Medication use among pregnant women with systemic lupus erythematosus and general population comparators

Objective

The aim was to characterize SLE medication trends before, during and after pregnancy and to compare other commonly used medications during SLE pregnancies with non-SLE pregnancies.

Methods

Women with pregnancies ending in live birth or stillbirth were identified from the Swedish Medical Birth Register (2006-12). National registers were used to identify women with prevalent SLE during pregnancy and a sample without SLE and to identify prescription medications dispensed from 3 months pre-pregnancy until 6 months postpartum. We reported the prevalence of DMARDs, systemic CSs and NSAIDs (aspirin reported separately) in SLE pregnancies. We calculated prevalence estimates of other medications that were dispensed during pregnancy to ⩾ 5% of SLE pregnancies and for the same medications among non-SLE pregnancies.

Results

There were 483 pregnancies among women with SLE and 5723 pregnancies among women without SLE. In SLE pregnancies, 49.3% had one or more dispensing for DMARDs during pregnancy; the prevalence was 48.0% for CSs, 40.8% for aspirin and 6.0% for other NSAIDs and varied by pregnancy period. The prevalence of common medications among SLE pregnancies was 1.2- to 20-fold higher than among non-SLE pregnancies; for example, dalteparin (20.9 vs 1.0%), paracetamol (18.2 vs 2.9%) and levothyroxine (15.9 vs 4.9%).

Conclusion

In nearly half of SLE pregnancies, women were dispensed DMARDs and CSs. Commonly used medications in SLE pregnancies had far higher prevalence estimates compared with non-SLE pregnancies. Research regarding benefits and risks of commonly used medications on SLE pregnancies, breast milk and long-term outcomes for offspring is needed.

Cervical neoplasia in systemic lupus erythematosus: a nationwide study

Objective

The aim was to examine the risk of cervical neoplasia in women with SLE, overall and with respect to treatment, compared with women from the general population.

Methods

By linking national Swedish registers, we assembled a cohort including women with SLE (n = 4976) and matched general population comparators (n = 29 703). Two subcohorts of treated SLE patients were defined on the basis of treatment with antimalarials (n = 1942) and other immunosuppressants (AZA, CYC, ciclosporin, MTX, MMF or rituximab; n = 2175). The main outcome was defined as a first cervical neoplasia (dysplasia or cancer) during follow-up. Secondary outcomes were first cervical intraepithelial neoplasia (CIN) 1; first CIN grades 2-3; and first invasive cervical cancer during follow-up (2006-12). Cox regression models estimated relative risks adjusted for age, level of education, health-care utilization, number of children, marital status, family history of cervical cancer and prior cervical screening.

Results

Based on 121 events of cervical neoplasia during 23 136 person-years among SLE patients, there was an increased risk of any cervical neoplasia compared with the general population [hazard ratio (HR) = 2.12 (95% CI: 1.65, 2.71)]. The risk of CIN 1 [HR = 2.33 (95% CI: 1.58, 3.44)], CIN 2-3 [HR = 1.95 (95% CI: 1.43, 2.65)], but not invasive cervical cancer [HR = 1.64 (95% CI: 0.54, 5.02)], was increased in women with SLE. The subcohort treated with other immunosuppressants was at highest risk of cervical neoplasia.

Conclusion

SLE is a risk factor for cervical neoplasia, in particular for pre-malignant cervical lesions. Among patients with SLE, the risk is higher among those treated with immunosuppresants compared with those treated with antimalarials.

Stroke in systemic lupus erythematosus: a Swedish population-based cohort study

Objective

To study the occurrence of ischaemic and haemorrhagic stroke in systemic lupus erythematosus (SLE) compared with the general population by age, sex and time since SLE diagnosis

Methods

Adults with incident SLE were identified from the Swedish National Patient Register (NPR, n=3390) and general population comparators from the Total Population Register were matched on age, sex and county (n=16730). Individuals were followed prospectively until first of death, December 2013, emigration or incident stroke (identified from the NPR, Cause of Death Register and the Stroke Register). Incidence rates, rate differences and HR were estimated comparing SLE with non-SLE. Estimates were stratified by sex, age and time since diagnosis.

