Quantitative measures to assess, monitor and predict morbidity and mortality in rheumatoid arthritis

Comparison of psychometric properties between the Labin, a new electronic dynamometer, and the Jamar: Preliminary results in healthy subjects

Many instruments exist for measuring grip strength. The Jamar hydraulic hand dynamometer is currently the gold standard. The Labin is a prototype electronic dynamometer that can also measure maximum grip strength. The main objective was to compare the Labin dynamometer with the gold standard instrument, the Jamar, in a healthy population, and secondarily to compare discomfort during use. A single-center exploratory study was conducted. The subjects enrolled had to be aged between 20 and 60, be volunteers and give consent. The required number of subjects was 30. The subjects were positioned according to American Society of Hand Therapists recommendations. Maximum grip force was measured in kilograms using the mean of three successive trials. The first dynamometer used was chosen randomly. The handle's discomfort during use was rated on a simple verbal scale from 0 to 10. Thirty-four subjects were included. The concordance coefficient for peak torque between the Labin and Jamar dynamometers was 0.90 for the dominant hand and 0.83 for the non-dominant hand. The intraclass correlation coefficient for peak torque with the Labin was 0.81 [0.69; 0.89] for the dominant hand and 0.86 [0.76; 0.92] for the non-dominant hand. In our study, we have shown that the Labin prototype has acceptable validity and reproducibility. The Labin will need to be tested in pathological conditions next.

Changes and sex differences in patient reported outcomes in rheumatoid factor positive RA-results from a community based study

BACKGROUND

Patient reported outcomes (PROs) are important measures in rheumatoid arthritis (RA). A register of patients with RA from all rheumatology care providers in Malmö, Sweden, was established in 1997 and has been continually updated. This register includes virtually all the RA patients in the area. The aim of this study was to analyse PROs in surveys of this population conducted between 1997 and 2009, and to assess differences in treatment and outcome in male and female patients.

METHOD

In 1997, 2002, 2005 and 2009, questionnaires were sent to the RA patients in the register (n = 1016 in 1997; n = 916 in 2002; n = 1625 in 2005; n = 1700 in 2009). Response rates varied between 62 % and 74 %, and 72-74 % was women. Questionnaire data included medication and measures of disability and health related quality of life. Data on rheumatoid factor (RF) tests were retrieved from the databases of the two clinical immunology laboratories in the area. In order to limit the impact of changes in the case mix over time, the study was restricted to RF positive patients. The analyses were stratified by sex.

RESULTS

Patients reported less severe outcomes for all measures in the later surveys compared to 1997, and patients' global disease activity assessment and self-reported pain were further improved in 2009 compared to 2005. Treatment with biologics increased over time from 1997 (none) to 2009 (29%), with no difference between men and women. Visual analogue scales (0-100) for patients' global assessment of disease activity [mean 45 (95 % CI (45-47) vs. 38 (35-40)] and pain [mean 46 (44-49) vs. 38 (36-40)] decreased from 1997 to 2009, with numerically greater improvement in male patients. The mean SF-36 physical component scores also improved, and were higher in men than in women in all surveys.

CONCLUSION

Pharmacologic treatment of RA became more extensive over time, and there was improvement in all PROs. Despite similar treatment, male patients reported better outcomes, in particular for pain and physical function, compared to female patients. We suggest that patient reported outcomes should be reported separately in male and female patients with RA.

Diagnostic and prognostic potential of gene microarrays in rheumatoid arthritis

Rheumatoid arthritis and juvenile rheumatoid arthritis are histopathologically similar diseases characterized by chronic inflammation of the synovium. The pathogenesis of these diseases is unknown, but the emergence of gene expression profiling provides considerable promise that some of the complex, interconnected immunopathologic events underlying these diseases will soon be better understood. This review will summarize the potential use of gene expression profiling as a diagnostic or prognostic modality, and the potential benefits or limits of such uses. It will conclude with a short discussion of the potential for using gene expression profiling to identify novel targets of therapy in rheumatoid arthritis and related diseases.

Remission by composite scores in rheumatoid arthritis: are ankles and feet important?

