Diagnosis of Inflammatory Bowel Disease-Associated Peripheral Arthritis: A Systematic Review.

BACKGROUND: Inflammatory bowel disease (IBD)-associated peripheral spondyloarthritis (pSpA) decreases quality of life and remains poorly understood. Given the prevalence of this condition and its negative impact, it is surprising that evidence-based disease definitions and diagnostic strategies are lacking. This systematic review summarizes available data to facilitate development and validation of diagnostics, patient-reported outcomes, and imaging indices specific to this condition. METHODS: A literature search was conducted. Consensus or classification criteria, case series, cross-sectional studies, cohort studies, and randomized controlled trials related to diagnosis were included. RESULTS: A total of 44 studies reporting data on approximately 1500 patients with pSpA were eligible for analysis. Data quality across studies was only graded as fair to good. Due to large heterogeneity, meta-analysis was not possible. The majority of studies incorporated patient-reported outcomes and a physical examination. A total of 13 studies proposed or validated screening tools, consensus, classification, or consensus criteria. A total of 28 studies assessed the role of laboratory tests, none of which were considered sufficiently accurate for use in diagnosis. A total of 17 studies assessed the role of imaging, with the available literature insufficient to fully endorse any imaging modality as a robust diagnostic tool. CONCLUSIONS: This review highlights existing inconsistency and lack of a clear diagnostic approach for IBD-associated pSpA. Given the absence of an evidence-based approach, a combination of existing criteria and physician assessment should be utilized. To address this issue comprehensively, our future efforts will be directed toward pursuit of a multidisciplinary approach aimed at standardizing evaluation and diagnosis of IBD-associated pSpA.

This systematic review highlights the lack of an evidence-based approach to the diagnosis of inflammatory bowel disease­associated peripheral spondyloarthritis and the need to standardize evaluation and diagnosis via multidisciplinary collaboration with development of patient-reported outcomes and imaging indices.

American College of Rheumatology and Food and Drug Administration Summit: Summary of the Meeting May 17-18, 2022.

The American College of Rheumatology and the US Food and Drug Administration co-sponsored a public meeting in May 2022 about challenges in the clinical development of drugs for rheumatoid arthritis (RA) and psoriatic arthritis (PsA), focusing on innovative clinical trial designs, outcome measures, and data collection methods. Recommendations include early dose-ranging studies and use of active comparators. Challenges and opportunities in assessing long-term safety by leveraging real-world data from electronic health records (EHRs) and claims data are discussed, along with insights from European registries and the evolving role of real-world evidence and artificial intelligence in regulatory evaluations. Endpoints for assessing disease activity and outcome measures used in RA and PsA trials are explored, emphasizing challenges in defining remission, assessing clinical response, and evaluating structural progression. The need for outcome measures that better reflect treatment targets and the potential of advanced imaging in future trials are highlighted. Challenges with placebo-controlled trials in RA are discussed and use of non-inferiority clinical trial design, in which new drugs are evaluated with active comparators, is proposed. Pragmatic trials in RA and PsA, employing decentralized approaches, are highlighted for their real-world relevance and administrative efficiencies. Strategies for identifying at-risk populations for RA and the challenges of using EHRs and insurance claims data in drug development are discussed. Registry data and digital health technologies show promise in bridging the gap between clinical trials and real-world effectiveness.

Sacroiliitis in inflammatory bowel disease.

PURPOSE OF REVIEW: This review summarizes the recent evidence regarding the epidemiology of inflammatory bowel disease (IBD) associated sacroiliitis, including the prevalence, pathogenesis, role of imaging, and therapeutic challenges. RECENT FINDINGS: Sacroiliitis is an underappreciated musculoskeletal manifestation of IBD, a chronic inflammatory condition of the gut affecting the younger population. Untreated sacroiliitis can lead to joint destruction and chronic pain, further adding to morbidity in IBD patients. Recent publications suggest sacroiliitis can be detected on abdominal imaging obtained in IBD patients to study bowel disease, but only a small fraction of these patients were seen by rheumatologists. Early detection of IBD-associated sacroiliitis could be achieved by utilization of clinical screening tools in IBD clinics, careful examination of existing computed tomography and MRI studies, and timely referral to rheumatologist for further evaluation and treatment. Current treatment approaches for IBD and sacroiliitis include several targeted biologic therapies, but IBD-associated sacroiliitis has limited options, as these therapies may not overlap in both conditions. SUMMARY: With the advances in imaging, sacroiliitis is an increasingly recognized comorbidity in IBD patients. Future studies focusing on this unique patient population will expand our understanding of complex pathophysiology of IBD-associated sacroiliitis and lead to identification of novel targeted therapies for this condition.