Results

We observed 126 strokes in SLE and 304 in the general population. Individuals with SLE had a twofold increased rate of ischaemic stroke compared with the general population (HR 2.2; 95% CI 1.7 to 2.8). The HR for intracerebral haemorrhage was 1.4 (95% CI 0.7 to 2.8). There was effect modification by sex and age, with the highest HRs for females and individuals <50 years old. The HR for ischaemic stroke was highest in the first year of follow-up (3.7; 95% CI 2.1 to 6.5).

Conclusions

The relative risk of ischaemic stroke in SLE was more than doubled compared with the general population, and importantly, the highest relative risks were observed within the first year after SLE diagnosis. Thus, the first encounter with patients presents an opportunity for rheumatologists to screen for risk factors and intervene.

Early-onset Preeclampsia in Lupus Pregnancy

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease that occurs during childbearing years and has been associated with preeclampsia. However, little is known about preeclampsia of early onset, which is associated with severe adverse maternal and perinatal outcomes.

METHODS

Using national population-based Swedish registers we identified women with SLE (≥2 visits with corresponding ICD codes) and a sample without SLE who gave birth to singleton infants 2001-12. Risk ratios (RR) and 95% confidence intervals (CI) for early-onset preeclampsia (defined by ICD codes corresponding to preeclampsia registered at <34 weeks) in SLE women were calculated based on adjusted modified Poisson models for first, subsequent, and all pregnancies.

RESULT

Among 742 births to women with SLE and 10 484 births to non-SLE women, there were 32 (4.3%) and 55 (0.5%) diagnoses of early-onset preeclampsia respectively. SLE was associated with an increased risk of early-onset preeclampsia (RR 7.8, 95% CI 4.8, 12.9, all pregnancies). The association remained similar upon restriction to women without pregestational hypertension. Adjustment for antiphospholipid syndrome (APS)-proxy attenuated the association. RRs for early-onset preeclampsia were smaller for subsequent pregnancies (RR 4.7, 95% CI 2.0, 11.2) compared to first and all (see above).

CONCLUSION

Women with SLE are at increased risk of early-onset preeclampsia and this increased risk may be independent of the traditional risk factors such as pregestational hypertension, APS, BMI, or smoking. Women with SLE during pregnancy should be closely monitored for early-onset preeclampsia and future research needs to identify the non-traditional preeclampsia factors that might cause this serious outcome.

Brief Report: Sex Ratio of Offspring Born to Women With Systemic Lupus Erythematosus or Rheumatoid Arthritis

OBJECTIVE

To determine whether the sex ratio among offspring born to women with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) is different from that in the general population.

METHODS

Women with a singleton delivery were identified from the Swedish Medical Birth Register (1973-2012) and linked to the National Patient Register (1964-2012) to identify those with prevalent SLE or RA. A sample of general population comparators was identified from the Swedish Total Population Register. We calculated the percentages of males born to women with SLE, women with RA, and women in the general population, as well as the risk ratio (RR) for having a male child among first births and all births. We also examined a history of antiphospholipid syndrome in the SLE population, using International Classification of Disease codes before or at delivery.

RESULTS

We identified 661 women with SLE and 1,136 women with RA before their first delivery. There were a total of 1,401 deliveries to women with SLE and a total of 2,674 deliveries to women with RA. Compared with women in the general population, women with SLE and those with RA had a lower risk of having a first-born male (RR 0.92 [95% confidence interval 0.85-1.00] and RR 0.93 [95% confidence interval 0.87-0.99], respectively). Among all births, the percentage of male offspring remained lower than that in the general population, but the difference was not statistically significant for RA.

CONCLUSION

The proportion of male offspring born to women with prevalent SLE or RA at delivery was lower than that in the general population, although the difference was small. Chronic inflammation may affect the sex ratio through fetal loss in early gestation.

Induction maintenance with tumour necrosis factor-inhibitor combination therapy with discontinuation versus methotrexate monotherapy in early rheumatoid arthritis: a systematic review and meta-analysis of efficacy in randomised controlled trials

Objective

To determine whether an induction-maintenance strategy of combined therapy (methotrexate (MTX)+tumour necrosis factor (TNF) inhibitor (TNFi)) followed by withdrawal of TNFi could yield better long-term results than a strategy with MTX monotherapy, since it is unclear if the benefits from an induction phase with combined therapy are sustained if TNFi is withdrawn.

