Estimating the cut-off point of Xerostomia Inventory questionnaire score to diagnose dry mouth based on non-stimulating saliva test: a diagnostic sensitivity and specificity study

Abstract Aim Xerostomia is defined as a subjective complaint of dry mouth and is a prevalent condition. The study aims to estimate the cut point of the xerostomia inventory (XI) questionnaire for diagnosing dry mouth based on a saliva test. Method This prospective study was conducted in Dentistry Sc...

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Main Authors: Donya Pourjahanshah, Amir Hossein Nekouei, Shahla Kakoei, AliAkbar Haghdoost
Format: Article
Language:English
Published: BMC 2025-03-01
Series:BMC Oral Health
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Online Access:https://doi.org/10.1186/s12903-025-05576-4
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author Donya Pourjahanshah
Amir Hossein Nekouei
Shahla Kakoei
AliAkbar Haghdoost
author_facet Donya Pourjahanshah
Amir Hossein Nekouei
Shahla Kakoei
AliAkbar Haghdoost
author_sort Donya Pourjahanshah
collection DOAJ
description Abstract Aim Xerostomia is defined as a subjective complaint of dry mouth and is a prevalent condition. The study aims to estimate the cut point of the xerostomia inventory (XI) questionnaire for diagnosing dry mouth based on a saliva test. Method This prospective study was conducted in Dentistry School of Kerman University of Medical Sciences. Eligibility criteria included individuals aged 40 and above who were capable of undergoing saliva testing. For each randomly selected participants, a non-stimulating saliva test as a reference test was taken between 9:00 AM and 12:00 PM. Participants were asked to avoid eating, drinking and smoking 60 min before and during the test. For 5 min, the patient poured the accumulated saliva in his mouth every 1 min by bending forward into the container. If the collected saliva was less than 0.1 ml during 1 min, the participant was diagnosed with dry mouth. The Persian version of the XI questionnaire as an index test was used to calculate the xerostomia score, which was determined by summing the scores for each question. The diagnostic power of the questionnaire was assessed using receiver operating characteristic curve, and Youden index was utilized to identify the positivity cut off point. Results In this research, 120 people who referred to the Faculty of Dentistry in 2022–2023 who were participated. Of all participants, 50% in the study were women. The average age of the participants in the study was 50.2 ± 7.2 years. Among the participants, 40 experienced dry mouth. The positivity cut-off point for the diagnosis of dry mouth was xerostomia score greater than 23.5, which has a sensitivity of 82.5% and a specificity of 81.5%. The area under curve for the questionnaire was 0.898. Conclusions The XI questionnaire cut point of 23.5 demonstrated high sensitivity and specificity for diagnosing dry mouth in individuals over 40 years old. Results for specific age or gender subgroups should be interpreted with caution.
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spelling doaj-art-cfbba9350526416eab81cebfbe20a7412025-08-20T02:56:12ZengBMCBMC Oral Health1472-68312025-03-012511810.1186/s12903-025-05576-4Estimating the cut-off point of Xerostomia Inventory questionnaire score to diagnose dry mouth based on non-stimulating saliva test: a diagnostic sensitivity and specificity studyDonya Pourjahanshah0Amir Hossein Nekouei1Shahla Kakoei2AliAkbar Haghdoost3Oral and Dental Diseases Research Center, Kerman University of Medical SciencesSocial Determinants on Oral Health Research Center, School of Dentistry, Kerman University of Medical SciencesOral and Dental Diseases Research Center, Kerman University of Medical SciencesHIV/STI Surveillance Research Center, and WHO Collaborating Center for HIV Surveillance, Institute for Futures Studies in Health, Kerman University of Medical SciencesAbstract Aim Xerostomia is defined as a subjective complaint of dry mouth and is a prevalent condition. The study aims to estimate the cut point of the xerostomia inventory (XI) questionnaire for diagnosing dry mouth based on a saliva test. Method This prospective study was conducted in Dentistry School of Kerman University of Medical Sciences. Eligibility criteria included individuals aged 40 and above who were capable of undergoing saliva testing. For each randomly selected participants, a non-stimulating saliva test as a reference test was taken between 9:00 AM and 12:00 PM. Participants were asked to avoid eating, drinking and smoking 60 min before and during the test. For 5 min, the patient poured the accumulated saliva in his mouth every 1 min by bending forward into the container. If the collected saliva was less than 0.1 ml during 1 min, the participant was diagnosed with dry mouth. The Persian version of the XI questionnaire as an index test was used to calculate the xerostomia score, which was determined by summing the scores for each question. The diagnostic power of the questionnaire was assessed using receiver operating characteristic curve, and Youden index was utilized to identify the positivity cut off point. Results In this research, 120 people who referred to the Faculty of Dentistry in 2022–2023 who were participated. Of all participants, 50% in the study were women. The average age of the participants in the study was 50.2 ± 7.2 years. Among the participants, 40 experienced dry mouth. The positivity cut-off point for the diagnosis of dry mouth was xerostomia score greater than 23.5, which has a sensitivity of 82.5% and a specificity of 81.5%. The area under curve for the questionnaire was 0.898. Conclusions The XI questionnaire cut point of 23.5 demonstrated high sensitivity and specificity for diagnosing dry mouth in individuals over 40 years old. Results for specific age or gender subgroups should be interpreted with caution.https://doi.org/10.1186/s12903-025-05576-4XerostomiaDry mouthSaliva testXerostomia Inventory questionnaireReceiver operating characteristicYouden index
spellingShingle Donya Pourjahanshah
Amir Hossein Nekouei
Shahla Kakoei
AliAkbar Haghdoost
Estimating the cut-off point of Xerostomia Inventory questionnaire score to diagnose dry mouth based on non-stimulating saliva test: a diagnostic sensitivity and specificity study
BMC Oral Health
Xerostomia
Dry mouth
Saliva test
Xerostomia Inventory questionnaire
Receiver operating characteristic
Youden index
title Estimating the cut-off point of Xerostomia Inventory questionnaire score to diagnose dry mouth based on non-stimulating saliva test: a diagnostic sensitivity and specificity study
title_full Estimating the cut-off point of Xerostomia Inventory questionnaire score to diagnose dry mouth based on non-stimulating saliva test: a diagnostic sensitivity and specificity study
title_fullStr Estimating the cut-off point of Xerostomia Inventory questionnaire score to diagnose dry mouth based on non-stimulating saliva test: a diagnostic sensitivity and specificity study
title_full_unstemmed Estimating the cut-off point of Xerostomia Inventory questionnaire score to diagnose dry mouth based on non-stimulating saliva test: a diagnostic sensitivity and specificity study
title_short Estimating the cut-off point of Xerostomia Inventory questionnaire score to diagnose dry mouth based on non-stimulating saliva test: a diagnostic sensitivity and specificity study
title_sort estimating the cut off point of xerostomia inventory questionnaire score to diagnose dry mouth based on non stimulating saliva test a diagnostic sensitivity and specificity study
topic Xerostomia
Dry mouth
Saliva test
Xerostomia Inventory questionnaire
Receiver operating characteristic
Youden index
url https://doi.org/10.1186/s12903-025-05576-4
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