Risk of cardiovascular mortality in patients with rheumatoid arthritis: a meta-analysis of observational studies

OBJECTIVE

To determine the magnitude of risk of cardiovascular mortality in patients with rheumatoid arthritis (RA) compared with the general population through a meta-analysis of observational studies.

METHODS

We searched Medline, EMBase, and Lilacs databases from their inception to July 2005. Observational studies that met the following criteria were assessed by 2 researchers: 1) prespecified RA definition, 2) clearly defined cardiovascular disease (CVD) outcome, including ischemic heart disease (IHD) and cerebrovascular accidents (CVAs), and 3) reported standardized mortality ratios (SMRs) and 95% confidence intervals (95% CIs). We calculated weighted-pooled summary estimates of SMRs (meta-SMRs) for CVD, IHD, and CVAs using the random-effects model, and tested for heterogeneity using the I(2) statistic.

RESULTS

Twenty-four studies met the inclusion criteria, comprising 111,758 patients with 22,927 cardiovascular events. Overall, there was a 50% increased risk of CVD death in patients with RA (meta-SMR 1.50, 95% CI 1.39-1.61). Mortality risks for IHD and CVA were increased by 59% and 52%, respectively (meta-SMR 1.59, 95% CI 1.46-1.73 and meta-SMR 1.52, 95% CI 1.40-1.67, respectively). We identified asymmetry in the funnel plot (Egger's test P = 0.002), as well as significant heterogeneity in all main analyses (P < 0.0001). Subgroup analyses showed that inception cohort studies (n = 4, comprising 2,175 RA cases) were the only group that did not show a significantly increased risk for CVD (meta-SMR 1.19, 95% CI 0.86-1.68).

CONCLUSION

Published data indicate that CVD mortality is increased by approximately 50% in RA patients compared with the general population. However, we found that study characteristics may influence the estimate.

Risk of incident cardiovascular events in patients with rheumatoid arthritis: a meta-analysis of observational studies

OBJECTIVE

To determine the magnitude of the risk of incident cardiovascular disease (CVD; fatal and non-fatal), including acute myocardial infarction (MI), cerebrovascular accidents (CVA) and congestive heart failure (CHF), in patients with rheumatoid arthritis (RA) compared to the general population through a meta-analysis of controlled observational studies.

METHODS

The authors searched the Medline, Embase, LILACS and Cochrane databases from their inception to June 2011. Observational studies meeting the following criteria were included: (1) prespecified RA criteria; (2) predefined CVD criteria for incident CVD (MI, CVA or CHF); (3) a comparison group; and (4) RR estimates, 95% CI or data for calculating them. The authors calculated the pooled RR using the random-effects model and tested for heterogeneity using the bootstrap version of the Q statistic.

RESULTS

Fourteen studies comprising 41 490 patients met the inclusion criteria. Overall, there was a 48% increased risk of incident CVD in patients with RA (pooled RR 1.48 (95% CI 1.36 to 1.62)). The risks of MI and CVA were increased by 68% (pooled RR 1.68 (95% CI 1.40 to 2.03)) and 41% (pooled RR 1.41 (95% CI 1.14 to 1.74)). The risk of CHF was assessed in only one study (RR 1.87 (95% CI 1.47 to 2.39)). Significant heterogeneity existed in all main analyses. Subgroup analyses showed that inception cohort studies were the only group that did not show a significantly increased risk of CVD (pooled RR 1.12 (95% CI 0.97 to 1.65)).

CONCLUSIONS

Published data indicate that the risk of incident CVD is increased by 48% in patients with RA compared to the general population. Sample and cohort type influenced the estimates of RR.

Validity of Diagnostic Codes for Acute Stroke in Administrative Databases: A Systematic Review

OBJECTIVE

To conduct a systematic review of studies reporting on the validity of International Classification of Diseases (ICD) codes for identifying stroke in administrative data.

METHODS

MEDLINE and EMBASE were searched (inception to February 2015) for studies: (a) Using administrative data to identify stroke; or (b) Evaluating the validity of stroke codes in administrative data; and (c) Reporting validation statistics (sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), or Kappa scores) for stroke, or data sufficient for their calculation. Additional articles were located by hand search (up to February 2015) of original papers. Studies solely evaluating codes for transient ischaemic attack were excluded. Data were extracted by two independent reviewers; article quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool.

