The Cough Severity Index (CSI) is a short, self-administered questionnaire that quantifies how severely chronic cough of upper airway origin affects a patient. It gives clinicians and researchers a statistically validated, easy-to-score measure for tracking symptom severity and treatment outcomes.
Description
The CSI is a 10-item patient-completed questionnaire. Each item is rated on a 5-point frequency scale from “never” to “always,” giving a total score from 0 to 40. The items were selected from an initial pool of 49 symptom statements generated by a clinical consensus of laryngologists and speech-language pathologists. Statistical analysis was combined with a second blinded clinician ranking of clinical relevance. The result is the smallest set of items that retains strong measurement properties.
The final items capture how cough affects the patient physically, socially and emotionally, including breathlessness during cough, voice impact, activity limitation, embarrassment and avoidance of social settings. All 10 items load on a single factor, so the score works as one summary measure of cough severity. The index measures symptom severity, not diagnosis, so it supplements the clinical evaluation. In the healthy control group, scores averaged 0.45, and a score more than two standard deviations above that mean (above about 3.2) indicates a symptomatic patient.
Applications
- Patient-reported endpoint in clinical trials of chronic cough therapeutics, including antitussive and neuromodulator drugs
- Outcome measure for cough suppression and speech-language pathology therapy programs
- Baseline and follow-up severity tracking in otolaryngology, laryngology, pulmonology and primary care clinics
- Monitoring response to medical management in patients with chronic cough, such as those with laryngopharyngeal reflux
- Integration into electronic health record, telehealth and digital patient-intake platforms
Advantages
- Brief at 10 items, so patients complete it quickly and clinicians score it easily
- Developed and validated specifically for upper airway chronic cough
- Reliable: internal consistency of 0.93 and test-retest reliability of r = 0.83
- Clearly separates symptomatic patients from healthy controls
- Detects significant change after treatment, making it suitable as an outcome measure
Invention Readiness
The CSI is fully developed and has been validated in a clinical population of 365 participants, including symptomatic patients, healthy controls and a pre-/post-treatment cohort. Data generated show strong internal consistency, stable test-retest reliability, clear separation between healthy and symptomatic participants, and a statistically significant score reduction following cough suppression therapy and medical management.
IP Status
Copyright
Related Publication(s)
Shembel, A. C., Rosen, C. A., Zullo, T. G., & Gartner-Schmidt, J. L. (2013). Development and validation of the Cough Severity Index: A severity index for chronic cough related to the upper airway. The Laryngoscope, 123(8), 1931–1936. https://doi.org/10.1002/lary.23916
