Reliability and validity of tongue color analysis in the prediction of symptom patterns in terms of East Asian Medicine

Development of the Short-Form Yin Deficiency Scale Using Three Item Reduction Approaches

Background

Yin deficiency (YD) is a pathological condition characterized by emaciation, afternoon fever, dry mouth, and night sweats. The incidence of YD is 23.3%. A 27-item Yin Deficiency Scale (YDS) was developed to estimate the clinical severity of YD. This study aimed to develop three short-form YDS versions to reduce the burden of response time, using three item-reduction approaches: Rasch, equidiscriminatory item-total correlation (EITC), and factor-based analyses.

Methods

Two datasets were analyzed from previous studies (169 outpatients from May to June 2009 and 237 healthy college students from January to April 2016). The optimal response category was examined using Rasch analysis. Items with higher item-total correlations were determined using the EITC. Using a factor-based approach, the items were reduced, while maintaining the original YDS construct. Reliability was estimated using the person separation index (PSI) and Cronbach's α values. The predictive accuracy was examined using the area under the curve (AUC). Finally, the relationship between YD and dysfunctional breathing (DB) was examined using factor scores from the YDS and the Korean version of the Nijmegen Questionnaire (KNQ).

Results

We developed two 14-item YDS versions using the Rasch and EITC approaches, and a 16-item YDS version using a factor-based approach. Rasch analysis suggested an optimal response category of five points. The PSI of Rasch and Cronbach's α of the EITC and factor-based versions were 2.19, 0.855, and 0.827. The AUCs of the three short-form YDS were 0.812, 0.811, and 0.818. The sensitivity of the EITC-YDS was 0.632, which was lower than its specificity of 0.875. The fatigue-related scores of the factor-based YDS were fairly correlated with the factor scores of the KNQ estimating the DB (r = 0.349-0.499).

Conclusion

The 14-item Rasch- and 16-item factor-based YDS may replace the original YDS during YD's primary screening, epidemiological surveys, and health checkups.

Development of the 8-Item Phlegm Pattern Questionnaire (PPQ-8) Using Rasch Analysis

The 25-item Phlegm Pattern Questionnaire (PPQ) has been widely used to examine the relationship between the phlegm pattern (PP), quality of life, tongue colour, vocal qualities, and dysfunctional breathing. However, the concerns of response burden and differences in the respondent's abilities or item difficulty for the original version of the PPQ have not been sufficiently addressed. This study aimed to develop a short-form PPQ using Rasch analysis, an item response theory. Based on the retrospective data, the response order, differential item functioning (DIF), dimensionality, reliability, concurrent validity, and fitting errors were examined for 291 normal participants and 61 inpatients. The discriminative ability of the short-form PPQ was examined using receiver operating characteristic curve analysis. Along with Rasch analysis, another short-form PPQ was developed using equidiscriminative item-total correlation (EITC) analysis and the results between the two short-form PPQs were compared accordingly. Rasch analysis results suggested a 6-point response category for the PPQ, and finally, 8 items without fitting errors or DIF variability were selected for the PPQ (PPQ-8). The PPQ-8 had satisfactory reliability (person separation index = 2.23), unidimensionality (unexplained variance in the first contrast = 1.598), fitting levels (infit mean square, 0.80-1.39; outfit mean square, 0.79-1.34), sensitivity (70.5%), and specificity (76.5%). The PPQ-8 had a moderate discriminative ability of the PP (area under the curve = 0.759), and the cut-off point was 23. Although the 8-item PPQ developed using EITC analysis showed similar levels of reliability, validity, and discriminative ability of the PP to the PPQ-8, it could not present the information of item hierarchy and differences in the respondents' abilities. In conclusion, the PPQ-8 by Rasch analysis is recommended for future use to evaluate the clinical severity of PP.