Methods

We performed a meta-analysis of trials using the initial combination of MTX+TNFi in conventional synthetic disease-modifying antirheumatic drug-naïve patients with early rheumatoid arthritis (RA). A systematic literature search was performed for induction-maintenance randomised controlled trials (RCTs) where initial combination therapy was compared with MTX monotherapy in patients with clinically active early RA. Our primary outcome was the proportion of patients who achieved low disease activity (LDA; Disease Activity Score (DAS)28<3.2) and/or remission (DAS28<2.6) at 12–76 weeks of follow-up. A random-effects model was used to pool the risk ratio (RR) for LDA and remission and heterogeneity was explored by subgroup analyses.

Results

We identified 6 published RCTs, 4 of them where MTX+adalimumab was given as initial therapy and where adalimumab was withdrawn in a subset of patients after LDA/remission had been achieved. 2 additional trials used MTX+infliximab as combination therapy. The pooled RRs for achieving LDA and clinical remission at follow-up after withdrawal of TNFi were 1.41 (95% CI 1.05 to 1.89) and 1.34 (95% CI 0.95 to 1.89), respectively. There was significant heterogeneity between trials due to different treatment strategies, which was a limitation to this study.

Conclusions

Initial therapy with MTX+TNFi is associated with a higher chance of retaining LDA and/or remission even after discontinuation of TNFi.

Sarcoidosis incidence and prevalence: a nationwide register-based assessment in Sweden

Our objective was to estimate the contemporary incidence and prevalence of sarcoidosis using Swedish population-based register data.Adults with any sarcoidosis-coded visit were identified from the National Patient Register (hospitalisations 1964-2013 and outpatient care 2001-2013). Demographic and medication dispensing data were retrieved from national registers. We estimated the prevalence of sarcoidosis in 2013 overall and by county of residence. The incidence of sarcoidosis during 2003-2012 was estimated by sex, age, education level and year of diagnosis. Case definitions were varied to test their robustness.More than 16 000 individuals had a history of sarcoidosis in 2013. When defined as two or more sarcoidosis-coded visits, the prevalence was 160 per 100 000. Using different definitions, the prevalence ranged from 152 (requiring a specialist visit) to 215 per 100 000 (only one visit required). The highest prevalence was observed in northern less densely populated counties. The incidence was 11.5 per 100 000 per year and varied by -10% to +30% depending on case definition. The incidence peaked in males aged 30-50 years and in females aged 50-60 years, but did not differ by education level and was stable over time.This study represents the largest epidemiological investigation of sarcoidosis using population-based individual-level data. Age at diagnosis in men was 10 years younger than in women and geographical variation was observed.

Cancer risk in patients with spondyloarthritis treated with TNF inhibitors: a collaborative study from the ARTIS and DANBIO registers

BACKGROUND

Safety data on cancer risks following tumour necrosis factor α inhibitors (TNFi) in patients with spondyloarthritis (SpA) (here defined as ankylosing spondylitis (AS), undifferentiated spondarthropaties (SpA UNS), psoriatic arthritis (PsA)) are scarce. Our objective was to assess risks for cancer overall and for common subtypes in patients with SpA treated with TNFi compared with TNFi-naïve patients with SpA and to the general population.

METHODS

From the Swedish (Anti-Rheumatic Therapy in Sweden (ARTIS)) and Danish (DANBIO) biologics registers, we assembled 8703 (ARTIS=5448, DANBIO=3255) patients with SpA initiating a first TNFi 2001-2011. From the Swedish National Patient and Population Registers we assembled a TNFi-naïve SpA cohort (n=28,164) and a Swedish age-matched and sex-matched general population comparator cohort (n=131 687). We identified incident cancers by linkage with the nationwide Swedish and Danish Cancer Registers 2001-2011, and calculated age-standardised and sex-standardised incidence ratios as measures of relative risk (RR).

RESULTS

Based on 1188 cancers among the TNFi-naïve patients with SpA, RR of cancer overall was 1.1 (95% CI 1.0 to 1.2). Based on 147 cancers among TNFi initiators with SpA, RR versus TNFi-naïve was 0.8 (95% CI 0.7 to 1.0) and results were similar for AS and PsA when analysed separately. Site-specific cancer RRs: prostate 0.5 (95% CI 0.3 to 0.8), lung 0.6 (95% CI 0.3 to 1.3), colorectal 1.0 (95% CI 0.5 to 2.0), breast 1.3 (95% CI 0.9 to 2.0), lymphoma 0.8 (95% CI 0.4 to 1.8) and melanoma 1.4 (95% CI 0.7 to 2.6).

