Reporting of determinants of health inequities and participant characteristics in randomized controlled trials of systemic lupus erythematosus in Canada: A scoping review

OBJECTIVE

To report participant characteristics relevant to identifying health inequities in systemic lupus erythematosus (SLE) randomized controlled trials conducted in Canada.

METHODS

We conducted a scoping review by searching MEDLINE (Ovid) and Embase (1990 to June 2023), and CENTRAL (inception to June 2023). Eligible studies: used an RCT design; evaluated interventions (pharmacologic and non-pharmacologic) among SLE patients aged ≥18 years; and were conducted in Canada. Data extraction was guided by the Campbell and Cochrane Equity Methods Group's PROGRESS-Plus framework on 11 factors leading to health inequities (Place of residence; Race, culture, ethnicity, and language; Occupation; Gender and sex; Religion; Education; Socioeconomic status; Social capital; Plus: Personal characteristics associated with discrimination; Features of relationships; and Time-dependent relationships).

RESULTS

Of 1901 unique records, 6 met the inclusion criteria. Sex and age were the only PROGRESS factors that were reported in all studies. The majority of participants were female (84.4% to 100%), and mean ages of participants ranged from 42 to 52.3 years. Place of residence, race, education, and social capital were reported in three studies. Socioeconomic status was reported in two studies, and occupation was reported in one study. Religion, features of relationships, and time-dependent relationships were not reported in any included studies.

CONCLUSION

Limited reporting of determinants of health inequities in RCTs for SLE in Canada suggests the need for reporting standards to support equity, diversity, and inclusion practices in research.

OP0093 INCREASED RISK OF SEVERE INFECTIONS AND MORTALITY IN PATIENTS WITH NEWLY DIAGNOSED ANTINEUTROPHIL CYTOPLASMIC ANTIBODY ASSOCIATED VASCULITIS: A POPULATION-BASED STUDY

Background

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) are a group of multisystem inflammatory diseases of the small blood vessels, characterized by leukocytoclastic inflammation of small blood vessels and triggered by production of ANCA autoantibodies [1]. Due to the multiorgan involvement and relapsing nature, AAV is among the systemic autoimmune rheumatic diseases with the highest morbidity and mortality [1, 2].

Objectives

To evaluate the risk of severe infection and infection-related mortality among patients with newly diagnosed AAV.

Methods

We conducted an age- and gender- matched cohort study of all patients with incident AAV between January 1, 1997 and March 31, 2015 using administrative health data from British Columbia, Canada. Primary outcome was the first severe infection after AAV onset necessitating hospitalization or occurring during hospitalization. Secondary outcomes were total number of severe infections and infection-related mortality.

Results

We identified 549 AAV patients and matched them with 5,490 non-AAV individuals from the general population, yielding 184 and 509 first severe infections during 2,539 and 33,342 person-years follow-up, respectively. The crude incidence rate ratios for first severe infection and infection-related mortality were 5.03 (95% CI, 4.25-5.96) and 3.72 (95% CI, 2.44-5.67), respectively. The corresponding adjusted hazard ratios were 3.77 (95% CI 2.94-4.85) and 3.84 (95% CI, 2.13-6.91). AAV patients had an increased risk of a greater total number of severe infections with crude rate ratio of 4.99 (95% CI, 4.42-5.62) and adjusted rate ratio of 3.20 (95% CI, 2.73-3.74).

Conclusion

AAV is independently associated with increased risks of first severe infection (3.8-fold), a greater total number of severe infections (3.2-fold) and infection-related mortality (3.8-fold).

References

[1]Jennette JC, Falk RJ, Bacon PA, et al. 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. Arthritis Rheum 2013;65(1):1-11.

[2]Little MA, Nightingale P, Verburgh CA, et al. Early mortality in systemic vasculitis: relative contribution of adverse events and active vasculitis. Ann Rheum Dis 2010;69(6):1036-43.

Table 1.

Risk of severe infection in AAV relative to non-AAV during follow-up

Post-AAV diagnosis first severe infectionAAV cohortNon-AAV cohortN=549N=5,490No. of events184509IR per 1,000 person-years72.4614.40IRR (95% CI)5.03 (4.25-5.96)1Age and gender adjusted HR (95% CI)5.29 (4.43-6.31)1All but GC adjusted HR (95% CI)3.32 (2.67-4.13)1Fully adjusted HR* (95% CI)3.77 (2.94-4.85)1Post-AAV total number of severe infectionsInfection episodes396868IR per 1,000 person-years116.4223.35IRR (95% CI)4.99 (4.42-5.62)1Age and gender adjusted rate ratio (95% CI)5.27 (4.78-5.93)1All but GC adjusted rate ratio (95% CI)3.13 (2.72-3.59)1Fully adjusted rate ratio* (95% CI)3.20 (2.73-3.74)1Infection-related mortalityNo. of infection-related death events2985IR per 1,000 person-years8.532.29IRR (95% CI)3.72 (2.44-5.67)1Age and gender adjusted HR (95% CI)4.43 (2.89-6.79)1All but GC adjusted HR (95% CI)3.67 (2.14-6.31)1Fully adjusted HR* (95% CI)3.84 (2.13-6.91)1

Abbreviations: AAV, Antineutrophil cytoplasmic antibody-associated vasculitides; IR, incidence rate; IRR, incidence rate ratio; HR, hazard ratio; CI, confidence interval.

*Adjusted for baseline covariates. All but GC HRs represent the total effect while fully adjusted HRs represent the direct effect of AAV.

Disclosure of Interests

None declared.

POS0521 RISKS OF SEVERE INFECTION AFTER THE INTRODUCTION OF bDMARDs IN NEWLY DIAGNOSED RHEUMATOID ARTHRITIS PATIENTS: A POPULATION-BASED INTERRUPTED TIME-SERIES ANALYSIS

Background

Biological disease-modifying anti-rheumatic drugs (bDMARDs) are effective in suppressing inflammation and preventing joint damage. But bDMARDs may be associated with increased risk of severe infection. Evidence on this is contradictory with some studies showing increased risk, whereas others reporting no significant changes.

Objectives

To determine the impact of the introduction of bDMARDs on severe infection among patients newly diagnosed with RA compared with non-RA individuals.

Methods

In this age- and gender-matched cohort study using administrative health data for the population of BC, Canada, all incident RA patients diagnosed between 1995–2007 were identified. Non-RA individuals were randomly selected from the general control population to match with RA. Incident RA/non-RA individuals were then divided into quarterly cohorts according to their diagnosis date. Two outcomes were examined: (1) first severe infection (FSI) after RA onset necessitating hospitalization or occurring during hospitalization; and (2) all severe infections (ASI) after RA onset. We calculated the 8-year FSI and ASI rate for each cohort. We conducted interrupted time-series analyses to compare levels and trends of FSI and ASI in RA and non-RA individuals diagnosed during pre-bDMARDs (1995–2001) and post-bDMARDs (2003–2007) periods. Adjusted 8-year FSI and ASI rates for RA and non-RA cohorts diagnosed five years after bDMARDs introduction were compared with expected rates assuming no bDMARDs introduction, based on extrapolation of pre-bDMARDs trends.

Results

A total of 60,226 and 588,499 incident RA/non-RA individuals were identified. We identified 8,954 FSI and 14,245 ASI in RA, and 56,153 FSI and 79,819 ASI in non-RA. The 8-year FSI rates among RA patients diagnosed in the pre-bDMARDs period decreased over time but leveled off among those diagnosed in the post-period (Figure 1). The adjusted difference between the post- and pre-bDMARDs secular trends of 8-year FSI rates was 0.68 (p=0.03) in RA and 0.03 (p=0.67) in non-RA (Table 1). The 8-year ASI rates among RA patients diagnosed in the pre-bDMARDs period decreased over time but increased significantly among those diagnosed in the post-period (Figure 1). The adjusted difference between the post- and pre-bDMARDs secular trends of 8-year ASI rates was 1.85 (p=0.001) in RA and 0.12 (p=0.29) in non-RA (Table 1). For RA cohort diagnosed 5 years after bDMARDs introduction, ASI rate increased by 20.4% than expected rates assuming no bDMARDs introduction. In contrast, ASI rate in non-RA increased by only 10.9%.

Table 1.

Results of interrupted time-series analysis of FSI/ASI rates, adjusting for age, gender, chronic obstructive pulmonary disease, Romano Charlson Comorbidity Index, diabetes, chronic kidney diseases, alcoholism, cancer, prior hospitalization with infection and socio-economic status at disease diagnosis year, using stepwise model selection

OutcomeParameterRANon-RAUnadj. Diff (95% CI)Adj. Diff (95% CI)Unadj. Diff (95% CI)Adj. Diff (95% CI)p-valuep-valuep-valuep-valueFSITrend0.63 (0.03, 1.22) 0.04410.68 (0.09, 1.27) 0.02920.08 (-0.08, 0.25) 0.32370.03 (-0.12, 0.19) 0.6728Level (1 year post-intervention)0.50 (-2.00, 2.99) 0.69890.31 (-1.88, 2.49) 0.78470.41 (-0.21, 1.03) 0.20410.26 (-0.24, 0.75) 0.31035 years post-intervention3.01 (-0.85, 6.87) 0.13313.02 (-0.48, 6.52) 0.09860.75 (-0.24, 1.73) 0.14330.39 (-0.46, 1.25) 0.3721ASITrend1.84 (0.83, 2.84) 0.00091.85 (0.81, 2.89) 0.00110.28 (0.04, 0.53) 0.03050.12 (-0.10, 0.34) 0.2877Level (1 year post-intervention)-1.21 (-5.41, 3.00) 0.5763-1.44 (-5.44, 2.56) 0.48501.46 (0.42, 2.49) 0.00851.20 (0.38, 2.02) 0.00645 years post-intervention6.14 (0.26, 12.01) 0.04665.97 (0.02, 11.93) 0.05602.60 (1.08, 4.12) 0.00171.69 (0.45, 2.92) 0.0109Figure 1.

Unadjusted rates.

Conclusion

Arthritis onset after bDMARDs introduction is associated with an elevated risk of severe infection in RA patients, compared with matched non-RA individuals.

Acknowledgements

We would like to thank the Ministry of Health of British Columbia and Population Data BC for providing access to the administrative data. All inferences, opinions, and conclusions drawn in this publication are those of the authors, and do not reflect the opinions or policies of the Data Stewards or the [British Columbia] Ministry of Health. No personal identifying information was made available as part of this study. Procedures used were in compliance with British Columbia’s Freedom in Information and Privacy Protection Act. Ethics approval was obtained from the University of British Columbia’s Behavioral Research Ethics Board (H15-00887).

