Prevalence and incidence in patients with autoimmune rheumatic diseases: A nationwide population-based study in Taiwan

Risk of rheumatoid arthritis in patients with hepatitis C virus infection receiving interferon-based therapy: a retrospective cohort study using the Taiwanese national claims database

OBJECTIVES

To illuminate the association between interferon-based therapy (IBT) and the risk of rheumatoid arthritis (RA) in patients infected with hepatitis C virus (HCV).

DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS

This retrospective cohort study used Taiwan's Longitudinal Health Insurance Database 2005 that included 18 971 patients with HCV infection between 1 January 1997 and 31 December 2012. We identified 1966 patients with HCV infection who received IBT (treated cohort) and used 1:4 propensity score-matching to select 7864 counterpart controls who did not receive IBT (untreated cohort).

OUTCOME MEASURES

All study participants were followed until the end of 2012 to calculate the incidence rate and risk of incident RA.

RESULTS

During the study period, 305 RA events (3.1%) occurred. The incidence rate of RA was significantly lower in the treated cohort than the untreated cohort (4.0 compared with 5.5 per 1000 person-years, p<0.018), and the adjusted HR remained significant at 0.63 (95% CI 0.43 to 0.94, p=0.023) in a Cox proportional hazards regression model. Multivariate stratified analyses revealed that the attenuation in RA risk was greater in men (0.35; 0.15 to 0.81, p=0.014) and men<60 years (0.29; 0.09 to 0.93, p=0.036).

CONCLUSIONS

This study demonstrates that IBT may reduce the risk of RA and contributes to growing evidence that HCV infection may lead to development of RA.

Patients with chronic periodontitis present increased risk for primary Sjögren syndrome: a nationwide population-based cohort study

Many reports have mentioned the association between chronic periodontitis (CP) and primary Sjögren syndrome (pSS). However, no cohort study has been performed for the risk of pSS in patients with CP. In this study, we evaluated the risk of pSS from CP exposure in a nationwide population-based cohort study in Taiwan. We studied the claims data of Taiwanese population from 2001 to 2012. We identified 76,765 patients with CP from the National Health Insurance Database in Taiwan. We also selected 76,765 controls that were randomly frequency matched by age, sex, and index year from the general population. We analyzed the risk of pSS by using Cox proportional hazards regression models including sex, age, and comorbidities. In this study, 76,765 patients with CP (mean age: 40.8 years) and 76,765 controls (mean age: 41.0 years) were followed-up for 8.54 and 8.49 years, respectively. A total of 869 cases of pSS were identified in CP cohort and 483 cases in non-CP cohort. Multivariate Cox regression analysis indicated that the incidence rate of pSS was significantly higher in CP cohort than those who in non-CP cohort (adjusted HR: 1.79, 95% CI [1.60–2.00]). Taken together, this nationwide retrospective cohort study demonstrated that the risk of pSS was significantly higher in patients with CP than in the general population. The association between CP and pSS was significant in the female group.

Experience of sleep disruption in primary Sjögren's syndrome: A focus group study

INTRODUCTION

Primary Sjögren's syndrome is the third most common systemic autoimmune rheumatic disease, following rheumatoid arthritis and systemic lupus erythematosus, and results in dryness, fatigue, discomfort and sleep disturbances. Sleep is relatively unexplored in primary Sjögren's syndrome. We investigated the experiences of sleep disturbances from the viewpoint of primary Sjögren's syndrome patients and their partners and explored the acceptability of cognitive behavioural therapy for insomnia.

METHOD

We used focus groups to collect qualitative data from 10 patients with primary Sjögren's syndrome and three partners of patients. The data were recorded, transcribed verbatim and analysed using thematic analysis.

RESULTS

Five themes emerged from the data: (a) Experience of sleep disturbances; (b) variation and inconsistency in sleep disturbances; (c) the domino effect of primary Sjögren's syndrome symptoms; (d) strategies to manage sleep; (e) acceptability of evidence-based techniques. Sleep disturbances were problematic for all patients, but specific disturbances varied between participants. These included prolonged sleep onset time and frequent night awakenings and were aggravated by pain and discomfort. Patients deployed a range of strategies to try and self-manage. Cognitive behavioural therapy for insomnia was seen as an acceptable intervention, as long as a rationale for its use is given and it is tailored for primary Sjögren's syndrome.

CONCLUSION

Primary Sjögren's syndrome patients described a range of sleep disturbances. Applying tailored, evidence-based sleep therapy interventions may improve sleep, severity of other primary Sjögren's syndrome symptoms and functional ability.

Low Levels of IgG Recognizing the α-1-Antitrypsin Peptide and Its Association with Taiwanese Women with Primary Sjögren's Syndrome

The aim of this study was to examine oxidative stress and low level of α-1-antitrypsin (A1AT) in primary Sjögren’s syndrome (pSS), and evaluate the associated autoreactivity against unmodified and their 4-hydroxy-2-nonenal (HNE)-modified peptides with pSS. Two differentially expressed proteins, α-1-acid glycoprotein 1 (A1AG1) and A1AT, exhibited 2-fold differences, and their HNE modifications were identified by depleted-albumin and immunoglobulin G (IgG) serum protein, in-solution digestion, in-gel digestion, and nano-liquid chromatography–tandem mass spectrometry (nano-LC-MS/MS) from pSS patients and age-matched healthy controls (HCs). Furthermore, levels of proteins, confirmation of HNE modifications, HNE-protein adducts and autoreactivity against unmodified and their HNE-modified peptides were further validated. Levels of the HNE-protein adduct and A1AG1 were significantly higher in pSS patients than HCs, but levels of A1AT were significantly lower in pSS patients compared to HCs. Only the HNE modification of A1AT was confirmed. Our study suggests that elevated HNE-protein adduct, oxidative stress, level (odds ratio (OR) 4.877, p = 0.003), lowered A1AT level (OR 3.910, p = 0.010) and a decreased level of anti-A1AT^50–63 IgG (OR 3.360, p = 0.010) showed an increased risk in pSS patients compared to HCs, respectively.

The worldwide incidence and prevalence of systemic lupus erythematosus: a systematic review of epidemiological studies

Objectives

The aim was to review the worldwide incidence and prevalence of SLE and variation with age, sex, ethnicity and time.

Methods

A systematic search of MEDLINE and EMBASE search engines was carried out using Medical Subject Headings and keyword search terms for Systemic Lupus Erythematosus combined with incidence, prevalence and epidemiology in August 2013 and updated in September 2016. Author, journal, year of publication, country, region, case-finding method, study period, number of incident or prevalent cases, incidence (per 100 000 person-years) or prevalence (per 100 000 persons) and age, sex or ethnic group-specific incidence or prevalence were collected.

