Treat-to-target in axial spondyloarthritis - what about physical function and activity?

In patients with axial spondyloarthritis (axSpA), pain, functional and structural impairments, reduced mobility and potential deformity of the axial skeleton are the most prominent health concerns. Limitations in physical function and spinal mobility are caused by both inflammation and structural damage, and therefore restrictions to physical function must be monitored throughout a patient's life. Consequently, the assessment of physical function is recommended as a key domain in the Assessment of Spondyloarthritis International Society-OMERACT Core Outcome Set. However, in comparison with disease activity, physical function seems to be a relatively neglected target of intervention in patients with axSpA, even though physical function is a major contributor to costs and disability in this disease. This Review aims to reacquaint rheumatologists with the targets for physical function, physical activity and performance by giving guidance on determinants of physical function and how physical function can be examined in patients with axSpA.

Successful evaluation of spinal mobility measurements with the Epionics SPINE device in patients with axial spondyloarthritis compared to controls

OBJECTIVE

To evaluate ES for quantification of spinal mobility in patients with axSpA.

METHODS

A total of 153 individuals, 39 females and 114 males, were examined:134 axSpA patients, 40 non-(nr-) and 94 radiographic (r)-axSpA, and 19 healthy controls (HC), respectively. The results were compared using mean ES scores and modeling was performed using multivariable logistic regression models resulting in good validity and high discriminative power.

RESULTS

ES measurements showed meaningful differences between axSpA patients and HC (all p<0.001) as well as between r- and nr-axSpA (p<0.01). In axSpA patients a negative correlation between ES and BASMI values was found: -0.76≤r≤-0.52 (p<0.05). BASFI scores showed a similar trend (r > -0.39). Patients with r-axSpA had a more limited and slower spinal mobility than those with nr-axSpA. Other patient reported outcomes did almost not correlate.

CONCLUSION

This study shows that the ES is an objective performance measure and a valid tool to assess spinal mobility in axSpA, also based on OMERACT criteria. RoK and RoM scores provide additional information on physical function of axSpA patients.

Responsiveness and Interpretability of 2 Measures of Physical Function in Patients With Spondyloarthritis

BACKGROUND

Maintenance or improvement of physical function is an important treatment target in the management of patients with axial spondyloarthritis (axSpA); measurement tools that can detect changes in physical function are therefore important.

OBJECTIVES

The objective of this study was to compare responsiveness and interpretability of the patient-reported Bath Ankylosing Spondylitis Functional Index (BASFI) and the Ankylosing Spondylitis Performed-Based Improvement (ASPI) in measuring change in physical function after exercise in patients with axSpA.

DESIGN

This was a sub-study of 58 patients nested within a randomized controlled trial comparing the effect of 12 weeks of exercise with usual care.

METHODS

Responsiveness and interpretability were assessed according to the Consensus-based Standards for the selection of health status Measurement Instrument. Responsiveness was assessed by testing 8 predefined hypotheses for ASPI and BASFI. Interpretability was assessed by: (1) using patients' reported change as an anchor ("a little better" = minimal important change) and (2) by categorizing patients with a 20% improvement as responders.

RESULTS

For ASPI and BASFI, 5 of 8 (63%) versus 2 of 8 (25%) of the predefined hypotheses for responsiveness were confirmed. The minimal important change values for improvement in physical function were 3.7 seconds in ASPI and 0.8 points (on a scale from 0 to 10) for BASFI. In the intervention group, 21 of 30 (70%) and 13 of 30 (43%) of the patients were categorized as responders measured with ASPI and BASFI, respectively. There was a tendency towards a floor effect in BASFI, as 8 of 58 (14%) patients scored the lowest value at baseline.

LIMITATIONS

This study was limited by its moderate sample size.

CONCLUSIONS

Our findings suggest that ASPI is preferable over BASFI when evaluating physical function after exercise interventions in patients with axSpA.