Disclosure of Interests

None declared.

POS0503 RISKS OF CARDIOVASCULAR EVENTS AFTER THE INTRODUCTION OF bDMARDs IN NEWLY DIAGNOSED RHEUMATOID ARTHRITIS PATIENTS: A POPULATION-BASED INTERRUPTED TIME-SERIES ANALYSIS

Background

Rheumatoid arthritis (RA) is associated with increased risk of cardiovascular (CV) events. Biological disease-modifying anti-rheumatic drugs (bDMARDs) are effective in suppressing inflammation and preventing joint damage and may help lower the risk of CV events. However, recent epidemiological studies have shown mixed results with some suggesting a lower risk of CV events, while others reporting no significant differences.

Objectives

To determine the impact of the introduction of bDMARDs on incident cardiovascular disease (CVD) among patients newly diagnosed with RA compared with matched non-RA individuals.

Methods

In this age- and gender-matched cohort study using administrative health data for the population of BC, Canada, all incident RA patients diagnosed between 1995–2007 were identified. Non-RA individuals were randomly selected from the general control population to match with RA. Incident RA and non-RA individuals were then divided into quarterly cohorts according to their diagnosis date. The outcome of interest was incident CVD event after RA onset, which include acute myocardial infarction, cerebrovascular accident, and venous thromboembolism. We calculated the 8-year incident CVD rate for each cohort. We conducted interrupted time-series analyses to compare levels and trends of CVD in RA and non-RA individuals diagnosed during pre-bDMARDs (1995–2001) and post-bDMARDs (2003–2007) periods with intervention time set at year of 2002. Adjusted 8-year CVD rates for RA and non-RA cohorts diagnosed five years after bDMARDs introduction were compared with expected rates assuming no bDMARDs introduction, based on extrapolation of pre-bDMARDs trends.

Results

A total of 60,226 and 588,499 incident RA and non-RA individuals were identified. We identified 6,740 and 48,653 incident CVD events in total in RA and non-RA individuals, respectively. We observe no change in the secular trends of the 8-year CVD rates in both RA and non-RA individuals diagnosed in pre- and post-bDMARDS periods (Figure 1): the adjusted difference between the post- and pre-bDMARDs secular trends of 8-year CVD rates was 0.23 (p=0.26) for RA patients and -0.07 (p=0.33) for non-RA individuals (Table 1). However, we observed a reduction in the level of CVD rates among RA patients diagnosed in the post-bDMARDs period and no change in non-RA (Figure 1): the adjusted difference in level comparing points immediately before and after the intervention, and accounting for pre-intervention trend was -1.61 (p=0.03) in RA, while it was -0.02 (p=0.93) in non-RA (Table 1).

Table 1.

Results of interrupted time-series analysis of incident CVD rates, adjusting for age, gender, chronic obstructive pulmonary disease, Romano Charlson Comorbidity Index, diabetes, angina, hypertension, chronic kidney disease, peripheral vascular disease, atrial fibrillation, glucocorticoid, non-steroidal anti-inflammatory drugs, CVD medications, fibrates, contraceptives, and aspirin use at disease diagnosis year, using stepwise model selection

OutcomeParameterRANon-RAUnadj. Diff (95% CI)Adj. Diff (95% CI)Unadj. Diff (95% CI)Adj. Diff (95% CI)p-valuep-valuep-valuep-valueCVDTrend-0.15 (-0.72, 0.42) 0.60860.23 (-0.17, 0.64) 0.2620-0.09 (-0.27, 0.08) 0.3084-0.07 (-0.20, 0.07) 0.3290Level (1 year post-intervention)-1.36 (-3.17, 0.45) 0.1474-1.61 (-2.96, -0.25) 0.02510.22 (-0.41, 0.84) 0.5011-0.02 (-0.44, 0.40) 0.93455 years post-intervention-1.96 (-4.48, 0.55) 0.1332-0.67 (-2.80, 1.46) 0.5418-0.15 (-1.06, 0.75) 0.7421-0.29 (-0.97, 0.39) 0.4102Figure 1.

Unadjusted rates.

Conclusion

Arthritis onset after bDMARDs introduction is associated with a significant reduction in the risk of incident CVD events among RA patients, but not in the matched non-RA individuals.

Acknowledgements

We would like to thank the Ministry of Health of British Columbia and Population Data BC for providing access to the administrative data. All inferences, opinions, and conclusions drawn in this publication are those of the authors, and do not reflect the opinions or policies of the Data Stewards or the [British Columbia] Ministry of Health. No personal identifying information was made available as part of this study. Procedures used were in compliance with British Columbia’s Freedom in Information and Privacy Protection Act. Ethics approval was obtained from the University of British Columbia’s Behavioral Research Ethics Board (H15-00887).

Disclosure of Interests

None declared.

OP0054 REDUCING THE BURDEN OF LOW BACK PAIN: RESULTS FROM A NEW MICROSIMULATION MODEL

Background

Low back pain (LBP) has been the leading cause of disability worldwide for the past 30 years. In 2019, LBP was responsible for 64 million years lived with disability (YLDs) [1].

Objectives

The purpose of the present study was to project and compare the impact of three strategies for reducing the population health burden of LBP: weight loss, ergonomic interventions, and an exercise program.

Methods

We have developed a microsimulation model of LBP in Canada using a novel simulation platform, SimYouLate. The initial population was derived from Cycle 1 (2001) of the Canadian Community Health Survey (CCHS). We modeled an open population 20 years of age and older. Key variables included age, sex, education, body mass index (BMI), type of work, having a back problem, pain level in persons with back problems, and exercise. The effects of interventions on the risk of LBP were obtained from the CCHS for the effect of BMI, the Global Burden of Disease Study for occupational risks, and a published meta-analysis for the effect of exercise. All interventions lasted from 2021 to 2040. Strength of the interventions varied over a wide range. YLDs were defined as LBP prevalence multiplied by disability weight. The population health impact of the interventions was calculated as a difference in YLDs between the base-case scenario and each intervention scenario and expressed as YLDs averted per intervention unit and as % of total LBP-related YLDs.

Results

In the base-case scenario, LBP in 2020 was responsible for 424,900 YLDs in Canada and the amount increased to 460,312 YLDs in 2040. The effects of the interventions on YLDs were as follows: 27,993 (95% CI 23,373, 32,614) YLDs averted over 20 years per 0.1 unit change in log-transformed BMI (10.5% change in BMI) among overweight and obese individuals, 19,416 (16,275, 22,557) YLDs averted per 1% reduction in the proportion of workers exposed to occupational risks, and 26,058 (22,455, 29,661) YLDs averted per 1% increase in the proportion of eligible patients with back problems participating in the exercise program. Table 1 shows the intervention impact as % of total LBP-related YLDs and Figure 1 shows YLD-equivalence between the interventions. A one unit reduction in BMI per year among the overweight and obese individuals would be approximately equivalent in terms of disability reduction to an effective ergonomic intervention in 35% of at-risk workers and an exercise intervention in 27% of eligible patients with back problems over the same period (Figure 1).

Table 1.

YLDs averted between 2021 and 2040 as % of total LBP-related YLDs, according to intervention type and level, in persons aged 20+ in Canada

InterventionEffect (%)95% LCL95% UCLReduction in BMI per year0.11.4-1.44.10.34.82.27.30.56.33.98.81.08.56.011.03.011.99.414.45.013.510.916.0Reduction in occupational exposure20%5.21.98.540%9.56.412.760%13.810.616.980%18.114.821.4100%22.418.825.9Increase in exercise participation20%6.62.810.440%12.48.716.060%18.114.521.780%23.920.127.6100%29.625.533.7

LCL: lower confidence limit. UCL: upper confidence limit.

Figure 1.

Equivalence between BMI, ergonomic and exercise interventions in terms of their impact on YLDs. Each point represents a specific number of YLDs averted. Values on the y-axis show reduction in % of workers at risk and increase in % exercising that are required to achieve the same reduction in YLDs as the corresponding reduction in BMI shown on the x-axis.

Conclusion

This is the first population-based microsimulation study to compare currently available preventive strategies in LBP in terms of YLDs averted and to provide measures of equivalence between these strategies.

References

[1]Hartvigsen J, Hancock MJ, Kongsted A, et al. What low back pain is and why we need to pay attention. Lancet 2018;391(10137):2356-2367.

Acknowledgements

The study was supported by a grant from the Canadian Institutes for Health Research (FRN 142440).

Disclosure of Interests

None declared.

OP0248 SEVERE COVID-19 OUTCOMES AMONG PATIENTS WITH AUTOIMMUNE RHEUMATIC DISEASES: A POPULATION-BASED STUDY

Background

Individuals with autoimmune rheumatic diseases (ARDs) may be at greater risk of severe COVID-19 outcomes than individuals in the general population.

Objectives

This study assesses the risk of COVID-19-related hospitalization, intensive care unit (ICU) admission, and COVID-19-specific mortality in patients with ARDs compared to matched general population comparators.

Methods

We conducted a population-based cohort study, using administrative datasets from British Columbia, Canada (February 2020-August 2021). Among all test-positive SARS-CoV-2 adults, we used ICD codes to identify all individuals with an ARD: rheumatoid arthritis (RA), psoriasis/psoriatic arthritis (PsO/PsA), ankylosing spondylitis (AS), and systemic autoimmune rheumatic diseases (SARDs), including systemic lupus erythematosus (SLE), Sjogren’s syndrome, systemic sclerosis, myositis, and adult systemic vasculitides. Individuals with an ARD were matched 1:5 to general population test-positive SARS-CoV-2 individuals on age (± 5 years), sex, month/year of initial positive SARS-CoV-2 test, and health authority. Conditional logistic regression models adjusting for socioeconomic status, Charlson comorbidity index, hypertension, rural address, and number of previous COVID-19 PCR tests were performed to assess risk of COVID-19-related hospitalizations, ICU admissions, and COVID-19-specific mortality (mortality with primary ICD code for COVID-19).

Results

The risk of COVID-19-related hospitalization was significantly increased for patients with ARDs overall (aOR: 1.30) (Table 1). Within ARDs, the patient group at greatest risk of hospitalization was adult systemic vasculitides (aOR: 2.18). The risk of ICU admission was significantly increased for patients with ARDs overall (aOR: 1.30). Within ARDs, the patient group at greatest risk of ICU admission was those with AS (aOR: 2.03). The risk of COVID-19-specific mortality was significantly increased for patients with ARDs overall (aOR: 1.24). Within ARDs, the patient group at greatest risk of COVID-19-specific mortality was those with AS (aOR: 2.15).