Extrarenal symptoms associate with worse quality of life in patients enrolled in the AMP RA/SLE Lupus Nephritis Network.

OBJECTIVE: Lupus nephritis (LN) can occur as an isolated component of disease activity or be accompanied by diverse extrarenal manifestations. Whether isolated renal disease is sufficient to decrease health related quality of life (HRQOL) remains unknown. This study compared Patient-Reported Outcomes Measurement Information System 29-Item (PROMIS-29) scores in LN patients with isolated renal disease to those with extrarenal symptoms to evaluate the burden of LN on HRQOL and inform future LN clinical trials incorporating HRQOL outcomes. METHODS: A total of 181 LN patients consecutively enrolled in the multicentre multi-ethnic/racial Accelerating Medicines Partnership completed PROMIS-29 questionnaires at the time of a clinically indicated renal biopsy. Raw PROMIS-29 scores were converted to standardized T scores. RESULTS: Seventy-five (41%) patients had extrarenal disease (mean age 34, 85% female) and 106 (59%) had isolated renal (mean age 36, 82% female). Rash (45%), arthritis (40%) and alopecia (40%) were the most common extrarenal manifestations. Compared with isolated renal, patients with extrarenal disease reported significantly worse pain interference, ability to participate in social roles, physical function, and fatigue. Patients with extrarenal disease had PROMIS-29 scores that significantly differed from the general population by > 0.5 SD of the reference mean in pain interference, physical function, and fatigue. Arthritis was most strongly associated with worse scores in these three domains. CONCLUSION: Most patients had isolated renal disease and extrarenal manifestations associated with worse HRQOL. These data highlight the importance of comprehensive disease management strategies that address both renal and extrarenal manifestations to improve overall patient outcomes.

Unique characteristics of anti-MDA-5 associated dermatomyositis in Southern California with a large Hispanic population.

OBJECTIVES: There is little to no data about the presentation and clinical course of anti-melanoma differentiation-associated gene-5 antibody (anti-MDA-5) dermatomyositis in a primarily U.S. Hispanic population. We describe the clinical course of anti-MDA-5 dermatomyositis in our majority Hispanic population. METHODS: This is a multicenter, retrospective case series of anti-MDA-5 dermatomyositis. Patients diagnosed with anti-MDA-5 dermatomyositis from June 2015 to March 2023 at four medical centers in Los Angeles, California, were included. Demographics and clinical characteristics were obtained. Descriptive statistics, Pearson's chi-squared, Fisher's exact, Wilcoxon rank sum, and Kruskal-Wallis tests were performed as applicable. RESULTS: Thirty anti-MDA-5 dermatomyositis patients were included. Twenty-two (73 %) were Hispanic. Twenty-one patients (70 %) were female, with a median age of 40.5 years. Hispanic patients were diagnosed with anti-MDA-5 dermatomyositis at a younger age than non-Hispanic patients (p = 0.025). Inflammatory arthritis was prominent; more males were affected than females (p = 0.027). Thirteen patients (43 %) were amyopathic. Twenty-five patients (83.3 %) had evidence of interstitial lung disease (ILD), and a higher ferritin level was associated with ILD (p = 0.049). There were six deaths (20 %); five (17 %) were ascribed to rapidly progressive ILD. CONCLUSION: ILD was the most common presentation of anti-MDA-5 dermatomyositis in our cohort and was associated with higher ferritin levels. Hispanic patients had a younger age of diagnosis than non-Hispanic patients. Necrotic skin lesions and inflammatory arthritis were frequently seen. This is the first study looking at clinical phenotypes and outcomes of anti-MDA-5 dermatomyositis in a primarily Hispanic U.S. POPULATION: Future studies are needed to better understand the clinical manifestations (to promptly recognize and treat) of this population of anti-MDA-5 dermatomyositis.

Sex Differences in Time to Initiate Nonsteroidal Anti-Inflammatory Drugs or Biologic Disease-Modifying Antirheumatic Drugs Among Patients With Axial Spondyloarthritis.