Current treatment strategies aim to achieve clinical remission in order to prevent the long-term consequences of rheumatoid arthritis (RA). Several composite indices are available to assess remission. All of them include joint counts as the assessment of the major 'organ' involved in RA, but some employ reduced joint counts, such as the 28-joint count, which excludes ankles and feet.

The aim of the present study was to determine the relevance of excluding joints of the ankles and feet in the assessment of RA disease activity and remission. Using a longitudinal observational RA dataset, we analyzed 767 patients (80% female, 60% rheumatoid factor-positive), for whom joint counts had been recorded at 2,754 visits. We determined the number of affected joints by the 28-JC and the 32-JC, the latter including ankles and combined metatarso-phalangeal joints (as a block on each side).

Several findings were supportive of the validity of the 28-joint count: (a) Absence of joint swelling on the 28-joint scale had a specificity of 98.1% and a positive predictive value (PPV) of 94.1% for the absence of swelling also on the 32-joint scale. For absence of tender joints, the specificity and PPV were 96.1% and 91.7%, respectively. (b) Patients with swollen or tender joints in the 32-JC, despite no joint activity in the 28-JC, were clearly different with regard to other disease activity measures. In particular, the patient global assessment of disease activity was higher in these individuals. Thus, the difference in the joint count was not relevant for composite disease activity assessment. (c) The disease activity score based on 28 joints (DAS28) may reach levels higher than 2.6 in patients with feet swelling since these patients often have other findings that raise DAS28. (d) The frequency of remission did not change when the 28-JC was replaced by 32-JC in the composite indices. (e) The changes in joint activity over time were almost identical in longitudinal analysis.

The assessment of the ankles and feet is an important part in the clinical evaluation of patients with RA. However, reduced joint counts are appropriate and valid tools for formal disease activity assessment, such as done in composite indices.

The influence of medication beliefs and other psychosocial factors on early discontinuation of disease-modifying anti-rheumatic drugs

OBJECTIVE

Although drug survival time might be a better measure of clinical effectiveness than drug adherence, there is little research literature in this area, in particular about the influence of medication beliefs and psychosocial factors. This study aimed to investigate the above relationships using patients who were newly diagnosed with rheumatoid arthritis (RA).

METHODS

Sixty-eight RA patients starting their first disease-modifying anti-rheumatic drug (DMARD) were interviewed shortly after initiating therapy, and then one year later. Before each meeting, patients were asked to complete a set of questionnaires, including Beliefs about Medication, Spielberger State-Trait Anxiety Inventory - Short Form, the modified Stanford Health Assessment Questionnaire, Beck Depression Inventory-1 and the Significant Others Scale. Relevant sociodemographic background, disease activity and drug history were obtained. Clinical measures such as grip strength and joint count were assessed.

RESULTS

A stepwise logistic regression analysis was applied to two patient groups: those who continued taking their DMARD one year later, and those who did not. No significant difference between the groups for levels of disability and disease activity were found. Only age and anxiety emerged as significant predictors of drug discontinuation at 52 weeks.

CONCLUSIONS

Contrary to expectation, this study demonstrated that older and less anxious patients were more likely to discontinue taking their initial DMARD within the first year. The study may have implications for counselling older and less anxious patients prior to DMARD therapy. However, there are limitations in generalizing the results because of the small population sample. It also did not take into account drug intolerance as a pertinent factor for early drug discontinuation.

Correlation of the score for subjective pain with physical disability, clinical and radiographic scores in recent onset rheumatoid arthritis

BACKGROUND

To analyse the relationship between subjective pain score and other measures of clinical, radiographic and functional status; in particular Larsen radiographic scores and Health Assessment Questionnaire (HAQ); in patients with severe rheumatoid arthritis (RA) with a disease duration of less than 3 years.

METHODS

In this cross sectional study of 105 patients with RA (76 women, 29 men: mean age 50.93; mean disease duration 15.86 months; 71% rheumatoid factor positive) subjective pain was assessed according to the Visual Analog Scale (VAS). Correlation coefficients between pain score and disease activity measures (patients' global assessment of disease by VAS, number of tender and swollen joints, morning stiffness, erythrocyte sedimentation rate [ESR], C-reactive protein [CRP] and titre of rheumatoid factor, radiographic evaluations (Larsen-Dale scores for radiographic damage of the small joints of the hands, wrist and feet), disability measures (health assessment questionnaire [HAQ]), and demographic variables were calculated; hierarchical regression analysis was done with subjective pain score as the dependent variable.