CONCLUSIONS

In patients with SpA, treatment with TNFi was not associated with increased risks of cancer, neither overall nor for the six most common cancer types.

Endometriosis and systemic lupus erythematosus: a population-based case-control study

OBJECTIVE

To investigate the association between endometriosis and systemic lupus erythematosus (SLE) in prospectively collected population-based data.

METHODS

We conducted a case-control study using Swedish registers, identifying female SLE cases from the National Patient Register and female controls sampled from the general population matched on birth year, sex and county during 1964-2011. We identified endometriosis diagnoses from the National Patient Register using ICD codes. We estimated odds ratios and 95% confidence intervals using conditional logistic regression models.

RESULTS

We identified 2834 cases of SLE and 14,164 controls. Seventy-eight cases were diagnosed with endometriosis prior to their SLE diagnosis and 288 controls were diagnosed prior to the index date. We observed a significant association between endometriosis and subsequent SLE with an odds ratio of 1.39 (95% confidence interval = 1.09-1.78). The association was similar when requiring a laparoscopy/laparotomy within six months of the endometriosis diagnosis (odds ratio = 1.33; 95% confidence interval = 0.84-2.12) while the association was stronger when restricted to endometriosis diagnosed at the same time as hysterectomy (odds ratio = 2.26; 95% confidence interval = 1.47-3.64).

CONCLUSIONS

Our findings suggest an association between endometriosis and SLE. Future prospective studies with extended follow-up will be necessary to clarify whether this association is influenced by the timing and severity of endometriosis diagnosis.

Case definitions in Swedish register data to identify systemic lupus erythematosus

OBJECTIVE

To develop and investigate the utility of several different case definitions for systemic lupus erythematosus (SLE) using national register data in Sweden.

METHODS

The reference standard consisted of clinically confirmed SLE cases pooled from four major clinical centres in Sweden (n=929), and a sample of non-SLE comparators randomly selected from the National Population Register (n=24,267). Demographics, comorbidities, prescriptions and autoimmune disease family history were obtained from multiple registers and linked to the reference standard. We first used previously published SLE definitions to create algorithms for SLE. We also used modern data mining techniques (penalised least absolute shrinkage and selection operator logistic regression, elastic net regression and classification trees) to objectively create data-driven case definitions. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for the case definitions identified.

RESULTS

Defining SLE by using only hospitalisation data resulted in the lowest sensitivity (0.79). When SLE codes from the outpatient register were included, sensitivity and PPV increased (PPV between 0.97 and 0.98, sensitivity between 0.97 and 0.99). Addition of medication information did not greatly improve the algorithm's performance. The application of data mining methods did not yield different case definitions.

CONCLUSIONS

The use of SLE International Classification of Diseases (ICD) codes in outpatient clinics increased the accuracy for identifying individuals with SLE using Swedish registry data. This study implies that it is possible to use ICD codes from national registers to create a cohort of individuals with SLE.

Stroke in systemic lupus erythematosus: a meta-analysis of population-based cohort studies

Previous studies of stroke in systemic lupus erythematosus (SLE) have had limited statistical power, combined stroke subtypes into composite outcomes, and lacked a reference population estimate. Therefore, we conducted a systematic review and meta-analysis of cohort studies to summarise the stroke subtype-specific risk in patients with SLE compared to the general population. A systematic search of MEDLINE and EMBASE was performed for cohort studies examining the risk of stroke in SLE and including a general population comparator. Random effects models were used to pool the risk ratio (RR) for stroke. Subgroup analyses were carried out to investigate potential sources of heterogeneity. 10 studies were included which reported RRs for overall stroke (n=5), ischaemic stroke (n=6), intracerebral haemorrhage (n=3) and subarachnoid haemorrhage (n=3). The pooled RR for overall stroke was 2.53 (95% CI 1.96 to 3.26), ischaemic stroke 2.10 (95% CI 1.68 to 2.62), intracerebral haemorrhage 2.72 (95% CI 2.15 to 3.44) and subarachnoid haemorrhage 3.85 (95% CI 3.20 to 4.64). Significant heterogeneity among studies for ischaemic stroke was detected (p=0.002). Relative risk of stroke was highest among individuals younger than 50 years of age. Individuals with SLE have a twofold higher risk of ischaemic stroke, a threefold higher risk of intracerebral haemorrhage, and an almost fourfold higher risk of subarachnoid haemorrhage compared to the general population. Future studies should focus on whether comorbidity and disease flares are related to stroke, when individuals are at the highest risk, and how the targeting of specific groups of patients with SLE may reduce this risk.

