Baseline patient reported outcomes are more consistent predictors of long-term functional disability than laboratory, imaging or joint count data in patients with early inflammatory arthritis: A systematic review

How to Distinguish Non-Inflammatory from Inflammatory Pain in RA?

PURPOSE OF THE REVIEW

Managing non-inflammatory pain in rheumatoid arthritis (RA) can be a huge burden for the rheumatologist. Pain that persists despite optimal RA treatment is extremely challenging for patient and physician alike. Here, we outline the latest research relevant to distinguishing non-inflammatory from inflammatory RA pain and review the current understanding of its neurobiology and management.

RECENT FINDINGS

Nociplastic pain is a recently introduced term by the international pain community. Its definition encompasses the non-inflammatory pain of RA and describes pain that is not driven by inflamed joints or compromised nerves, but that is instead driven by a functional reorganisation of the central nervous system (CNS). Insights from all areas of nociplastic pain research, including fibromyalgia, support a personalised pain management approach for non-inflammatory pain of RA, with evidence-based guidelines favouring use of non-pharmacological interventions. Future developments include novel CNS targeting pharmacotherapeutic approaches to treat nociplastic pain.

Associations between smoking history, baseline pain interference and symptom distribution, and physical function at discharge, in individuals seeking care for musculoskeletal pain

OBJECTIVE

Study of the association between smoking and pain intensity has produced conflicting results; with less focus on pain interference. Different pain constructs could have varying associations with smoking behaviors. This study sought to investigate the association between smoking history and not only pain intensity, but also pain interference, symptom distribution and physical function.

METHODS

Smoking history (current, past, or none), pain interference (Pain, Enjoyment of Life, and General Activity scale), symptom distribution and physical function scores were extracted from medical records of patients seen in physical therapy for common sites of musculoskeletal pain (lumbar and cervical spine, knee, or hip). Generalized linear models assessed the relationship between smoking history and pain/function.

RESULTS

833 patients from an integrated healthcare system were included (mean: 57.6 years, SD=16.3; 43 % male). After controlling for several variables, current smokers had significantly higher baseline pain interference scores compared to never and former smokers (beta [B]: 0.65, 95 %CI: 0.13 to 1.18, P=.02). Smoking was not a significant predictor of symptom distribution at baseline [B: 0.17, 95 %CI -0.06 to 0.42, P=.16] or physical function scores at discharge [B: -0.03, 95 %CI: -0.08 to 0.02, P=.25].

CONCLUSION

Smokers experienced a greater impact of pain at baseline. However, symptom distribution at intake and function upon discharge were similar between all smoking groups. These findings suggest smoking cessation and abstinence may be important recommendations to help curb pain interference.

Prognostic modeling in early rheumatoid arthritis: reconsidering the predictive role of disease activity scores

OBJECTIVE

In this prospective cohort study, we provide several prognostic models to predict functional status as measured by the modified Health Assessment Questionnaire (mHAQ). The early adoption of the treat-to-target strategy in this cohort offered a unique opportunity to identify predictive factors using longitudinal data across 20 years.

METHODS

A cohort of 397 patients with early RA was used to develop statistical models to predict mHAQ score measured at baseline, 12 months, and 18 months post diagnosis, as well as serially measured mHAQ. Demographic data, clinical measures, autoantibodies, medication use, comorbid conditions, and baseline mHAQ were considered as predictors.

RESULTS

The discriminative performance of models was comparable to previous work, with an area under the receiver operator curve ranging from 0.64 to 0.88. The most consistent predictive variable was baseline mHAQ. Patient-reported outcomes including early morning stiffness, tender joint count (TJC), fatigue, pain, and patient global assessment were positively predictive of a higher mHAQ at baseline and longitudinally, as was the physician global assessment and C-reactive protein. When considering future function, a higher TJC predicted persistent disability while a higher swollen joint count predicted functional improvements with treatment.