Results

The highest estimates of incidence and prevalence of SLE were in North America [23.2/100 000 person-years (95% CI: 23.4, 24.0) and 241/100 000 people (95% CI: 130, 352), respectively]. The lowest incidences of SLE were reported in Africa and Ukraine (0.3/100 000 person-years), and the lowest prevalence was in Northern Australia (0 cases in a sample of 847 people). Women were more frequently affected than men for every age and ethnic group. Incidence peaked in middle adulthood and occurred later for men. People of Black ethnicity had the highest incidence and prevalence of SLE, whereas those with White ethnicity had the lowest incidence and prevalence. There appeared to be an increasing trend of SLE prevalence with time.

Conclusion

There are worldwide differences in the incidence and prevalence of SLE that vary with sex, age, ethnicity and time. Further study of genetic and environmental risk factors may explain the reasons for these differences. More epidemiological studies in Africa are warranted.

Prevalence of Primary Sjögren's Syndrome in a US Population-Based Cohort

OBJECTIVE

To report the point prevalence of primary Sjögren's syndrome (SS) in the first US population-based study.

METHODS

Cases of all potential primary SS patients living in Olmsted County, Minnesota, on January 1, 2015, were retrieved using Rochester Epidemiology Project resources, and ascertained by manual medical records review. Primary SS cases were defined according to physician diagnosis. The use of diagnostic tests was assessed and the performance of classification criteria was evaluated. The number of prevalent cases in 2015 was also projected based on 1976-2005 incidence data from the same source population.

RESULTS

A total of 106 patients with primary SS were included in the study: 86% were female, with a mean ± SD age of 64.6 ± 15.2 years, and a mean ± SD disease duration of 10.5 ± 8.4 years. A majority were anti-SSA positive (75%) and/or anti-SSB positive (58%), but only 22% met American-European Consensus Group or American College of Rheumatology criteria, because the other tests required for disease classification (ocular dryness objective assessment, salivary gland functional or morphologic tests, or salivary gland biopsy) were rarely performed in clinical practice. According to the physician diagnosis, the age- and sex-adjusted prevalence of primary SS was 10.3 per 10,000 inhabitants, but according to classification criteria, this prevalence was only 2.2 per 10,000. The analysis based on previous incidence data projected a similar 2015 prevalence rate of 11.0 per 10,000.

CONCLUSION

The prevalence of primary SS in this geographically well-defined population was estimated to be between 2 and 10 per 10,000 inhabitants. Physicians rarely used tests included in the classification criteria to diagnose the disease in this community setting.

Cumulative immunosuppressant exposure is associated with diversified cancer risk among 14 832 patients with systemic lupus erythematosus: a nested case-control study

Objectives

Immunosuppressive therapy is necessary to alter the natural course of SLE. However, immunosuppressant-related cancer risk is a major concern. The aim of this study was to determine whether immunosuppressant use is associated with cancer risk in SLE.

Methods

We designed a retrospective nested case-control study within an SLE population based on the National Health Insurance Research Database in Taiwan. We screened 14 842 patients with SLE from 2001 to 2013 and compared patients with SLE complicated by later cancer with patients with SLE but without cancer. The cumulative dose of immunosuppressants was calculated from the SLE diagnosis date to the occurrence of cancer. The immunosuppressants of interest were AZA, CYC, MTX, HCQ and systemic glucocorticoids. Adjusted odds ratios (ORs) for cancer were calculated in conditional Cox regression models after propensity score matching.

Results

The top five types of cancers were breast (16.9%), haematological (11.7%), colorectal (11.0%), lung (10.6%) and hepatobiliary (10.4%) cancers. After matching, this study included 330 cancer patients and 1320 matched cancer-free patients. The adjusted analyses showed an association of a higher cumulative CYC dose (OR = 1.09, 95% CI: 1.04, 1.13) and lower HCQ dose (OR = 0.93, 95% CI: 0.90, 0.97) with cancer risk in comparison with the controls.

Conclusion

Diverse cancer risks are associated with different immunosuppressants in patients with SLE. CYC increases the risk of cancer, and HCQ decreases this risk in SLE patients, both in a dose-dependent manner.

Incidence and Mortality of Physician-Diagnosed Primary Sjögren Syndrome: Time Trends Over a 40-Year Period in a Population-Based US Cohort

OBJECTIVE

To estimate the incidence and mortality rates, and their evolution over time, of physician-diagnosed primary Sjögren syndrome (pSS) in residents of Olmsted County, Minnesota.

PATIENTS AND METHODS

Medical records of patients with a diagnosis or suspicion of SS in Olmsted County from January 1, 2006, through December 31, 2015, were reviewed to identify incident cases of pSS (defined by physician diagnosis). These cases were combined with those from a 1976 through 2005 incident cohort (n=111) from the same population. Incidence rates were age and sex adjusted to the 2010 US white population. Survival rates were compared with the expected rates in the population of Minnesota.

RESULTS

With 61 incident cases of pSS diagnosed in Olmsted County from 2006 through 2015, the total cohort included 172 patients with incident pSS from 1976 through 2015. Of the 172 patients, 151 (88%) were women and 161 (94%) were white, with a mean ± SD age at diagnosis of 58.3±16.7 years. The average age- and sex-adjusted annual incidence for 2006 through 2015 was 5.9 per 100,000 population (95% CI, 4.4-7.4 per 100,000 population), and the overall incidence for the entire period was 5.8 per 100,000 (95% CI, 4.9-6.6 per 100,000). The incidence increased with calendar time over the 40-year period (P=.005). There was no difference in mortality in the pSS cohort compared with expected (standardized mortality ratio, 1.15; 95% CI, 0.86-1.50).

CONCLUSION

The average annual incidence of pSS in this population-based cohort was 5.8 per 100,000, with a progressive increase over the 40 years of the study. Overall survival of patients with pSS was not different from that of the general population.

Incidence, mortality, and causes of death in physician-diagnosed primary Sjögren's syndrome in Korea: A nationwide, population-based study

OBJECTIVES

The objective of this study was to investigate the epidemiological features of primary Sjögren's syndrome (pSS) in Korea at a national level, including the incidence, mortality, and causes of death.

METHODS

We used a national, population-based registry database called the Rare Intractable Disease Registration Program from the Health Insurance Review and Assessment Service to obtain pSS patient data for the period between 2010 and 2014. pSS was diagnosed by a physician based on uniform criteria. We also used data from Statistics Korea to confirm the mortality and causes of death.

RESULTS

Between 2010 and 2014, the total number of patients newly diagnosed with pSS was 5891, resulting in an annual incidence of 2.34 per 100,000 individuals. The female-to-male ratio was 14.5:1. A total of 114 pSS patients died during the study period. The overall survival rate of pSS patients was 99.0%, and the 1-year, 2-year, and 5-year survival rates were 98.7%, 98.1%, and 97.1%, respectively, and the standardized mortality ratio (SMR) was 1.47 (2.14 for males and 1.35 for females). The most common causes of death were respiratory disease (n = 25; 21.9%) followed by circulatory diseases (n = 21; 18.4%), musculoskeletal connective tissue diseases (n = 21; 18.4%), and cancer (n=19; 16.7%).