The Ankylosing Spondylitis Performance Index: Reliability and Feasibility of an Objective Test for Physical Functioning

OBJECTIVE

Physical function in patients with axial spondyloarthritis (axSpA) is currently evaluated through questionnaires. The Ankylosing Spondylitis Performance Index (ASPI) is a performance-based measure for physical functioning, which has been validated in Dutch patients with radiographic (r-) axSpA. The interrater reliability has not yet been determined. To our knowledge, this study is the first to evaluate the validity, reliability, and feasibility of the ASPI in another patient population, including both r- and nonradiographic (nr-) axSpA patients.

METHODS

Patients with axSpA were recruited from rheumatology clinics in Santiago, Chile. Dutch instructions were translated to Spanish by a forward-backward procedure. Study visits were performed at baseline and 1-4 weeks later. Four ASPI observers were involved, measuring the performance times of the 3 ASPI tests. Validity was assessed through a patient questionnaire (numeric rating scale 0-10: ≥ 6 sufficient). For reliability, intraclass correlation coefficients (ICC) were calculated (with 95% CI). Correlations between the ASPI and disease variables were tested with regression analyses.

RESULTS

Sixty-eight patients were included (57% male, 52% r-axSpA). All patients understood the Spanish instructions and considered the ASPI to reach its aim (84%) and representativeness (85%) for physical functioning. The overall interrater (n = 62) and test-retest (n = 39) reliability (ICC) of the 3 tests combined were 0.93 (0.88-0.96) and 0.94 (0.87-0.97), respectively. Eighty-two percent of the patients completed all tests and 94% finished in < 15 min (feasibility).

CONCLUSION

This study demonstrated a high validity and feasibility in an entirely different population, with both r-axSpA and nr-axSpA. The interrater and test-retest reliability was excellent. The ASPI instructions are now available for Spanish-speaking patients.

[Epionics SPINE-use of an objective method to examine spinal mobility in patients with axial spondyloarthritis]

Axial spondylarthritis (axSpA) is a chronic inflammatory disease of the spine that can be associated with loss of physical function, mobility and upright postural impairment. Established tools for the assessment of function that are largely based on subjective perception are semiquantitatively recorded by standardized questionnaires (Bath ankylosing spondylitis functional index, BASFI), while measurement of spinal mobility of patients with axSpA is based on physical examination of various movement regions particularly the axial skeleton (Bath ankylosing spondylitis metrology index, BASMI). Recently, a performance test has been added to assess the range of motion and speed of certain tasks (AS performance-based improved test, ASPI); however, since these tests have limited reliability and reproducibility, more objective tests would be desirable. In this study the spinal mobility of patients with axSpA was quantified using the Epionics SPINE device (ES) and data were evaluated using the outcome measures in rheumatology (OMERACT) criteria. The ES automatically measures various patterns of spinal movements using electronic sensors, which also assess the range and speed of carrying out movements. Patients with back pain from other causes and persons without back pain served as controls. The measurement results obtained with ES differed between the groups and correlated with BASMI values (r = 0.53-0.82, all p = <0.03). Patients with radiographically detectable axSpA had more limited and slower mobility than those with non-radiographically detectable axSpA. Overall, the results presented here suggest that ES measurements represent a valid and objective measurement procedure of spinal mobility for axSpA patients.

Instrumented BASFI (iBASFI) Shows Promising Reliability and Validity in the Assessment of Activity Limitations in Axial Spondyloarthritis

OBJECTIVE

The Bath Ankylosing Spondylitis Functional Index (BASFI) is the most popular method to assess activity capacity in axial spondyloarthritis (axSpA), to our knowledge. It is endorsed by the Assessment of Spondyloarthritis international Society. But it may have recall bias or aberrant self-judgments in individual patients. Therefore, we aimed to (1) develop the instrumented BASFI (iBASFI) by adding a body-worn accelerometer with automated algorithms to performance-based measurements (PBM), (2) study the iBASFI's core psychometric properties, and (3) reduce the number of iBASFI items.

METHODS

Twenty-eight patients with axSpA wore a 2-axial accelerometer while completing 12 PBM derived from the BASFI. A chronometer and both manual and "automated algorithm-based" acceleration segmentation identified movement time. Test-retest trials and methods (algorithm vs manual segmentation/chronometer/BASFI) were compared with ICC, standard error of measurement [percentage of movement time (SEM%)], and Spearman ρ correlation coefficients. Linear regression identified the optimal set of reliable iBASFI PBM.