Cohort profile: systemic lupus erythematosus in Sweden: the Swedish Lupus Linkage (SLINK) cohort

PURPOSE

A cohort of individuals with systemic lupus erythematosus (SLE) was identified through linkage of several national registers to investigate important epidemiological questions using not only population-based data to minimise selection bias, but also to identify matched comparators from the general population to serve as controls. This cohort was established to overcome the general dearth of data in SLE epidemiology.

PARTICIPANTS

All individuals registered in Sweden with a personal identity number and who have obtained medical care at any hospital or public non-primary outpatient specialist care with suspected SLE were identified. Inpatient register data date back to the 1960s, although complete national coverage of the inpatient register was achieved in 1987. In 2001, the outpatient component was also added to the register, representing the entire country of Sweden. For each suspected individual with SLE, up to five individuals from the general population were identified and matched on sex, birth year and county of residence.

FINDINGS TO DATE

We have linked this study population to a number of national and quality registers in Sweden to identify first-degree relatives, deaths, births, dispensed prescriptions, comorbidities and disease end points, such as stroke and cancer, as well as basic health economic data. We found geographic variability in the prevalence of SLE by county. We have also shown that being first-born confers a reduced odds of having SLE in childhood and early adulthood.

FUTURE PLANS

In addition to updating the national register linkage with several more years of follow-up data, we are adding several quality registers in Sweden, including the Tuberculosis register and the Social Insurance Office database. While these updates are ongoing and additional follow-up accumulates, we are studying a number of outcomes in SLE, including stroke, pregnancy and death. We will continue to present findings at scientific conferences and in the peer-reviewed literature.

Monocyte chemotactic protein-1 elevation prior to the onset of rheumatoid arthritis among women

OBJECTIVE

To examine monocyte chemotactic protein-1 (MCP-1) concentration and future rheumatoid arthritis (RA) risk, and investigate effect modification by human leukocyte antigen-shared epitope (HLA-SE) and several lifestyle factors.

METHODS

We conducted a nested case-control study using stored plasma samples from the Nurses' Health Studies. Each pre-RA case was matched to three controls (N case = 220, N control = 675). Odds ratios (OR) for RA associated with MCP-1 concentration and interactions with HLA-SE, smoking, BMI and alcohol intake were estimated.

RESULTS

MCP-1 concentration was associated with both seropositive and seronegative RA, in particular <5 years of blood draw (OR: 2.42), and among HLA-SE positive (OR: 2.05). No interactions with smoking, BMI or alcohol were detected.

CONCLUSION

MCP-1 was associated with risk of RA, especially among HLA-SE positive, but did not differ by smoking status, BMI or alcohol intake.

Perinatal risk factors for future SLE: a population-based nested case-control study

OBJECTIVE

To investigate the association between perinatal characteristics and the offspring's risk of lupus using population-based registers in Sweden.

METHODS

We conducted a nested case-control study, identifying systemic lupus erythematosus (SLE) cases from the National Patient Register and controls sampled from the general population matched on birth year, sex, and residential county. We obtained data on the mother's health and age during pregnancy and characteristics of labor and delivery from the Medical Birth Register (births from 1973 through 2008) for cases and controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression models overall and separately for males and females.

RESULTS

We identified 774 cases and 3337 controls. Age at which SLE was first observed ranged from 0 to 36 years old. High birth weight was not a risk factor for SLE and did not differ by sex. Males had a 2.4-fold increased odds of SLE if born preterm (<37 weeks; OR = 2.41; 95% CI 1.09, 5.36). Birth order was significantly associated with SLE, particularly among females (first born vs. not OR = 0.77, 95% CI 0.64, 0.94; continuous birth order OR = 1.12. 95% CI 1.02, 1.24).

CONCLUSION

Being born first was associated with reduced odds of SLE and the odds of SLE increased by 12% for every additional birth. Preterm birth was associated with increased odds in males only. Unlike previous work, high birth weight was not a risk factor for SLE.

