se = sensitivity, and Sp = specificity (1). Besides sensitivity and specificity, the only extra input required for unbiased estimation of prevalence is the proportion who tested positive.…”

“…However, we do believe that the association between male sex and NHL in primary SS is not coincidental or linked to recruitment or selection bias. As noted by Haacke and colleagues, the risk of lymphoma is associated with higher disease activity (1,2), consensually assessed by the ESSDAI score (2,3). We want to bring to their attention that recent analyses of the largest international primary SS cohort, which included 9,974 patients, showed that male patients with primary SS, compared to female patients, are characterized by higher disease activity at diagnosis.…”