RESULTS

Seventy-seven studies published from 1976-2015 were included. The sensitivity of ICD-9 430-438/ICD-10 I60-I69 for any cerebrovascular disease was ≥ 82% in most [≥ 50%] studies, and specificity and NPV were both ≥ 95%. The PPV of these codes for any cerebrovascular disease was ≥ 81% in most studies, while the PPV specifically for acute stroke was ≤ 68%. In at least 50% of studies, PPVs were ≥ 93% for subarachnoid haemorrhage (ICD-9 430/ICD-10 I60), 89% for intracerebral haemorrhage (ICD-9 431/ICD-10 I61), and 82% for ischaemic stroke (ICD-9 434/ICD-10 I63 or ICD-9 434&436). For in-hospital deaths, sensitivity was 55%. For cerebrovascular disease or acute stroke as a cause-of-death on death certificates, sensitivity was ≤ 71% in most studies while PPV was ≥ 87%.

CONCLUSIONS

While most cases of prevalent cerebrovascular disease can be detected using 430-438/I60-I69 collectively, acute stroke must be defined using more specific codes. Most in-hospital deaths and death certificates with stroke as a cause-of-death correspond to true stroke deaths. Linking vital statistics and hospitalization data may improve the ascertainment of fatal stroke.

Impact of statin adherence on cardiovascular disease and mortality outcomes: a systematic review

AIMS

While suboptimal adherence to statin medication has been quantified in real-world patient settings, a better understanding of its impact is needed, particularly with respect to distinct problems of medication taking. Our aim was to synthesize current evidence on the impacts of statin adherence, discontinuation and persistence on cardiovascular disease and mortality outcomes.

METHODS

We conducted a systematic review of peer-reviewed studies using a mapped search of Medline, Embase and International Pharmaceutical Abstracts databases. Observational studies that met the following criteria were included: defined patient population;statin adherence exposure; defined study outcome [i.e. cardiovascular disease (CVD), mortality]; and reporting of statin-specific results.

RESULTS

Overall, 28 studies were included, with 19 studies evaluating outcomes associated with statin adherence, six with statin discontinuation and three with statin persistence. Among adherence studies, the proportion of days covered was the most widely used measure, with the majority of studies reporting increased risk of CVD (statistically significant risk estimates ranging from 1.22 to 5.26)and mortality (statistically significant risk estimates ranging from 1.25 to 2.54) among non-adherent individuals. There was greater methodological variability in discontinuation and persistence studies. However, findings of increased CVD (statistically significant risk estimates ranging from 1.22 to 1.67) and mortality (statistically significant risk estimates ranging from 1.79 to 5.00) among nonpersistent individuals were also consistently reported.

CONCLUSIONS

Observational studies consistently report an increased risk of adverse outcomes associated with poor statin adherence. These findings have important implications for patients and physicians and emphasize the importance of monitoring and encouraging adherence to statin therapy.

Validity of myocardial infarction diagnoses in administrative databases: a systematic review

BACKGROUND

Though administrative databases are increasingly being used for research related to myocardial infarction (MI), the validity of MI diagnoses in these databases has never been synthesized on a large scale.

OBJECTIVE

To conduct the first systematic review of studies reporting on the validity of diagnostic codes for identifying MI in administrative data.

METHODS

MEDLINE and EMBASE were searched (inception to November 2010) for studies: (a) Using administrative data to identify MI; or (b) Evaluating the validity of MI codes in administrative data; and (c) Reporting validation statistics (sensitivity, specificity, positive predictive value (PPV), negative predictive value, or Kappa scores) for MI, or data sufficient for their calculation. Additonal articles were located by handsearch (up to February 2011) of original papers. Data were extracted by two independent reviewers; article quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool.

RESULTS

Thirty studies published from 1984-2010 were included; most assessed codes from the International Classification of Diseases (ICD)-9th revision. Sensitivity and specificity of hospitalization data for identifying MI in most [≥50%] studies was ≥86%, and PPV in most studies was ≥93%. The PPV was higher in the more-recent studies, and lower when criteria that do not incorporate cardiac troponin levels (such as the MONICA) were employed as the gold standard. MI as a cause-of-death on death certificates also demonstrated lower accuracy, with maximum PPV of 60% (for definite MI).

CONCLUSIONS

Hospitalization data has higher validity and hence can be used to identify MI, but the accuracy of MI as a cause-of-death on death certificates is suboptimal, and more studies are needed on the validity of ICD-10 codes. When using administrative data for research purposes, authors should recognize these factors and avoid using vital statistics data if hospitalization data is not available to confirm deaths from MI.