CONCLUSIONS

The national incidence of pSS in Korea presented in this study was lower in comparison with reports from other countries. However, the mortality rate was significantly higher than the corresponding values in the age- and gender-matched general population. The higher mortality in pSS patients is attributable to respiratory diseases and lung cancer.

Familial risk of systemic sclerosis and co-aggregation of autoimmune diseases in affected families

Background

Systemic sclerosis (SSc) is a rare and devastating disease affecting skin and internal organs. Familial aggregation of SSc and co-aggregation with other autoimmune diseases is rarely reported.

Methods

We identified 23,658,577 beneficiaries registered with the National Health Insurance database in 2010, 1891 of whom had SSc. We identified 21,009,551 parent–child relationships and 17,168,340 full sibling pairs. The familial risks of SSc and other autoimmune diseases and familial transmission were estimated.

Results

The prevalence of SSc in the general population was 0.008 %. There are 3801 individuals had at least one first-degree relative with SSc, among them 3 people had SSc which was equivalent to a prevalence of 0.08 %. The adjusted relative risk (RR) (95 % CI) for SSc was 81.21 (11.40–579.72) for siblings of SSc patients. The familial transmission (genetic plus shared environmental contribution to total phenotypic variance of SSc) was 0.72. However, 84.1 % of patients were expected to be sporadic cases. The RR (95 % CI) in first-degree relatives of SSc patients was 2.64 (1.46–4.75) for rheumatoid arthritis, 6.51 (4.05–10.46) for systemic lupus erythematosus, 2.77 (1.04–7.35) for Sjögren’s syndrome, 8.05 (2.03–31.92) for idiopathic inflammatory myositis, and 1.52 (1.15–2.01) for psoriasis.

Conclusions

The risks of SSc and other autoimmune diseases are increased in relatives of people with SSc, and family factors explain over two-thirds of the phenotypic variance of the disease. These findings may be useful in counselling families of patients with SSc and for further genetic studies.

The usage of biological DMARDs and clinical remission of rheumatoid arthritis in China: a real-world large scale study

The aims of this study are to characterize the biological disease-modifying antirheumatic drug (bDMARD) usage patterns in real-life and examine the remission rate of rheumatoid arthritis (RA) patients receiving bDMARDs in routine clinical practice in China. Consenting RA patients (≥18 years) from 15 teaching hospitals and receiving marketed bDMARDs were included. In total, 802 patients (81.3 % women, 49.0 ± 13.9 years) were included; 89.5 % were receiving a combination of bDMARDs and conventional synthetic DMARDs (csDMARDS), whereas 10.5 % were receiving bDMARD monotherapy. Etanercept (including Enbrel® and local brand Yi Sai Pu® and Qiangke®), tocilizumab, adalimumab, and infliximab were used by 66.6 %, 17.0 %, 7.5 %, and 6.6 % patients, respectively. Etanercept was used at a mean weekly dose of 38.2 ± 15.6 mg for 25.5 ± 47.0 weeks and tocilizumab at 94.5 ± 21.9 mg for 4.7 ± 7.5 weeks. Overall rate of remission was 12.6 %, 5.4 % , and 3.5 % based on DAS28, CDAI, and SDAI scores, respectively. Compared with patients receiving bDMARDs for <3 months, those receiving bDMARDs for ≥3 months exhibited significantly lower DAS28 scores (p < 0.0001), and a significantly higher proportion of patients who received bDMARDs for ≥12 months achieved the treatment goal (remission or low disease activity, 62.5 % vs. 18.3 %, p < 0.0001). Patients receiving combination therapy with csDMARDs exhibited lower DAS28 scores than patients receiving bDMARD monotherapy (4.3 vs. 4.8, p = 0.011). This large-scale real-world study showed that bDMARD usage patterns in routine clinical practice in China were in accordance with international guidelines for RA management despite the short treatment duration. Longer duration of bDMARD usage and combination therapy showed a favored outcome of RA.

Association of Sjögrens Syndrome in Patients with Chronic Hepatitis Virus Infection: A Population-Based Analysis

Objective

The association between Sjögren’s syndrome (SS) and chronic hepatitis virus infection is inconclusive. Hepatitis B (HBV) and hepatitis C virus (HCV) infections are highly prevalent in Taiwan. We used a population-based case-control study to evaluate the associations between SS and HBV and HCV infections.

Materials and Methods

We identified 9,629 SS patients without other concomitant autoimmune diseases and 38,516 sex- and age-matched controls without SS from the Taiwan National Health Insurance claims data between 2000 and 2011. We utilized multivariate logistic regression to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of the associations between SS and HBV and HCV infections. Sex- and age-specific (<55 and ≥55 years) risks of SS were evaluated.

Results

The risk of SS was higher in patients with HCV than in those without chronic viral hepatitis (OR = 2.49, 95% CI = 2.16–2.86). Conversely, HBV infection was not associated with SS (OR = 1.10, 95% CI = 0.98–1.24). Younger HCV patients were at a higher risk for SS (<55 years: OR = 3.37, 95% CI = 2.62–4.35; ≥55 years: OR = 2.20, 95% CI = 1.84–2.62). Men with HCV were at a greater risk for SS (women: OR = 2.26, 95% CI = 1.94–2.63; men: OR = 4.22, 95% CI = 2.90–6.16). Only men with chronic HBV exhibited a higher risk of SS (OR = 1.61, 95% CI = 1.21–2.14).

Conclusion

HCV infection was associated with SS; however, HBV only associated with SS in men.

The global burden of SLE: prevalence, health disparities and socioeconomic impact

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease that can potentially lead to serious organ complications and even death. Its global burden - in terms of incidence and prevalence, differential impact on populations, economic costs and capacity to compromise health-related quality of life - remains incompletely understood. The reported worldwide incidence and prevalence of SLE vary considerably; this variation is probably attributable to a variety of factors, including ethnic and geographic differences in the populations being studied, the definition of SLE applied, and the methods of case identification. Despite the heterogeneous nature of the disease, distinct patterns of disease presentation, severity and course can often be related to differences in ethnicity, income level, education, health insurance status, level of social support and medication compliance, as well as environmental and occupational factors. Given the potential for the disease to cause such severe and widespread organ damage, not only are the attendant direct costs high, but these costs are sometimes exceeded by indirect costs owing to loss of economic productivity. As an intangible cost, patients with SLE are, not surprisingly, likely to endure considerably reduced health-related quality of life.

Patterns and Etiologies of Uveitis at a Tertiary Referral Center in Taiwan

PURPOSE

To analyze the patterns and etiologies of uveitis at a tertiary referral center in Taiwan.

METHODS

This retrospective chart review of uveitis patients from January 2001 to December 2014 updates a previous study a decade ago (2003).