Table 1.

Risk of severe COVID-19 outcomes among patients with ARDs

HospitalizationsICU admissionsCOVID-19-specific mortalityn (%)aOR (95% CI)n (%)aOR (95% CI)n (%)aOR (95% CI)ARDs (6,279)780 (12.4)1.30 (1.19, 1.43)225 (3.6)1.30 (1.11, 1.51)229 (3.7)1.24 (1.05, 1.47)ARD comparators (31,130)2,843 (9.1)1.00807 (2.6)1.00847 (2.7)1.00RA(2,067)321 (15.5)1.34 (1.15, 1.54)95 (4.6)1.30 (1.03, 1.65)103 (5.0)1.18 (0.92, 1.52)RA comparators (10,197)1,151 (11.3)1.00336 (3.3)1.00400 (3.9)1.00PsO/PsA(2,695)263 (9.8)1.17 (1.01, 1.37)65 (2.4)0.90 (0.68, 1.19)68 (2.5)0.93 (0.68, 1.26)PsO/PsA comparators (13,411)1,052 (7.8)1.00332 (2.5)1.00309 (2.3)1.00AS(529)51 (9.6)1.36 (0.95, 1.94)20 (3.8)2.03 (1.18, 3.50)13 (2.5)2.15 (1.02, 4.55)AS comparators (2,631)180 (6.8)1.0048 (1.8)1.0032 (1.2)1.00SARDs(1,118)168 (15.0)1.62 (1.32, 2.00)52 (4.7)1.74 (1.24, 2.44)49 (4.4)1.44 (1.00, 2.10)SARDs comparators (5,532)490 (8.9)1.00135 (2.4)1.00157 (2.8)1.00SLE(239)37 (15.5)1.88 (1.18, 3.00)11 (4.6)1.67 (0.75, 3.74)<50.85 (0.17, 4.29)SLE comparators (1,187)77 (6.5)1.0026 (2.2)1.0013 (1.1)1.00Sjogren’s(96)15 (15.6)2.07 (0.94, 4.58)<5*<5*Sjogren’s comparators (477)35 (7.4)1.0014 (2.9)1.0015 (3.2)1.00Myositis(30)5 (16.7)3.18 (0.69, 14.55)<5*<5*Myositis comparators (150)12 (8.0)1.00<51.007 (4.7)1.00Vasculitides(82)25 (30.5)2.18 (1.17, 4.05)8 (9.8)1.70 (0.70, 4.16)<5*Vasculitides comparators (404)64 (15.8)1.0021 (5.2)1.0016 (4.0)1.00

Results for systemic sclerosis not presented; sample size too small.

*Unable to be calculated (small sample size)

Conclusion

The risk of severe COVID-19 outcomes is increased in some ARDs, although magnitude differs across individual diseases. Strategies to mitigate risk, such as booster vaccination, prompt diagnosis, and early intervention with available therapies (e.g., oral antivirals) should be prioritized in these groups according to risk.

Acknowledgements

This work was supported by the Michael Smith Foundation for Health Research (grant COV-2020-1075) and the BC SUPPORT Unit (grant C19-PE-V3).

Disclosure of Interests

None declared

OP0039 RISK OF ARRHYTHMIA AMONG NEW USERS OF HYDROXYCHLOROQUINE: A LONGITUDINAL POPULATION-BASED COHORT STUDY ON NEWLY DIAGNOSED RHEUMATOID ARTHRITIS AND SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS

Background

Previous findings on hydroxychloroquine (HCQ) use and the risk of arrhythmia are contradictory and low-level evidence-based results. Additional research is required to evaluate the safety profile of HCQ to arrhythmia in managing rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

Objectives

To assess the association between HCQ initiation and risk of incident arrhythmia among newly diagnosed RA and SLE patients.

Methods

All patients with incident RA or SLE and no arrhythmic events or anti-arrhythmic medications and no HCQ use prior to disease index date in British Columbia, Canada, between January 1997 and March 2015 were identified using administrative databases. HCQ initiator and HCQ non-initiator groups were identified and matched 1:1 by propensity scores using baseline confounders on demographics including presence of RA or SLE disease and duration of disease prior to the index date of HCQ initiators or non-initiators, comorbidities, other medications, and healthcare utilization. Matching was done within the same calendar year to account for a potential secular trend in HCQ use and risk of arrhythmia. Outcomes were any new arrhythmias, atrial fibrillation, abnormal electrocardiogram including prolonged QT syndrome and conduction disorder, and other unspecified arrhythmias during follow-up. We used Cox proportional hazard models with death as a competing event to assess the association of HCQ initiation and the outcomes.

Results

We identified 11,518 HCQ initiators (10,655 RA and 863 SLE patients, mean ± SD age 55.9 ± 15.1 years, 76.1% female) and 11,518 HCQ non-initiators (10,639 RA and 879 SLE patients, mean ± SD age 56.0 ± 16.2 years, 76.4% female) after 1:1 propensity score matching. Over the mean follow-up of eight years, there were 1,610 and 1,646 incident arrhythmias in the HCQ initiator and non-initiator groups, respectively. The crude incidence rates of arrhythmia were 17.5, and 18.1 per 1,000 person-years, respectively. Cumulative risk of incident arrhythmia remained similar for both groups. (Figure 1). Adjusted hazard ratio (aHR) of incident arrhythmia from the Cox proportional hazard model for HCQ initiators was 0.99 (95% CI: 0.92-1.06) compared to non-initiators (Table 1). The corresponding aHRs for HCQ initiators in subtypes of arrhythmia – atrial fibrillation, abnormal electrocardiogram, and other unspecified arrhythmias were 0.95 (95% CI: 0.84-1.06), 1.04 (95% CI: 0.87-1.26), and 0.96 (95% CI: 0.86-1.08), respectively.

Table 1.

Incident arrhythmias of any type among RA and SLE patients initiating HCQ prescription compared with HCQ non-initiators

HCQ initiatorHCQ non-initiatorParticipants (number)11,51811,518Mean follow-up (years)8.007.89Events (number)1,6101,646Crude incidence rate per 1000 person-years17.4818.12Unadjusted HR (95% CI)0.98 (0.91-1.05)1.00 (reference)Adjusted# HR (95% CI)0.99 (0.92-1.06)1.00 (reference)

Abbreviations: HCQ, hydroxychloroquine; HR, hazard ratio.

#The multivariable Cox proportional hazard model was adjusted for baseline confounders on demographics, comorbidities, medications, and healthcare utilization.

Figure 1.

Cumulative risk of incident arrhythmias for HCQ initiators and non-initiators over the follow-up time.

Conclusion

There is no increased risk of any type of arrhythmia among new users of HCQ in RA and SLE patients. We believe the results of this large cohort study will add to the confidence with which HCQ can be used in RA and SLE management.

Disclosure of Interests

None declared.

RetINal Toxicity And HydroxyChloroquine Therapy (INTACT): protocol for a prospective population-based cohort study

PURPOSE

Hydroxychloroquine (HCQ) is an important medication for patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and other rheumatic diseases. Although it is well-tolerated and cost-effective, the risk of HCQ retinal toxicity is of increasing concern. The aim of this study is to re-examine the HCQ retinal toxicity incidence rate, risk factors and clinical course after discontinuation.

METHODS

We designed a prospective population-based cohort study in adult patients with SLE or RA, currently receiving HCQ for five or more years, who are residents of British Columbia (BC), Canada. Based on administrative data, we identified 5508 eligible participants (1346 SLE and 4162 RA). They will participate in annual or biannual retinal screening over 5 years in alignment with the recently revised American Academy of Ophthalmology guidelines. To standardise procedures for retinal screening, imaging, diagnostic criteria, severity staging and data transfer, a consensus meeting was convened in December 2019 with participation of BC retinal specialists and the research team. Agreement was attained on: use of spectral domain-optical coherence tomography as the primary objective screening modality; classification of images into categories of normal, equivocal or abnormal; and transferring the equivocal and abnormal images plus corresponding subjective test results via cloud-based server from each clinic to a reading centre. Confirmation of HCQ retinal toxicity diagnoses and severity staging will be performed by three independent and masked reviewers. The incidence of HCQ retinal toxicity will be calculated, accounting for the competing risk of death. Hazard ratios for each risk factor will be calculated for the risk of HCQ retinopathy, after adjusting for confounders. We will also estimate the risk of HCQ retinal toxicity progression over 5 years.

ETHICS AND DISSEMINATION

This study has received approval from the University of British Columbia Clinical Research Ethics Board (H20-00736) and the Vancouver Coastal Health Research Institute.

Has the incidence of total joint arthroplasty in rheumatoid arthritis decreased in the era of biologics use? A population-based cohort study

OBJECTIVES

To determine whether the introduction of biological disease-modifying anti-rheumatic drugs (bDMARDs) was associated with reduced incidences of total hip and knee arthroplasty (THA/TKA) among patients with rheumatoid arthritis (RA) compared with osteoarthritis (OA).

METHODS

Using a population-based cohort in British Columbia, Canada, RA and OA patients diagnosed between 1995-2007 were divided into semi-annual cohorts according to diagnosis date. For each cohort, we calculated 8-year incidence rates of THA and TKA. We compared levels and trends of THA/TKA incidence in RA/OA patients diagnosed during pre-bDMARDs (1995-2001) and post-bDMARDs (2003-2007) periods using interrupted time-series analysis, adjusting for baseline characteristics. Adjusted 8-year TJA incidence estimated for RA/OA cohorts diagnosed five years after bDMARDs introduction were compared with expected rates assuming no bDMARDs introduction, based on extrapolation of pre-bDMARDs trends.

RESULTS

We identified 60,227 RA and 288,260 OA incident cases. For cohorts diagnosed pre-bDMARDs, 8-year THA/TKA incidence rates increased over time in both RA and OA. For cohorts diagnosed post-bDMARDs, these rates decreased over time in RA but continued to increase for OA. For RA, differences between the post- and pre-bDMARDs secular trends in incidence rates were -0.49 (p = 0.002) for THA and -0.36 (p = 0.003) for TKA, compared to + 0.40 (p = 0.006) and +0.54 (p < 0.001), respectively, for OA. For RA cohorts diagnosed five years after bDMARDs introduction, 8-year incidence were 26.9% and 12.6% lower for THA and TKA, respectively, than expected rates. In contrast, corresponding rates in OA were higher by 11.7% and 16.6%, respectively.