OBJECTIVE: We evaluated sex differences in time to initiation of receiving nonsteroidal anti-inflammatory drugs (NSAIDs) or biologic disease-modifying antirheumatic drugs (bDMARDs) among patients with axial spondyloarthritis (axSpA). METHODS: Using the 2013 to 2018 IBM MarketScan Database, we identified 174,632 patients with axSpA aged ≥18 years. We evaluated the time between axSpA diagnosis and the first prescription NSAID dispensing (among those with no baseline NSAIDs reception) or bDMARDs infusion/procedure claim (among those who were dispensed two or more different prescription NSAIDs in the baseline period). Adjusted hazard ratios (aHRs) for time to initiation of patients receiving NSAIDs or bDMARDs were computed using survival analyses. Cox proportional hazard models estimated associations between sex and predictors of treatment initiation. RESULTS: Average age at diagnosis was 48.2 years, 65.7% were female, and 37.8% were dispensed one or more NSAIDs before axSpA diagnosis. Of those who did not receive two or more different prescription NSAIDs before diagnosis, NSAID reception was initiated earlier in female patients than in male patients (NSAID reception initiators: female patients (32.9%), male patients (29.3%); aHR 1.14, 95% confidence interval [CI] 1.11-1.16). Among those who received two or more different prescription NSAIDs in the baseline period, 4.2% received a bDMARD, whereas 77.9% continued receiving NSAIDs after diagnosis. Time to bDMARD reception initiation was longer for female patients than for male patients (aHR 0.61, 95% CI 0.52-0.72), but bDMARDs were received sooner among those who received NSAIDs in the baseline period. CONCLUSION: Prescription NSAID reception was more common than initiation of receiving bDMARDs among patients newly diagnosed with axSpA. Female patients appeared more likely to continue receiving NSAIDs after diagnosis, and the time to initiation of receiving bDMARDs was longer for female patients than for male patients.

Screening Tools for Spondyloarthritis in Patients With Psoriasis, Uveitis, and Inflammatory Bowel Disease: A Scoping Review.

OBJECTIVE: Extramusculoskeletal manifestations of spondyloarthritis (SpA) may precede the development of articular features. Patients seen in ophthalmology, dermatology, and gastroenterology clinics with uveitis, psoriasis, or inflammatory bowel disease (IBD) may have undiagnosed SpA. We set out to identify and evaluate screening tools for SpA in patients with psoriasis, uveitis, and IBD and determine factors that influence the performance of these instruments. METHODS: This scoping review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Embase, and Web of Science were searched from inception to January 2022. RESULTS: We identified 13 screening tools for psoriatic arthritis, 2 SpA screening tools for uveitis, and 3 SpA screening tools for IBD. All screening tools were patient-oriented questionnaires except for the Dublin Uveitis Evaluation Tool, a physician-applied algorithm. The questionnaires varied in length, scoring method, cutoff score, and spectrum of included SpA features. Average completion time was less than five minutes. Across the three patient populations, the sensitivities and specificities of these screening tools were comparable in the primary validation cohorts. Sensitivities and specificities were generally lower in secondary validation studies, with marked variability among cohorts. CONCLUSION: Our results highlight the heterogeneity and limitations of existing SpA screening tools. Although these tools show promise for use within a specific target population, none are generalizable to all patients with extramusculoskeletal manifestations at risk of SpA. Future studies should explore the utility of a generic patient-oriented SpA screening tool that can be applied to patients with psoriasis, uveitis, or IBD; is easy to use and comprehend; and captures all clinical domains of SpA.

Longitudinal patterns and predictors of response to standard-of-care therapy in lupus nephritis: data from the Accelerating Medicines Partnership Lupus Network.