RESULTS

We identified 450 patients, among whom anterior uveitis was most common, followed by panuveitis, posterior uveitis, and intermediate uveitis. A specific diagnosis was identified in 331 patients. In 73 infectious uveitis cases, herpetic anterior uveitis was the leading cause, followed by endogenous bacterial endophthalmitis and acute retinal necrosis. In 258 non-infectious uveitis cases, HLA-B27-associated uveitis was most commonly seen, followed by Vogt-Koyanagi-Harada disease and Posner-Schlossman syndrome. Compared with our previous study, we found more viral infection and sarcoidosis but fewer cases of Behçet disease, tuberculosis, and toxoplasmosis.

CONCLUSIONS

Our results provide useful information about the patterns and etiologies of uveitis in a selected population in Taiwan.

Recent Advances in Defining the Genetic Basis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is the most common inflammatory arthritis and exhibits genetic overlap with other autoimmune and inflammatory disorders. Although predominant associations with the HLA-DRB1 locus have been known for decades, recent data have revealed additional insight into the likely causative variants within HLA-DRB1 as well as within other HLA loci that contribute to disease risk. In addition, more than 100 common variants in non-HLA loci have been implicated in disease susceptibility. Genetic factors are involved not only in the development of RA, but also with various disease subphenotypes, including production and circulating levels of autoantibodies and joint destruction. The major current challenge is to integrate these new data into a precise understanding of disease pathogenesis, including the critical cell types and molecular networks involved as well as interactions with environmental factors. We predict that delineating the functional effects of genetic variants is likely to drive new diagnostic and therapeutic approaches to the disease.

Incidence and Prevalence of Rheumatoid Arthritis in a Health Management Organization in Argentina: A 15-year Study

Objective.

To estimate incidence and prevalence rates of rheumatoid arthritis (RA) in the city of Buenos Aires (CABA), Argentina, using data from a university hospital–based health management organization.

Methods.

Global, age-specific, and sex-specific incidence and prevalence rates were calculated for members of the Hospital Italiano Medical Care Program (HIMCP), age ≥ 18 years. Incidence study followed members with continuous affiliation ≥ 1 year from January 2000 to January 2015 until he/she voluntarily left the HIMCP, RA was diagnosed, death, or study finalization. Cases from the Rheumatology Section database, electronic medical records, laboratory database, and pharmacy database were filtered with the 2010 American College of Rheumatology/European League Against Rheumatism criteria. Prevalence was calculated on January 1, 2015, and standardized for CABA. Capture-recapture (C-RC) analysis estimated true population sizes.

Results.

In the study period, incidence rates (cases per 100,000 person-yrs) were 18.5 (95% CI 16.7–20.4) overall, 25.2 (95% CI 22.4–28.0) for women, and 8.8 (95% CI 6.8–10.8) for men. Prevalence rates (percentage of RA cases in the sample population) were 0.329 (95% CI 0.298–0.359) overall, 0.464 (95% CI 0.417–0.510) for women, and 0.123 (95% CI 0.093–0.152) for men. Standardized CABA prevalence rate was 0.300 (95% CI 0.292–0.307). C-RC adjusted rates were almost the same as unadjusted rates.

Conclusion.

This study’s incidence and prevalence rates are in the lower range of the rates found around the world. Our female to male prevalence ratio was 4:1. Our peak incidence age was in the sixth and seventh decades for both sexes.

Prevalence of Skin and Skin-Related Diseases in the Rochester Epidemiology Project and a Comparison with Other Published Prevalence Studies

In Olmsted County, Minn., USA, reliable, population-based epidemiologic research studies can be performed because of a unique medical records linkage system, the Rochester Epidemiology Project (REP). Our objective was to summarize the epidemiologic data describing the prevalence of skin and skin-related diseases derived from the REP and to compare the findings with those from other studies worldwide. Retrospectively, we reviewed the results of population-based REP studies reporting the prevalence of skin and skin-related diseases over more than 4 decades and compared them to other published prevalences globally. Prevalences from the REP reported per 100,000 persons were as follows: hidradenitis suppurativa, 130.0; psoriasis, 700.0; psoriatic arthritis in 1992, 100.0, and in 2000, 160.0; Behçet disease, 5.2; scleroderma, 13.8; dermatomyositis, 21.42; systemic lupus erythematosus (SLE), from 30.5 to 122.0 suspected SLE, 32.8; combined SLE, 41.8; discoid lupus erythematosus, 27.6, and cutaneous lupus erythematosus, 70.4 and 73.2 (from 2 studies). Many of the population-based prevalences of specific skin and skin-related diseases derived from the REP are different from those estimated globally. Suggested reasons for disparity in the prevalences globally may include differences in the type of reported prevalence, study methodology, geographic areas, ethnic groups, age distribution, and socioeconomic status.

Sex differences in the incidence of skin and skin-related diseases in Olmsted County, Minnesota, United States, and a comparison with other rates published worldwide

Many skin and skin-related diseases affect the sexes unequally, with attendant implications for public health and resource allocation. To evaluate better the incidence of skin and skin-related diseases affecting males vs. females, we reviewed published population-based epidemiology studies of skin disorders performed utilizing Rochester Epidemiology Project data. Females had a higher incidence of the following diseases: connective tissue diseases (scleroderma, morphea, dermatomyositis, primary Sjögren syndrome, systemic lupus erythematosus [not in all studies]), pityriasis rosea, herpes progenitalis, condyloma acuminatum, hidradenitis suppurativa, herpes zoster (except in children), erythromelalgia, venous stasis syndrome, and venous ulcers. Males had a higher incidence of psoriasis and psoriatic arthritis, basal cell carcinoma (exception, females aged ≤40 years), squamous cell carcinoma, and lentigo maligna. Incidence rates were equal in males and females for cutaneous malignant melanoma (exception, higher in females aged 18-39 years), lower-extremity cellulitis, cutaneous nontuberculous mycobacterial infection, Behçet disease, delusional infestation, alopecia areata, and bullous pemphigoid. Many of the population-based sex-specific incidence rates of skin and skin-related diseases derived from the Rochester Epidemiology Project are strikingly different from those estimated elsewhere. In general, females are more commonly affected by skin and skin-related diseases. The reasons for this imbalance remain to be determined and are likely multifactorial.

The impact of introducing biologics to patients with rheumatoid arthritis in Taiwan: a population-based trend study

AIM

The biologics used to treat rheumatoid arthritis (RA) patients with a catastrophic illness certificate have been free without co-payment since 2003 in Taiwan. The purpose of this study was to explore the trend of health care expenditures and the cost of biologics for the treatment of RA patients between 1999 and 2009.

METHODS

This study used a specially requested nation-wide RA patient claim dataset from National Health Insurance program. We identified all patients by both the primary diagnosis code ICD-9-CM 714.0 and the catastrophic illness certificate for RA. A total of 30 013 patients were recorded in the treated RA cohort from 1999 to 2009.The growth rates before and after introducing biologics were compared and tested.