CONCLUSION

Arthritis onset after bDMARDs introduction is associated with a significant reduction in THA/TKA incidence in RA, but not in OA. The reduction reflects a significant improvement in RA treatment during the biological era.

Hydroxychloroquine and Mortality Among Patients With Systemic Lupus Erythematosus in the General Population

OBJECTIVE

Hydroxychloroquine (HCQ) has been associated with improved survival among patients with systemic lupus erythematosus (SLE) from tertiary referral centers. We aimed to determine the potential impact of HCQ use on the risk of mortality among SLE patients in the general population.

METHODS

We conducted a nested case-control study within an incident SLE cohort from the entire population of British Columbia, Canada. Deceased patients were matched with up to 3 living controls by age, sex, and SLE disease duration. HCQ exposure was categorized by the time between the last HCQ prescription date covered (i.e., end of supply) and the index date (i.e., death date) as current (<30 days), recent (30-365 days), remote (>365 days), or never used. We used conditional logistic regression to assess the risk of all-cause mortality associated with current or recent HCQ exposure compared with remote HCQ users.

RESULTS

Among 6,241 patients with incident SLE, we identified 290 deceased patients and 502 matched SLE controls. Adjusted odd ratios for all-cause mortality were 0.50 (95% confidence interval [95% CI] 0.30-0.82) for current users and 2.47 (95% CI 1.21-5.05) for recent users compared with remote users. Associations were similar in subgroups according to SLE duration (≤5 years versus >5 years).

CONCLUSION

Our general population data support a substantial survival benefit associated with current HCQ use. Increased mortality among patients who had discontinued HCQ recently could be due to a sick stopper effect or the loss of actual HCQ benefits.

POS0303 PREVENTION OF CHRONIC DISEASES DUE TO INFLAMMATION IN INFLAMMATORY ARTHRITIS: RESULTS OF A DELPHI PROCESS TO SELECT CARE RECOMMENDATIONS FOR AN ELECTRONIC MEDICAL RECORD (EMR) INTERVENTION

Background:

Inflammatory arthritis (IA) predisposes patients to several chronic conditions including cardiovascular diseases (CVD), diabetes (DM), osteoporosis (OP) and infections, likely due to systemic effects of inflammation. Studies have found that patients with IA often receive suboptimal care for screening and managing these conditions.

Objectives:

This is the first phase of a study which will develop and pilot test automated EMR reminders for family physicians. The reminders will prompt family physicians to screen for and address risk factors for these conditions. We conducted a Delphi process to select care recommendations to be addressed by the EMR reminders.

Methods:

We conducted a review of current BC, Canadian and international guidelines for screening and addressing risk factors for CVD, DM, OP and infection. A list of 22 care recommendations, including their level of evidence and risks/benefits of implementation, was reviewed by a panel of six family physicians, three rheumatologists and three IA patients, in a three-round online modified Delphi process. Panelists rated each care recommendation, using 9-point scales, on 1) their clinical importance, 2) their likelihood of improving outcomes, and 3) implementation feasibility. Results were discussed in an online forum. Panelists then rated slightly revised care recommendations, modified based on feedback from the discussion. Care recommendations were retained if the median rating was ≥7 with no disagreement as defined by the RAND/UCLA Method handbook.

Results:

A list of 15 care recommendations was selected by the Delphi process for EMR integration, including recommendations that address CVD risk assessment (1), hypertension screening (1), DM screening (2), fracture risk assessment (1), BMD testing (1), osteoporosis prevention (1) and treatment (1) with bisphosphonates, preventing infections through immunization (2), minimizing steroids (1) and hepatitis screening (1), screening for hydroxychloroquine retinal toxicity (1), and counselling for lifestyle modifications (2). We excluded 7 recommendations which addressed lipid testing (1), BMD testing in steroid users (1), immunizations (2), weight management (1), and DMARD laboratory test monitoring (2). Recommendations were excluded on the basis of importance (1) or feasibility (6).

Conclusion:

The results of the Delphi process will inform the development of reminders, integrated in EMRs, that will support family physicians in their efforts to engage IA patients in addressing risk factors for chronic diseases related to inflammation. We hope to improve the prevention of these diseases, which represent an important cause of morbidity and mortality for people with inflammatory arthritis.

Acknowledgements:

Iman Sheriff’s work on this project was funded by the CRA summer studentship programme. Dr. Lacaille is supported by the Mary Pack Chair in Arthritis Research from UBC and The Arthritis Society of Canada. Thank you to all who participated in the Delphi survey.

Disclosure of Interests:

None declared

OP0043 INCREASED RISK OF SEVERE INFECTIONS AND MORTALITY IN PATIENTS WITH NEWLY DIAGNOSED SYSTEMIC LUPUS ERYTHEMATOSUS: A POPULATION-BASED STUDY

Background:

Systemic lupus erythematosus (SLE) is a chronic disease with a broad spectrum of autoantibodies and clinical manifestations. As much as 45% of SLE patients were reported to suffer from severe infections1,2. However, due to the high cost of recruiting patients, we still do not have a holistic picture of the SLE-infection association. Administrative data which encompass all provincially funded healthcare service data shows promising opportunities to advance the knowledge and management of the SLE patients which cannot be evaluated by the conventional clinical setting with small sample size and selective samples3,4,5.

Objectives:

To evaluate the risk of severe infection and infection-related mortality among patients with newly diagnosed systemic lupus erythematosus.

Methods:

We conducted an age- and gender- matched cohort study of all patients with incident SLE between January 1, 1997 and March 31, 2015 using administrative health data from British Columbia, Canada. Primary outcome was the first severe infection after SLE onset necessitating hospitalization or occurring during hospitalization. Secondary outcomes were total number of severe infections and infection-related mortality.

Results:

We identified 5,169 SLE patients and matched them with 25,845 non-SLE individuals from the general population, yielding 955 and 1,986 first severe infections during 48,367 and 260,712 person-years follow-up, respectively. The crude incidence rate ratios for first severe infection and infection-related mortality were 2.59 (95% CI, 2.39-2.80) and 2.20 (95% CI, 1.76-2.73), respectively. The corresponding adjusted hazard ratios were 1.82 (95% CI 1.66-1.99) and 1.61 (95% CI, 1.24-2.08). SLE patients had an increased risk of a greater total number of severe infections with crude rate ratio of 3.24 (95% CI, 3.06-3.43) and adjusted rate ratio of 2.07 (95% CI, 1.82-2.36).

Conclusion:

SLE is associated with increased risks of first severe infection (1.8-fold), a greater total number of severe infections (2.1-fold) and infection-related mortality (1.6-fold).

References:

[1]Yurkovich M, Vostretsova K, Chen W, Aviña-Zubieta JA. Overall and cause-specific mortality in patients with systemic lupus erythematosus: a meta-analysis of observational studies. Arthritis Care Res (Hoboken) 2014;66(4):608-16.

[2]Petri M. Infection in systemic lupus erythematosus. Rheum Dis Clin North Am 1998;24(2):423-56.

[3]Cervera R, Khamashta MA, Font J, et al. Morbidity and mortality in systemic lupus erythematosus during a 10-year period: a comparison of early and late manifestations in a cohort of 1,000 patients. Medicine (Baltimore) 2003;82(5):299-308.

[4]Goldblatt F, Chambers S, Rahman A, Isenberg DA. Serious infections in British patients with systemic lupus erythematosus: hospitalisations and mortality. Lupus 2009;18(8):682-9.

[5]Bosch X, Guilabert A, Pallares L, et al. Infections in systemic lupus erythematosus: a prospective and controlled study of 110 patients. Lupus 2006;15(9):584-9.

Disclosure of Interests:

None declared

SAT0605 TRENDS OF TOTAL JOINT ARTHROPLASTY AMONG PATIENTS WITH OSTEOARTHRITIS, RHEUMATOID ARTHRITIS AND ANKYLOSING SPONDYLITIS IN BRITISH COLUMBIA, CANADA, 1998-2013

Background:

Total joint replacement or arthroplasty (TJA) is an expensive surgical treatment for severe arthritis when other treatments have failed. Given the substantial changes in the available treatments over the past 2 decades, it is of interest to describe the trends in the use of TJA among patients with different types of arthritis in the general population.

Objectives:

The aim of this study was to examine longitudinal trends of TJA including total hip, knee and shoulder replacement performed in British Columbia, Canada, between the year of 1998 and 2013 due to three different types of arthritis conditions:1) Osteoarthritis (OA), 2) Rheumatoid arthritis (RA) and 3) Ankylosing spondylitis (AS).

Methods:

We analyzed large, population-based administrative data obtained from Population Data BC that includes patients aged 20+ in B.C., Canada, linked to diagnostic codes of hospitalizations and physician visits. Using the Canadian Classification of Diagnostic, Therapeutic and Surgical Procedures (CCP) procedure codes and the Canadian Classification of Health Intervention (CCI) procedure codes, we identified total joint arthroplasty procedures (TJA) including total hip arthroplasty (THA), total knee arthroplasty (TKA) and total shoulder arthroplasty (TSA) performed among OA, RA and AS prevalent cases. We calculated annual rates of THA, TKA and TSA performed among OA, RA and AS patients. We divided the study period into four equal-length periods and calculated period prevalence rates of THA, TKA and TSA per 100,000 person years as the ratio of the number of cases per period (numerator) to the total follow up time within the same period (denominator). We performed trend tests to test if there are changes in these rates over time.

Results:

For OA and RA, TKA was the most common types of TJA performed, while THA remained to be the most common types of TJA performed among AS patients. For OA, period prevalence rate of THA, TKA and TSA increased during the study period (Table 1.). For RA patients, THA and TKA rates showed a decreasing trend. For AS patients, THA rates decreased and TSA increased. For RA and AS, TSA rates did not show a significant trend.

Table 1.

Trends in arthroplasty rates (cases per 100,000 person years) among patients with OA, RA and AS by arthroplasty site.

Period1998-20012002-20052006-20092010-2013Period Trend (P†)Among OA patients THA816.26920.621035.51947.030.05459 (0.0002) TKA1024.71244.711653.891475.440.13114 (<0.0001) TSA25.9632.0143.253.920.2495 (0.0007)Among RA patients THA79.5355.6346.3133.11-0.28321 (<0.0001) TKA131.66111.99106.0874.79-0.16765 (0.0001) TSA19.4416.6213.7713.13-0.1391 (0.221)Among AS patients THA89.0176.7510.0215.48-0.6753 (<0.0001) TKA<5<5<57.740.6263 (0.0178) TSA<5<5<5<5-0.4196 (0.354)

†Pvalues were derived in Poisson regression analysis.

