The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) Calculator is a widely used clinical tool developed to measure the severity and impact of symptoms in individuals living with ankylosing spondylitis (AS). Ankylosing spondylitis is a chronic inflammatory disease that mainly affects the spine and sacroiliac joints, but it can also involve other joints and organs. It often causes pain, stiffness, and reduced mobility, especially in the morning or after periods of inactivity.
The BASDAI Calculator is designed to quantify the disease activity through a patient’s own assessment of their symptoms. It consists of six key questions that ask about common symptoms experienced by people with AS:
Each symptom is rated on a scale from 0 (no problem) to 10 (worst possible), allowing the calculator to produce a final score between 0 and 10. A score above 4 is typically considered to indicate high disease activity that may require a change in treatment. The calculation is simple but highly informative, offering both patients and healthcare providers a snapshot of how active the disease is and how it is impacting daily life.
Using the BASDAI Calculator is simple and only takes a few minutes. It is designed for individuals with ankylosing spondylitis to self-assess their current level of disease activity. Follow these steps to complete the calculator and receive your score:
The BASDAI Calculator helps you better understand your current condition and whether your treatment may need adjustment. You can share the result with your doctor during consultations to support more informed decisions.
The BASDAI Questionnaire is a self-assessment tool made up of six simple questions that focus on the most common and impactful symptoms of ankylosing spondylitis. Each question asks you to rate the severity of your symptoms over the past week using a scale from 0 (no problem) to 10 (very severe). Your responses help determine the overall level of disease activity.
How would you rate your overall level of fatigue or tiredness during the past week? Fatigue is a common symptom of ankylosing spondylitis and can significantly affect your daily life.
How would you rate the overall pain you have experienced in the areas most commonly affected by ankylosing spondylitis — your neck, back, and hips?
Have you noticed swelling or pain in joints other than your neck, back, and hips? This question helps capture peripheral joint involvement, which can occur alongside spinal symptoms.
Are there any areas of your body that are especially tender or sensitive to touch or pressure? This question relates to tenderness or discomfort you may feel in certain spots, which can be a sign of inflammation or flare-ups.
What is the severity of your morning stiffness after waking up? Stiffness is a hallmark symptom of AS and often feels worse in the morning or after periods of rest.
How long does your morning stiffness last? Choose the time range that best represents your experience — from no stiffness to stiffness lasting two hours or more.
Answering all six questions as accurately as possible will allow the calculator to give you a reliable BASDAI score, which you can use to monitor your condition or share with your healthcare provider.
Once you complete the BASDAI questionnaire, the calculator will provide you with a score ranging from 0 to 10. This score represents your level of disease activity due to ankylosing spondylitis. The higher the score, the more active and severe your symptoms are likely to be.
The BASDAI score is used by rheumatologists and other specialists to:
A single BASDAI score offers a helpful snapshot, but it’s most powerful when used regularly. Monitoring your score over time allows for better tracking of disease patterns and more informed treatment discussions.
While the BASDAI Calculator is a helpful self-assessment tool, it does not replace professional medical evaluation. If you are experiencing persistent or worsening symptoms of ankylosing spondylitis, it is important to consult a healthcare provider for a proper diagnosis and treatment plan.
An early and accurate diagnosis, along with the right treatment, can help slow disease progression, manage symptoms, and improve quality of life. Your doctor may also recommend imaging tests, lab work, or adjustments to your medication based on your BASDAI score and other clinical findings.
Tip: Bring your BASDAI score and a summary of your symptoms to your appointment. This can help your doctor better understand your condition and make more informed treatment decisions.
The BASDAI Calculator helps individuals with ankylosing spondylitis assess the severity of their symptoms and overall disease activity. It provides a score that can guide discussions with healthcare providers about treatment effectiveness and possible adjustments.
No, it is not a diagnostic tool. The calculator is designed for people who have already been diagnosed with ankylosing spondylitis to monitor their condition. Only a qualified healthcare provider can diagnose AS through clinical evaluation and testing.
A BASDAI score of 4 or above usually indicates high disease activity. This suggests that your symptoms are significantly affecting your daily life and that a change in treatment may be necessary. It’s recommended to consult your doctor if your score is consistently high.
You can use the calculator regularly—weekly, monthly, or before doctor appointments—to monitor changes in your condition. Frequent tracking helps detect patterns and assess how well your treatment is working.
Yes, the BASDAI Calculator is designed for self-assessment. However, the results should always be discussed with your healthcare provider for accurate interpretation and guidance.
Not necessarily. A low score may indicate that your symptoms are currently mild or well-controlled, but only a healthcare provider can determine if you are in remission based on a full clinical evaluation.
No, you should never change or stop your medication without consulting your doctor. The BASDAI score is just one tool among many used to guide treatment decisions.
The BASDAI Calculator provided on this page is intended for informational and educational purposes only. It is designed to help individuals with ankylosing spondylitis better understand their symptoms and disease activity. However, it is not a substitute for professional medical advice, diagnosis, or treatment.
Always seek the guidance of your physician or other qualified healthcare professional with any questions you may have regarding your health or medical condition. Never disregard medical advice or delay seeking it because of something you have read or calculated using this tool.
This calculator does not store or transmit any personal information, and the results are meant for personal use only. The creators of this tool are not responsible for any medical decisions made based on the calculator’s output without proper medical consultation.
If you are experiencing severe or worsening symptoms, or if your BASDAI score is consistently high, consult your healthcare provider promptly for a full evaluation and appropriate care.