BASFI

Abstract: OBJECTIVE Disease status, in terms of disease activity, disease progression and prognosis is difficult to define in ankylosing spondylitis (AS). No gold standard exists. Therefore, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), a self-administered instrument, has been developed as a new approach to defining disease activity in patients with AS. METHODS The index, designed by a multidisciplinary team with input from patients, consists of six 10 cm horizontal visual analog scales to measure severity of fatigue, spinal and peripheral joint pain, localized tenderness and morning stiffness (both qualitative and quantitative). The final BASDAI score has a range of 0 to 10. The index was distributed to a cross section of patients, including inpatients receiving 3 weeks of intensive physiotherapy treatment and hospital outpatients. BASDAI was completed by a total of 154 patients. Validation of the new instrument was achieved through analysis of user friendliness, reliability (consistency), score distribution and sensitivity to change. Comparisons were made with a previous Bath disease activity index (DAI) and the Newcastle Enthesis Index. RESULTS The BASDAI was found by patients to be quick and simple to complete (mean: 67 s). Test-retest reliability was good (r = 0.93; p < 0.001), as was the distribution of scores across the scale (score range: 0.5-10; mean: 4.31). BASDAI was sensitive to change, reflecting a 16% (mean) improvement in inpatient scores after 3 weeks of treatment. It is superior to the DAI in terms of construct and content validity and to the Enthesis Index in all aspects. CONCLUSION In summary, BASDAI is user friendly, reliability, sensitive to change and reflects the entire spectrum of disease. It is a comprehensive self-administered instrument for assessing disease activity in AS.

Abstract: OBJECTIVE After pain and stiffness, one of the most important complaints of patients with ankylosing spondylitis (AS) is disability. The main aims of treatment are to control pain but also to improve function. Various methods of assessing function exist but are either not specific for the disease or have not been adequately validated. As a result of this deficiency we developed the Bath Ankylosing Spondylitis Functional Index (BASFI) as a new approach to defining and monitoring functional ability in patients with AS. METHODS This self-assessment instrument was designed by a team of medical professionals in conjunction with patients, and consists of 8 specific questions regarding function in AS and 2 questions reflecting the patient's ability to cope with everyday life. Each question is answered on a 10 cm horizontal visual analog scale, the mean of which gives the BASFI score (0-10). The questionnaire was completed 257 times in total: once by 116 outpatients and by 47 inpatients on 3 occasions over a 3-week intensive physiotherapy course. In addition, the instrument was compared with the Dougados functional index. RESULTS Patients scores covered 95% of the BASFI range, giving a normal distribution of results. In contrast only 65% of the Dougados functional index scale was used. Furthermore, over the 3 week period of inpatient treatment, the BASFI revealed a significant improvement in function (20%, p = 0.004) while there was a less impressive change in the Dougados functional index (6%, p = 0.03). This demonstrates the superior sensitivity of the BASFI: Consistency was good for both indices (p < 0.001), as was the relationship between patient perception of function and function as assessed by an external observer (p < 0.001). CONCLUSION The BASFI satisfies the criteria required of a functional index: it is quick and easy to complete, is reliable and is sensitive to change across the whole spectrum of disease.

Abstract: OBJECTIVE To determine the most appropriate clinical measurements for the assessment of ankylosing spondylitis (AS) to develop the new metrology index. METHODS One hundred and ninety-three individuals with AS were studied. The patients reflected the entire spectrum of cases of AS. Metrology was performed on 327 occasions. First the metrology (20 measurements) of 43 patients was analyzed. From this, 5 simple clinical measurements were defined which most accurately reflect axial status: cervical rotation, tragus to wall distance, lateral flexion, modified Schober's, and intermalleolar distance. These measurements were assessed for reliability, speed and both inter and intraobserver variability in another 40 patients. RESULTS Analysis of the first group of 43 patients and a subsequent group of 54 patients, using the 5 measurements that constitute this new Bath AS Metrology Index (BASMI), demonstrated that they accurately and reliably mirror the 20 clinical measurements assessed previously (r = 0.92, p < 0.001). In a new group of 40 patients the measurements were demonstrated to be accurate and reproducible for both intraobserver variability (r = 0.99, p < 0.001) and interobserver variability (r = 0.97, p < 0.001). In a further 56 patients, admitted for inpatient therapy, an improvement in the BASMI from 3.34 (SD 2.71) to 2.16 (SD 2.42) was noted over a period of 3 weeks (regardless of disease severity) which indicates a sensitivity to change (chi 2 = 6.55, p < 0.01). The mean improvement over baseline was about 30%. CONCLUSION Five clinical measurements provide a composite index (BASMI) and define disease status in AS. The BASMI is quick (7 min), reproducible and sensitive to change across the disease spectrum.