[The BASDAI-D--an instrument to defining disease status in ankylosing spondylitis and related diseases]

Quantitative scintigraphy in discriminating sacroiliac joint physiological and pathological uptake

Background

Bone scintigraphy is a highly sensitive diagnostic nuclear medicine imaging technique that uses a radiotracer to evaluate the distribution of active bone formation in the skeleton related to malignant and benign diseases, as well as physiological processes. Subjective increase of the radioactivity at the sacroiliac joint in cancer patients could indicate physiological, metastatic, or inflammatory (sacroiliitis) cause. In this single-center study, we aimed to settle the normal sacroiliac index (SII) in males and females and if it differs from side to other, as a more accurate quantitative method than qualitative one, and assess its validity in discriminating the cause in pathological increase.

Results

Sacroiliac index can differentiate physiological uptake at the SIJ from pathological uptake with a highly significant value (P < 0.001). Using SII at a cutoff value 1.17 had 100% sensitivity and specificity in differentiating between the two conditions. The normal SII in our institute ranged from 0.9 to 1.14 with no significant difference between right and left SIJs. The mean SII was 1.33 ± 0.11 in patients with ankylosing spondylitis (AS) and 1.38 ± 0.1 in metastatic cases with no significant difference in SII between the two diseased groups (P = 0.49).

Conclusion

Bone scintigraphy is widely used in our institute and qualitative assessment of SIJ uptake is sometimes confusing. In this study, we assessed the normal SII range in physiological uptake and assessed a cutoff value (which is lower than other races) above which any increase in SIJ uptake is considered pathological. We could not confirm a cutoff value to discriminate between AS and metastatic affection of SIJ.

Widespread pain in axial spondyloarthritis: clinical importance and gender differences

Background

There is a remarkable lack of detailed knowledge on pain areas in axial spondyloarthritis (axSpA), and their clinical relevance is largely unknown. Pain area may reflect local disease processes, but amplification of nervous system signalling may alter this relationship. Also, gender differences in pain area may exist in axSpA, possibly confounding disease activity outcomes. Therefore, we firstly detailed pain locations in axSpA and evaluated gender differences. Secondly, we explored the relationship of regional pain definitions with clinical outcomes. Finally, we explored the role of pain area in the assessment of disease activity.

Methods

Body charts informed on the presence of axial, peripheral articular and non-articular pain in 170 patients (108 men, 62 women) with axSpA. Multivariate Odds Ratios (ORs) were used to compare genders. General linear models were used to explore clinical differences in disease activity (Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]), activity limitations (Bath Ankylosing Spondylitis Functional Index [BASFI]), fear of movement (Tampa Scale for Kinesiophobia 11-item version [TSK-11]), anxiety (Hospital Anxiety and Depression Scale subscale anxiety [HADS-A]) and depression (HADS subscale depression [HADS-D]) between four subgroups classified by widespread non-articular pain (WNAP+/−) and physician global assessment of disease activity (PGDA+/−) (p < .05). Principal Component Analysis (PCA) was performed to explore gender differences in the structure of disease activity.

Results

Axial thoracic pain was least prevalent (lumbar, 74.4%; cervical, 47.6%; cervicothoracic, 47.6%; thoracic, 32.4%), but it was about three times more likely in women (OR, 2.92; p = .009). Axial cervicothoracic junction pain spread more diffusely in women (OR, 2.48; p = .018). Women exhibited a two- to threefold increased likelihood of widespread axial (OR, 3.33; p = .007) and peripheral articular (OR, 2.34; p = .023) pain. A subgroup of WNAP+/PGDA− combined with low PGDA (27% of all patients) was associated with worse BASFI, BASDAI, HADS-A and HADS-D in men and worse TSK-11 and HADS-A in women (p < .05). Disease activity outcomes showed a two-factor structure in women but not in men.

Conclusions

In patients with axSpA, the location and spread of pain was different between genders and was related to worse clinical status. On the basis of pain area and PGDA, clinical subgroups exhibiting a remarkably distinct health status were identified. Outcome instruments such as BASDAI should acknowledge gender differences to ensure structural validity.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1626-8) contains supplementary material, which is available to authorized users.

Study protocol for a cluster randomized controlled trial to evaluate a referral strategy for axial spondyloarthritis in young primary care patients with chronic low back pain; an impact study

BACKGROUND

Axial spondyloarthritis (axSpA) is a disabling inflammatory joint disease with chronic low back pain (CLBP) as leading symptom. Recognizing axSpA in the large amount of CLBP patients is difficult for general practioners (GP). This evaluation aims to assess the effect of a referral strategy for axSpA in young primary care patients with CLBP by comparing the use of the strategy with usual care. The effect is measured at three different levels; by patient reported outcomes (the clinical effect), process and costs evaluation.