Among patients with OA, annual TJA rates per 100,000 persons show an overall increasing trend. The TJA rates remained relatively flat from 1998 to 2003, started to increase and peaked in 2006, and declined slightly thereafter (Figure 1.). Among patients with inflammatory arthritis (RA and AS), annual TJA rates decreased over the study period (Figure 1.). Annual proportion of TJA perfromed due to inflammatory arthritides significantly decreased from 1998 to 2013 (4.3% versus 1.0%) (Figure 2.).

Conclusion:

There have been important changes in the annual rate of total joint replacement in B.C., Canada, during the study period from 1998 to 2013. TJA use increased in OA patients but decreased in patients with inflammatory arthritis (RA and AS). Effective treatment for inflammatory arthritis, such as TNF-α inhibitors introduced in British Columbia in 2001-2002, may have effectively reduced the need for arthroplasty in RA and AS.

Acknowledgments:

This study was supported by CIHR (team grant THC-135235), and NSERC (RGPIN-2018-04313).

Disclosure of Interests:

None declared

SAT0242 REGIONAL VARIATION IN CARDIOVASCULAR DISEASE AMONG SLE PATIENTS

Objectives:

To evaluate whether the risk of cardiovascular disease (CVD) including myocardial infarction (MI) and cerebrovascular (CVA) differs across geographic regions among SLE patients.

Methods:

We identified SLE patients using two ICD codes 60 days apart within two years recorded in Medical Services Plan (MSP) or hospital discharge database (DAD). We defined the second of two diagnosis dates as the index date. We included incident SLE patients (7-year continuous registries in MSP before the first diagnosis date) with an index date between 1997 and 2012 and excluded patients with previous MI or CVA before the index date. We followed each patient from the index date up to 10 years and censored at the date of death date, leaving the province, or March 31, 2015.

We assessed the incident CVD that was defined as the first ever diagnosis of MI or CVA recorded in DAD or as the primary cause of death in Vital Statistics. We also evaluated MI and CVA separately.

The Province’s publicly administered and funded health care system is organized into five regional health authorities (HA): Interior (IHA), Fraser (FHA), Vancouver Coastal (VCHA), Vancouver Island (VIHA), and Northern (NHA) [Figure 1(a)].We assigned each patient the HA she/he was registered at the index date. We extracted baseline covariates using the information during a period of 365 days prior to the index date, including socio-demographic characteristics, health care resource use, comorbidities, and prescription medication use. We calculated the incident rate (IR) of MI, CVA, and CVD (first ever MI or CVA) by HA. Using Cox Proportional Hazard model adjusting for potential confounders at baseline, we estimated the adjusted hazard ratios (aHR) of CVD for each HA compared to FHA or VCHA which have the large proportion of provincial population and SLE patients. We evaluated the regional disparities in MI and CVA separately using the same methods.

Figure 1.

HA and CVD Incident Rate

Results:

We included 3,960 incident SLE patients free of CVD at baseline with a mean (SD) age of 48.5 (15.8), including 726 (18.3%) from IHA, 1634 (42.3%) from FHA, 854 (21.6%) from VCHA, 504 (12.7%) from VIHA, and 242 (6.1%) from NHA. During 26378 person-year (PY) follow-up, 133 patients developed incident CVD including 91 MI and 43 CVA. [Table 1]

Table 1.

Incident Rates and HR

HAIncidenceaHR (95%CI)NPYIR (95%CI)10,000 PYReference: FHAReference: VCHACVDIHA35457976(54,105)1.93(1.17,3.2)2.05(1.17,3.58)FHA391119735(25,47)ref1.06(0.64,1.76)VCHA27584446(31,66)0.94(0.57,1.57)refVIHA22316570(44,103)1.65(0.96,2.83)1.74(0.98,3.11)NHA10159263(31,110)1.81(0.86,3.8)1.92(0.88,4.17)MIIHA24457952(34,76)2.09(1.14,3.83)1.81(0.95,3.47)FHA271119724(16,34)ref0.87(0.48,1.56)VCHA21584436(23,54)1.15(0.64,2.07)refVIHA12316538(20,64)1.29(0.64,2.58)1.12(0.54,2.31)NHA7159244(19,85)2.11(0.88,5.11)1.84(0.74,4.56)CVAIHA11457924(12,41)1.79(0.71,4.55)2.35(0.8,6.88)FHA121119711(6,18)ref1.31(0.49,3.48)VCHA7584412(5,23)0.76(0.29,2.03)refVIHA10316532(16,55)2.79(1.14,6.85)3.66(1.34,10.01)NHA<5159219(5,49)1.45(0.36,5.72)1.89(0.44,8.22)

The IR of CVD varied from 35 in FHA to 76 per 10,000 PY in IHA [Figure 1(b)]. IHA had significantly higher risk of CVD than FHA (aHR=1.93, 95%CI=1.17~3.2) and VCHA (aHR=2.05, 95%CI=1.17~3.58).

The IR of MI varied from 24 in FHA to 52 per 10,000 PY in IHA [Figure 2(a)]. IHA had significantly higher risk of MI than FHA (aHR=2.09, 95%CI=1.14~3.83).

Figure 2.

MI and CVA incident Rate by HA

The IR of CVA varied from 11 in FHA to 32 per 10,000 PY in VIHA [Figure 2(b)]. VIHA had significantly higher risk of CVA than FHA (aHR=2.79, 95%CI=1.14~6.85) and VCHA (aHR=3.66, 95%CI=1.34~10.01).

Conclusion:

Compared with FHA and VCHA, IHA had higher risk of CVD and VIHA had higher risk of CVA. IHA also had higher risk of MI than FHA.

Disclosure of Interests:

None declared

SAT0175 IMPACT OF ANTIMALARIAL ADHERENCE ON MORTALITY AMONG PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: A POPULATION-BASED COHORT STUDY

Background:

Evidence has consistently shown that adherence to AM is poor in systemic lupus erythematosus (SLE) patients. However, data on the impact of adherence to AM on mortality is scarce.

Objectives:

To assess the effect of AM adherence on all-cause mortality in SLE patients from the general population.

Methods:

This study used administrative databases from British Columbia, Canada. We created an incident SLE cohort between January 01, 1997, and March 31, 2015, using the physician billing data and a 7-year washout period. The inclusion criteria were at least two physician visits, at least two months apart, within two years, with an ICD-9 code (710.0) or ICD-10 code (M32.1, M32.8, M32.9) for SLE. Follow-up started at the first day of having both SLE and AM, i.e., at the SLE index date (second ICD code) for those whose first AM use occurred before the SLE index date, or the date of the first AM use if otherwise. Our outcome was all-cause mortality, obtained from the vital statistics registry. In the analysis, the follow-up time was divided into 30-days windows, for a total of 293,190 person-months. For each window, a measure of adherence, the proportion of days covered (PDC), was calculated and categorized as adherent (PDC≥0.90), non-adherent (0<PDC<0.90), and discontinuer (no drug or PDC = 0). We used both Cox’s proportional hazards models and marginal structural models (MSM) to estimate the effect of AM adherence on all-cause mortality. Both analysis controlled for baseline demographics (age, sex, residence, income quintile), as well as the following baseline and time-varying covariates: immunosuppressive and other medications, hospitalizations, impatient, and other visits, and Charlson comorbidity index. To account for the possibility of a few time-varying covariates being mediators in the causal pathway from AM adherence to mortality, which may cause the Cox model to yield biased estimates of the adherence effects, we conducted the MSM analysis that can produce valid estimates as it balances the distributions of time-varying confounders among the three adherence groups via inverse probability weighting.

Results:

We identified 3,385 individuals with incident SLE (mean age 47.3 years, 89% were women) who had at least one filled AM prescription. Over the mean follow-up of 6.66 years, 288 (8.5%) incident SLE patients died. The incidence rate (IR) of mortality for AM adherent, non-adherent, and discontinuer patients were 4.31, 11.86, and 19.51 per 1000 person-years, respectively. Using the Cox model, the adjusted hazard ratio (HRs) obtained for AM adherent and non-adherent SLE patients were 0.20 and 0.66, respectively, compared to discontinuer SLE patients (Table 1). Using MSM, those adjusted HRs were found as 0.18 and 0.64. Also, the adjusted HRs for adherers compared to the non-adherers were 0.30 (Cox) and 0.28 (MSM). A statistically significant linear trend in the HRs of mortality risk over the adherence levels was found (Table 1, Linear Trend).

Table 1.Adherence LevelsNo. of DeathsIR Ratios (95%CI)Adjusted Cox HRs (95%CI)Adjusted MSM HRs (95%CI)Discontinuer (Reference)198Non-adherent470.61(0.44-0.84)0.66(0.47-0.93)0.64(0.46-0.89)Adherent430.22(0.16-0.31)0.20(0.14-0.28)0.18(0.12-0.25)Contrast: Partial vs. Full0.36(0.24-0.55)0.30(0.19-0.46)0.28(0.18-0.42)Linear Trend0.32(0.25-0.41)0.29(0.23-0.37)

Conclusion:

SLE patients that adhere to AM therapy have a lower risk of death than patients who do not adhere or who discontinue AM (5 and 3 times, respectively) in both the MSM and Cox analysis. Our findings support the importance of AM adherence to prevent premature deaths in SLE patients.

Disclosure of Interests:

None declared

OP0191 ASSOCIATION OF TRAMADOL WITH ALL-CAUSE MORTALITY, CARDIOVASCULAR DISEASE, VENOUS THROMBOEMBOLISM AND HIP FRACTURES AMONG PATIENTS WITH OSTEOARTHRITIS. A POPULATION-BASED STUDY

Background:

Both tramadol (narcotic-like drug) and nonsteroidal anti-inflammatory drugs (NSAIDs) are prescribed for pain relief among osteoarthritis (OA) patients. Evidence comparing risks of adverse events between tramadol and NSAIDs users is inconclusive.

Objectives:

To examine the association of tramadol with all-cause mortality, cardiovascular disease (CVD), venous thromboembolism (VTE) and hip fractures (HFx) compared with NSAIDs and codeine in OA.

