Validation of a Digital Caries Risk Assessment Questionnaire Against the CAMBRA Protocol in an Egyptian Adult Population

Validation of a Digital Caries Risk Assessment Questionnaire Against the CAMBRA Protocol in an Egyptian Adult Population: A Cross-Sectional Diagnostic Agreement Study

This study is designed as a cross-sectional diagnostic agreement study conducted in accordance with the Standards for Reporting Diagnostic Accuracy Studies (STARD 2015) and the Guidelines for Reporting Agreement and Precision of Patient-reported Assessments (GRAPPA). The study evaluates the diagnostic agreement between the Digital Caries Risk Questionnaire (DCRQ), a novel patient self-administered digital instrument, and the Caries Management by Risk Assessment (CAMBRA) protocol as the primary clinical comparator. The Decayed, Missing, and Filled Teeth (DMFT) index is used as the reference standard for cumulative caries experience, with a threshold of DMFT ≥ 4 to identify individuals with high caries experience. Although the DMFT index reflects previous disease experience rather than future disease risk, it provides an objective clinical outcome for assessing construct validity. Accordingly, CAMBRA serves as the primary comparator for risk classification, whereas the DMFT index supports validation by evaluating the relationship between questionnaire-derived risk categories and cumulative clinical disease burden.

The methodological rationale for this study is based on the current evidence supporting contemporary caries risk assessment models. CAMBRA is recognized as one of the most extensively validated and widely implemented caries risk assessment systems and has demonstrated diagnostic performance comparable to other internationally accepted risk assessment models. Systematic evidence has shown that these validated models provide acceptable discriminatory ability and calibration for identifying individuals at increased risk of developing dental caries. Furthermore, recent evidence synthesizing longitudinal cohort studies has identified a consistent set of adult caries risk factors, including smoking, systemic diseases, water fluoridation exposure, educational level, fluoride toothpaste use, dietary sugar intake, bacterial plaque accumulation, and previous caries experience. These established determinants are comprehensively represented within the nine domains of the DCRQ, supporting its content validity. In addition, previous validation studies of simplified questionnaire-based caries risk assessment instruments have demonstrated acceptable internal consistency, good test-retest reliability, and significant associations between increasing risk categories and objective clinical indicators such as DMFT scores, plaque accumulation, white spot lesions, and active cavitated lesions. Collectively, these findings support the use of a cross-sectional diagnostic agreement design in which questionnaire-derived risk classification is evaluated against an established clinical risk assessment protocol and validated using objective measures of cumulative caries experience.

Study Overview

• Status: Recruiting
• Conditions: Dental Caries; Caries Risk
• Intervention / Treatment: Diagnostic test: Digital Caries Risk Assessment

• Study Type: Observational
• Enrollment (Estimated): 384

Contacts and Locations

• Study Contact: Name: Shereen Assem El Sherif, Dr.; Phone Number: +201066668112; Email: selsherif@msa.edu.eg
• Study Contact Backup: Name: Nermeen Kamal Hamza, Professor; Phone Number: +201211110660; Email: nhamza@msa.edu.eg

Study Locations

• Egypt
  • Sixth of October
    • Giza, Sixth of October, Egypt, 12566
      • Recruiting
      • October University for Modern Sciences and Arts
      • Contact: Shereen Assem El Sherif, Dr.; Phone Number: 01066668112; Email: selsherif@msa.edu.eg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

The study will be conducted at the Dental Outpatient Clinic, Faculty of Dentistry, MSA University (October University for Modern Sciences and Arts), 6th October City, Cairo, Egypt. Consecutive sampling will be employed on designated study days to minimise selection bias, consistent with STARD 2015 recommendations for diagnostic accuracy studies.

Description

• Inclusion Criteria

  1. Adults aged 18 to 65 years.
  2. Egyptian nationals or individuals who have resided in Egypt for at least 5 years.
  3. Able to read and understand Arabic or English.
  4. Presence of at least 10 natural teeth.
  5. Presenting for routine dental examination, preventive care, or treatment planning.
  6. Able and willing to provide written informed consent.

• Exclusion Criteria

  1. Presence of acute dental pain or a dental emergency requiring immediate treatment at the time of enrollment.
  2. Severe cognitive impairment or psychiatric disorder that would interfere with completion of the questionnaire or informed consent.
  3. Currently participating in another oral health research study.
  4. Complete edentulism or extensive fixed prosthetic rehabilitation that precludes assessment of the Decayed, Missing, and Filled Teeth (DMFT) index.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Digital caries risk assessment

