Bath Ankylosing Spondylitis Functional Index (BASFI)

Evaluates how autoimmune AS symptoms such as pain and stiffness in articulations affect daily activities.

In the text below the calculator you can find more information on how the index is administered and interpreted.

The BASFI consists of 10 items describing daily activities and evaluates how easy it is for the patient suffering from the autoimmune disease ankylosing spondylitis (AS) to perform them.

Each item in the index is scored on a visual analogue scale, from 0 to 10, where the higher the score, the higher the impairment in performing the everyday activity described by the item.

BASFI was created by Calin et al. during a 1994 study that took place at University of Bath, England.

163 patients have completed the questionnaire, of which 116 were outpatients who completed it once while 47 were inpatients that completed the questionnaire three times.

The patients scores, covered 95% of the BASFI score range, an improvement compared to other functional indices such as the Dougados, whose results only covered 65% of its score range.

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Bath ankylosing spondylitis functional index explained

The BASFI is a self-administering questionnaire that evaluates, on a visual analogue scale, functional limitation in patients with the inflammatory autoimmune disease ankylosing spondylitis (AS).

It addresses pain and stiffness control in a specific manner for AS patients and can be used for monitoring therapeutic results over time, thus helping the efficient relief of some of the symptoms and in improving perception about the disability.

The ten items in the BASFI are preceded by the following instruction:

Please evaluate on a scale from 0 (easy) to 10 (impossible) how hard you find the following situations to be:

Putting on your socks or tights without help or aids (e.g. sock aids)?
Bending forward from the waist to pick up a pen from the floor without an aid?
Reaching up to a high shelf without help or aids (e.g. helping hand)?
Getting up out of an armless dining room chair without using your hands or any other help?
Getting up off the floor without any help from lying on your back?
Standing unsupported for 10 minutes without discomfort?
Climbing 12-15 steps without using a handrail or walking aid (one foot on each step)?
Looking over your shoulder without turning your body?
Doing physically demanding activities (e.g. physiotherapy exercises, gardening or sports)?
Doing a full day activities whether it be at home or work?

BASFI interpretation

The BASFI score consists of the sum of the user answers which are physically plotted on a visual analogue scale or selected on a scale between 0 and 10.

The patient is asked to think of what they experience during activities such as getting dressed, standing up or climbing up the stairs.

The activities are rated from 0, which means no impairment, to 10, which means severe impairment.

There is no specified cut off point, however, the higher the score, the higher the functional impairment caused by ankylosing spondylitis.

Ankylosing spondylitis guidelines

AS is a long term auto immune condition caused by the HLA-B27 gene. It involves the inflammation of the spine, in the form of spinal arthritis that in time and left untreated, leads to the ankylosis of the vertebral and sacroiliac joints.

Back pain and stiffness unrelieved by rest are the most common symptoms, along fatigue, pain and swelling in the knees or hips.

Diagnosis takes place through magnetic resonance imaging, Schober’s test and radiography. In blood laboratory results it was observed an increase in C-reactive protein and in the erythrocyte segmentation rate, which are signs of inflammation.

Due to the incurability of the disease, treatment mainly focuses on relieving the symptoms and re-establishing a degree of normal functioning through painkiller, NSAID medication and organized physical exercise or physiotherapy.

About the study

BASFI was created by Calin et al. in 1994 as a method of assessing function, that is specific to patients suffering from ankylosing spondylitis.

The model consists of 8 specific questions about function in AS and 2 questions about the patient’s ability to fulfil daily activities.

During the study, 163 patients have completed the questionnaire, 116 of them were outpatients who completed it once while 47 were inpatients who were scored on three different occasions. The patients scores covered 95% of the BASFI score range.

The BASFI was also compared with the Dougados functional index and was found to have superior sensitivity to change across the whole spectrum of disease.