Methods:

Design: Sequential propensity score-matched cohort study. Sample: All patients with OA who received medical care from 2005 to 2014 in the entire province of British Columbia, Canada. Tramadol cohort: Initial prescription of tramadol (n=56325). Four comparator cohorts: the initiation of one of the following: naproxen (n=13798), diclofenac (n=17675), cyclooxygenase-2 [Cox-2] inhibitor (n= 17039), or codeine (a weak opioid) (n=7813). Patients required to be prescribed neither tramadol nor its comparators during the year before the initial prescription date (i.e., index date). Outcomes: 1) all-cause mortality;first ever2) CVD, 3) VTE, 4) HFx within the 1styear after the initiation of tramadol or its comparators. Follow-up: from index date until the event occurred, disenrollment, or the end of a 1-year follow-up period. Statistical analysis: We created baseline covariates (demographics, comorbidities, medications and health resource utilization) from the year prior to the index date. Calendar years from 2005 to 2014 were divided into 10 blocks; propensity scores were calculated using logistic regression within each block. We used 1:1 greedy matching method. We estimated hazard ratios (HRs) using Cox proportional hazard models.

Results:

After propensity score matching, 112650 patients with OA were included (mean age of 68 years, 62.8% were females). During the 1-year follow-up, 296 deaths (21.5/1000 person-years) occurred in the tramadol cohort and 246 (17.8/1000 person-years) in the naproxen cohort (Table 1). All-cause mortality was higher for tramadol compared with all NSAIDs cohorts, but not with the codeine cohort (Table 1, Figure 1). Tramadol initiators have also a higher risk of CVD and VTE compared with the diclofenac and Cox-2 inhibitor initiators with HRs ranging from 1.2 to 1.7. Furthermore, tramadol was also associated with a higher risk of HFx compared with all NSAIDs cohorts (HRs ranging from 1.4 to 1.5). No significant difference was found between tramadol and codeine (Table 1).

Table 1Group1Group2Group3Group4All-cause MortalityTramadolNaproxenTramadolDiclofenacTramadolCox-2 inhibitorTramadolCodeineOA (n)13798137981767517675170391703978137813Death (n)296246439345402267168199Rate (/1000 PY)21.517.824.819.523.615.721.525.5HR (95% CI)1.2 (1.0-1.4)1.01.3 (1.1-1.5)1.01.5 (1.3-1.8)1.00.8 (0.7-1.0)1.0CVDOA (n)11708117081492414924147791477968096809CVD (n)309319410349404353156164Rate (/1000 PY)26.427.327.523.427.323.922.924.1HR (95% CI)1.0 (0.9-1.1)1.01.2 (1.1-1.3)1.01.2 (1.0-1.3)1.00.9 (0.8-1.1)1.0VTEOA (n)13472134721723017230166991669976607660VTE (n)4137604070402830Rate (/1000 PY)3.02.83.52.34.22.43.73.9HR (95% CI)1.2 (0.9-1.6)1.01.5 (1.1-1.9)1.01.7 (1.3-2.3)1.01.0 (0.7-1.4)1.0HFxOA (n)13378133781721617216166701667075937593HFx (n)6649885991603540Rate (/1000 PY)5.03.75.13.45.53.64.65.3HR (95% CI)1.4 (1.0-1.8)1.01.5 (1.2-1.9)1.01.5 (1.2-1.9)1.00.9 (0.7-1.2)1.0

Conclusion:

OA patients initiating tramadol have an increased risk of mortality, CVD, VTE, and HFx within 1 year compared with NSAIDs, but no statistically significant difference in the risk was observed between tramadol and codeine.

Disclosure of Interests:

None declared

OP0010 EFFECTIVENESS OF THE MAKING IT WORK™ PROGRAM AT IMPROVING PRESENTEEISM AND WORK CESSATION IN WORKERS WITH INFLAMMATORY ARTHRITIS – RESULTS OF A RANDOMIZED CONTROLLED TRIAL

Background:

Arthritis often leads to presenteeism (decreased at-work productivity), missed days from work and permanent work disability, leading to reduced quality of life and high costs to individuals and society. Yet, health services addressing the employment needs of people with arthritis are lacking.

Objectives:

We evaluated the effectiveness of the Making-it-WorkTM(MiW) program, an online self-management program developed to help people with inflammatory arthritis (IA) deal with employment issues.

Methods:

A multi-center RCT evaluated the effectiveness of MiW at improving presenteeism and preventing work cessation (WC) over two years. Participants were recruited from rheumatologist practices, consumer organizations and arthritis programs, in three Canadian provinces. Eligibility criteria: diagnosis of IA, employed, age 18-59, and concerned about ability to work. Participants were randomized 1:1 to MiW or usual care plus printed material on workplace tips. MiW consists of five online self-learning modules and group meetings, and individual vocational counselling and ergonomic consultations. Questionnaires were administered every 6 months. Outcomes were presenteeism [Rheumatoid Arthritis Work Instability Scale (RA-WIS)], time to WC ≥ 6 months, and time to WC ≥ 2 months (secondary outcome). Baseline characteristics (age, gender, ethnicity, occupation, education, disease duration and self-employment) were collected. Intention-to-treat (ITT) longitudinal analysis of RA-WIS using linear mixed effect regression models with 2-year comparison as primary endpoint and survival analysis for time to WC using Kaplan-Meier and Cox Proportional Hazard models were performed. Robustness analyses were conducted by using various missing values imputation methods like last observation carried forward, imputation using worse possible outcomes and model-based multiple imputations; using square root transformation of RA-WIS outcome; and adjusting for baseline covariates. SAS version 9.4 was used.

Results:

A total of 564 participants were recruited, with 478 (84.75%) completing 2-year follow-up. Baseline characteristics were similar between groups. Mean RA-WIS scores were significantly lower in the intervention group from 6 months onwards, with the greatest difference observed at 2 years (-1.78, 95%CI: -2.7, -0.9, p < .0001), yielding a standardized effect size of 32%. Satisfactory robustness was observed. Work cessation occurred less often in intervention than control groups, but only reached statistical significance for WC ≥ 2 months (WC ≥ 6 months: 31 versus 44 events, aHR 0.70, 95%CI: 0.44, 1.11, p = 0.13; WC ≥ 2 months: 39 versus 61 events, aHR: 0.65, 95%CI: 0.43, 0.98, p = 0.04).

Conclusion:

Results of the RCT reveal the program was effective at improving presenteeism and preventing short-term WC. Effectiveness at preventing long-term work disability will be assessed at 5 years. This program fills one of the most important and costly unmet needs for people with inflammatory arthritis.

References:

[1]Carruthers EC, Rogers P, Backman CL, et al. “Employment and arthritis: making it work” a randomized controlled trial evaluating an online program to help people with inflammatory arthritis maintain employment (study protocol).BMC Med Inform Decis Mak. 2014;14:59. Published 2014 Jul 21. doi:10.1186/1472-6947-14-59

Disclosure of Interests:

Andre Luquini: None declared, Yufei Zheng: None declared, Hui Xie: None declared, Catherine Backman: None declared, Pamela Rogers: None declared, Alex Kwok: None declared, Astrid Knight: None declared, Monique Gignac: None declared, Dianne Mosher: None declared, Linda Li: None declared, John Esdaile: None declared, Carter Thorne Consultant of: Abbvie, Centocor, Janssen, Lilly, Medexus/Medac, Pfizer, Speakers bureau: Medexus/Medac, Diane Lacaille: None declared

Risk of venous thromboembolism in ankylosing spondylitis: a general population-based study

Background

Venous thromboembolism (VTE), including pulmonary embolism (PE) and deep venous thrombosis (DVT), can be life threatening. An increased frequency of VTE has been found in inflammatory conditions. To date, evidence assessing whether this risk is also greater in patients with ankylosing spondylitis (AS) is scarce.

Methods

Using the provincial British Columbia, Canada healthcare database that encompasses all residents within the province, we conducted matched cohort analyses of incident PE, DVT and overall VTE among incident cases of AS and compared them with individuals randomly selected from the general population without AS. We calculated incidence rates (IRs) of VTE and multivariable analyses after adjusting for traditional risk factors using Cox models.

Results

Among 7190 incident cases of AS, 35 developed PE and 47 developed DVT. IRs of PE, DVT and overall VTE per 1000 person-years for patients with AS were 0.79, 1.06, 1.56 compared with 0.40, 0.50, 0.77 in the control cohort. Corresponding fully adjusted HRs (95% CI) of PE, DVT and VTE were 1.36 (0.92 to 1.99), 1.62 (1.16 to 2.26) and 1.53 (1.16 to 2.01), respectively. The risks of PE, DVT and VTE were highest in the first year of diagnosis with HR (95% CI) of 2.88 (0.87 to 9.62), 2.20 (0.80 to 6.03) and 2.10 (0.88 to 4.99), respectively.

Conclusions

These findings demonstrate an increased risk of VTE in the general AS population. This risk appears the most prominent in the first year after diagnosis.

Responsiveness of health state utility values in knee osteoarthritis

OBJECTIVE

Adaptive tests are increasingly being used to assess health-related quality of life in patients with a variety of medical conditions, including osteoarthritis (OA) of the knee. This approach has recently been used to assess health state utility valuations (HSUV) for use in quality-adjusted life-year calculations. To accurately assess incremental value for money, these tools must be responsive. Therefore, we examined the responsiveness of the Health Utilities Index mark 3 (HUI3) and Paper Adaptive Test-5D (PAT-5DQOL) in a group of patients with knee OA.

METHODS

We used patient-level data from a randomized controlled trial evaluating a pharmacist-initiated multidisciplinary intervention in newly diagnosed patients with knee OA. The mean change for utility scores from baseline to 6 months was calculated, as well as effect size (ES) and standardized response mean (SRM) for the HUI3 and PAT-5DQOL, and generalized additive model plots, using the Western Ontario and McMaster Osteoarthritis index as a reference standard.

RESULTS

When patients were assessed based on whether their condition had improved, remained unchanged, or worsened over time, the PAT-5DQOL showed greater responsiveness in patients whose condition had either improved or worsened. ES and SRM were generally small for both instruments.

CONCLUSION

The PAT-5DQOL is more responsive to change over time than the HUI3 in patients with knee OA.

Lifetime trajectory of physical activity according to energy expenditure and joint force

OBJECTIVE

To develop and demonstrate the feasibility of a method for estimating lifetime hip and knee cumulative joint force using survey data on physical activity, and to construct and describe lifetime trajectories of energy expenditure and hip and knee joint force.

METHODS

Exposure data on lifetime physical activity, including type (occupational, household, and recreation) and dose (frequency, intensity, and duration), were collected from a Canada-wide population study of adults ages ≥45 years. Subjects were ranked in 2 ways: in terms of physical activity-related energy expenditure and in terms of a cumulative peak force index (CPFI) for the hip and knee, which is a measure of lifetime exposure and is a time/joint force product involving years of force and subject bodyweight. A relative joint loading index was calculated as the ratio of joint force (CPFI score) to energy expenditure.