RESULTS

We found that from 1999 to 2009 the adjusted incidence rate for RA stably increased. Drug costs accounted for 53.2-70.3% of the total medical cost during the study period. There was a significant increase in biologics cost, climbing rapidly from 2.8% in 2003 to 60.4% of the total drug cost in 2009. The growth rate of outpatient drug costs was much higher after the introduction of biologics (2003-2009), which was 207.8% versus 42.0% as compared to the earlier period (1999-2002). Biologics such as etanercept, adalimumab and rituximab, were the crucial factors responsible for this increase in drug cost.

CONCLUSIONS

The financial impact of adopting new biologics on healthcare costs is a critical issue that needs to be addressed by the National Health Insurance.

Overall and cause-specific mortality in systemic lupus erythematosus: an updated meta-analysis

AIMS

This study aimed to assess all-cause and cause-specific standardized mortality ratios (SMRs) in patients with systemic lupus erythematosus (SLE).

METHODS

We surveyed studies examining all-cause and/or cause-specific SMR in patients with SLE compared to the general population using PUBMED, EMBASE and Cochrane databases and manual searches. We performed a meta-analysis of all-cause, sex-specific, ethnicity-specific, and cause-specific SMRs in SLE patients.

RESULTS

Fifteen reports including 26,101 patients with SLE with 4640 deaths met the inclusion criteria. Compared to the general population, all-cause SMR was significantly increased 2.6-fold in patients with SLE (SMR 2.663, 95% CI 2.090-3.393, p < 1.0 × 10(-8)). Stratification by ethnicity showed that all-cause SMR was 2.721 (95% CI 1.867-3.966, p = 1.9 × 10(-6)) in Caucasians and 2.587 (95% CI 1.475-4.535, p = 0.001) in Asians. Sex-specific meta-analysis revealed that all-cause SMR was 3.141 (95% CI 2.351-4.198, p < 1.0 × 10(-8)) for women and 3.516 (95% CI 2.928-4.221, p < 1.0 × 10(-8)) for men. The risk of mortality was significantly increased for mortality due to renal disease (SMR 4.689, 95% CI 2.357-9.330, p = 1.10 × 10(-5)), cardiovascular disease (CVD) (SMR 2.253, 95% CI 1.304-3.892, p = 0.004), and infection (SMR 4.980, 95% CI 3.876-6.398, p < 1.0 × 10(-8)), although there was no significant increase in SMR for mortality due to cancer (SMR 1.163, 95% CI 0.572-2.363, p = 0.676).

CONCLUSIONS

Patients with SLE had higher rates of death from all causes, regardless of sex, ethnicity, renal disease, CVD or infection. However, the risk of death due to malignancy was not increased.

Mortality in systemic lupus erythematosus in the United Kingdom 1999-2012

OBJECTIVES

To estimate the mortality associated with SLE during the period 1999-2012 by age, gender and region; and to ascertain the cause of death for people with SLE.

METHODS

A retrospective cohort study using the UK Clinical Practice Research Datalink. Incident SLE cases diagnosed between 1999 and 2012 were matched by age, sex and practice to four controls. Age-, gender- and region-specific mortality rates were calculated per 1000 person-years and compared with control mortality rates using mortality rate ratios (MRRs). For individuals with linked Office of National Statistics data, cause of death was summarized by International Classification of Disease-10 chapter heading.

RESULTS

Of 2740 incident cases, 227 died, giving a mortality rate of 15.84/1000 person-years (95% CI 13.91, 18.04). This was 67% higher than in controls (MRR 1.67, 95% CI 1.43, 1.94, P < 0.001). Men with SLE had higher rates of mortality than females with SLE. Compared with controls, the mortality rate for males with SLE was 1.80 times that of male controls (95% CI 1.32, 2.45, P < 0.001); for females the mortality rate was 1.64 times higher (95% CI 1.37, 1.96, P < 0.001). The age-specific mortality rates increased significantly with age; however, the MRR diminished from 3.81 (95% CI 1.43, 10.14) in those aged <40 years to 0.82 (95% CI 0.36, 1.83) in those ⩾90 years. There was no significant difference in mortality between regions. Circulatory system disease and malignancy were the most frequent causes of death in both cases and controls.

CONCLUSION

There remains an increased mortality for people with SLE compared with matched controls, particularly at younger ages.

Is drug discontinuation risk of adalimumab compared with etanercept affected by concomitant methotrexate dose in patients with rheumatoid arthritis?

OBJECTIVE

To compare drug discontinuation risk between adalimumab (ADA) and etanercept (ETN) treatment among anti-tumor necrosis factor (anti-TNF)-naïve rheumatoid arthritis (RA) patients, in particular the influence of concomitant dose of methotrexate (MTX).

METHODS

This retrospective nationwide population-based cohort study identified 4,592 anti-TNF-naïve RA patients in whom ETN (n=2,609) or ADA (n=1,983) was initiated using National Health Insurance claims data. After adjustment for prior medication, concomitant medication, and baseline demographic data, the relative risk of drug discontinuation in ADA users compared with ETN users was quantified by calculating adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) using Cox proportional hazard regression analyses, stratified by the follow-up time (≤1 year, >1 year) and/or concomitant MTX dose (≤10 mg/wk, >10 mg/wk).

RESULTS

ADA users had a higher risk of drug discontinuation compared with ETN users during the first year of follow-up (aHR, 1.13; 95% CI, 1.01-1.27), but not during all treatment periods (aHR, 1.06; 95% CI, 0.98-1.16) or after 1 year (aHR, 0.99; 95% CI, 0.87-1.13). However, ADA users had a significantly higher risk of drug discontinuation compared with ETN users among patients on concomitant MTX >10 mg/wk during all treatment periods (aHR, 1.27; 95% CI, 1.10-1.47), during the first year of follow-up (aHR, 1.48; 95% CI, 1.22-1.78), or after 1 year (aHR, 1.42; 95% CI, 1.06-1.90), but not among patients on concomitant MTX 0-10 mg/wk.

CONCLUSION

This population-based cohort study demonstrated a modification effect of concomitant MTX dose on the relative risk of anti-TNF discontinuation for ADA compared with ETN among anti-TNF-naïve RA patients. However, the lack of exact cause of anti-TNF discontinuation limited causal inference of such a concomitant MTX dose-related modification effect.

Male fertility potential alteration in rheumatic diseases: a systematic review

BACKGROUND

Improved targeted therapies for rheumatic diseases were developed recently resulting in a better prognosis for affected patients. Nowadays, patients are living longer and with improved quality of life, including fertility potential. These patients are affected by impaired reproductive function and the causes are often multifactorial related to particularities of each disease. This review highlights how rheumatic diseases and their management affect testicular function and male fertility.

MATERIALS AND METHODS

A systematic review of literature of all published data after 1970 was conducted. Data was collected about fertility abnormalities in male patients with systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, ankylosing spondylitis, Behçet disease and gout. Two independent researchers carried out the search in online databases.