RESULTS

Good to excellent test-retest reliability was found for 8/12 iBASFI items (ICC range 0.812-0.997, SEM range 0.4-30.4%), typically with repeated and fast movements. Automated algorithms excellently mimicked manual segmentation (ICC range 0.900-0.998) and the chronometer (ICC range 0.878-0.998) for 10/12 iBASFI items. Construct validity compared with the BASFI was confirmed for 7/12 iBASFI items (δ range 0.504-0.755). Together, sit-to-stand speed test (stBeta 0.483), cervical rotation (stBeta -0.392), and height (stBeta -0.375) explained 59% of the variance in the BASFI (p < 0.01).

CONCLUSION

The proof-of-concept iBASFI showed promising reliability and validity in measuring activity capacity. The number of the iBASFI's PBM may be minimized, but further validation in larger axSpA cohorts is needed before its clinical use.

Objective evaluation of physical functioning after tumor necrosis factor inhibitory therapy in patients with ankylosing spondylitis: a selection of 3 feasible performance-based tests

OBJECTIVE

(1) To select a limited number of performance-based tests that are reliable, show improvement in physical functioning after tumor necrosis factor inhibitor (TNFi) therapy in patients with ankylosing spondylitis (AS), and generate information equivalent to the full set of tests, and (2) are feasible for use in daily clinical practice.

METHODS

Eight performance-based tests were evaluated. To eliminate redundant testing, the tests that showed adequate reliability, the highest standardized response mean (SRM), and the largest proportion of patients with an improved performance-based physical functioning were selected. The selected tests were combined into a new criterion for improvement in physical functioning (AS Performance-based Improvement; ASPI). The number and percentage of improved patients identified with the ASPI and identified with the full set of performance tests were compared.

RESULTS

Reliability for all tests was adequate to excellent (ICC 0.73-0.96). The tests for bending, putting on socks, and getting up from the floor had the highest SRM (0.52-0.74) and showed the largest proportion of improved patients after TNFi therapy. The combination of these 3 tests was feasible in daily clinical practice and showed improved physical functioning after TNFi therapy in 67% of the patients.

CONCLUSION

The 3 selected tests are recommended for use in daily practice because they generate information comparable to the full set. They are reliable and feasible, and the combination of these tests showed improved physical functioning after TNFi therapy in 67% of the patients. Evaluation of physical functioning might be improved by adding these tests to other AS outcome measures.

Golimumab administered subcutaneously every 4 weeks in ankylosing spondylitis: 5-year results of the GO-RAISE study

Objective

Assess golimumab efficacy/safety through 5 years in patients with active ankylosing spondylitis (AS).

Methods

356 patients with AS were randomly assigned to placebo, golimumab 50 mg or 100 mg every 4 weeks. At week 16, patients with inadequate response early escaped with blinded dose adjustments (placebo to 50 mg, 50 mg to 100 mg). At week 24, all patients receiving placebo crossed over to 50 mg. Blinded active therapy continued through week 104; from week 104 to week 252, the golimumab dose could be adjusted. Intent-to-treat and observed efficacy data were assessed by randomised treatment groups.

Results

At week 256, and with >4.5 years of golimumab, overall intent-to-treat Assessment in SpondyloArthritis international Society criteria for 20% improvement (ASAS20) and ASAS40 response rates were 66.0% (235/356) and 57.0% (203/356), respectively; Bath AS Disease Activity Index 50% improvement response was 55.9% (199/356). Observed response rates among the 255 (72%) patients who continued golimumab through week 252 were consistent, albeit somewhat higher. Among patients who increased golimumab from 50 to 100 mg, 60.6% (20/33) and 44.7% (17/38) achieved ASAS20/ASAS40 responses, respectively, following ≥2 consecutive doses of golimumab 100 mg. Golimumab safety through week 268 was similar to that through week 24 regardless of dose.

Conclusions

Clinical improvements observed in patients treated with golimumab through week 24 were sustained through week 256 (5 years). Long-term golimumab safety is consistent with that of other established tumour-necrosis-factor-antagonists.

Trial registration number

ClinicalTrials.gov: NCT00265083.