Diagnostic test: Digital Caries Risk Assessment; The Digital Caries Risk Questionnaire (DCRQ) is a patient self-administered digital instrument encompassing nine weighted risk domains: (1) disease indicators and dental history; (2) dietary and lifestyle habits; (3) oral hygiene practices and fluoride use; (4) salivary and gingival health; (5) medical conditions; (6) current medications; (7) water source and fluoride exposure; (8) tobacco and nicotine use; and (9) clinical symptoms. Each domain generates a weighted subscore; domain scores are summed to yield a total score (maximum 160 points), with predefined override rules applied to prevent underestimation of risk in participants presenting with strong disease indicators (e.g., multiple restorations, root canal treatments, or persistent dental pain), ensuring clinically appropriate classification regardless of total score. The total score maps to one of four ordered risk categories: Low (0-39), Moderate (40-79), High (80-119), and Very High (120-160).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cohen's weighted kappa	The primary outcome is Cohen's weighted kappa (κw) with quadratic weights, computed between DCRQ and CAMBRA 4-level classifications (Low / Moderate / High / Very High). Both instruments share a 4-tier structure; no category collapsing is required. Minimum acceptable agreement: κw ≥ 0.41 (lower bound of 95% CI), corresponding to moderate agreement per Landis and Koch (1977). The 95% CI will be computed by bootstrap resampling (2,000 iterations).	Baseline (single study visit)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic accuracy of the Digital Caries Risk Questionnaire (DCRQ) for identifying participants with high cumulative caries experience (DMFT ≥ 4).	Diagnostic accuracy will be evaluated by calculating sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) using DMFT ≥ 4 as the reference standard.	Baseline (single study visit)
Discriminative ability of the DCRQ for identifying participants with high cumulative caries experience.	Receiver operating characteristic (ROC) curve analysis will be performed to determine the area under the curve (AUC) and the optimal DCRQ score cut-off for predicting DMFT ≥ 4.	Baseline (single study visit)
Independent predictors of high cumulative caries experience.	Multivariable logistic regression will be used to identify independent predictors of DMFT ≥ 4 and estimate the contribution of each DCRQ domain after adjustment for relevant covariates.	Baseline (single study visit)
Internal consistency of the DCRQ.	Internal consistency reliability will be assessed using Cronbach's alpha coefficient.	Baseline (single study visit)
Test-retest reliability of the DCRQ.	Test-retest reliability will be assessed using the intraclass correlation coefficient (ICC) in a nested subset of 60 participants who complete the DCRQ on two occasions separated by a 14-day interval.	14 days after baseline
Performance of the DCRQ across participant subgroups.	Diagnostic performance and agreement of the DCRQ will be evaluated according to age, sex, educational level, and smoking status.	Baseline (single study visit)

Collaborators and Investigators

• Sponsor: October University for Modern Sciences and Arts

Publications and helpful links

General Publications

• Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977 Mar;33(1):159-74.
• Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig L, Lijmer JG, Moher D, Rennie D, de Vet HC, Kressel HY, Rifai N, Golub RM, Altman DG, Hooft L, Korevaar DA, Cohen JF; STARD Group. STARD 2015: an updated list of essential items for reporting diagnostic accuracy studies. BMJ. 2015 Oct 28;351:h5527. doi: 10.1136/bmj.h5527.
• Featherstone JDB, Chaffee BW. The Evidence for Caries Management by Risk Assessment (CAMBRA(R)). Adv Dent Res. 2018 Feb;29(1):9-14. doi: 10.1177/0022034517736500.
• Catala-Benavent I, Iranzo-Cortes JE, Almerich-Torres T, Marquez-Arrico CF, Almerich-Silla JM, Montiel-Company JM. Comparative Study of Methods for Caries Risk Evaluation: CAMBRA, the Cariogram, and Caries Risk Semaphore. J Clin Med. 2025 Jul 30;14(15):5378. doi: 10.3390/jcm14155378.
• Iqbal A, Siddiqui YD, Chaudhary FA, Abideen MZU, Hussain T, Arjumand B, Almuhaiza M, Mustafa M, Khattak O, Attia RM, Rashed AA, Sultan SE. Caries risk assessment by Caries Management by Risk Assessment (CAMBRA) Protocol among the general population of Pakistan-a multicenter analytical study. PeerJ. 2024 Jan 31;12:e16863. doi: 10.7717/peerj.16863. eCollection 2024.
• Featherstone JDB, Crystal YO, Alston P, Chaffee BW, Domejean S, Rechmann P, Zhan L, Ramos-Gomez F. A Comparison of Four Caries Risk Assessment Methods. Front Oral Health. 2021 Apr 28;2:656558. doi: 10.3389/froh.2021.656558. eCollection 2021.
• Department of Error. Lancet. 2020 Nov 14;396(10262):1562. doi: 10.1016/S0140-6736(20)32226-1. Epub 2020 Oct 23. No abstract available.
• Flahault A, Cadilhac M, Thomas G. Sample size calculation should be performed for design accuracy in diagnostic test studies. J Clin Epidemiol. 2005 Aug;58(8):859-62. doi: 10.1016/j.jclinepi.2004.12.009.
• Young DA, Featherstone JD, Roth JR, Anderson M, Autio-Gold J, Christensen GJ, Fontana M, Kutsch VK, Peters MC, Simonsen RJ, Wolff MS. Caries management by risk assessment: implementation guidelines. J Calif Dent Assoc. 2007 Nov;35(11):799-805.

Helpful Links

• GSMA Intelligence. The Mobile Economy: Middle East and North Africa 2023. London: GSMA Intelligence; 2023.
• Basic oral health surveys provide a sound basis for assessing the current oral health status of a population and its future needs for oral health care. The World Health Organization (WHO) has a long tradition of epidemiological survey methodology

Study record dates

Study Major Dates

• Study Start (Actual): June 5, 2026
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): November 1, 2026

Study Registration Dates

• First Submitted: July 9, 2026
• First Submitted That Met QC Criteria: July 15, 2026
• First Posted (Actual): July 21, 2026

Study Record Updates

• Last Update Posted (Actual): July 21, 2026
• Last Update Submitted That Met QC Criteria: July 15, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: digital health; Egypt; preventive dentistry; caries risk assessment; CAMBRA; oral health questionnaire; diagnostic agreement; MENA
• Additional Relevant MeSH Terms: Stomatognathic Diseases; Tooth Diseases; Tooth Demineralization; Dental Caries
• Other Study ID Numbers: REC-D 12346-6

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No