BACKGROUND: Leveraging the Accelerating Medicines Partnership (AMP) Lupus Nephritis (LN) dataset, we evaluated longitudinal patterns, rates, and predictors of response to standard-of-care therapy in patients with lupus nephritis. METHODS: Patients from US academic medical centers with class III, IV, and/or V LN and a baseline urine protein/creatinine (UPCR) ratio ≥ 1.0 (n = 180) were eligible for this analysis. Complete response (CR) required the following: (1) UPCR < 0.5; (2) normal serum creatinine (≤ 1.3 mg/dL) or, if abnormal, ≤ 125% of baseline; and (3) prednisone ≤ 10 mg/day. Partial response (PR) required the following: (1) > 50% reduction in UPCR; (2) normal serum creatinine or, if abnormal, ≤ 125% of baseline; and (3) prednisone dose ≤ 15 mg/day. RESULTS: Response rates to the standard of care at week 52 were CR = 22.2%; PR = 21.7%; non-responder (NR) = 41.7%, and not determined (ND) = 14.4%. Only 8/180 (4.4%) patients had a week 12 CR sustained through week 52. Eighteen (10%) patients attained a week 12 PR or CR and sustained their responses through week 52 and 47 (26.1%) patients achieved sustained PR or CR at weeks 26 and 52. Week 52 CR or PR attainment was associated with baseline UPCR > 3 (ORadj = 3.71 [95%CI = 1.34-10.24]; p = 0.012), > 25% decrease in UPCR from baseline to week 12 (ORadj = 2.61 [95%CI = 1.07-6.41]; p = 0.036), lower chronicity index (ORadj = 1.33 per unit decrease [95%CI = 1.10-1.62]; p = 0.003), and positive anti-dsDNA antibody (ORadj = 2.61 [95%CI = 0.93-7.33]; p = 0.069). CONCLUSIONS: CR and PR rates at week 52 were consistent with the standard-of-care response rates observed in prospective registrational LN trials. Low sustained response rates underscore the need for more efficacious therapies and highlight how critically important it is to understand the molecular pathways associated with response and non-response.

Pregnancy Outcomes in a Diverse US Lupus Cohort.

OBJECTIVE: Although the population of patients with systemic lupus erythematosus (SLE) is racially and ethnically diverse, many study populations are homogeneous. Further, data are often lacking on critical factors, such as antiphospholipid antibodies (aPLs). We investigated live birth rates in patients with SLE at Kaiser Permanente Northern California, including race and ethnicity and aPL data. METHODS: Electronic health records of pregnancies with outcomes observed from 2011 to 2020 were identified among patients with SLE. Prevalent SLE was defined as two or more International Classification of Diseases-coded visits seven or more days apart before the last menstrual period. We summarized patient characteristics, medication orders, health care use, and medication use. Pregnancy outcomes (live birth, stillbirth, spontaneous abortion, ectopic pregnancy, and molar pregnancy) were presented overall and stratified by race and ethnicity, aPL status, and nephritis history. RESULTS: We identified 657 pregnancies among 453 patients with SLE. The cohort was diverse, reflecting the Northern California population (27% Asian, 26% Hispanic, 26% Non-Hispanic White, 13% Non-Hispanic Black, 5% multiracial, and approximately 2% Pacific Islander and Native American). Approximately 74% of observed pregnancies ended in live birth, 23% resulted in spontaneous abortion, 2% were ectopic or molar pregnancies, and <1% were stillbirths. There was limited variability in live births by race and ethnic group (72%-79%), aPL status (69.5%-77%), and nephritis history (71%-75%). CONCLUSION: Our findings are consistent with previous studies; however, some methodologic differences may yield a range of live birth rates. We found that approximately 74% of pregnancies in patients with SLE ended in live birth, with modest variability in spontaneous abortion by race and ethnicity, nephritis history, and aPL status.

Hydroxychloroquine in Lupus Pregnancy and Risk of Preeclampsia.

OBJECTIVE: Systemic lupus erythematosus (SLE) disproportionately affects women during childbearing years, and hydroxychloroquine (HCQ) is the standard first-line treatment. Preeclampsia complicates up to one-third of pregnancies in lupus patients, although reports vary by parity and multifetal gestation. We investigated whether taking HCQ early in pregnancy may reduce the risk of preeclampsia. METHODS: We studied 1,068 live birth singleton pregnancies among 1,020 privately insured patients with SLE (2007-2016). HCQ treatment was defined as three months preconception through the first trimester, and prescription fills were a proxy for taking HCQ. Modified Poisson regression estimated risk ratios (RRs) and 95% confidence intervals (CIs), stratified by parity. Propensity scores accounted for confounders, and stratified analyses examined effect modification. RESULTS: Approximately 15% of pregnant patients were diagnosed with preeclampsia. In 52% of pregnancies, patients had one or more HCQ fills. Pregnant patients exposed to HCQ had more comorbidities, SLE activity, and azathioprine treatment. We found no evidence of a statistical association between HCQ and preeclampsia among nulliparous (RR 1.26 [95% CI 0.82-1.93]) and multiparous pregnancies (RR 1.20 [95% CI 0.80-1.70]). Additional controls for confounding decreased the RRs toward the null (nulliparous pregnancy, propensity score-adjusted [PS-adj] RR 1.09 [95% CI 0.68-1.76]; multiparous pregnancy, PS-adj RR 1.01 [95% CI 0.66-1.53]). CONCLUSION: Using a large insurance-based database, we did not observe a decreased risk of preeclampsia associated with HCQ treatment in pregnancy, although we cannot rule out residual and unmeasured confounding and misclassification. Further studies leveraging large population-based data and prospective collection could characterize how HCQ influences preeclampsia risk in pregnant patients with SLE and among persons at greater risk of hypertensive disorders of pregnancy.

