Julia F. Simard

Nationwide prevalence of rheumatoid arthritis and penetration of disease-modifying drugs in Sweden

Objective To provide Swedish nationwide data on the prevalence of rheumatoid arthritis (RA), including variations by age, sex, geography, demography and education level, and assess antirheumatic treatment penetration. Methods Patients ≥16 years assigned an RA diagnosis were identified from inpatient (n=96 560; 1964–2007) and specialist outpatient care (n=56 336; 2001–2007) in the Swedish National Patient Register, and the Swedish Rheumatology Quality Register (n=21 242; 1995–2007). Data on prescriptions, demography, vital status and educational level were retrieved from national registers. Results A total of 58 102 individuals (mean age 66 years; 73% women) assigned an RA diagnosis were alive in Sweden in 2008, corresponding to a cumulative prevalence of 0.77% (women 1.11%, men 0.43%). The 2001–2007 period prevalence was 0.70%. Restriction to patients with ≥2 visits or diagnosis from a rheumatologist/internist reduced the overall cumulative prevalence to 0.68%. Whereas urban/rural differences (crude 0.65–1.00%) were explained by age differences, the age/sex-adjusted prevalence remained higher in patients with ≤9 years education (0.86%) than for those with 10–12 years (0.82%) and >12 years (0.65%). Treatment exposures (76% any disease-modifying antirheumatic drugs (DMARDs) or steroids, 64% any DMARD, 15% biological agents) varied with age; use of biological agents decreased from 22% in 16–59 years olds to 3% in ≥80 years olds. Any DMARD use correspondingly decreased from 71% to 43%. Applying age cut-off points from previous northern European and North American prevalence studies reduced or eliminated between-study differences. Conclusion This nationwide approach yielded a prevalence of RA similar to previous regional assessments. While displaying only modest geographical variation and no urban/rural gradient, prevalence was associated with educational level. Although most patients received antirheumatic drugs, age was a strong treatment determinant.

Evidence for differential acquired drug resistance to anti-tumour necrosis factor agents in rheumatoid arthritis

Background: Acquired drug resistance or gradual drug failure has been described with most disease modifying antirheumatic drugs (DMARDs) and is also starting to be recognised with anti-tumour necrosis factor (anti-TNF) agents. Objective: To study acquired drug resistance to anti-TNF agents in rheumatoid arthritis (RA). Methods: Swiss health authorities requested continuous monitoring of patients receiving biological agents. Intensification of co-therapy with traditional DMARDs, gradual dose escalation, and drug discontinuation rates in all patients receiving infliximab, etanercept, or adalimumab, adjusting for potential confounders, were analysed. Intensification of DMARD co-therapy and time to discontinuation of the three anti-TNF agents were analysed using a proportional hazards models. Dose escalation and evolution of RA disease activity (DAS28) were analysed using a longitudinal regression model. Results: 1198 patients contributing 1450 patient-years of anti-TNF treatment met the inclusion criteria. The rate of intensification of traditional DMARD co-therapy over time was significantly higher with infliximab (hazards ratio = 1.73 (99% confidence interval (CI) 1.19 to 2.51)) than with the two other agents. Infliximab also showed significant dose escalation over time, with an average dose increase of +12% (99% CI 8% to 16%) after 1 year, and +18% (99% CI 11% to 25%) after 2 years. No significant differences in discontinuation rates were seen between the three anti-TNF agents (ANOVA, p = 0.67). Evolution of disease activity over time indicated a lower therapeutic response to infliximab (DAS28, p<0.001) compared with etanercept, after 6 months’ treatment. Conclusions: In this population, infliximab was associated with a higher risk of requiring intensification of DMARD co-therapy than the other anti-TNF agents and a significant dose escalation over time. Analysis of RA disease activity indicated a reduced therapeutic response to infliximab after the first 6 months of treatment, suggestive of acquired drug resistance.

