Accuracy of a questionnaire on xerostomia as a screening tool for hyposalivation

Abstract

Objective: Determine the accuracy of a questionnaire on xerostomia as a screening tool for hyposalivation. Methods: A total of 402 adults awaiting dental care at a public healthcare service answered an eight-item questionnaire addressing xerostomia and were submitted to stimulated sialometry, with ≤ 0.7 mL/min considered indicative of hyposalivation. Reproducibility and internal consistency of the questionnaire were evaluated. The correlation between the score and salivary flow was investigated. The total score was also compared between groups with and without hyposalivation and diagnostic precision measures were calculated. Results: Hyposalivation was identified in 162 participants (40.3%) and a total of 229 (57.0%) answered affirmatively to at least one question. The responses to each question revealed variable reproducibility (κ = 0.450–0.785) and satisfactory internal consistency (Cronbach's α = 0.70). Individuals with a larger number of positive answers had lower salivary flow (Spearman's ρ = −0.193; P < 0.001). The mean number of positive answers was greater in the group with a clinical diagnosis of hyposalivation compared to those without low salivary flow. The sensitivity of the screening tool was 64.8%, with an area under the ROC curve of 0.60 (95% confidence interval: 0.547–0.645; P < 0.001). Conclusion: The questionnaire proved to be useful for the epidemiological screening of individuals with possible hyposalivation.