CONCLUSION

In our study of mHAQ prediction in RA patients receiving treat-to-target therapy, patient-reported outcomes were most consistently predictive of function. Patients with high disease activity due predominantly to tenderness scores rather than swelling may benefit from less aggressive treatment escalation and an emphasis on non-pharmacological therapies, allowing for a more personalized approach to treatment. Key Points • Long-term use of the treat-to-target strategy in this patient cohort offers a unique opportunity to develop prognostic models for functional outcomes using extensive longitudinal data. • Patient reported outcomes were more consistent predictors of function than traditional prognostic markers. • Tender joint count and swollen joint count had discordant relationships with future function, adding weight to the possibility that disease activity may better guide treatment when the components are considered separately.

The role of pain catastrophizing in pain perception among patients with rheumatoid arthritis without clinical signs of inflammation

OBJECTIVE

Pain in rheumatoid arthritis (RA) is considered to be associated with non-inflammatory factors, including physical disabilities, psychiatric disorders, and pain catastrophizing (PC). PC is reportedly a key driver in the development of pain in patients with RA without clinical signs of inflammation; however, previous studies enroled patients with RA who were potentially in an inflammatory state. Hence, our aim was to investigate the role of PC as the possible link between pain, physical disabilities, and psychiatric disorders in patients with RA without clinical signs of inflammation.

MATERIALS AND METHODS

In this cross-sectional study, 81 patients with RA without clinical signs of inflammation were included; all patients had serum C-reactive protein levels <0.5 mg/dL, without any inflammatory joints. We examined the demographic and clinical data and administered the pain visual analogue scale (VAS), pain catastrophizing scale (PCS), Health Assessment Questionnaire Disability Index (HAQ-DI), and patient version of the Brief Scale for Psychiatric Problems in Orthopaedic Patients (pBS-POP). A series of multivariate-adjusted multiple regression analyses were performed to examine the associations between PC and pain intensity, physical disabilities, and psychiatric disorders.

RESULTS

We found associations between all the above-mentioned variables in separate models with HAQ-DI, pBS-POP, and PCS scores. However, in the model associated with pain VAS, the PCS score (β = 0.34, p = 0.0073) emerged as the only variable showing a statistically significant association.

CONCLUSIONS

PC is associated with pain in patients with RA without clinical signs of inflammation, and this association may be mediated through pathways involving physical disabilities and psychiatric disorders.

Smoking, but not use of complementary and alternative medicine predicts residual functional disability in patients with inflammatory arthritis on biologic disease-modifying anti-rheumatic drugs: Results from the Singapore National Biologics Register

AIMS

To describe inflammatory arthritis (IA) patients initiating biologic disease-modifying anti-rheumatic drugs (bDMARDs) who use complementary and alternative medicine (CAM), and determine the impact of CAM on predicting modified Health Assessment Questionnaire (mHAQ) at 6 months.

METHODS

This was a prospective inception cohort study of patients ≥21 years old initiating a bDMARD for IA after July 2016. Data were obtained via questionnaires and abstraction from medical records. Baseline characteristics between ever-CAM and CAM non-users were compared. CAM as a predictor of mHAQ ≥1 at 6 months after bDMARD initiation was analyzed using multivariate logistic regression, adjusting for other baseline characteristics.

RESULTS

We recruited 299 patients (36.2% male, mean age 49.0 years). There were 45.8% who had rheumatoid arthritis, 54.2% had a spondyloarthropathy, median disease duration of 1.1 years and median mHAQ of 0.4. Compared to CAM non-users, ever-CAM users had a lower mean body mass index, were less likely to speak English, and more likely to smoke and drink alcohol. There was no association of CAM use with high mHAQ and no interaction with smoking. Smoking (odds ratio [OR] 938.9; 95% CI 3.20-275 884.1), baseline mHAQ (OR 252.2; 95% CI 5.34-11 899.2) and Charlson's Comorbidity Index score ≥4 (OR 237.4; 95% CI 1.22-46 184.4) independently predicted high mHAQ at 6 months.

CONCLUSIONS

CAM use was not associated with high mHAQ at 6 months. Smoking was an independent predictor of residual functional disability at 6 months, even after adjusting for age, comorbidity and baseline mHAQ. Greater emphasis on smoking cessation may improve long-term functional outcomes in IA patients on bDMARDs.

Exploring the disparity between inflammation and disability in the 10-year outcomes of people with rheumatoid arthritis

OBJECTIVES

To identify groups of people with RA with different disability trajectories over 10 years, despite comparable levels of inflammation.