The Swedish Rheumatology Quality Register: optimisation of rheumatic disease assessments using register-enriched data

New therapeutic options are constantly emerging for the treatment of rheumatic diseases. To evaluate the safety and efficacy of newly introduced anti-rheumatic treatment alternatives, registers are an important source of information. The Swedish Rheumatology Quality Register (SRQ) collects clinical data on patients with rheumatoid arthritis, as well as other rheumatic diseases, and may be enriched with data on comorbid conditions, prescription drug dispensings, and mortality from national data sources in Sweden. In this setting, many different outcomes can be investigated over a long period of time in a diverse population of patients recruited in daily clinical practice.

Circulating 25-hydroxyvitamin D level and risk of developing rheumatoid arthritis

OBJECTIVE

The aim of this study was to examine the relationship between preclinical circulating 25-hydroxyvitamin D [25(OH)D] and RA in two nested case-control studies within the prospective cohort Nurses' Health Study (NHS) and NHS II (NHSII).

METHODS

We included 166 women with RA and blood specimens collected 3 months to 16 years prior to the first RA symptom and 490 matched controls (3:1, matched on age, date of blood draw, hormonal factors). We calculated the odds ratio (OR) and 95% CI for incident RA using conditional logistic regression multivariable adjusted models, including additional covariates for smoking status, parity and breastfeeding, alcohol consumption, BMI, median income and region of residence in the USA. We repeated analyses stratified by time from blood draw to RA diagnosis (3 months to <4 years or ≥4 years) and meta-analysed estimates from the two cohorts using fixed effects models.

RESULTS

Incident RA was confirmed in 120 NHS [mean age 63.8 years (s.d. 8.2)] and 46 NHSII participants [mean age 48.5 years (s.d. 4.7)]. Mean time from blood draw to RA diagnosis was 7.8 years (s.d. 4.2) for NHS and 4.2 years (s.d. 2.0) for NHSII participants. Meta-analysis of crude and multivariable-adjusted conditional logistic models did not show significant associations between circulating 25(OH)D and RA. However, among NHSII women with blood drawn between 3 months and <4 years prior to RA diagnosis, there was a 20% decreased risk of RA associated with each 1 ng/ml increase in 25(OH)D [OR 0.80 (95% CI 0.64, 0.99)].

CONCLUSION

We did not observe a significant association between circulating 25(OH)D levels and RA, except for among a small subset of NHSII women with levels measured closest to RA diagnosis.

Being overweight or obese and risk of developing rheumatoid arthritis among women: a prospective cohort study

OBJECTIVES

To examine the relationship between being overweight or obese and developing rheumatoid arthritis (RA) in two large prospective cohorts, the Nurses' Health Study (NHS) and Nurses' Health Study II (NHSII).

METHODS

We followed 109 896 women enrolled in NHS and 108 727 in NHSII who provided lifestyle, environmental exposure and anthropometric information through biennial questionnaires. We assessed the association between time-varying and cumulative Body Mass Index (BMI) in WHO categories of normal, overweight and obese (18.5-<25, 25.0-<30, ≥30.0 kg/m(2)) and incident RA meeting the 1987 American College of Rheumatology (ACR) criteria. We estimated HRs for overall RA and serologic subtypes with Cox regression models adjusted for potential confounders. We repeated analyses restricted to RA diagnosed at age 55 years or younger.

RESULTS

During 2 765 195 person-years of follow-up (1976-2008) in NHS and 1 934 518 person-years (1989-2009) in NHSII, we validated 1181 incident cases of RA (826 in NHS, 355 in NHSII). There was a trend toward increased risk of all RA among overweight and obese women (HR (95% CI) 1.37 (0.95 to 1.98) and 1.37 (0.91, 2.09), p for trend=0.068). Among RA cases diagnosed at age 55 years or younger, this association appeared stronger (HR 1.45 (1.03 to 2.03) for overweight and 1.65 (1.34 to 2.05) for obese women (p trend <0.001)). Ten cumulative years of being obese, conferred a 37% increased risk of RA at younger ages (HR 1.37 (1.11 to 1.69)).

CONCLUSIONS

Risks of seropositive and seronegative RA were elevated among overweight and obese women, particularly among women diagnosed with RA at earlier ages.

Are patients with rheumatoid arthritis still at an increased risk of tuberculosis and what is the role of biological treatments?

Objective

To estimate the risk of tuberculosis (TB) in patients with rheumatoid arthritis (RA) both with and without exposure to biological therapy and to directly compare the risks between therapies.