Twenty Years of SPARTAN: From Inception to Impact (SPARTAN 2023 Annual Meeting Proceedings).

PURPOSE OF REVIEW: This review takes a look at the past, present, and future of SPARTAN, the Spondyloarthritis Research and Treatment Network, an organization of North American healthcare professionals dedicated to advancing research, education, and patient care in spondyloarthritis. RECENT FINDINGS: In 2022, SPARTAN completed the Classification of Axial SpondyloarthritiS Inception Cohort (CLASSIC) study, a collaboration with the Assessment in SpondyloArthritis International Society (ASAS). CLASSIC aimed to validate the 2009 ASAS classification criteria for axial spondyloarthritis. Other ongoing SPARTAN endeavors include the development of US referral recommendations for axial spondyloarthritis, an update of the 2019 ACR/SAA/SPARTAN treatment recommendations for axial spondyloarthritis and multiple educational initiatives. Twenty years after its inception, SPARTAN continues to grow and broaden its impact, guided by the SPARTAN vision of "a world free of spondyloarthritis through leadership in research and education."

Multimorbidity phenotypes in ankylosing spondylitis and their association with disease activity and functional impairment: Data from the prospective study of outcomes in ankylosing spondylitis cohort.

OBJECTIVES: To examine the association of multimorbidity phenotypes at baseline with disease activity and functional status over time in ankylosing spondylitis (AS). METHODS: Patient-reported AS morbidities (comorbidities, N = 28 and extra-musculoskeletal manifestations, EMMs, N = 3) within 3 years of enrollment with a prevalence ≥1 %, were included from the Prospective Study of Outcomes in Ankylosing Spondylitis (PSOAS) cohort. We defined multimorbidity as ≥2 morbidities (MM2+) and substantial multimorbidity as ≥5 morbidities (MM5+). Multimorbidity clusters or phenotypes were identified using K-median clustering. Disease activity (ASDAS-CRP) and functional status (BASFI) measures were collected every 6 months. Generalized estimating equation method was used to examine the associations of multimorbidity counts and multimorbidity clusters with measures of disease activity and functional status over time. RESULTS: Among 1,270 AS patients (9,885 visits) with a median follow-up of 2.9 years (IQ range: 1.0-6.8 years), the prevalence of MM2+ and MM5+ was 49 % and 9 % respectively. We identified five multimorbidity clusters: depression (n = 321, 25 %), hypertension (n = 284, 22 %), uveitis (n = 274, 22 %), no morbidities (n = 238, 19 %), and miscellaneous (n = 153, 12 %). Patients in the depression cluster were more likely to be female and had significantly more morbidities and worse disease activity and functional status compared to those with no morbidities. CONCLUSION: Approximately 49 % of AS patients in the PSOAS cohort had multimorbidity and five distinct multimorbidity phenotypes were identified. In addition to the number of morbidities, the type of morbidity appears to be important to longitudinal outcomes in AS. The depression cluster was associated with worse disease activity and function.

Interaction effects of significant risk factors on low bone mineral density in ankylosing spondylitis.