RESULTS

A total of 4,269 subjects completed the baseline measurements. Lifetime energy expenditure and hip and knee CPFI scores were higher for occupational and household activity than sport. The mean lifetime energy expenditure from total physical activity in the study sample was 119.1 metabolic equivalent-hours/week. Women had slightly higher total lifetime energy expenditure and CPFI scores than men. The relative joint loading index was highest for male household and sport activity and lowest for female occupational activity.

CONCLUSION

Lifetime cumulative hip/knee joint force trajectories were successfully constructed from survey data and followed expected trends. Comparing energy expenditure with joint force revealed variation by age, sex, and activity type, indicating these measures may help distinguish the numerous benefits of physical activity from possible risks.

The impact of cost sharing of prescription drug expenditures on health care utilization by the elderly: own- and cross-price elasticities

PURPOSE

To estimate healthcare demand elasticity and evaluate the impact of deductible/co-payment policy changes for prescription drugs on the use of drugs and physician visits among seniors with rheumatoid arthritis (RA) in British Columbia (BC), Canada.

METHODS

According to the BC drug insurance program, prior to 2002, seniors co-paid the dispensing fee of each prescription to an annual maximum of CAN$ 200 (plan A). Starting in 2002, this plan was split into plan A and plan A1 (Premium Assistance) such that the co-payment amount equaled a maximum of CAN$ 25 and CAN$ 10 per prescription to an annual maximum of CAN$ 275 and CAN$ 200, respectively. Because of the endogeneity of the beneficiary price in the presence of a non-linear price schedule resulting from the cost-sharing policy, we implemented the method of instrumental variables to estimate price elasticities. The instrument was based on the price an individual would face under the new cost-sharing policy if their consumption remained at the pre-policy level.

RESULTS

A total of 8017 patients were included. The estimated own-price elasticity of demand for prescription drugs and the cross-price elasticity of demand for physician visits were found to be negative and positive, respectively. The implications of our findings were that when cost sharing for prescription drugs increased, the demand for prescription drugs decreased and the demand for physician visits increased.

CONCLUSIONS

In a predominantly publicly funded health care system, the selective introduction of market driven cost containment concepts such as patient cost-sharing might have the unintended impact of increasing overall health utilization for seniors with RA.

Multifocal idiopathic fibrosclerosis: treatment of 2 cases with cyclosporine

We describe 2 cases of multifocal idiopathic fibrosclerosis treated successfully with cyclosporine. The first patient presented with chronic abdominal pain and was subsequently found to have retroperitoneal fibrosis with ureteral obstruction. Other findings included cholangiolar fibrosis, retroorbital pseudotumors, submandibular gland enlargement, subcutaneous fibrotic masses, and elevated erythrocyte sedimentation rate (ESR) and serum creatinine. He initially responded well to temporary ureteral stenting followed by combination therapy with steroids and cyclosporine. He relapsed when cyclosporine was stopped, but subsequently remitted completely when cyclosporine was reintroduced. The second patient presented with long-standing abdominal pain with retroperitoneal fibrosis, submandibular gland enlargement, and an enlarged pancreas with a localized mass, all of which improved significantly with 6 months of therapy with cyclosporine. Cyclosporine was well tolerated with no significant side effects in the 2 patients. A review of the literature is presented.

Classification systems in orthopaedics

Classification systems help orthopaedic surgeons characterize a problem, suggest a potential prognosis, and offer guidance in determining the optimal treatment method for a particular condition. Classification systems also play a key role in the reporting of clinical and epidemiologic data, allowing uniform comparison and documentation of like conditions. A useful classification system is reliable and valid. Although the measurement of validity is often difficult and sometimes impractical, reliability-as summarized by intraobserver and interobserver reliability-is easy to measure and should serve as a minimum standard for validation. Reliability is measured by the kappa value, which distinguishes true agreement of various observations from agreement due to chance alone. Some commonly used classifications of musculoskeletal conditions have not proved to be reliable when critically evaluated.

Immune responses to cartilage link protein and the G1 domain of proteoglycan aggrecan in patients with osteoarthritis

OBJECTIVE

To determine whether patients with osteoarthritis (OA) express cellular immunity to cartilage link protein (LP) and the G1 globular domain of proteoglycan (PG) aggrecan, and whether immunity to the G1 domain is influenced by the removal of keratan sulfate (KS).

METHODS

LP and the G1 globular domain of PG were isolated from human and/or bovine cartilage and used in proliferation assays with peripheral blood lymphocytes (PBL) from 42 patients with OA and 40 healthy control subjects.

RESULTS

Patients with OA expressed a higher prevalence of cellular immunity to human cartilage LP (42.4%) compared with the control group (13.3%). The prevalence of immune reactivity to bovine LP in patients with OA was lower (35.7%) compared with the immunity to human LP, but remained similar in the control group (13.8%). PBL from patients with OA exhibited low reactivity to the native G1 domain of bovine PG. However, removal of KS chains from the G1 globular domain resulted in increased cellular immune responses to the G1 domain in OA patients (45.8%) compared with the control group (7.7%).

CONCLUSION

These results indicate the presence of immunity to cartilage-derived LP and the G1 globular domain of PG aggrecan in patients with OA and the inhibitory effect of KS chains on the G1 domain on the expression of this immunity in OA patients. This immune reactivity is commonly observed in patients with inflammatory joint disease and can experimentally induce arthritis. Thus, it may be involved in the pathogenesis of OA.

Autoimmunity to cartilage link protein in patients with rheumatoid arthritis and ankylosing spondylitis

OBJECTIVE

To determine whether patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) express cellular immunity to cartilage link protein (LP).

METHODS

LP was purified from human fetal epiphyseal and bovine adult nasal cartilage. It was used in proliferation assays with the peripheral blood lymphocytes (PBL) isolated from 83 patients with RA, 21 patients with AS, and 30 healthy controls.

RESULTS

Patients with RA (34%) and AS (71%) expressed a significantly higher prevalence of cellular immune responses to human LP compared with the healthy control group (13%). Such significant differences were not observed for bovine LP. Half the patients with RA responding to LP exhibited cellular immunity to both human and bovine protein. In the AS group, PBL from a majority of responders to LP recognized only human LP.

CONCLUSION

These data suggest that LP is a potential autoantigen in the development of RA and AS and that cellular immune reactivity to common and distinct LP epitopes in patients with RA and AS may play a role in the pathogenesis of these diseases.

Cellular immunity to the G1 domain of cartilage proteoglycan aggrecan is enhanced in patients with rheumatoid arthritis but only after removal of keratan sulfate

OBJECTIVE

To determine whether patients with rheumatoid arthritis (RA) express cellular immunity to the purified G1 globular domain of cartilage proteoglycan (PG) aggrecan and whether it is influenced by the removal of keratan sulfate (KS) chains from the molecule.

METHODS

The G1 globular domain of PG was purified from mature bovine articular cartilage, digested with keratanase, and used in proliferation assays with peripheral blood lymphocytes (PBL) isolated from 43 patients with RA, 11 patients with nonarticular rheumatism (NAR), including soft tissue rheumatism and mechanical back pain, and 13 healthy age- and sex-matched control subjects.

RESULTS

Removal of KS chains from the G1 globular domain resulted in significantly increased prevalence and values of cellular immune responses to G1 in RA patients compared with the control and NAR groups. In the majority of RA patients, KS chains on G1 significantly inhibited its immune recognition by PBL. There was no significant effect of KS removal on the immunity to G1 in patients with NAR and in the healthy control group.

CONCLUSION

These results reveal that immune reactivity to the G1 globular domain of the cartilage PG aggrecan is enhanced in patients with RA but only when KS chains are removed. Thus, KS chains inhibit immune responses to this domain of aggrecan. Since immunity to the G1 globular domain of aggrecan induces an erosive polyarthritis in BALB/c mice after removal of KS chains, immunity to the G1 globular domain, cleaved by proteases to remove KS chains, may play a role in the pathogenesis of RA.

Murine cross-reactive T-cell epitopes of Neisseria meningitidis outer membrane proteins

Five non-covalent vaccines of outer membrane proteins (OMPs) complexed to capsular polysaccharide were prepared from Neisseria meningitidis serogroup B strains. Each vaccine contained distinct serotype (class 2/3) and subtype (class 1) OMPs. The cross-reactivity of the T-cell response to the meningococcal vaccine-associated proteins was examined in an in vitro T-cell proliferative assay, following antigenic priming of mice with one of these vaccines (MB6:P1.6) or with its purified class 1 (subtype P1.6) and class 2 (serotype 6) proteins. Cross-reactive T-cell epitopes were found in all five vaccine preparations on both the class 1 and class 2/3 OMPs. Priming of mice with the subtype P1.6 N-terminal peptide led to a significant but small increase in T-cell proliferation with the MB6:P1.6 vaccine.

Open-label tolerability study of enteric-coated naproxen in the treatment of osteoarthritis and rheumatoid arthritis

Two hundred and ninety-six patients were enrolled in a 6-month, open-label tolerability study of enteric-coated naproxen in patients with rheumatoid arthritis (n = 174) and osteoarthritis (n = 122). Thirty percent of the patients were greater than 65 years of age. Under standard clinical prescribing conditions, enteric-coated naproxen 500 mg twice daily and 375 mg twice daily demonstrated an acceptable tolerability profile that was not different from what one would expect with standard naproxen.

Specificity of the immune response to the group B polysaccharide of Neisseria meningitidis

A panel of monoclonal antibodies (mAb) and polyclonal sera of murine, human and equine origin, of IgM isotype and with specificity for Neisseria meningitidis group B polysaccharide, an alpha(2----8)-linked homopolymer of sialic acid, were examined for their antigenic and biological specificities. The nature of the antigenic determinants on B polysaccharide was investigated using a series of N-acyl derivatives of B polysaccharide, two sialic acid polymers containing alpha(2----9)-linkages and a series of polynucleotides. The panel of antibodies recognized an array of unrelated antigenic determinants on the B polysaccharide, despite its structural simplicity, and all but one were highly effective in an in vitro bactericidal assay and/or in an in vivo murine passive protection model. There was no evidence that B polysaccharide induced antibody capable of blocking biological activity (blocking antibody).