Rheumatoid arthritis, anti-tumour necrosis factor therapy, and risk of malignant melanoma: nationwide population based prospective cohort study from Sweden

Objectives To investigate the potential association between tumour necrosis factor (TNF) inhibitor treatment and malignant melanomas in rheumatoid arthritis, melanoma risks in rheumatoid arthritis patients not treated with biological drugs, and risk of all site cancer with TNF inhibitors as used in rheumatoid arthritis. Design Population based cohort study. Setting Prospectively recorded data from national clinical, health, and demographic registers in Sweden 2001-10. Patients with rheumatoid arthritis treated (n=10 878) or not (n=42 198) with TNF inhibitors and matched general population comparators (n=162 743). Main outcome measures The primary outcome was first invasive melanoma in people without any history of invasive cancer of any type. Hazard ratios were estimated using Cox regression, comparing non-biological drug treated rheumatoid arthritis patients with the general population comparator and TNF inhibitor treated rheumatoid arthritis patients with those not treated with biological drugs. Secondary outcomes included in situ melanomas, second primary melanomas, and all site cancer. Results 113 first invasive melanomas occurred in rheumatoid arthritis patients not treated with biological drugs, and 393 occurred in the general population comparator cohort. Rheumatoid arthritis patients not treated with biological drugs were not at significantly increased risk of melanoma compared with the general population (hazard ratio 1.2, 95% confidence interval 0.9 to 1.5). 38 first invasive melanomas occurred in rheumatoid arthritis patients treated with TNF inhibitors; these patients had an increased risk of melanoma compared with rheumatoid arthritis patients not treated with biological drugs (hazard ratio 1.5, 1.0 to 2.2; 20 additional cases per 100 000 person years). The risk of a second primary melanoma was non-significantly increased (hazard ratio 3.2, 0.8 to 13.1; n=3 v 10) in rheumatoid arthritis patients treated with TNF inhibitors compared with those not treated with biological drugs. Conclusion Overall, patients with rheumatoid arthritis who have not been treated with biological drugs are not at increased risk of invasive melanoma compared with the general population. Rheumatoid arthritis patients selected for TNF inhibitor treatment are not at increased overall risk for cancer but have a 50% increased relative risk of invasive melanoma. Given the small increase in absolute risk, these finding may not markedly shift the overall risk-benefit balance of TNF inhibitors as used in clinical practice but might do so in patients at high risk of melanoma for other reasons.

Predictors of the first cardiovascular event in patients with systemic lupus erythematosus - a prospective cohort study

IntroductionCardiovascular disease (CVD) is a major cause of premature mortality among Systemic lupus erythematosus (SLE) patients. Many studies have measured and evaluated risk factors for premature subclinical atherosclerosis, but few studies are prospective and few have evaluated risk factors for hard endpoints, i.e. clinically important cardiovascular events (CVE). We investigated the impact of traditional and lupus associated risk factors for the first ever CVE in a longitudinal cohort of SLE patients.MethodsA total of 182 SLE patients (mean age 43.9 years) selected to be free of CVE were included. Cardiovascular and autoimmune biomarkers were measured on samples collected after overnight fasting at baseline. Clinical information was collected at baseline and at follow up. End point was the first ever CVE (ischemic heart, cerebrovascular or peripheral vascular disease or death due to CVD). Impact of baseline characteristics/biomarkers on the risk of having a first CVE was evaluated with Cox regression.ResultsFollow up was 99.5% after a mean time of 8.3 years. Twenty-four patients (13%) had a first CVE. In age-adjusted Cox regression, any positive antiphospholipid antibody (aPL), elevated markers of endothelial activation (von Willebrand factor (vWf), soluble vascular cellular adhesion molecule-1 (sVCAM-1)) and fibrinogen predicted CVEs. Of SLE manifestations, arthritis, pleuritis and previous venous occlusion were positively associated with future CVEs while thrombocytopenia was negatively associated. Among traditional risk factors only age and smoking were significant predictors. In a multivariable Cox regression model age, any positive aPL, vWf and absence of thrombocytopenia were all predictors of the first CVE.ConclusionsIn addition to age, positive aPL, biomarkers indicating increased endothelial cell activity/damage, and absence of thrombocytopenia were independent predictors of CVEs in this prospective study. Our results indicate that activation of the endothelium and the coagulation system are important features in SLE related CVD. Furthermore, we observed that the risk of CVEs seems to differ between subgroups of SLE patients.

