Overview: This specialized BASDAI assessment tool is designed for patients with Ankylosing Spondylitis (AS). It implements the validated Bath Ankylosing Spondylitis Disease Activity Index to help users evaluate their disease activity and treatment effectiveness. This tool is for informational purposes and complements, but does not replace, professional medical advice.

This free online calculator is designed for individuals managing Ankylosing Spondylitis (AS), an inflammatory condition primarily affecting the spine. Our tool utilizes the validated Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) to help gauge your current disease activity and treatment response.

Understanding Ankylosing Spondylitis (AS)

Ankylosing Spondylitis is a chronic form of arthritis characterized by inflammation, pain, and stiffness in the spine and other joints. Symptoms typically develop gradually, often beginning in early adulthood with lower back discomfort. This is a lifelong condition where stiffness may progressively increase over time.

Common symptoms associated with AS can include persistent back pain and stiffness, swelling in other joints, significant fatigue, unexplained weight loss, occasional fever, and eye inflammation known as anterior uveitis. While the exact cause is not fully understood, genetics and environmental factors play a role. Although there is no cure, treatments like medication, targeted exercise, physical therapy, and sometimes surgery can manage symptoms and slow progression.

The BASDAI Score: Meaning and Purpose

The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) is a straightforward, clinically-validated questionnaire developed to assess the level of disease activity in AS patients. Created by a specialist team in Bath, England, it provides a quick snapshot, typically taking just a couple of minutes to complete.

This index focuses on six key areas related to the major symptoms of AS: overall fatigue, level of spinal pain, joint pain or swelling, areas of localized tenderness, and both the duration and severity of morning stiffness. Respondents rate each area on a scale from 0 (no problem) to 10 (severe problem).

How the BASDAI Score Calculator Works

Our scientific calculator simplifies the BASDAI scoring process. You will answer six questions, each corresponding to a primary symptom. For every question, you select a value between 0 and 10 based on your personal experience over the past week.

A score of 0 indicates you have no issues with that specific symptom, while a 10 represents the most severe manifestation. The tool then automatically processes your inputs using the standard BASDAI formula to generate your total score.

Interpreting Your BASDAI Score and Results

The final BASDAI score is calculated using a specific formula that averages your responses. The scores from questions five and six, both concerning morning stiffness, are averaged together before being included in the final calculation. This results in a total score that also ranges from 0 to 10.

Interpreting the score is crucial for disease management. A result of 4 or higher generally indicates that the disease is not optimally controlled. Individuals with a score at this level are often considered good candidates for reviewing and potentially adjusting their treatment plan.

The standard BASDAI formula is: 


BASDAI = (Q1 + Q2 + Q3 + Q4 + (Q5 + Q6)/2) / 5

Where Q1 to Q6 represent the scores (0-10) for each of the six questions.