METHODS

Data for this analysis came from three European prospective cohort studies of people with RA [Norfolk Arthritis Register (NOAR), Early RA Network (ERAN), Étude et Suivi des Polyarthrites Indifférenciées Récentes (ESPOIR)]. Participants were assessed regularly over 8 (ERAN) to 10 (NOAR/ESPOIR) years. Inclusion criteria were: recruited after 1 January 2000, <24 months baseline symptom duration, and disability (HAQ) and inflammation [two-component DAS28 (DAS28-2C)] recorded at baseline and at one other follow-up. People in each cohort also completed patient-reported outcome measures at each assessment (pain, fatigue, depressive symptoms). Group-based trajectory models were used to identify distinct groups of people with similar HAQ and DAS28-2C trajectories over follow-up.

RESULTS

This analysis included 2500 people with RA (NOAR: 1000, ESPOIR: 766, ERAN: 734). ESPOIR included more women and the participants were younger [mean (standard deviation) age: NOAR: 57.1 (14.6), ESPOIR: 47.6 (12.5), ERAN: 56.8 (13.8); women: NOAR: 63.9%, ESPOIR: 76.9%, ERAN: 69.1%). Within each cohort, two pairs of trajectories following the hypothesized pattern (comparable DAS28-2Cs but different HAQs) were identified. Higher pain, fatigue and depressive symptoms were associated with increased odds of being in the high HAQ trajectories.

CONCLUSION

Excess disability is persistent in RA. Controlling inflammation may not be sufficient to alleviate disability in all people with RA, and effective pain, fatigue and mood management may be needed in some groups to improve long-term function.

The point of no return? Functional disability transitions in patients with and without rheumatoid arthritis: A population-based cohort study

OBJECTIVE

To assess transition probability between different levels of functional disability (FD) and time spent with FD in patients with versus without rheumatoid arthritis (RA) after RA incidence/index date.

METHODS

This retrospective population-based cohort study included Olmsted County, Minnesota residents (1987 ACR criteria met in 1999-2013) and comparators without RA from the same area with similar age, sex and RA incidence/index date. Activities of Daily Living (ADL) were obtained by self-report questionnaires annually since 1999. FD was defined as having difficulty with ≥1 ADL. Multistate modeling was used to estimate the probability of transitioning between FD states.

RESULTS

Five hundred fifty-eight patients with RA and 457 comparators completed ≥2 questionnaires and were included. Patients with RA had increased risk of transitioning from no FD to FD: Hazard Ratio (HR) 2.4; 95%CI:1.9-3.0. Each additional FD at RA onset reduced the probability of returning to no FD by 14%. However, the probability of having ≥1 FD was stable between RA incidence and 10-year follow-up. In the first 15 years of disease, patients with RA spent on average 10.1 years without FD and 3.4 years with ≥1 FD versus 11.6 years and 2.0 years (p<0.001) in comparators.

CONCLUSION

Patients with RA remain functionally disadvantaged compared to individuals without RA. The likelihood of returning to no FD in RA decreases with each additional preexisting FD. However, the probability of FD does not increase within 10 years of RA onset, potentially reflective of the benefits of disease-modifying treatments in RA.

Impact of autoimmune serology test results on RA classification and diagnosis

Rheumatoid arthritis (RA) is the most common systemic autoimmune disease and also the most severe arthritic disorder. The measurement of rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) in serum supports the diagnosis of RA, which gained increasing significance over the last 65 years. However, a high variability between RF and ACPA methods has been described, impacting the diagnostic performance of the current ACR/EULAR RA classification criteria.

The great number of commercially available assays, often lacking traceability to an international standard, is a major factor attributing to this in-between assay variability. The adoption of an international standard for ACPA, as is since long available for rheumatoid factor, is therefore highly desirable.

Further harmonization in clinical interpretation of RF/ACPA assays could be obtained by harmonization of the cut-offs, for both the low and high antibody levels, based on predefined specificity in disease controls. Reporting test result specific likelihood ratios (LR) adds value in the interpretation of autoantibody tests. However, a good understanding of the control population used to define antibody test result interval-associated LRs is crucial in defining the diagnostic performance characteristics of antibody serology.

Finally, specificity in RA classification can be improved by refining serological weight scoring taking into account the nature of the antibody, the antibody level and double RF + ACPA positivity.