METHODS/DESIGN

This study design is a cluster randomized controlled trial with GP as clusters. GPs throughout the Netherlands are invited to participate and randomized to either the intervention or the control group. Patients from participating GPs are invited to participate if they have ever been registered with low back pain, without radiation (ICPC L03) and aged 18-45 years. To be included in the study, patients need to have current low back pain and chronic low back pain (>12 weeks). In the intervention arm a referral strategy for axSpA will be applied in CLBP patients, in the control arm care as usual will be provided for CLBP patients. The referral strategy consists of four easy to use variables. All are questions about the back pain complaints of the patients. Data is prospectively collected in an online database at baseline (T0), 4 months (T1), 12 months (T2) and 24 months (T3). After time point T1 (4 months) patients from the control group will also receive the intervention i.e. the application of a referral strategy for axSpA. The effect of the referral strategy is measured at three different levels, by patient outcomes (e.g. pain scores, quality of life), process measures (e.g. number of axSpA diagnoses by rheumatologists) and by costs (work productivity and health care resources use). Our primary outcome is the Roland Morris Disability Questionnaire after 4 months, secondary outcomes are pain and quality of life. Costs will be assessed before and after the use of the referral strategy, to estimate if the use of the strategy will lead to a reduction in health care costs and improvement in work participation.

DISCUSSION

It is anticipated that using the axSpA referral strategy for primary care CLBP patients will increase the quality of life of CLBP patients, will result in more (correct) diagnoses of axSpA by the rheumatologists, and will be cost-effective. Ultimately, the results of this study may contribute to the startup of a national implementation of the axSpA referral strategy to identify timely CLBP patients with axSpA.

TRIAL REGISTRATION

NCT01944163 , date of registration; September 6, 2013 (Clinicaltrials.gov).

[Self-monitoring in inflammatory rheumatic diseases]

BACKGROUND

Active involvement of patients in their care has led to better treatment and outcomes. Tight control concepts emphasize the need for regular assessments including patients' active involvement by self-monitoring.

METHODS

The literature was screened with respect to published experiences of self-monitoring of rheumatoid arthritis and spondyloarthritides. The use of "patient-reported outcome" (PRO) instruments can facilitate self-monitoring. Potentially applicable PROs and their correlations to clinical parameters as well as modern data acquisition modes are presented.

RESULTS

Some experiences for self-monitoring have been reported. Recommendations from national and international professional rheumatology societies do not yet consider self-monitoring; however, PROs might be used for self-monitoring but instructions for patients on "how to deal with self-monitored PRO values" are missing.

CONCLUSION

Self-monitoring of inflammatory rheumatic diseases seems feasible. Further evaluation studies are warranted to guarantee an optimized direct patient involvement in their management beyond outpatient care in hospitals and private practices so that they can thus contribute to a better outcome.

[Structural validity of the Short Form 36 (SF-36) in patients with rheumatic diseases]

BACKGROUND

Quality of life is gaining relevance as a criterion of success in therapeutic outcome studies. In order to record quality of life, disease-specific instruments are being used as well as generic instruments. Generic instruments offer the possibility to compare outcome among different indications; however for this it is necessary to prove the differential factorial validity of the instrument's structure.

AIM OF THE STUDY

Using structural equation modeling the SF-36 was administered to a sample of patients with rheumatic diseases. The sensitivity to change of the measure was calculated after six months. Furthermore, age- and sex-specific scale values were calculated and compared with norm data.

METHODS

SF-36 data of 436 patients as well as sex and age from two scientific rehabilitation research projects were pooled for this secondary analysis.

RESULTS

The structure of the questionnaire proves to be acceptable and comparable with international results. The confirmatory analysis supports the best fit for a model with crossloadings assuming correlated main dimensions. Sensitivity to change is low in general. The best effect size is found for the subscale pain. The comparison with norm data shows that patients are impaired particularly within their physical health (regarding the SF subscales) both at the beginning of the treatment and after six months. In all age groups men have better conditions than women.

CONCLUSIONS

The generic SF-36 show sufficient factorial validity. From this point of view there is no objection to using the SF-36 in patients with rheumatic diseases. Indeed the use of the SF summary scales as a representation of (uncorrelated) physical and mental health must be questioned critically.