Gaps in care for rheumatoid arthritis: A population study

OBJECTIVE

Treatment guidelines for rheumatoid arthritis (RA) now recommend early, aggressive, and persistent use of disease-modifying antirheumatic drugs (DMARDs) to prevent joint damage in all people with active inflammation, and evaluation by a rheumatologist, when possible. This research assesses whether care for RA, at a population level, is consistent with current treatment guidelines.

METHODS

Using administrative billing data from the Ministry of Health in 1996-2000, all prevalent RA cases in British Columbia, Canada were identified. Data were obtained on all medications and all provincially-funded health care services.

RESULTS

We identified 27,710 RA cases, yielding a prevalence rate of 0.76%, consistent with epidemiologic studies. DMARD use was inappropriately low. Only 43% of the entire RA cohort received a DMARD at least once over 5 years, and 35% over 2 years. When used, DMARDs were started in a timely fashion, but were not used consistently. Care by a rheumatologist increased DMARD use 31-fold. Yet, only 48% and 34% saw a rheumatologist over 5 and 2 years, respectively. DMARD use was significantly more frequent, persistent, and more often used as combination therapy with continuous rheumatologist care. DMARDs were used by 84% and 73%, 40%, and 10% of people followed by rheumatologists continuously and intermittently, internists, and family physicians, respectively (P < 0.001). NSAID use, physiotherapy, and orthopedic surgeries were similar across these 4 care groups.

CONCLUSION

RA care in the British Columbia population was not consistent with current treatment guidelines. Efforts to educate family physicians and consumers about the shift in RA treatment paradigms and to improve access to rheumatologists are needed.

Validity of heart failure diagnoses in administrative databases: a systematic review and meta-analysis

Objective

Heart failure (HF) is an important covariate and outcome in studies of elderly populations and cardiovascular disease cohorts, among others. Administrative data is increasingly being used for long-term clinical research in these populations. We aimed to conduct the first systematic review and meta-analysis of studies reporting on the validity of diagnostic codes for identifying HF in administrative data.

Methods

MEDLINE and EMBASE were searched (inception to November 2010) for studies: (a) Using administrative data to identify HF; or (b) Evaluating the validity of HF codes in administrative data; and (c) Reporting validation statistics (sensitivity, specificity, positive predictive value [PPV], negative predictive value, or Kappa scores) for HF, or data sufficient for their calculation. Additional articles were located by hand search (up to February 2011) of original papers. Data were extracted by two independent reviewers; article quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. Using a random-effects model, pooled sensitivity and specificity values were produced, along with estimates of the positive (LR+) and negative (LR−) likelihood ratios, and diagnostic odds ratios (DOR = LR+/LR−) of HF codes.

Results

Nineteen studies published from1999–2009 were included in the qualitative review. Specificity was ≥95% in all studies and PPV was ≥87% in the majority, but sensitivity was lower (≥69% in ≥50% of studies). In a meta-analysis of the 11 studies reporting sensitivity and specificity values, the pooled sensitivity was 75.3% (95% CI: 74.7–75.9) and specificity was 96.8% (95% CI: 96.8–96.9). The pooled LR+ was 51.9 (20.5–131.6), the LR− was 0.27 (0.20–0.37), and the DOR was 186.5 (96.8–359.2).

Conclusions

While most HF diagnoses in administrative databases do correspond to true HF cases, about one-quarter of HF cases are not captured. The use of broader search parameters, along with laboratory and prescription medication data, may help identify more cases.

Increased risk of cardiovascular and cerebrovascular diseases in individuals with ankylosing spondylitis: a population-based study

OBJECTIVE

To estimate the excess risk of cardiovascular and cerebrovascular diseases among individuals with ankylosing spondylitis (AS) in Quebec compared with the general population of Quebec.

METHODS

A retrospective cohort study was conducted using population-based administrative data from Quebec. The cohort included all adult individuals with at least 1 AS diagnosis on physician billing or hospital discharge records between 1996 and 2006. A comparison cohort was generated using a 1% random sample of individuals without AS. Cardiovascular and cerebrovascular diseases, and associated hospitalizations, were classified into 1 of 6 subcategories: congestive heart failure, valvular (aortic or nonaortic) heart disease, ischemic heart disease, cerebrovascular disease, or "other" cardiovascular disease. The age- and sex-stratified prevalence estimates, and standardized prevalence ratios, of cardiovascular or cerebrovascular disease in patients with AS, compared to that in the general population, were calculated.