Anxiety and Depressive Symptoms Are Not Associated With Future Pediatric Crohn's Disease Activity

BACKGROUND

Studies of adults with Crohn's disease (CD) suggest that poor mental health precedes worsening disease activity. We evaluated whether depression and/or anxiety forecast worsening pediatric CD disease activity.

METHODS

Through the Inflammatory Bowel Disease Partners Kids & Teens internet-based cohort, children with CD age 9 to 17 completed Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric measures and the short Crohn's disease activity index (sCDAI). Using general linear models, we examined how baseline PROMIS Pediatric anxiety and depressive symptom scores independently associate with subsequent sCDAI scores (average survey interval 6.4 months). Models included baseline PROMIS Pediatric anxiety and depressive symptoms scores, baseline sCDAI, sex, age, parental education, race/ethnicity, and prior IBD-related surgery. We performed a post hoc subanalysis of children in baseline remission (sCDAI <150) with otherwise identical models.

RESULTS

We analyzed 159 children with CD (mean age 14 years, 45% female, 84% in baseline remission). We found no association between baseline PROMIS Pediatric anxiety score and subsequent sCDAI (change in sCDAI for 3-point change in PROMIS Pediatric -0.89; 95% CI -4.81 to 3.03). Baseline PROMIS Pediatric depressive symptoms score was not associated with future sCDAI (change in sCDAI for 3-point change in PROMIS Pediatric <0.01; 95% CI -4.54 to 4.53). In a subanalysis of patients in remission at baseline, the lack of association remained.

CONCLUSION

We found that neither anxiety nor depressive symptoms associate with subsequent disease activity in pediatric CD. These findings contrast with adult IBD studies, thus underschoring the unique pathophysiology, natural history, and outcomes of pediatric CD.

Current favourable 10-year outcome of patients with early rheumatoid arthritis: data from the ESPOIR cohort

OBJECTIVE

To report the 10-year outcome of an inception cohort of patients with early rheumatoid arthritis (RA), the ESPOIR cohort, and predictors of outcome.

METHODS

From 2003 to 2005, 813 patients were included if they had early arthritis (< 6 months) with a high probability of RA and had never been prescribed DMARDs. Multivariate analysis was used to evaluate predictors of outcome.

RESULTS

In total, 521 (64.1%) RA patients were followed up for 10 years; 35 (4.3%) died which appears similar to the French general population. Overall, 480 (92.1%) patients received a DMARD; 174 (33.4%) received at least one biologic DMARD, 13.6% within 2 years. At year 10, 273 (52.4%) patients were in DAS28 remission, 40.1% in sustained remission, 14.1% in drug-free remission, 39.7% in CDAI remission. Half of the patients achieved a HAQ-DI < 0.5. SF-36 physical component and pain were well controlled. Structural progression was weak, with a mean change from baseline in modified Sharp score of 11.0 ± 17.9. Only 34 (6.5%) patients required major joint surgery. A substantial number of patients showed new comorbidities over 10 years. Positivity for ACPA was confirmed as a robust predictor of long-term outcome.

CONCLUSIONS

We report a very mild 10-year outcome of a large cohort of patients with early RA diagnosed in the early 2000s, which was much better than results for a previous cohort of patients who were recruited in 1993. This current favourable outcome may be related to more intensive care for real-life patients.

Machine-learning-based knowledge discovery in rheumatoid arthritis-related registry data to identify predictors of persistent pain

Early detection of patients with chronic diseases at risk of developing persistent pain is clinically desirable for timely initiation of multimodal therapies. Quality follow-up registries may provide the necessary clinical data; however, their design is not focused on a specific research aim, which poses challenges on the data analysis strategy. Here, machine-learning was used to identify early parameters that provide information about a future development of persistent pain in rheumatoid arthritis (RA). Data of 288 patients were queried from a registry based on the Swedish Epidemiological Investigation of RA. Unsupervised data analyses identified the following 3 distinct patient subgroups: low-, median-, and high-persistent pain intensity. Next, supervised machine-learning, implemented as random forests followed by computed ABC analysis-based item categorization, was used to select predictive parameters among 21 different demographic, patient-rated, and objective clinical factors. The selected parameters were used to train machine-learned algorithms to assign patients pain-related subgroups (1000 random resamplings, 2/3 training, and 1/3 test data). Algorithms trained with 3-month data of the patient global assessment and health assessment questionnaire provided pain group assignment at a balanced accuracy of 70%. When restricting the predictors to objective clinical parameters of disease severity, swollen joint count and tender joint count acquired at 3 months provided a balanced accuracy of RA of 59%. Results indicate that machine-learning is suited to extract knowledge from data queried from pain- and disease-related registries. Early functional parameters of RA are informative for the development and degree of persistent pain.