RESULTS

The Spearman's correlation coefficient comparing subjective pain and HAQ was 0.421 (p < 0.001), between subjective pain and global assessment of disease and morning stiffness was 0.573 (p < 0.001) and 0.427 (p < 0.001) respectively, and between pain and number of tender and swollen joints 0.037 and 0.050 respectively (p > 0.05). In regression analysis, global assessment of disease by patients explained 32.8% of the variation in pain intensity score, morning stiffness 10.7%, CRP 4.0%, HAQ 3.8% and Larsen-Dale scores explained 2.1%; other variables were not significant in the model.

CONCLUSIONS

Pain scores of patients with early severe rheumatoid arthritis are correlated at higher levels with patients' global assessment of disease and with morning stiffness rather than with radiographic or other clinical variables such as number of tender and swollen joints.

How can the risk of long-term consequences of rheumatoid arthritis be reduced?

The long-term natural history of rheumatoid arthritis includes early radiographic damage and progression, severe functional declines, work disability and increased mortality rates. Emerging evidence suggests that this natural history may be favourably affected by disease-modifying anti-rheumatic drugs (DMARDs), which slow the radiographic progression and functional decline. It is necessary to document both the efficacy of these drugs in randomized controlled clinical trials and their long-term effectiveness in clinical observational studies. Although a 20% improvement in inflammatory measures in the American College of Rheumatology Core Data Set (ACR20) distinguishes DMARDs from placebo in clinical trials, it is not clear that a control of inflammation at this level, or even at 50%, is sufficient to prevent long-term damage. There is limited financial support for long-term observational studies, which depend on data from the clinical experience of rheumatologists. Quantitative databases from clinical care, can be developed to document long-term outcomes in patients with early rheumatoid arthritis to include additional physical, radiographic, laboratory and patient questionnaire quantitative data. Patient self-report questionnaires appear to provide the least expensive and most effective measures toward this goal.

No increased mortality in patients with rheumatoid arthritis: up to 10 years of follow up from disease onset

OBJECTIVE

To investigate mortality, functional capacity, and prognostic factors for mortality in an inception cohort of patients with recently diagnosed RA followed up for up to 10 years.

METHODS

The observed mortality of this inception cohort with recently diagnosed RA, was analysed in relation to the expected mortality, calculated with the aid of life tables of the general population of the Netherlands (matched for age and sex). Functional capacity was measured by the Health Assessment Questionnaire. Prognostic factors for mortality were analysed multivariately by the Cox proportional hazards model.

RESULTS

Between January 1985 and April 1997, 622 patients entered the study, and were included in the analysis of mortality. The death rate in the first 10 years of the disease was not significantly different from that of the general population. Fifty five patients from the study group died (16% up to 10 years of follow up). The most commonly reported causes of death were of cardiovascular and respiratory origin. The other causes of death could be classified into cancer, sepsis, amyloidosis, leukaemia, renal insufficiency of unknown cause, perforation of the oesophagus, probably related to the treatment with non-steroidal anti-inflammatory drugs, and pancytopenia during aurothioglucose treatment. Functional capacity improved significantly during the first six years compared with the value at start. Statistically significant predictors for death were age at the start and male sex.

CONCLUSIONS

In contrast with earlier studies performed, no excess mortality in the first 10 years of an inception cohort of patients with RA was seen. In addition, the functional capacity was relatively constant during the first six years after an initial improvement from baseline. Age at start and male sex were the only statistically significant predictors for death.