RESULTS

The AS cohort included 8,616 individuals diagnosed over the period 1996-2006. The prevalence of cardiovascular and cerebrovascular diseases increased with increasing age for all cardiovascular disease subgroups, and was similar for individuals of both sexes. Age- and sex-stratified prevalence ratios were highest in younger individuals with AS. The age- and sex-standardized prevalence ratios comparing the risk among those with AS to the risk in the general population were as follows: for aortic valvular heart disease 1.58 (95% confidence interval [95% CI] 1.31-1.91), for nonaortic valvular heart disease 1.58 (95% CI 1.43-1.74), for ischemic heart disease 1.37 (95% CI 1.31-1.44), for congestive heart failure 1.34 (95% CI 1.26-1.42), for "other" cardiovascular disease 1.36 (95% CI 1.29-1.44), for cerebrovascular disease 1.25 (95% CI 1.15-1.35), and for any hospitalization for a cardiovascular or cerebrovascular disease 1.31 (95% CI 1.22-1.41).

CONCLUSION

Compared with the general population, patients with AS are at increased risk for many types of cardiovascular and cerebrovascular diseases, and are more likely to be hospitalized for these diseases. The excess risk is greatest in younger patients with AS.

Use of nonbiologic disease-modifying antirheumatic drugs and risk of infection in patients with rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is associated with increased frequency of and mortality from infections, which may be related to host factors, RA itself, inflammation, or medication side effects. This study was undertaken to determine the effect of nonbiologic disease-modifying antirheumatic drugs (DMARDs) on infection risk in RA.

METHODS

We performed a retrospective, longitudinal study of a population-based RA cohort in British Columbia, Canada, followed from January 1996 to March 2003 using administrative data. We evaluated mild infections (requiring a physician visit or antibiotics) and serious infections (requiring or complicating hospitalization). Adjusted risk of mild and serious infections associated with DMARD exposure was estimated using generalized estimating equation extension of multivariate Poisson regression models, after adjusting for baseline covariates (age, sex, RA duration, socioeconomic status) and time-dependent covariates (corticosteroids, comorbidity, prior infections).

RESULTS

A total of 27,710 individuals with RA provided 162,710 person-years of followup. Of these, 25,608 (92%) had at least 1 mild infection and 4,941 (18%) had at least 1 serious infection. Use of DMARDs without corticosteroids was associated with a small decrease in mild infection risk of statistical significance but unclear clinical significance (adjusted rate ratio [RR] 0.90, 95% confidence interval [95% CI] 0.88-0.93 relative to no corticosteroid or DMARD use). Use of DMARDs without corticosteroids was not associated with increased serious infection risk (adjusted RR 0.92, 95% CI 0.85-1.0). Use of corticosteroids increased the risk of mild and serious infections.

CONCLUSION

Our results indicate that use of nonbiologic DMARDs, including methotrexate, does not increase the risk of infection in RA, whereas use of corticosteroids does. This has important implications for counseling individuals with RA concerning risks and benefits of DMARDs.

Immediate and past cumulative effects of oral glucocorticoids on the risk of acute myocardial infarction in rheumatoid arthritis: a population-based study

OBJECTIVES

To determine the effect of glucocorticoids (GCs) on acute myocardial infarction (MI) risk in patients with RA.

METHODS

Using administrative health data, we conducted a population-based cohort study of 8384 incident RA cases (1997-2006). Primary exposure was incident GC use. MI events were ascertained using hospitalization and vital statistics data. We used Cox proportional-hazards models and modelled GC use as four alternative time-dependent variables (current use, current dose, cumulative dose and cumulative duration), adjusting for demographics, comorbidities, cardiovascular drug use, propensity score and RA characteristics. Sensitivity analyses explored potential effects of unmeasured confounding.

RESULTS

Within 50 238 person-years in 8384 RA cases, we identified 298 incident MI events. Multivariable models showed that current GC use was associated with 68% increased risk of MI [Hazard ratio (HR) = 1.68, 95% CI 1.14, 2.47]. Similarly, separate multivariable models showed that current daily dose (HR = 1.14, 95% CI 1.05, 1.24 per each 5 mg/day increase), cumulative duration of use (HR = 1.14, 95% CI 1.00, 1.29 per year of GC use) and total cumulative dose (HR = 1.06, 95% CI 1.02, 1.10 per gram accumulated in the past) were also associated with increased risk of MI. Furthermore, in the same multivariable model, current dose and cumulative use were independently associated with an increased risk of MI (10% per additional year on GCs and 13% per 5 mg/day increase).

CONCLUSION

GCs are associated with an increased risk of MI in RA. Our results suggest a dual effect of GCs on MI risk, an immediate effect mediated through current dosage and a long-term effect of cumulative exposure.