Quadrivalent Human Papillomavirus Vaccine Effectiveness: A Swedish National Cohort Study

Background Incidence of condyloma, or genital warts (GW), is the earliest possible disease outcome to measure when assessing the effectiveness of human papillomavirus (HPV) vaccination strategies. Efficacy trials that follow prespecified inclusion and exclusion criteria may not be fully generalizable to real-life HPV vaccination programs, which target a broader segment of the population. We assessed GW incidence after on-demand vaccination with quadrivalent HPV vaccine using individual-level data from the entire Swedish population. Methods An open cohort of girls and women aged 10 to 44 years living in Sweden between 2006 and 2010 (N > 2.2 million) was linked to multiple population registers to identify incident GW in relation to HPV vaccination. For vaccine effectiveness, incidence rate ratios of GW were estimated using time-to-event analyses with adjustment for attained age and parental education level, stratifying on age at first vaccination. Results A total of 124 000 girls and women were vaccinated between 2006 and 2010. Girls and women with at least one university-educated parent were 15 times more likely to be vaccinated before age 20 years than girls and women whose parents did not complete high school (relative risk ratio = 15.45, 95% confidence interval [CI] = 14.65 to 16.30). Among those aged older than 20 years, GW rates declined among the unvaccinated, suggesting that HPV vaccines were preferentially used by women at high risk of GW. Vaccination effectiveness was 76% (95% CI = 73% to 79%) among those who received three doses of the vaccine with their first dose before age 20 years. Vaccine effectiveness was highest in girls vaccinated before age 14 years (effectiveness = 93%, 95% CI = 73% to 98%). Conclusions Young age at first vaccination is imperative for maximizing quadrivalent HPV vaccine effectiveness.

Juvenile idiopathic arthritis and risk of cancer: a nationwide cohort study.

OBJECTIVE Reports of therapy-related adverse events suggest an elevated rate of malignancy in patients with juvenile idiopathic arthritis (JIA) treated with biologic therapies. However, the scarcity of data on the underlying risk of malignancy in JIA hampers interpretation of these signals. Therefore, the aim of this study was to determine the risk of cancer in patients with JIA as compared with that in the general population. METHODS Through linkage with a national database, the Swedish Patient Register (comprising inpatient discharges in 1969-2007 and specialist outpatient visits in 2001-2007 in Sweden), a national JIA cohort (n = 9,027) was identified, and each JIA case was matched with 5 general population comparators. Using data from the Swedish Cancer, Census, Death, and Biologics Registers, the occurrence of cancer, vital status, and start of a biologic therapy were identified. The relative risk (RR) of first occurrence of a primary cancer in patients who had not been treated with biologics (biologics-naive patients with JIA) was estimated using Poisson regression, stratified a priori by year of earliest identification of JIA (before 1987 versus 1987 and thereafter). In sensitivity analyses, the data were followed up to 1999, when biologics first became available. RESULTS In this biologics-naive JIA cohort, 60 malignancies were observed during 131,144 person-years of followup, compared with 266 cancers observed during 661,758 person-years in the general population comparator (0.46 cases/1,000 person-years versus 0.40 cases/1,000 person-years; RR 1.1, 95% confidence interval [95% CI] 0.9-1.5). Patients with JIA identified before 1987 were not at increased risk of cancer, whereas JIA identified in 1987 and thereafter was significantly associated with incident lymphoproliferative malignancies (RR 4.2, 95% CI 1.7-10.7) and cancers overall (RR 2.3, 95% CI 1.2-4.4). Sensitivity analyses did not reveal any ready explanation for this heterogeneity. CONCLUSION Although absolute risks were low, an elevated risk of malignancy was observed among biologics-naive patients in whom the diagnosis of JIA was made in the past 20 years, which may have implications for the interpretation of cancer signals in patients with JIA treated with newer therapies.

Risk factors for cardiovascular mortality in patients with systemic lupus erythematosus, a prospective cohort study

IntroductionSystemic lupus erythematosus (SLE) is a chronic autoimmune disease. Cardiovascular disease (CVD) is common and a major cause of mortality. Studies on cardiovascular morbidity are abundant, whereas mortality studies focusing on cardiovascular outcomes are scarce. The aim of this study was to investigate causes of death and baseline predictors of overall (OM), non-vascular (N-VM), and specifically cardiovascular (CVM) mortality in SLE, and to evaluate systematic coronary risk evaluation (SCORE).Methods208 SLE patients were included 1995-1999 and followed up after 12 years. Clinical evaluation, CVD risk factors, and biomarkers were recorded at inclusion. Death certificates and autopsy protocols were collected. Causes of death were divided into CVM (ischemic vascular and general atherosclerotic diseases), N-VM and death due to pulmonary hypertension. Predictors of mortality were investigated using multivariable Cox regression. SCORE and standardized mortality ratio (SMR) were calculated.ResultsDuring follow-up 42 patients died at mean age of 62 years. SMR 2.4 (CI 1.7-3.0). 48% of deaths were caused by CVM. SCORE underestimated CVM but not to a significant level. Age, high cystatin C levels and established arterial disease were the strongest predictors for all- cause mortality. After adjusting for these in multivariable analyses, only smoking among traditional risk factors, and high soluble vascular cell adhesion molecule-1 (sVCAM-1), high sensitivity C-reactive protein (hsCRP), anti-beta2 glycoprotein-1 (abeta2GP1) and any antiphospholipid antibody (aPL) among biomarkers, remained predictive of CVM.ConclusionWith the exception of smoking, traditional risk factors do not capture the main underlying risk factors for CVM in SLE. Rather, cystatin C levels, inflammatory and endothelial markers, and antiphospholipid antibodies (aPL) differentiate patients with favorable versus severe cardiovascular prognosis. Our results suggest that these new biomarkers are useful in evaluating the future risk of cardiovascular mortality in SLE patients.