Immunogenicity in adult males of a Neisseria meningitidis group B vaccine composed of polysaccharide complexed with outer membrane proteins

Twenty five adult male volunteers were given a vaccine composed of the capsular B polysaccharide non-covalently complexed to serotype 6 outer membrane proteins (OMP) of Neisseria meningitidis. Subjects were divided into three dose groups receiving 50, 100 or 150 micrograms vaccine in aluminium hydroxide in each of three injections spaced 4 weeks apart. Systemic signs/symptoms considered clinically significant were recorded on 6% (4/70) of occasions and were succeeded by withdrawal of two volunteers from the study. Local injection site reactions, mostly mild to moderate, were reported after all vaccinations with one such reaction leading to a third volunteer withdrawing from the study. Geometric mean anti-B responses before immunization and 1 week after the third immunization (9 weeks) were 3.60 and 7.12 micrograms ml-1 in the 50 micrograms group (p less than 0.05) 2.05 and 12.19 micrograms ml-1 in the 100 micrograms group (p less than 0.001), and 3.68 and 14.20 micrograms ml-1 in the 150 micrograms group (p less than 0.001). The anti-B response was predominantly of the IgM isotype and persistence above prevaccination levels was evident for at least 12 months. Anti-type 6 OMP responses were also evidenced with geometric mean multiplicative increases over prevaccination levels at 9 weeks and 6 months of 7.8 and 4.2 for the 50 micrograms group, 11.6 and 5.6 for the 100 micrograms group and 6.8 and 3.4 for the 150 micrograms group. The bulk of this response was of the IgG isotype. Passive protection of mice was achieved with both pre- and post-vaccination (9 weeks; 100 and 150 micrograms groups) pools of sera.(ABSTRACT TRUNCATED AT 250 WORDS)

Passive transfer of meningococcal group B polysaccharide antibodies to the offspring of pregnant rabbits and their protective role against infection with Escherichia coli K1

Pregnant rabbits vaccinated with meningococcal group B polysaccharide complexed to outer membrane proteins (serotype 6) responded to produce IgG, IgM and IgA anti-B polysaccharide antibodies, which were passively transferred to the offspring (IgG preferentially) and could be detected in their sera immediately after birth. These antibody levels were sustained in the mothers but diminished in the offspring to background levels at day 22 after birth. In a subsequent experiment, rabbits immunized with the group B vaccine had offspring that proved considerably more resistant to infection with Escherichia coli K1 than the control litters from non-immune mothers. Although not complete, protection was statistically of high significance and correlated well with the anti-B polysaccharide titres obtained in the mothers.

Reticuloendothelial system Fc receptor function in systemic lupus erythematosus: effect of decreased sensitization on clearance of autologous erythrocytes

Recent reports of reticuloendothelial system Fc receptor function using anti-Rh(D) coated red blood cells (RBC) provide conflicting data regarding the degree of abnormality in systemic lupus erythematosus (SLE). The effect of different sensitizing doses of anti-Rh(D) on Fc receptor function was evaluated in 10 controls and 9 patients with SLE (5 with renal disease, 4 without) using 1 microgram anti-Rh(D) (6,700 molecules anti-Rh(D)/RBC by saturation analysis) and 0.125 microgram anti-Rh(D) (1,100 molecules/RBC). At the lower sensitizing dose the sensitivity of the assay was significantly increased. To correctly interpret the significance of studies of Fc receptor function from different centers, it is necessary to know the exact sensitizing doses used for each study.

Thymic-dependence and immune memory in mice vaccinated with meningococcal polysaccharide group B complexed to outer membrane protein

Athymic mice were capable of producing IgM antibodies to B polysaccharide of N. meningitidis when immunized with the polysaccharide complexed to outer membrane proteins, whereas no immunogenicity could be demonstrated with the purified polysaccharide. Transfer of T cells to athymic cells demonstrated that the primary anti-B response was truly thymus-independent but the bulk of the secondary response was thymus-dependent. Transfer of T and B cells purified from spleens of immune mice into irradiated recipients showed the presence of memory T cells, but no memory B cells could be found.

The randomized clinical trial in orthopaedics: obligation or option?

The classic randomized clinical trial is difficult to apply to the evaluation of surgical procedures. After reviewing the structure and rationale of cohort studies and randomized clinical trials, four types of bias in randomized clinical trials that present difficulties in clinical studies are identified. Other problems that may limit the willingness of orthopaedic surgeons to conduct randomized clinical trials relate to the surgical procedure itself, the outcome of the trial of interest, surgical philosophy, and the ethical implications for a surgeon of a randomized clinical trial. A recently proposed variation of the classic randomized clinical-trial model, the randomized-surgeon design, appears to solve some of these problems.

Effect of aluminum ions on chemical and immunological properties of meningococcal group B polysaccharide

Soluble salts of aluminum were examined for their capacity to complex with purified meningococcal group B polysaccharide. The formation of the complexes resulted, first, in a markedly reduced rate of internal esterification at acid pH and, consequently, prolonged stability of the antigen as measured by its reactivity with antibody at pH 4 and, second, in an increased resistance to neuraminidase. Al3+ complexes of B polysaccharides were tested for immunogenicity in mice and found to be no better than the purified polysaccharide in the Na+ or Ca2+ form. However, when Neisseria meningitidis type 6 protein (outer membrane) complexed to B polysaccharide was tested, a substantial increase in anti-B titers was detected, whereas antiprotein titers remained unchanged. The possibility of using combinations of metal-polysaccharide-outer membrane protein complexes as vaccines for humans is discussed.

Immunity and protection of mice against Neisseria meningitidis group B by vaccination, using polysaccharide complexed with outer membrane proteins: a comparison with purified B polysaccharide

A methodology for preparing outer membrane proteins (type specific) complexed to group B polysaccharide of Neisseria meningitidis is described. These complexes, low in nucleic acid and lipopolysaccharide content, were immunogenic in mice with induction of humoral antigroup B and antiprotein responses. Immunized mice were also protected against challenge with N. meningitidis group B strains of the same or a different type from that used for vaccination. Both immunity and protection were enhanced when the mice received a secondary immunization with the protein-polysaccharide complex. Additional data have shown the capacity of purified B polysaccharide to induce immunological memory, even though it is incapable of inducing a humoral response when given alone.

A controlled two-centre trial of parenteral methotrexate therapy for refractory rheumatoid arthritis

Forty-eight patients with rheumatoid arthritis refractory to other treatments were studied in a placebo controlled trial of methotrexate (MTX) in 2 institutions. Once weekly for 6 weeks, the patients were injected with placebo (Group 1), MTX 10 mg (Group 2), or MTX 25 mg (Group 3). Then, for the next 6 weeks, Group 1 received MTX, either 10 or 25 mg/wk, and Groups 2 and 3 continued their same dose. Adverse reactions necessitated change from 25 mg to 10 mg in some patients, but no major side effects of MTX were noted. At 6 weeks, the effect of the 2 MTX doses did not differ significantly but patients on MTX had fared significantly better (p less than 0.005 - less than 0.001) than those given placebo. At 12 weeks, all indices showed significant improvement in Group 1 and maintenance or enhancement of the improvement in Groups 2 and 3. We conclude that weekly low dose MTX therapy is efficacious for refractory rheumatoid arthritis.

An immunogenetic study of older age onset rheumatoid arthritis

Thirty-two patients with older age onset rheumatoid arthritis (ORA), defined as disease onset after age 60, were selected for HLA typing. The majority (69%) were rheumatoid factor (RF) seronegative. An increase in HLA-DR4, though not statistically significant, was seen in ORA (38% vs 17% normals). This antigen was strongly associated with RF seropositivity (70%, p less than 0.01) and rheumatoid nodules (75%, p less than 0.01) in ORA. We conclude that the immunogenetics of ORA are similar to that described for adult RA in general.

Radionuclide joint imaging

Radionuclide joint imaging with the technetium-99m-labeled phosphates is a sensitive technique for the detection of inflammatory articular disease, although it is nonspecific as to the cause of the increased uptake and offers poor resolution in comparison to conventional radiography. There does not appear to be any place for the routine use of joint imaging of the peripheral joints, as there is little evidence that it benefits patient management. Scintigraphy is of benefit in the detection of osteomyelitis, Legg-Perthes' disease, and osteonecrosis, where changes may antedate roentgenologic abnormalities. Technetium-99m-phosphates may have an increasing role in the evaluation of knee and hip prosthetic joint loosening and infection, especially regarding the femoral components. Scintigraphy may be useful in excluding synovitis and allaying concern in selected patients with chronic articular pain in whom a conventional diagnostic evaluation is unrewarding. Attempts have been made to use radionuclide joint imaging to quantitate the degree of synovitis present in individual joints, particularly the sacroiliac joints. To date, reliable methods that distinguish normal from abnormal joints have not been established, although this remains an area of potential usefulness and active research. Scintigraphy with 99mTc-phosphates is useful in the detection of spinal fracture and pseudoarthrosis in individuals with ankylosing spondylitis.

A clinical study of older age rheumatoid arthritis with comparison to a younger onset group

The clinical features, therapy and course of disease in a group of 34 patients with older age onset rheumatoid arthritis (ORA) defined as disease onset after age 60 are compared with a group of 34 rheumatoid patients whose disease onset began at a younger age (YRA). Onset of rheumatoid arthritis (RA) beyond age 60 is not uncommon as ORA represented 33% of all RA patients seen in our rheumatic disease unit. The ORA patients had a shorter mean disease duration (p less than 0.001) and a tendency to less rheumatoid factor seropositivity (p = 0.06) despite random selection for active disease of less than 10 years' duration. Suppressive therapy was employed less frequently in ORA (p less than 0.01) than in YRA but the use of other therapeutic modalities and the last recorded functional class were similar in the 2 groups. ORA patients did have greater functional incapacity at some point in their disease course (p less than 0.01) as well as a greater frequency of weight loss (p less than 0.001) and other acute systemic features at onset than YRA patients. Seronegative ORA appeared to have a favourable disease course in comparison with seropositive ORA.

Immunoglobulin isotype in the murine response to polysaccharide antigens

Murine antisera specific for the alpha (1 leads to 3) and alpha (1 leads to 6)-linked glucosyl determinants of dextran, as well as for meningococcal polysaccharide group C, have been examined for the distribution of their immunoglobulin classes and subclasses. Whereas the thymus-independent anti-alpha (1 leads to 3) dextran response in BALB/c mice was found to be IgM greater than IgG3 greater than IgA, thus corresponding to previously published work, neither the alpha (1 leads to 6) response in its thymus-dependent or-independent form, nor the response to purified meningococcal polysaccharide, corresponded to this pattern. No preference for any of the IgG subclasses appeared for these antigens when given as thymus-independent carbohydrates. On the other hand, thymus-dependent forms of alpha (1 leads to 6) dextran showed an IgG1 greater than IgG3 greater than IgG2 pattern.