Improvement in 5-year mortality in incident rheumatoid arthritis compared with the general population-closing the mortality gap

OBJECTIVE

Excess mortality in rheumatoid arthritis (RA) is expected to have improved over time, due to improved treatment. Our objective was to evaluate secular 5-year mortality trends in RA relative to general population controls in incident RA cohorts diagnosed in 1996-2000 vs 2001-2006.

METHODS

We conducted a population-based cohort study, using administrative health data, of all incident RA cases in British Columbia who first met RA criteria between January 1996 and December 2006, with general population controls matched 1:1 on gender, birth and index years. Cohorts were divided into earlier (RA onset 1996-2000) and later (2001-2006) cohorts. Physician visits and vital statistics data were obtained until December 2010. Follow-up was censored at 5 years to ensure equal follow-up in both cohorts. Mortality rates, mortality rate ratios and HRs for mortality (RA vs controls) using proportional hazard models adjusting for age, were calculated. Differences in mortality in RA versus controls between earlier and later incident cohorts were tested via interaction between RA status (case/control) and cohort (earlier/later).

RESULTS

24 914 RA cases and controls experienced 2747 and 2332 deaths, respectively. Mortality risk in RA versus controls differed across incident cohorts for all-cause, cardiovascular diseases (CVD) and cancer mortality (interactions p<0.01). A significant increase in mortality in RA versus controls was observed in earlier, but not later, cohorts (all-cause mortality adjusted HR (95% CI): 1.40 (1.30 to 1.51) and 0.97 (0.89 to 1.05), respectively).

CONCLUSIONS

In our population-based incident RA cohort, mortality compared with the general population improved over time. Increased mortality in the first 5 years was observed in people with RA onset before, but not after, 2000.

Problems faced at work due to inflammatory arthritis: new insights gained from understanding patients' perspective

OBJECTIVE

A qualitative study was conducted to better understand patients' perspective on their experience at work in relation to their inflammatory arthritis (IA). Objectives were to identify the problems and barriers to employment that persons with IA face at work because of arthritis, understand why these issues are problematic, and identify strategies helpful for maintaining employment.

METHODS

Five focus groups were conducted with 36 employed adults with IA (75% rheumatoid arthritis) recruited from rheumatology practices and outpatient arthritis treatment programs. Script design used brainstorming techniques to identify problems and helpful strategies, and root cause analysis to capture in-depth information about underlying causes of problems. Descriptive qualitative analysis of transcripts was performed by 2 researchers independently to identify problems and organize them into topics and broad categories.

RESULTS

Problems clustered around 4 categories: arthritis symptoms, working conditions, interpersonal difficulties at work, and emotional challenges. New insights gained included identifying fatigue as the aspect of IA most limiting employment; challenges posed by invisibility, fluctuation, and unpredictability of arthritis; complexity of interpersonal relationships at work; reluctance to disclose or draw attention to arthritis; numerous barriers to using available supports and requesting job accommodations, including fear of disclosure and concern it could be perceived by coworkers as favoritism; loss of self-efficacy at work; and many emotional challenges.

CONCLUSION

This research identified new issues that are meaningful to individuals working with arthritis and that deserve greater attention by professionals counseling people on employment, in intervention efforts to help maintain employment, and in arthritis employment studies.

Steroid-sparing effects of methotrexate in systemic lupus erythematosus: a double-blind, randomized, placebo-controlled trial

OBJECTIVE

To assess the potential benefits of methotrexate in patients with systemic lupus erythematosus (SLE).

METHODS

A 12-month, double-blind, placebo-controlled trial of methotrexate with folic acid was conducted. Intent-to-treat analyses were performed with mixed linear models and alpha = 0.04 (96% confidence interval [96% CI]) to account for interim analysis of longitudinal data to assess the treatment effects on lupus disease activity and daily steroid dose across monthly measurements, and to test if the treatment effects depended on selected participant characteristics.

RESULTS

Of 215 participants screened, 94 were excluded, 35 declined, and 86 were randomized (methotrexate = 41, placebo = 45). The groups were balanced for demographic and disease characteristics. Antimalarial use was more frequent in the placebo group, which was adjusted for in multivariable analyses. Sixty participants (27 methotrexate, 33 placebo) completed the study and 26 terminated early. Among participants who had the same baseline prednisone dose, those taking methotrexate received, on average, 1.33 mg/day less prednisone during the trial period (96% CI 0.06, 2.72 mg/day; a 22% reduction of their average-during-trial daily dose) compared with those in the placebo group. For the primary measure of disease activity (revised Systemic Lupus Activity Measure), methotrexate use was also associated with a marginally significant reduction in the mean during-trial score of 0.86 units (96% CI 0.01, 1.71; P = 0.039). A significant interaction between treatment and baseline damage was found (P = 0.001).