RESULTS

A total of 19 articles were included addressing the following diseases: 7 systemic lupus erythematosus, 6 Behçet disease, 4 ankylosing spondylitis, 2 rheumatoid arthritis, 2 dermatomyositis and one gout. Systemic lupus erythematosus clearly affects gonadal function impairing spermatogenesis mainly due to antisperm antibodies and cyclophosphamide therapy. Behçet disease, gout and ankylosing spondylitis patients, including those under anti-TNF therapy in the latter disease, do not seem to have reduced fertility whereas in dermatomyositis, the fertility potential is hampered by disease activity and by alkylating agents. Data regarding rheumatoid arthritis is scarce, gonadal dysfunction observed as consequence of disease activity and antisperm antibodies.

CONCLUSIONS

Reduced fertility potential is not uncommon. Its frequency and severity vary among the different rheumatic diseases. Permanent infertility is rare and often associated with alkylating agent therapy.

Acarbose Decreases the Rheumatoid Arthritis Risk of Diabetic Patients and Attenuates the Incidence and Severity of Collagen-induced Arthritis in Mice

Acarbose has been found to decrease some inflammatory parameters in diabetic patients. This study aimed to examine the influence of acarbose on rheumatoid arthritis (RA) risk in diabetes mellitus (DM) patients and on the incidence and severity of collagen-induced arthritis (CIA) in mice. In a nationwide, matched case–control study, we identified 723 incident RA cases and selected 7,230 age-, sex- and RA diagnosis date–matched controls from all newly treated DM patients. We found that use of acarbose at > 16,950 mg per year was associated with a lower RA risk (odds ratio 0.60; 95% CI, 0.41–0.89). In the CIA mouse study, acarbose was orally administered from days -7 to 38 relative to type II collagen (CII) immunization. The results revealed that acarbose at the dose of 500 mg/kg/day attenuated the incidence and severity of arthritis and the expression of proinflammatory cytokines, including TNF-α, IL-6 and IL-17 in the paw tissues. Acarbose further decreased the productions of anti-CII-IgG, IL-17 and IFN-γ by collagen-reactive lymph node cells. This work suggests that the use of acarbose decreased RA risk in DM patients and the incidence of CIA in mice. Acarbose also attenuated the severity of CIA via anti-inflammatory and immunomodulatory effects.

Diagnostic performance of anti-cyclic citrullinated peptide and rheumatoid factor in patients with rheumatoid arthritis

AIM

To compare the diagnostic performance of rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (anti-CCP) in the diagnosis of patients with rheumatoid arthritis (RA) in Taiwan.

METHODS

Serum concentrations of RF and anti-CCP were measured in 246 cases, including 39 patients with RA and 207 patients with other rheumatic diseases (non-RA). The age, sex, clinical presentation, RF, anti-CCP results and the final diagnoses were recorded and analyzed. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+) and negative likelihood ratio (LR-) were calculated.

RESULTS

Among all 246 patients, 39 (15.9%) were diagnosed with RA and 207 (84.1%) were diagnosed with other rheumatic diseases (non-RA). In the diagnosis of RA, the sensitivity, specificity, PPV, NPV, LR+ and LR- of the RF test were 67%, 79%, 37%, 93%, 3.12, and 0.42, respectively. The corresponding data for the anti-CCP test were 79%, 98%, 86%, 96%, 32.91 and 0.21, respectively. The presence of either anti-CCP or RF increased the sensitivity to 85%, and when they both were present, the specificity increased to 98%. Among the 39 RA patients, 26 (66.7%) tested positive for RF, and 31 (79.5%) tested positive for anti-CCP. RF was positive in two of eight anti-CCP-negative patients with RA, and anti-CCP was positive in seven of 13 RF-negative patients with RA.

CONCLUSIONS

The RF and anti-CCP tests are complementary, and the co-detection of these antibodies can increase the detection rate and provide important clinical value in the diagnosis of RA. Both anti-CCP and RF positivity are useful for the diagnosis of RA, and use of both tests together improves the diagnostic sensitivity.

The Core Pattern Analysis on Chinese Herbal Medicine for Sjögren's syndrome: A Nationwide Population-Based Study

This large-scale survey aimed to evaluate frequencies and patterns of Chinese herbal medicine (CHM) used for Sjögren's syndrome (SS) in Taiwan by analyzing the National Health Insurance Research Database (NHIRD) for cases in which CHM was used as an alternative therapy to Western medicine for improving patients' discomforts. We analyzed cases of SS principal diagnosis (ICD-9:710.2) with a catastrophic illness certificate (CIC) in traditional Chinese medicine (TCM) outpatient clinics from three cohorts of the Longitudinal Health Insurance Database (LHID) in the NHIRD between 2002 and 2011. CHM prescription patterns for SS were evaluated from claimed visitation files and corresponding prescription files. There were 15,914 SS patients with CIC (SS/CIC), and we found only 130 SS/CIC cases visiting TCM clinics in LHID2000, 133 in LHID2005, and 126 in LHID2010. After removing duplicate data, 366 SS/CIC and 4,867 visits were analyzed. The 50–59 year age group showed the highest ratio (29.51%) in both women and men. “Qi-Ju-Di-Huang-Wan” and “Xuan-Shen” (Scrophularia ningpoensis Hemsl.) was the most commonly used formula and single herb, respectively. “Qi-Ju-Di-Huang-Wan, Gan-Lu-Yin, Xuan-Shen, Mai-Men-Dong (Ophiopogon japonicus (L. f.) Ker-Gawl.), and Sheng-Di-Huang (raw Rehmannia glutinosa Libosch)” were the core pattern prescriptions in treating SS/CIC.

Increased risk of depression in patients with rheumatoid arthritis: a seven-year population-based cohort study

OBJECTIVE

Rheumatoid arthritis (RA) is a costly and crippling autoimmune disease that can lead to the development of depression, contributing to suboptimal clinical outcomes. However, no longitudinal studies have identified an association between rheumatoid arthritis and subsequent depression. This study aimed to investigate the incidence and risk factors of depression among RA patients in Taiwan.

METHODS

Using Taiwan's National Health Insurance Research Database, we identified 3,698 newly diagnosed RA patients aged 18 years or older, together with 7,396 subjects without RA matched by sex, age and index date, between 2000 and 2004. The incidence of depression and the risk factors among RA cases were evaluated using Cox proportional-hazard regression.

RESULTS

The incidence of depression was 1.74-fold greater in the RA cohort than in the non-RA cohort (11.80 versus 6.89 per 1,000 person-years; p<0.01). Multivariate analysis showed that RA subjects who were female, were older, or had comorbidities such as stroke, chronic kidney disease, or cancer had a significantly greater risk of depression compared with those without these conditions.

CONCLUSION

This population-based cohort study showed a strong relationship between RA and a subsequent risk of depression. The findings could be beneficial to healthcare providers for identifying individuals with a higher predisposition for depression, thereby possibly facilitating the provision of an appropriate rehabilitation intervention after RA onset to support the patient's adaptation.