Cumulative patient-based disease activity monitoring in rheumatoid arthritis - predicts sustained remission, flare and treatment escalation

OBJECTIVE

Patient-based Disease Activity Score 2 (PDAS2) had been developed for RA patients to self-assess and record disease activity in between clinic visits. This study explored the clinical utility of time-integrated cumulative PDAS2 (cPDAS2) on predicting sustained remission or low disease activity state (LDAS), flare and treatment escalation.

METHODS

We recruited 100 patients to record PDAS2 at home fortnightly between two consecutive clinic visits. Rheumatologists adjusted treatment according to disease activity recorded during clinic consultation while blinded to home PDAS2 scores. cPDAS2 calculated from the area-under-curve of all PDAS2 scores were compared with disease activities at both visits. cPDAS2 and ΔcPDAS2 (change from PDAS2 at the first visit) were tested to determine their ability to predict ACR/EULAR remission, SDAI flare-up (from remission/LDAS to moderate/high disease activity) and treatment escalation. Optimal cut-points were determined by Receiver Operator Characteristic curve.

RESULTS

Mean age of the patients was 59 years, mean RA duration 14 years, 90% were female, 71% seropositive and 64% in remission/LDAS. The home PDAS2 completion rate was 92%. PDAS2 scores were done 7.5 times every 15 days over a 16-week follow-up (all medians). The sensitivity of cPDAS2 in predicting Boolean/SDAI remission at two visits, DAS28, SDAI and CDAI remission or LDAS were 93%, 84%, 73% and 80% respectively. cPDAS2 ≥ 0.29 predicted flare (P = 0.04), with specificity 79% and negative predicting value (NPV) 88%. Rheumatologists' decision to escalate treatment was predicted by (cPDAS2 ≥ 4.33 and ΔcPDAS2 ≥ 0.059) (P = 0.007) with specificity 88% and NPV 89%, and (cPDAS2 ≥ 4.33 or ΔcPDAS2 ≥ 0.059) (P = 0.02) with both sensitivity and NPV 100%.

CONCLUSION

PDAS2 monitoring at home is feasible. cPDAS2 is useful to predict flare and treatment escalation.

Unacceptable pain in the BARFOT inception cohort of patients with rheumatoid arthritis: a long-term study

Objectives: Pain is the most common and troublesome complaint in rheumatoid arthritis (RA). This study aimed to assess the prevalence and clinical implications of unacceptable pain in an inception cohort of patients with RA. Method: This study followed 477 patients from the BARFOT (Better Anti-Rheumatic FarmacOTherapy) early RA cohort for 15 years. Unacceptable pain was defined as ≥ 40 mm on a visual analogue scale for pain, while tolerable pain denoted no pain or pain below this cut-off, according to the patient acceptable symptom state concept. Results: Unacceptable pain was frequent. At the 15 year follow-up visit, 34% had unacceptable pain. Patients with unacceptable pain had, compared with patients with tolerable pain, significantly more disease activity, worse patient global assessment, and worse function on the Health Assessment Questionnaire and Signals of Functional Impairment, but the degree of joint destruction was similar. Disease-modifying anti-rheumatic drug treatment was similar, but patients with unacceptable pain were more often treated with corticosteroids. At 15 years, patients with unacceptable pain who were in remission (33%) had less inflammation and better function than those not in remission, suggesting the presence of non-inflammatory causes of pain. Conclusions: In this cohort of patients with RA, pain was frequent and severe, with negative effects on experienced health and function. Unacceptable pain was frequent and occurred also in patients in remission, indicating that pain in RA is multifactorial and should always be regarded as an important concern in itself. The cause of pain should be recognized and treated appropriately.