CONCLUSION

Methotrexate conferred a significant advantage in participants with moderately active lupus by lowering daily prednisone dose and slightly decreasing lupus disease activity. As a therapeutic option in moderate SLE, methotrexate can be considered to be steroid sparing.

Managing arthritis and employment: Making arthritis-related work changes as a means of adaptation

OBJECTIVE

To understand arthritis-related workplace changes, including occasional work loss and changes to the type and hours of work, and the factors associated with them using theories of adaptation and behavior change as a framework.

METHODS

Participants were 492 employed individuals with rheumatoid arthritis or osteoarthritis. They completed an interview-administered, structured questionnaire assessing demographic, workplace, and psychosocial variables, as well as such work transitions as changes to the hours, type, and nature of work. Hypotheses were examined using multiple linear regression.

RESULTS

Seventy percent of respondents made at least 1 work change. Younger participants and those with greater workplace activity limitations reported more changes. Work changes were associated with greater depression. A hypothesized 3-way interaction among people's perceptions of their capacity, their future job expectations, and whether they had told their employer about their arthritis was significant.

CONCLUSION

This study extends arthritis employment research by examining a range of work changes. It highlights the dynamic interplay among arthritis, workplace, and psychosocial variables to understand adaptation to arthritis disability.

Malignancies in the rheumatoid arthritis abatacept clinical development programme: an epidemiological assessment

OBJECTIVE

To provide context for the malignancy experience in the rheumatoid arthritis (RA) abatacept clinical development programme (CDP) by performing comparisons with similar RA patients and the general population.

METHODS

Malignancy outcomes included total malignancy (excluding non-melanoma skin cancer (NMSC)), breast, colorectal, lung cancers and lymphoma. Comparisons were made between the observed incidence in patients within the abatacept CDP and RA patients on disease-modifying antirheumatic drugs (DMARD) identified from five data sources: the population-based British Columbia RA Cohort, the Norfolk Arthritis Register, the National Data Bank for Rheumatic Diseases, the Sweden Early RA Register and the General Practice Research Database. Age and sex-adjusted incidence rates (IR) and standardised incidence ratios (SIR) were used to compare events in the abatacept trials with the RA DMARD cohorts and the general population.

RESULTS

A total of 4134 RA patients treated with abatacept in seven trials and 41,529 DMARD-treated RA patients in the five observational cohorts was identified for study inclusion. In the abatacept-treated patients, the 51 malignancies (excluding NMSC), seven cases of breast, two cases of colorectal, 13 cases of lung cancer and five cases of lymphoma observed were not greater than the range of expected cases from the five RA cohorts. The SIR comparing RA patients with the general population were consistent with those reported in the literature.

CONCLUSIONS

The IR of total malignancy (excluding NMSC), breast, colorectal, lung cancers and lymphoma in the abatacept CDP were consistent with those in a comparable RA population. These data suggest no new safety signals with respect to malignancies, which will continue to be monitored.

Association between dinucleotide repeat in non-coding region of interferon-gamma gene and susceptibility to, and severity of, rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis ranges from a mild, non-deforming arthropathy with little long-term disability to severe, incapacitating, deforming arthritis which may be refractory to conventional disease-modifying agents. Epidemiological studies show an important genetic influence in rheumatoid arthritis, and MHC region genes and cytokine genes within and outside this region have been considered as candidates. We did a case-control study to test whether polymorphisms in the interferon-gamma gene are associated with severity of rheumatoid arthritis.

METHODS

Interferon gamma dinucleotide repeat polymorphisms were examined with quantitative genescan technology, and HLA-DR alleles were identified by PCR and restriction-fragment-length polymorphism analysis. We studied 60 patients with severe rheumatoid arthritis, 39 with mild disease, and 65 normal controls.

FINDINGS

Susceptibility to, and severity of, rheumatoid arthritis were related to a microsatellite polymorphism within the first intron of the interferon-gamma gene. A 126 bp allele was seen in 44 (73%) of 60 patients with severe rheumatoid arthritis, compared with eight (21%) of 39 with mild disease (odds ratio 10.66 [95% CI 4.1-24.9]), and with eight (12%) of 65 normal controls (19.59 [7.7-49.9]). Conversely, a 122 bp allele at the same locus was found in four (7%) patients with severe disease compared with 25 (64%) of those with mild disease (0.04 [0.01-0.1]) and with 52 (80%) of controls (0.018 [0.005-0.06]).

