An Updated Patient-Centered Sialadenitis Instrument: The Obstructive Salivary Problem Impact Test (SPIT)

The Chronic Obstructive Sialadenitis Symptoms questionnaire (COSS) was created to assess chronic sialadenitis symptoms and treatment response, but its development lacked patient input and validation. We analyzed COSS responses and feedback from sialadenitis patients and physician experts to create the novel obstructive Salivary Problem Impact Test (SPIT), a new standardized measure of sialadenitis-associated symptoms.

We analyzed COSS responses via exploratory factor analysis (EFA) to identify essential symptom domains and reduce overlap in questions. Sialadenitis patients evaluated the significance of index symptoms identified from the literature review. Expert physicians rated symptom relevance in clinical assessment. An updated questionnaire (SPIT) was piloted with both patient and expert interviews to optimize structure and readability. The SPIT was assessed for internal consistency, construct validity, and test-retest stability.

EFA of 310 COSS responses demonstrated 3 main symptom domains (functional impact, pain, swelling) that explained 58.4% of response variance. Results were not statistically different when collapsing from 11 to 5 question response options. Experts (n = 5) ranked gland swelling, mealtime pain, and foul taste as most clinically important, while patients (n = 12) ranked swelling, non-mealtime pain, and difficulty eating as most bothersome. Most patients experienced sialadenitis-related functional or psychosocial impairment. Following interviews for question refinement, a 25-question survey was finalized. SPIT responses from 50 sialadenitis patients demonstrated internal consistency (Cronbach's alpha = 0.96), 14-day stability (p < 0.001), and agreement with Oral Health Impact Profile-14 scores (p < 0.0001).

We developed the SPIT instrument to improve usability and content validity in chronic sialadenitis evaluation. The psychometric assessment demonstrated high construct validity and test-retest reliability. Further work will assess longitudinal changes with treatment.

4 Laryngoscope, 133:539-546, 2023.