Incidence of Genital Warts in Sweden Before and After Quadrivalent Human Papillomavirus Vaccine Availability

BACKGROUND More than 90% of genital warts (GW) cases are caused by human papillomavirus (HPV) types 6 and 11. The introduction of HPV vaccines necessitates the estimation of the population-based incidence of GW immediately before and after vaccination uptake. METHODS Incidence proportions were calculated using the entire population aged 10–44 years living in Sweden during 2006–2010. The Prescribed Drug Register and the National Patient Register were used to define GW episodes. Time trends were estimated using Poisson regression. RESULTS In 2010, age-stratified incidence proportions of GW were highest for 20-year-old women (956 cases/100 000), while the incidence proportion among males was greatest at the slightly older age of 24 years (1137 cases/100 000). Crude rates were marginally higher among males than among females during 2006–2007 and appeared to later diverge. Between 2008 and 2010, the overall incidence appeared to increase among males, and the incidence among females declined. Females aged 17 and 18 years had a >25% decline in GW rates between 2006 and 2010, with significant decreases through the age of 25 years. CONCLUSIONS This study provides a reasonable estimation of the incidence of GW in the Swedish population by use of register data, with results comparable to those from previous smaller studies. There was a downward trend of GW incidence among younger females between 2006 and 2010.

Drug survival on TNF inhibitors in patients with rheumatoid arthritis comparison of adalimumab, etanercept and infliximab

Objective To compare drug survival on adalimumab, etanercept and infliximab in patients with rheumatoid arthritis (RA). Methods Patients with RA (n=9139; 76% women; mean age 56 years) starting their first tumour necrosis factor (TNF) inhibitor between 2003 and 2011 were identified in the Swedish Biologics Register (ARTIS). Data were collected through 31 December 2011. Drug survival over up to 5 years of follow-up was compared overall and by period of treatment start (2003–2005/2006–2009; n=3168/4184) with adjustment for age, sex, education, period, health assessment questionnaire (HAQ), disease duration, concomitant disease modifying antirheumatic drug (DMARD) treatment and general frailty (using hospitalisation history as proxy). Results During 20 198 person-years (mean/median 2.2/1.7 years) of follow-up, 3782 patients discontinued their first biological (19/100 person-years; 51% due to inefficacy, 36% due to adverse events). Compared with etanercept, infliximab (adjusted HR 1.63, 95% CI 1.51 to 1.77) and adalimumab initiators had higher discontinuation rates (1.26, 95% CI 1.16 to 1.37), and infliximab had a higher discontinuation rate than adalimumab (1.28, 95% CI 1.18 to 1.40). These findings were consistent across periods, but were modified by time for adalimumab versus etanercept (p<0.001; between-drug difference highest the 1st year in both periods). The discontinuation rate was higher for starters in 2006–2009 than 2003–2005 (adjusted HR 1.12, 95% CI 1.04 to 1.20). The composition of 1-year discontinuations also changed from 2003–2005 vs 2006–2009: adverse events decreased from 45% to 35%, while inefficacy increased from 43% to 53% (p<0.001). Conclusions Discontinuation rates were higher for infliximab compared with adalimumab and etanercept initiators, and for adalimumab versus etanercept during the 1st year. Discontinuation rates increased with calendar period, as did the percentage discontinuations due to inefficacy.

Incidence of Rheumatoid Arthritis in Sweden: A Nationwide Population-Based Assessment of Incidence, Its Determinants, and Treatment Penetration

To estimate the nationwide incidence of rheumatoid arthritis (RA) in Sweden, including its variation across age, sex, geography, and demography, and to describe the sensitivity of register‐based incidence estimates to different RA case definitions.