The International Tinnitus Journal

The reliability and validity of the Dutch version of the Composite Autonomic Symptom Scale and its relationship with Pupillometry in chronic pain patients.

Wim E Tuinebreijer, Henk M. Koning*

Background: Functional disorders of the Autonomic Nervous System (ANS) are associated with chronic pain syndromes. The COMPASS 31 score is a validated measure of the severity of autonomic impairment. Pupillometry is a rapid, non-invasive, and valuable indicator of autonomic nervous system function. Objectives: The present study aimed to develop and evaluate the reliability of the Dutch version of the COMPASS-31 and to determine whether pupillometry is related to the autonomic scores of the COMPASS-31. Methods: A retrospective study of all chronic pain patients who had Pupillometry and completed the COMPASS-31 score in Pain Clinic De Bilt in the period from January 2025 to May 2025 (n=62). We explored the reliability of the COMPASS-31 test by determining Cronbach‘s alpha and Intra-Class Correlation Coefficients (ICC agreement). We also calculated the Spearman correlation coefficients among the six domains of the COMPASS-31 and pupillometry observations and among the items of the COMPASS-31 and pupillometry values. Results: This study examined 62 pain patients using the patient-reported outcome measure COMPASS-31 after it was translated into Dutch and utilized a pupillometer. We calculated the correlations between the COMPASS-31 items and the pupillometry values. These correlations reveal a clear relationship between pupillometry and the COMPASS-31 items that assess autonomic symptoms related to the light perception reaction of the eyes, as well as the response after standing up and experiencing a dry mouth. Conclusion: The COMPASS-31 is a moderately reliable patient-reported outcome questionnaire looking at multidimensional autonomic domains. The significant relationship between the COMPASS-31 and pupillometry demonstrates construct validity. Objective measurements, such as pupillometry, are not superior to subjective measurements like the patient-reported outcome COMPASS-31.