Background: To analyze individually and interactively critical risk factors, which are closely related to low bone mineral density (BMD) in patient with ankylosing spondylitis (AS). Methods: A total of 249 AS patients who visited China-Japan Friendship Hospital were included in this training set. Patients with questionnaire data, blood samples, X-rays, and BMD were collected. Logistic regression analysis was employed to identify key risk factors for low BMD in different sites, and predictive accuracy was improved by incorporating the selected significant risk factors into the baseline model, which was then validated using a validation set. The interaction between risk factors was analyzed, and predictive nomograms for low BMD in different sites were established. Results: There were 113 patients with normal BMD, and 136 patients with low BMD. AS patients with hip involvement are more likely to have low BMD in the total hip, whereas those without hip involvement are more prone to low BMD in the lumbar spine. Chest expansion, mSASSS, radiographic average grade of the sacroiliac joint, and hip involvement were significantly associated with low BMD of the femoral neck and total hip. Syndesmophytes, hip involvement and higher radiographic average grade of the sacroiliac joint increases the risk of low BMD of the femoral neck and total hip in an additive manner. Finally, a prediction model was constructed to predict the risk of low BMD in total hip and femoral neck. Conclusions: This study identified hip involvement was strongly associated with low BMD of the total hip in AS patients. Furthermore, the risk of low BMD of the femoral neck and total hip was found to increase in an additive manner with the presence of syndesmophytes, hip involvement, and severe sacroiliitis. This finding may help rheumatologists to identify AS patients who are at a high risk of developing low BMD and prompt early intervention to prevent fractures.

Postpartum Depression in Reproductive-Age Women With and Without Rheumatic Disease: A Population-Based Matched Cohort Study.

OBJECTIVE: To examine postpartum depression (PPD) among women with axial spondyloarthritis (axSpA), psoriatic arthritis (PsA), or rheumatoid arthritis (RA) in comparison with a matched population without rheumatic disease (RD). METHODS: A retrospective analysis using the 2013-2018 IBM MarketScan Commercial Claims and Encounters Database was conducted. Pregnant women with axSpA, PsA, or RA were identified, and the delivery date was used as the index date. We restricted the sample to women ≤ 55 years with continuous enrollment ≥ 6 months before date of last menstrual period and throughout pregnancy. Each patient was matched with 4 individuals without RD on: (1) maternal age at delivery, (2) prior history of depression, and (3) duration of depression before delivery. Cox frailty proportional hazards models estimated the crude and adjusted hazard ratios (aHR) and 95% CI of incident postpartum depression within 1 year among women with axSpA, PsA, or RA (axSpA/PsA/RA cohort) compared to the matched non-RD comparison group. RESULTS: Overall, 2667 women with axSpA, PsA, or RA and 10,668 patients without any RD were included. The median follow-up time in days was 256 (IQR 93-366) and 265 (IQR 99-366) for the axSpA/PsA/RA cohort and matched non-RD comparison group, respectively. Development of PPD was more common in the axSpA/PsA/RA cohort relative to the matched non-RD comparison group (axSpA/PsA/RA cohort: 17.2%; matched non-RD comparison group: 12.8%; aHR 1.22, 95% CI 1.09-1.36). CONCLUSION: Postpartum depression is significantly higher in women of reproductive age with axSpA/PsA/RA when compared to those without RD.

Inflammatory Bowel Disease Prevalence: Surveillance data from the U.S. National Health and Nutrition Examination Survey.

Determining the overall US prevalence of Inflammatory Bowel Disease (IBD) is essential to national level prevention programs and population risk assessment; however currently US IBD prevalence remains uncertain. We used US National Health and Nutrition Examination Survey (NHANES) data to estimate the population-based prevalence of a self-reported history of medically diagnosed IBD, comparing to prior reports. Lifetime IBD prevalence for adults aged 20 + years was estimated in the independently conducted NHANES II (1976-80) and NHANES 2009-10 surveys. Participants were considered to have IBD if they reported being told by a physician they had Crohn's Disease (CD) or ulcerative colitis (UC). Clinically relevant NHANES data were analyzed to assess the self-reports. Survey design variables and sample weights were used to account for the complex survey design. The NHANES 2009-10 US IBD diagnosed prevalence was 1.2% (95% CI 0.8,1.6%), or an estimated 2.3 million persons. UC prevalence was 1.0% (95% CI 0.5,1.4%; 1.9 million persons) and CD prevalence was 0.3% (95% CI 0.1,0.4%; 578,000 persons). NHANES II UC prevalence was 1.0 (95% CI 0.8,1.2%), similar to 2009-10. UC prevalence was higher for ages ≥ 50 years in both surveys. NHANES 2009-10 data showed no UC sex differences, but women had higher UC prevalence in NHANES II. Remarkably, UC prevalence was similar between the two NHANES surveys fielded 30 years apart. The NHANES data are consistent with IBD prevalences reported in previous US nationally representative surveys, indicating that diagnosed IBD may affect approximately 1% of the US adult population.