A comparison of two comorbidity instruments in arthritis

Comorbidity (CM) is a powerful predictor of health outcome and cost, as well as an important confounder in many epidemiologic studies. However, choosing the most appropriate CM measurement instrument is difficult because comparative data on how the available instruments perform in various disease settings are limited. We collected CM data (from the complete medical records) for two population-based prevalence cohorts with rheumatoid arthritis (RA) and osteoarthritis (OA) and a comparison cohort without arthritis (NA), using two different CM instruments: the Charlson CM index (Charl), which is based on 17 diagnoses each weighted by mortality risk, and the Index of Coexistent Diseases (ICED), which estimates the severity and frequency of 14 comorbid conditions and provides an assessment of the impairment or disability caused by each. Cox proportional hazards modeling was used to assess the impact of the two types of comorbidity scores (Charl and ICED) on survival after prevalence (index) date, adjusting for the age, sex, and disease status. There were 450, 441, and 889 individuals in the RA, OA, and NA groups, respectively, with a mean follow-up period of 10.6 years. During the follow-up, 293, 307, and 546 deaths occurred in the RA, OA, and NA groups, respectively. The mean age and percent females were: 63.3 years, 74%; 70.7 years, 74%; and 67.5 years, 75% for the RA, OA, and NA groups, respectively. Comorbidity was highest in RA, intermediate in OA, and lowest in NA by both Charl and ICED. Cox proportional hazards modeling demonstrated that both Charl and ICED were highly statistically significant predictors of mortality (P<0.0001) after adjusting for age, sex, and disease state (RA, OA, or NA) and that ICED remained highly significant as a predictor of mortality, even after adjusting for Charl. We conclude that estimating CM from medical records using ICED, an instrument that incorporates an assessment of impairment and disability, is feasible and that such as assessment provides information that independently predicts mortality, even after adjusting for the results of traditional diagnosis-based CM measures, such as Charl.

Abnormal directed migration of blood polymorphonuclear leukocytes in rheumatoid arthritis. Potential role in increased susceptibility to bacterial infections

Rheumatoid arthritis (RA) patients are at higher risks of bacterial infection than healthy subjects. Polymorphonuclear leukocytes (PMN) are the first line of nonspecific cellular defence against these infections. We tested the hypothesis that abnormal directed migration of PMN may be one reason for the increased infection rate of RA patients. PMN migration was investigated in 68 peripheral blood samples of 15 RA patients compared with 64 samples of healthy controls in a novel whole blood in vitro membrane filter assay. The migration of PMNs from RA patients and controls was stimulated using the bacterial chemoattractant N-formyl-methionyl-leucyl-phenylalanine (fMLP). Unstimulated PMN migration of RA patients was increased compared with healthy controls as measured by the following parameters: (a) absolute number of migrant PMNs (1954+/-87 vs. 1238 +/-58 PMN/mm2), (b) percentage of PMNs migrated into the filter (total migration index, TMI) (28.6+/-0.9 vs. 24.0+/-0.8%), (c) the distance half the migrating PMNs had covered (distribution characteristic, DC) (22.6+/-1.1 vs. 16.1+/-0.6 mm) and (d) the product of TMI and DC (neutrophil migratory activity, NMA) (669.0+/-45.0 vs. 389.0+/-18.9). fMLP stimulated PMNs of RA patients showed defective migration compared to unstimulated samples as shown by (a) a reduced number of migrant PMNs (1799+/-93 PMN/mm2), (b) lower TMI (26.1+/-0.9%), (c) unremarkable altered distribution characteristic (22.9+/-0.8 mm) and (d) significant reduced migratory activity (600.0+/-30.0). Our data suggest that the high incidence of infections in RA patients may partly be caused by defective migratory activity of PMNs to bacterial chemoattractants as demonstrated by fMLP.

Measures of activity and damage in rheumatoid arthritis: depiction of changes and prediction of mortality over five years

OBJECTIVE

To analyze various quantitative measures of inflammatory activity and joint damage, including articular, radiographic, laboratory, questionnaire, and physical function measures, in regard to changes in status in surviving patients and prediction of mortality in non-survivors over 5 years in a cohort of patients with rheumatoid arthritis (RA) monitored in the mid-1980s and early 1990s.

METHODS

A comprehensive evaluation, which included a complete joint count, radiograph, laboratory tests, physical measures of function, and self-report questionnaire scales, was performed at baseline and 5 years later in 210 consecutive patients with RA.