INTERPRETATION

This association may be valuable for understanding the mechanism of disease progression, for predicting the course of the disease, and for guiding therapy.

Systematic review and meta-analysis of validation studies on a diabetes case definition from health administrative records

OBJECTIVES

Health administrative data are frequently used for diabetes surveillance. We aimed to determine the sensitivity and specificity of a commonly-used diabetes case definition (two physician claims or one hospital discharge abstract record within a two-year period) and their potential effect on prevalence estimation.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched Medline (from 1950) and Embase (from 1980) databases for validation studies through August 2012 (keywords: "diabetes mellitus"; "administrative databases"; "validation studies"). Reviewers abstracted data with standardized forms and assessed quality using Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria. A generalized linear model approach to random-effects bivariate regression meta-analysis was used to pool sensitivity and specificity estimates. We applied correction factors derived from pooled sensitivity and specificity estimates to prevalence estimates from national surveillance reports and projected prevalence estimates over 10 years (to 2018).

RESULTS

The search strategy identified 1423 abstracts among which 11 studies were deemed relevant and reviewed; 6 of these reported sensitivity and specificity allowing pooling in a meta-analysis. Compared to surveys or medical records, sensitivity was 82.3% (95%CI 75.8, 87.4) and specificity was 97.9% (95%CI 96.5, 98.8). The diabetes case definition underestimated prevalence when it was ≤10.6% and overestimated prevalence otherwise.

CONCLUSION

The diabetes case definition examined misses up to one fifth of diabetes cases and wrongly identifies diabetes in approximately 2% of the population. This may be sufficiently sensitive and specific for surveillance purposes, in particular monitoring prevalence trends. Applying correction factors to adjust prevalence estimates from this definition may be helpful to increase accuracy of estimates.

Identification of modifiable work-related factors that influence the risk of work disability in rheumatoid arthritis

OBJECTIVE

To define work-related factors associated with increased risk of work disability (WD) in people with rheumatoid arthritis (RA).

METHODS

Questionnaires were mailed to all RA patients who used a province-wide arthritis treatment program between 1991 and 1998 (n = 1,824). The association between risk factors and WD (defined as no paid work due to RA for at least 6 months) was assessed using multiple logistic regression analysis, controlling for significant sociodemographic and disease-related variables.

RESULTS

Of the original 1,824 patients, 581 were eligible and responded to the questionnaire. Work survival analysis revealed a steady rate of WD starting early, with 7.5%, 18%, and 27% work disabled at 1, 5, and 10 years, respectively. Significant determinants in multiple logistic regression were physical function (Health Assessment Questionnaire), pain (visual analog scale), and 6 work-related factors: self employment, workstation modification, work importance, family support toward employment, commuting difficulty, and comfort telling coworkers about RA.

CONCLUSION

Work disability occurs early in RA. Novel work-related factors were identified, which are potentially modifiable, to help RA patients stay employed.

Determination of the minimal clinically important difference for seven fatigue measures in rheumatoid arthritis

OBJECTIVE

To estimate the minimal clinically important difference (MCID) of seven measures of fatigue in rheumatoid arthritis.

STUDY DESIGN AND SETTING

A cross-sectional study design based on interindividual comparisons was used. Six to eight subjects participated in a single meeting and completed seven fatigue questionnaires (nine sessions were organized and 61 subjects participated). After completion of the questionnaires, the subjects had five one-on-one 10-minute conversations with different people in the group to discuss their fatigue. After each conversation, each patient compared their fatigue to their conversational partners on a global rating. Ratings were compared to the scores of the fatigue measures to estimate the MCID. Both nonparametric and linear regression analyses were used.

RESULTS

Nonparametric estimates for the MCID relative to "little more fatigue" tended to be smaller than those for "little less fatigue." The global MCIDs estimated by linear regression were: Fatigue Severity Scale, 20.2; Vitality scale of the MOS-SF36, 14.8; Multidimensional Assessment of Fatigue, 18.7; Multidimensional Fatigue Inventory, 16.6; Functional Assessment of Chronic Illness Therapy-Fatigue, 15.9; Chalder Fatigue Scale, 9.9; 10-point numerical Rating Scale, 19.7, for normalized scores (0-100). The standardized MCIDs for the seven measures were roughly similar (0.67-0.76).

CONCLUSION

These estimates of MCID will help to interpret changes observed in a fatigue score and will be critical in estimating sample size requirements.

Stand Up and Be Counted: Measuring and Mapping the Rheumatology Workforce in Canada

OBJECTIVE

To characterize the practicing rheumatologist workforce, the Canadian Rheumatology Association (CRA) launched the Stand Up and Be Counted workforce survey in 2015.