Methods

Data from the Swedish National Population Registers, Tuberculosis Register and the Swedish Biologics Register were used to conduct a prospective population-based national cohort study (2002–2011). We estimated the rate of incident TB in the general population and in a cohort of biological-naïve and biological-exposed patients diagnosed with RA. Cox models were used to estimate HRs with particular attention to risks by calendar and follow-up time and individual biologics.

Results

Compared to the general population, RA patients not exposed to biologicals had a fourfold increased risk of TB (HR 4.2; 95% CI 2.7 to 6.7), which did not decline over calendar time. In contrast, the risk of TB in the biological-exposed RA population decreased since 2002 compared with biological-naïve; from HR=7.9 (95% CI 3.3 to 18.9) in 2002–2006 to HR=2.4 (95% CI 0.9 to 6.1) in 2007–2011. The HRs for most recent exposure to adalimumab and infliximab compared with etanercept were 3.1 (95% CI 0.8 to 12.5) and 2.7 (95% CI 0.7 to 10.9), respectively, and the HR for etanercept compared with biological-naïve RA was 1.7 (95% CI 0.6 to 4.6).

Conclusions

In the past decade, the risk of TB has decreased among biological-exposed RA patients but remains higher than in biological-naïve RA patients. Most cases of TB in RA occur in biological-naïve RA patients, underscoring the elevated risk also in these patients.

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.

Patients with ulcerative colitis miss more days of work than the general population, even following colectomy

BACKGROUND & AIMS

It is unclear whether colectomy restores the ability of patients with ulcerative colitis (UC) to work to precolectomy levels. We estimated the burden of sick leave and disability pension in a population-based cohort of patients with UC and the effects of colectomy.

METHODS

We performed a register-based cohort study using the Swedish National Patient Register and identified working-age patients with UC in 2005 (n = 19,714) and patients who underwent colectomies between 1998 and 2002 (n = 807). Sick leave and disability pension data were retrieved from Statistics Sweden (1995-2005). Data from each patient in the study were compared with those from 5 age-, sex-, education-, and county-matched individuals from the general population.

RESULTS

In 2005, 15% of patients with prevalent UC received a disability pension, compared with 11% of the general population, and 21% vs 13% had ≥1 sick leave episode (P < .001 for each comparison). The annual median work days lost was 0 in both groups, but patients with UC had higher mean (65 vs 45 days; difference, 20; 95% confidence interval [CI], 18-22 days) and 75th percentile work days lost (37 vs 0 days; difference, 37; 95% CI, 36-38 days). Among patients who underwent colectomies, annual days lost increased from a mean of 40 (median, 0) days 3 years before surgery to 141 (median, 99) days during the year of surgery (P < .001). The number then decreased to a mean of 85 days 3 years after surgery (median, 0). The corresponding 75th percentile days were 17, 207, and 130, respectively. Three years after colectomy, 12% did not work at all compared with 7.2% of the general population (risk difference, 5.2%; 95% CI, 2.7%-7.7%) and compared with 5.9% 3 years before colectomy (P < .001).

CONCLUSIONS

Patients with UC miss more work days than the general population in Sweden. Although most patients had no registered work loss 3 years after colectomy, work loss was not restored to presurgery or general population levels in the group that underwent colectomy during several years of follow-up.

Exposure to ultraviolet-B and risk of developing rheumatoid arthritis among women in the Nurses' Health Study

OBJECTIVE

To examine the association between ultraviolet-B (UV-B) light exposure and rheumatoid arthritis (RA) risk among women in two large prospective cohort studies, the Nurses' Health Study (NHS) and the Nurses' Health Study II (NHSII).

METHODS

A total of 106 368 women from NHS, aged 30-55 years in 1976, and 115 561 women from NHSII, aged 25-42 in 1989, were included in the analysis. We identified women with incident RA from the start of each cohort until 2008 (NHS) and 2009 (NHSII). Cumulative average UV-B flux, a composite measure of ambient UV exposure based on latitude, altitude and cloud cover, was estimated according to state of residence and categorised as low, medium or high. Estimates of UV-B at birth and age 15 years were also examined. We used multivariable-adjusted Cox proportional hazards models to estimate HR and 95% CI.

RESULTS

1314 incident RA cases were identified in total. Among NHS participants, higher cumulative average UV-B exposure was associated with decreased RA risk; those in the highest versus lowest category had a 21% decreased RA risk (HR (95% CI); 0.79 (0.66 to 0.94)). UV-B was not associated with RA risk among younger women in NHSII (1.12 (0.87 to 1.44)). Results were similar for UV-B at birth and at age 15.