Chronic hepatitis C virus infection is associated with the development of rheumatoid arthritis: a nationwide population-based study in taiwan

OBJECTIVE

The association between chronic hepatitis virus infection and rheumatoid arthritis (RA) remains debatable. This nationwide population-based cohort study assessed the risk of RA among patients with a chronic infection of hepatitis B and/or C virus.

MATERIALS AND METHODS

We used data extracted from the claims of 1,000,000 randomly sampled individuals covered under the Taiwan National Health Insurance program. Among the 49,892 persons identified in 2000-2010 with chronic hepatitis virus infection, 35,652 had chronic HBV infection alone, 10,253 had chronic HCV infection alone, and 3,987 had chronic HBV/HCV dual infections. The comparison cohort comprised 199,568 persons matched on sex, age and calendar year without chronic hepatitis virus infection. All study participants were free of RA at baseline and traced through 2011 with new RA cases identified.

RESULTS

After adjusting for covariates, chronic HCV infection alone was significantly associated with an increased risk for RA (hazard ratio (HR)  = 2.03, 95% confidence interval (CI)  = 1.27-3.22). The increased risk for RA among participants with chronic HCV infection remained significant after restricting the analysis to those who were prescribed disease-modifying anti-rheumatic drugs. The corresponding HR for the overall sample was 1.89 (95% CI  = 1.15-3.11). However, HBV carriers did not appear to be at a significantly higher risk for RA.

CONCLUSION

Our data imply that chronic HCV infection is associated with RA development.

The incidence and prevalence of systemic lupus erythematosus in the UK, 1999-2012

Objectives

To estimate the incidence and prevalence of systemic lupus erythematosus (SLE) in the UK over the period 1999–2012.

Methods

A retrospective cohort study using the Clinical Practice Research Datalink (CPRD). The incidence was calculated per 100 000 person-years and the prevalence was calculated per 100 000 people for the period 1999–2012 and stratified by year, age group, gender, region and ethnicity. Three definitions of SLE were explored: (1) systemic lupus, (2) a fully comprehensive definition of lupus including cutaneous only lupus and (3) requiring supporting evidence of SLE in the medical record.

Results

Using our primary definition of SLE, the incidence during the study period was 4.91/100 000 person-years (95% CI 4.73 to 5.09), with an annual 1.8% decline (p<0.001). In contrast, the prevalence increased from 64.99/100 000 in 1999 (95% CI 62.04 to 67.93) (0.065%) to 97.04/100 000 in 2012 (95% CI 94.18 to 99.90) (0.097%). SLE was six times more common in women. The peak age of incidence was 50–59 years. There was regional variation in both incidence and prevalence. People of Black Caribbean ethnicity had the highest incidence and prevalence. Alternative definitions of SLE increased (definition 2) or decreased (definition 3) estimates of incidence and prevalence, but similar trends were found.

Conclusions

The incidence of SLE has been declining but the prevalence has been increasing in the UK in recent years. Age, gender, region and ethnicity are risk factors for SLE. This is the first study to report ethnic differences on the incidence and prevalence of SLE using the CPRD.

Prevalence of gout with comorbidity aggregations in southern Taiwan

OBJECTIVE

Comorbidity is an important concern for chronic gout patients. We evaluated the relationship between comorbidity profiles and gout in Taiwan aborigines and Taiwanese Han.

METHODS

We used the claims data from the Taiwan national health insurance database for 2004 to 2006. Physician-diagnosed gout and comorbidities were coded using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). Total sampling from Pingtung County of southern Taiwan included 37,482 aborigines (gout cases, n=3906 and controls, n=33,576) and 37,451 Han (gout cases, n=1115 and controls, n=36,336).

RESULTS

In 2006, the gout prevalences were 10.42% and 2.98% (prevalence ratio [PR]=3.50) in the aborigines and Han general populations, respectively. The prevalences of uric acid nephrolithiasis and tophi were higher in aborigines (0.42% and 0.30%, respectively) than in Han (0.09% and 0.04%, respectively). When stratified by comorbidity status, the prevalences of gout were 4.49% and 27.34% in aborigines and 1.52% and 9.44% in Han (approximate PR=3.00). Similarly, the prevalence ratios of gout in the comorbidity group, compared with the non-comorbidity group, were 6.09 in aborigines and 6.23 in Han. Multivariate odds ratios [ORs] showed that hypercholesterolemia, hyperglyceridemia, essential hypertension and renal insufficiency were the common comorbidities of gout (OR≥1.63); heart failure exerted a significant effect only in aborigines (OR=1.55). For five comorbidity factors, patients with multiple comorbidities had higher gout prevalence (maximum OR=12.90).

CONCLUSION

Gout prevalence was higher in aborigines, both with and without comorbidities, than in Han. The comorbid diseases and comorbidity aggregations showed a substantial association with gout occurrence in both ethnicities.

Epidemiology of primary Sjögren's syndrome: a systematic review and meta-analysis

OBJECTIVE

Epidemiological studies of primary Sjögren's syndrome (pSS) are crucial for describing the burden to society and the public medical system and for shedding light on aetiology. Previous reports of the epidemiology of pSS show variable outcomes. We conducted a systematic review of the epidemiology of pSS to assess the prevalence rates (PRs) and incidence rates (IRs), and to investigate possible geographic variations in pSS.

METHODS

A systematic literature search of PubMed and Embase (updated to 22 October 2013) was performed to identify all published reports on the epidemiology of pSS. The incidence and prevalence rates of pSS were summarised with IRs or PRs and 95% CIs.

RESULTS

The literature search yielded 1880 related citations. Only 21 fulfilled the inclusion criteria. According to a random-effects model, the pooled IR for pSS was 6.92 (95% CI 4.98 to 8.86) per 100 000 person-years. The overall PR was 60.82 (95% CI 43.69 to 77.94) cases per 100 000 inhabitants with a slightly lower estimate of Baodong Qin is BDQ, Jiaqi Wang is JQW, Zaixing Yang is ZXY, Renqian Zhong is RQZ. 43.03 (25.74 to 60.31) cases per 100 000 inhabitants when only considering population-based studies. The female/male ratio in incidence data was 9.15 (95% CI 3.35 to 13.18). The female/male ratio in prevalence data was 10.72 (95% CI 7.35 to 15.62). The overall age of pSS patients was 56.16 years (95% CI 52.54 to 59.78).

CONCLUSIONS

Incidence and prevalence rates of pSS vary widely around the world. The results help us better understand the global epidemiology of pSS. Large population-based studies combining meticulous case-finding and case-ascertainment strategies are needed.

Association between autoimmune rheumatic diseases and the risk of dementia

AIM

Autoimmune rheumatic diseases (ARD) are characterized by systemic inflammation and may affect multiple organs and cause vascular events such as ischemic stroke and acute myocardial infarction. However, the association between ARD and increased risk of dementia is uncertain. This is a retrospective cohort study to investigate and compare the risk of dementia between patients clinically diagnosed with ARD and non-ARD patients during a 5-year follow-up period.