METHODS

The survey was distributed electronically to 695 individuals, of whom 519 were expected to be practicing rheumatologists. Demographic and practice information were elicited. We estimated the number of full-time equivalent rheumatologists per 75,000 population from the median proportion of time devoted to clinical practice multiplied by provincial rheumatologist numbers from the Canadian Medical Association.

RESULTS

The response rate was 68% (355/519) of expected practicing rheumatologists (304 were in adult practice, and 51 pediatric). The median age was 50 years, and one-third planned to retire within the next 5-10 years. The majority (81%) were university-affiliated. Rheumatologists spent a median of 70% of their time in clinical practice, holding 6 half-day clinics weekly, with 10 new consultations and 45 followups seen per week. Work characteristics varied by type of rheumatologist (adult or pediatric) and by practice setting (community- or university-based). We estimated between 0 and 0.8 full-time rheumatologists per 75,000 population in each province. This represents a deficit of 1 to 77 full-time rheumatologists per province/territory to meet the CRA recommendation of 1 rheumatologist per 75,000 population, depending on the province/territory.

CONCLUSION

Our results highlight a current shortage of rheumatologists in Canada that may worsen in the next 10 years because one-third of the workforce plans to retire. Efforts to encourage trainees to enter rheumatology and strategies to support retention are critical to address the shortage.

The validity of administrative data to identify hip fractures is high--a systematic review

OBJECTIVE

To determine the validity of the diagnostic algorithms for osteoporosis and fractures in administrative data.

STUDY DESIGN AND SETTING

A systematic search was conducted to identify studies that reported the validity of a diagnostic algorithm for osteoporosis and/or fractures using administrative data.

RESULTS

Twelve studies were reviewed. The validity of the diagnosis of osteoporosis in administrative data was fair when at least 3 years of data from hospital and physician visit claims were used (area under the receiver operating characteristic [ROC] curve [AUC]=0.70) or when pharmacy data were used (with or without the use of hospital and physician visit claims data, AUC>0.70). Nonetheless, the positive predictive values (PPVs) were low (<0.60). There was good evidence to support the use of hospital data to identify hip fractures (sensitivity: 69-97%; PPV: 63-96%) and the addition of physician claims diagnostic and procedural codes to hospitalization diagnostic codes improved these characteristics (sensitivity: 83-97%; PPV: 86-98%). Vertebral fractures were difficult to identify using administrative data. There was some evidence to support the use of administrative data to define other fractures that do not require hospitalization.

CONCLUSIONS

Administrative data can be used to identify hip fractures. Existing diagnostic algorithms to identify osteoporosis and vertebral fractures in administrative data are suboptimal.

A Canadian study of the total medical costs for patients with systemic lupus erythematosus and the predictors of costs

OBJECTIVE

We conducted a cost identification analysis on 164 consecutive patients with systemic lupus erythematosus (SLE) who entered the Montreal General Hospital Lupus Registry between January 1977 and January 1990, compared their costs to the population of Quebec, and determined the predictors of cost.

METHODS

In January 1990 and 1991, participants completed questionnaires on health services utilization and on employment history over the preceding 6 months, as well as on functional, psychological, and social well-being. The societal burden of SLE was determined in terms of direct costs (all resources consumed in patient care) and indirect costs (wages lost due to lack of work force participation because of morbidity).

RESULTS

The mean total annual cost for 1989, as assessed in January 1990 and expressed in 1990 Canadian dollars, was $13,094. Although only 44% of the patients were fully employed, indirect costs were responsible for 54% of this total ($7,071). Ambulatory costs, primarily diagnostic procedures, medications, and visits to health care professionals, comprised 55% of direct costs ($3,331). The results of the 1990 cost determination were similar. On average, hospitalizations among SLE patients were 4 times more frequent than among the general population of Quebec (matched for age and sex), and the number of ambulatory visits to physicians was double that for the average resident of Quebec. Higher 1989 values of creatinine and a poorer level of physical functioning were the best predictors of higher 1990 direct costs (R2 = 0.29). A poorer SLE well-being score, a combination of education and employment status, and a weaker level of social support were the best predictors of higher indirect costs (R2 = 0.29).

CONCLUSION

The direct and indirect costs for patients with SLE are substantial, and their respective predictors are distinct. Direct costs arise from organic complications which induce functional disability. Predictors of indirect costs are potentially amenable to psychological or social interventions and may be more easily modified than the determinants of direct costs, thereby improving patient outcome while simultaneously reducing disease costs.