CONCLUSIONS

These results suggest that ambient UV-B exposure is associated with a lower RA risk in NHS, but not NHSII. Differences in sun-protective behaviours (eg, greater use of sun block in younger generations) may explain the disparate results.

Incidence of progressive multifocal leukoencephalopathy in patients with rheumatoid arthritis: a national population-based study

BACKGROUND

Cases of progressive multifocal leukoencephalopathy (PML), a rare but serious disease, have been reported in patients with rheumatoid arthritis (RA) in association with biological therapy, but little is known about the incidence of PML in patients with RA in the absence of treatment exposure.

OBJECTIVE

To estimate the incidence rate of PML in patients with RA compared with the general population, with and without exposure to biological agents.

METHODS

Patients with adult onset RA, exposure to biological agents and a diagnosis of PML from 1999 through 2009 were identified from national registries and linked using each Swedish resident's unique personal identification number. General population comparators matched on age, sex and county were also identified. Crude and age- and sex-standardised incidence rates (cases per 100 000 person-years) were calculated with 95% CI.

RESULTS

66 278 patients with RA and 286 949 general population comparators were included in the study. The incidence rate of PML in the overall RA population was 1.0 (95% CI 0.3 to 2.5) compared with 0.3 (95% CI 0.1 to 0.6) in the general population. The difference in incidence rate was 0.7 (95% CI -0.3 to 17). Among all patients exposed to biological agents, only one patient was diagnosed with PML.

CONCLUSION

Data from this national population-based cohort study suggest that patients with RA may have an increased rate of PML compared with the general population.

Is there a sex bias in prescribing anti-tumour necrosis factor medications to patients with rheumatoid arthritis? A nation-wide cross-sectional study

OBJECTIVES

To determine whether men and women with rheumatoid arthritis are prescribed anti-tumour necrosis factor (anti-TNF) treatment at different levels of disease activity.

METHODS

Data from the Swedish national biologics registry ARTIS were used to analyse characteristics of patients' disease at the start of the first anti-TNF treatment. Means for men and women were compared using t-tests, and non-normally distributed covariates were compared using the Wilcoxon rank-sum test. Linear regression models, adjusted for age and calendar year, were used to investigate the association between sex and each disease activity measurement.

RESULTS

Women were younger and had longer disease duration at treatment start than men. Tender joint count, erythrocyte sedimentation rate, patient's global assessment, patient-reported pain and health assessment questionnaire scores were significantly higher in women, whereas men had a higher level of C-reactive protein (p<0.05 for all comparisons). Swollen joint count and physician's global assessment did not differ by sex.

CONCLUSIONS

For women with rheumatoid arthritis, treatment with anti-TNF therapy was initiated at a higher level of subjective disease activity than for men, but at the same level of physician-reported disease activity. These data imply that patients' subjectively experienced disease activity may be discounted in the treatment decision.

A prospective study of periodontal disease and risk of rheumatoid arthritis

OBJECTIVE

To test for an association between periodontal disease (PD) and incident rheumatoid arthritis (RA) in a large prospective cohort.

METHODS

We conducted a prospective analysis of history of periodontal surgery, tooth loss, and risk of RA among 81,132 women in the Nurses' Health Study prospective cohort. Periodontal surgery and tooth loss were used as proxies for history of PD. There were 292 incident RA cases diagnosed from 1992 to 2004. Information on periodontal surgery and tooth loss in the past 2 years was collected by questionnaire in 1992. Cox proportional hazards models were used to assess relationships between periodontal surgery, tooth loss, and risk of RA adjusting for age, smoking, number of natural teeth, body mass index, parity, breastfeeding, postmenopausal status, postmenopausal hormone use, father's occupation, and alcohol intake.

RESULTS

Compared with those who reported no history of periodontal surgery or tooth loss, women with periodontal surgery or tooth loss did not have a significantly elevated risk of RA in multivariable-adjusted models (RR 1.24, 95% CI 0.83, 1.83; and RR 1.18, 95% CI 0.47, 2.95, respectively). In analyses stratified by ever and never-smokers, ever-smokers with periodontal surgery had an increased risk that was also nonsignificant. Those with severe PD (both history of periodontal surgery and tooth loss) did not have a significant increased risk.

CONCLUSION

In this large cohort of American women, there was no evidence of an increased risk of later-onset RA among those with a history of periodontal surgery and/or tooth loss.