METHODS

Data were obtained from the Longitudinal Health Insurance Database 2000 (LHID2000). We included 1221 patients receiving ambulatory or hospitalization care and 6105 non-ARD patients; patients were matched by sex, age, and the year of index use of health care. Each patient was studied for 5 years to identify the subsequent manifestation of dementia. The data obtained were analyzed by Cox proportional hazard regression.

RESULTS

During the 5-year follow-up period, 30 ARD (2.48%) and 141 non-ARD patients (2.31%) developed dementia. During the 5-year follow-up period, there were no significant differences in the risks of any type of dementia (adjusted hazard ratio (HR), 1.18; 95% CI, 0.79-1.76) in the ARD group after adjusting for demographics and comorbidities.

CONCLUSIONS

Within the 5-year period, patients with and without ARD were found to have similar risks of developing dementia.

Epidemiology of primary Sjögren's syndrome in a French multiracial/multiethnic area

OBJECTIVE

To describe the epidemiology of primary Sjögren's syndrome (SS) in a multiracial/multiethnic population.

METHODS

A cross-sectional study with 5 case-retrieval sources identified adults with primary SS living in the Greater Paris area (population 1,172,482 adults) in 2007. Diagnoses were verified by the American-European Consensus Group (AECG) criteria and study-specific enlarged criteria based on the presence of ≥3 of 4 AECG items among subjective oral or ocular dryness, anti-SSA/SSB positivity, and positive minor salivary gland biopsy results. Prevalence estimates were standardized to those for the world population and a 5-source capture-recapture analysis (CRA) was used. Racial/ethnic differences in primary SS features were evaluated.

RESULTS

In all, 133 subjects met the AECG criteria and 203 met the enlarged criteria. The 2007 prevalence of primary SS was 1.02 cases per 10,000 adults (95% confidence interval [95% CI] 0.85-1.22) for the AECG criteria and 1.52 cases per 10,000 adults (95% CI 1.30-1.76) for the enlarged criteria. The CRA indicated completeness of case findings of ∼90%. Compared to subjects with European backgrounds, those with non-European backgrounds had 2.1-2.3 times higher primary SS prevalence and were younger (P < 0.0001) and were more likely to have polyclonal hypergammaglobulinemia (P < 0.0001) and anti-SSA/SSB antibodies (P = 0.0005 and P < 0.0001 for the AECG and enlarged criteria, respectively).

CONCLUSION

The figure of 1.02–1.52 cases per 10,000 adults we found and estimates from the few other population-based census surveys support that the prevalence of diagnosed primary SS is between 1 and 9 cases per 10,000 (0.01-0.09%) [corrected] in the general population. Non-European race/ethnicity may be associated with increased primary SS risk and a distinct disease profile.

Increased frequency and costs of ambulatory medical care utilization prior to the diagnosis of rheumatoid arthritis: a national population-based study

OBJECTIVE

To investigate the frequency and costs associated with ambulatory medical care utilization over an 8-year period in patients prior to the diagnosis of rheumatoid arthritis (RA).

METHODS

We used Taiwan's National Health Insurance Research Database to identify 691 newly diagnosed RA cases between 2005 and 2010. We selected 1,382 controls without RA, frequency matched by sex, age, and the catastrophic illness certificate application year of the cases. The frequency and costs of ambulatory medical care utilization between the RA patients and controls were compared using the 2-sample Kolmogorov-Smirnov test.

RESULTS

The median frequency of ambulatory medical care utilization was significantly higher in RA patients compared with controls (29 versus 13; P < 0.001) in the year before diagnosis. The differences remained significant throughout all 8 annual periods before diagnosis. Similarly, the inflation-adjusted costs of ambulatory medical care utilization in RA patients increased annually over the study period, from a median of $212 eight years preceding diagnosis to $798 one year preceding diagnosis. Frequency of ambulatory medical care utilization due to diseases of the musculoskeletal system and connective tissue (P < 0.001), acute respiratory infections (P < 0.001), diseases of the upper respiratory tract (P = 0.01), and diseases of the upper gastrointestinal tract (P = 0.04) were higher among RA patients in the 2-year period preceding diagnosis.

CONCLUSION

We found increased frequency and costs of ambulatory care utilization among RA patients in Taiwan preceding diagnosis of RA.

Systemic sclerosis increases the risks of deep vein thrombosis and pulmonary thromboembolism: a nationwide cohort study

OBJECTIVES

Few Asian studies have evaluated the risks of deep vein thrombosis (DVT) and pulmonary thromboembolism (PTE) in patients with SSc. We conducted a nationwide population-based cohort study to evaluate how SSc affected the incidence of DVT and PTE in Taiwan.

METHODS

We identified patients with an SSc diagnosis in Taiwan between 1998 and 2010 using the Catastrophic Illness Patient Database and the National Health Insurance Research Database. Each SSc patient was frequency matched to four control patients based on age, sex and index year and all patients were observed from the index date until the appearance of a DVT or PTE event or 31 December 2010. We calculated the hazard ratios and 95% CIs of DVT and PTE in the SSc and comparison cohorts using the Cox proportional hazards regression model.

RESULTS

We observed 1895 SSc patients and 7580 control patients for ∼10,128 and 46,488 person-years, respectively. The mean ages of the SSc and comparison cohorts were 50.3 and 49.9 years, respectively. After adjusting for age, sex and co-morbidities, the risks of DVT and PTE among the SSc patients were 10.5- and 7.00-fold higher than those of the control patients. The probability of developing DVT and PTE increased in the years following the SSc diagnosis.

CONCLUSION

SSc patients exhibited a significantly higher risk of developing DVT and PTE compared with the general population. Thus multidisciplinary teams should guide the assessment, treatment and holistic care of SSc patients.

A bibliometric study of literature on SLE research in PubMed (2002–2011)

Objective

The objective of this paper is to study the distribution regularity, development tendency and research hot spots of systemic lupus erythematosus (SLE) literature published in journals indexed in PubMed over a 10-year period using the bibliometric analysis method.

Methods

Citations from 2002 to 2011 were downloaded from the PubMed database. The core of the search was the Medical Subject Headings (MeSH) “Lupus Erythematosus, Systemic.” The period of study was set from 2002 to 2011.

Results

A total of 14,053 articles were retrieved. These articles were published in 1627 different journals, nine journals contributing to one-third of all the literature. The first three journals containing the most articles were Lupus, Arthritis Rheum and J Rheumatol. America was the most productive world area followed by Japan, China and the United Kingdom. When normalized by population, Israel, Monaco and Iceland ranked as the top three. When normalized by GDP, Israel, Tunisia and Serbia were in leading positions. The steady increase of publication in SLE research can be seen during the whole study period from 2002 to 2011.

Conclusion

SLE has become a field of interest over the period 2002 to 2011. However, lupus research publications in developing countries have lagged behind.