RESULTS

Five years after baseline, 206 of the 210 patients were accounted for: 37 had died, 130 had a comprehensive repeat assessment, and 39 had a more limited repeat assessment. In surviving patients, most measures of activity were generally unchanged or somewhat better, including joint tenderness, pain on motion, and swelling; erythrocyte sedimentation rate and rheumatoid factor; as well as questionnaire scores for pain, global status, helplessness, and difficulty in performing 8 activities of daily living (ADL) according to a modified Health Assessment Questionnaire (MHAQ). By contrast, measures of damage, including joint deformity, grip strength, walk time, and radiographic scores, indicated worse status. Mortality over 5 years was predicted significantly in univariable analyses by American College of Rheumatology (formerly the American Rheumatism Association) Functional Class, limited joint motion, scores for MHAQ, global status, helplessness, grip strength, walk time, button time, and number of comorbidities and duration of diseases, as well as the sociodemographic measures of age and formal education. In multivariable Cox regressions, age, comorbidities, MHAQ, and other measures of functional status were the most effective predictors of 5-year mortality.

CONCLUSION

In patients with RA, most measures of inflammatory activity were unchanged and sometimes better, while measures of damage indicated worse status in the same patients over 5 years. Measures indicating functional disability, as well as age and comorbidities, predict 5-year mortality more effectively than radiographic and laboratory data. Measures of inflammatory activity may underestimate long-term outcomes in RA, and long-term studies should include measures of damage.

Outcome measures, pooled index and quality of life instruments in rheumatoid arthritis

BACKGROUND AND OBJECTIVE

A variety of outcome measures are used in evaluating disease activity and therapeutic efficacy in rheumatoid arthritis (RA) studies, and this makes comparisons of drug efficacy difficult. Some of the endpoints used are not standardized and/or are insensitive to change. The purpose of this report is to present a critical appraisal of outcome measures and quality of life assessments in RA studies.

METHOD

An overview of the literature was undertaken to determine the extent to which there is consensus among experts in this area of research.

RESULTS

The data suggest that the core set of endpoints in RA clinical studies should include tender joint count swollen joint count, patients' assessment of pain, patients' and physicians' global assessments, patients' assessment of physical function and acute phase reactant level. When trials of disease-modifying antirheumatic drugs (DMARD) last for more than a year, radiography may be useful. A 'pooled index' may be valuable, and its construction is discussed. Quality of life (QoL) instruments facilitate a fuller examination of the effects of health care interventions and these should be used to complement the more traditional clinical endpoints in the core set. The instruments most commonly used in RA research are identified.

CONCLUSIONS

We conclude that randomized clinical trials of treatments in RA should now ideally use the core set of clinical endpoints and validated QoL instruments for assessing safety and efficacy.

Mortality in rheumatoid arthritis

Patients with rheumatoid arthritis (RA) have a substantially reduced life expectancy. The standardized mortality ratio in different studies has ranged from 1.13 to 2.98. This mainly applies to rheumatoid factor (RF)-positive cases, although there is a subgroup of RF-negative cases with an adverse long-term prognosis. Clinically based studies probably overestimate the true shortening of life span and population-based studies may underestimate it. Excess mortality from infection and from renal disease likely reflects the presence of severe disease, whereas most of the added mortality from gastrointestinal causes is treatment related. The reasons for the surplus of mortality from cardiovascular causes are not fully known. RF may have a direct role, and preillness factors such as smoking may predipose patients to RA and also render them susceptible to cardiovascular diseases. The excess mortality associated with RA is appreciably higher than is apparent from the cases in which RA is regarded as an underlying cause of death. The effect of treatment on mortality remains largely unknown.

Prognostic factors of severe rheumatoid arthritis

As one proposes sometimes more aggressive immunomodulatory treatment early in the process of rheumatoid arthritis, it becomes necessary to think about the prognostic factors early in the disease process that can predict eventual later poor outcome. We summarize the literature of the last 10 years dealing with this topic.

Validity and reliability of the twenty-eight-joint count for the assessment of rheumatoid arthritis activity

OBJECTIVE

To investigate the validity of the 28-joint count for assessment of joint involvement in patients with rheumatoid arthritis (RA).

METHODS

Joint involvement as determined by the 28- and the 66/68-joint count was compared using data from 735 prospectively studied RA patients.

RESULTS

The joints included in the 28-joint count were more commonly involved than other joints, and findings from the 28-joint count correlated highly with those from the 66/68-joint count in all analyses.

CONCLUSION

The 28-joint count is a reliable and valid measure for joint assessment. It is easier to perform than the 66/68-joint count, and it addresses the joints that are critically involved.