Application of computer tongue image analysis technology in the diagnosis of NAFLD

Nonalcoholic fatty liver disease (NAFLD), a leading cause of chronic hepatic disease, can progress to liver fibrosis, cirrhosis, and hepatocellular carcinoma. Therefore, it is extremely important to explore early diagnosis and screening methods. In this study, we developed models based on computer tongue image analysis technology to observe the tongue characteristics of 1778 participants (831 cases of NAFLD and 947 cases of non-NAFLD). Combining quantitative tongue image features, basic information, and serological indexes, including the hepatic steatosis index (HSI) and fatty liver index (FLI), we utilized machine learning methods, including Logistic Regression, Support Vector Machine (SVM), Random Forest (RF), Gradient Boosting Decision Tree (GBDT), Adaptive Boosting Algorithm (AdaBoost), Naïve Bayes, and Neural Network for NAFLD diagnosis. The best fusion model for diagnosing NAFLD by Logistic Regression, which contained the tongue image parameters, waist circumference, BMI, GGT, TG, and ALT/AST, achieved an AUC of 0.897 (95% CI, 0.882-0.911), an accuracy of 81.70% with a sensitivity of 77.62% and a specificity of 85.22%; in addition, the positive likelihood ratio and negative likelihood ratio were 5.25 and 0.26, respectively. The application of computer intelligent tongue diagnosis technology can improve the accuracy of NAFLD diagnosis and may provide a convenient technical reference for the establishment of early screening methods for NAFLD, which is worth further research and verification.

Laser tongue debridement for oral malodor-A novel approach to halitosis

STUDY OBJECTIVE

Malodor is a multifactorial condition with oral pathology representing the main culprit and the tongue being the first to second contributor to the malodor. Bacterial load can represent a quantifiable measure regardless of the original pathology. We hypothesize that reduction in malodor can be represented by tongue changes both in appearance, bacterial and biofilm load reduction (measured by CFU and volatile gases measurement), organoleptic measurement and subjective improvement.

METHODS

A randomized controlled prospective study under IRB approval. Diagnostic criteria for enrollment and follow up were organoleptic test by 2 judges, Halimeter reading, tongue colors changes HALT questionnaire and direct aerobic and anaerobic tongue cultures measured by CFU. Patients were treated with laser tongue debridement (LTD) with an Er,Cr:YSGG solid state laser has been shown to be effective in biofilm reduction.

RESULTS

54 patients recruited with 35 available for follow up. Improvement was observed on all objective and QOL subjective parameters. Treatment was tolerated well with minimal discomfort.

CONCLUSIONS

The tongue is proven to be a major contributor to oral malodor and must be addressed in treatment protocol. LTD significantly reduces malodor by subjective and objective criteria. While impossible to determine whether the tongue serves as a bacterial reservoir or is the origin for oral bacteria it is clear that LTD improves oral hygiene and reduces malodor. LTD is safe and easy to perform. We encourage LTD to be a crucial part of any oral malodor treatment protocol.

TRIAL REGISTRATION

clinical trials, NCT04120948. Registered 25 September 2019 - Retrospectively registered, https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S00098SX&selectaction=Edit&uid=U0000W0Y&ts=51&cx=-elnx7e.

Relationship between Tongue Temperature Estimated by Infrared Thermography, Tongue Color, and Cold-Heat Pathological Patterns: A Retrospective Chart Review Study

Tongue diagnosis is a technique used to determine cold-heat pathologic patterns (CHPPs). Herein, we reviewed electronic medical records of tongue temperature measured using infrared thermography (IRT), tongue color (luminance, green/red, and blue/yellow balance), cold-heat pattern questionnaires (CHPQ), and body temperature for 134 women with gynecological problems (age, 38.97 ± 11.49 years). The temperatures of seven tongue regions (root, center, tip, and both sides of the center and root) were determined, and the effects of age, regional differences, and their correlations with color parameters were examined. Factor analysis was conducted separately with the 10 cold pattern (CP) and 10 heat pattern (HP) items. Tongue temperature showed an age effect (β; -0.198 to -0.210) and regional differences (both sides of the root > center and root > tip). Tongue temperature was positively correlated with luminance (r: 0.236-0.246), indicating that a higher temperature was associated with a brighter color. The factor analysis extracted two factors (cold sensitivity-pain and discharge-complexion factors) from the CP items and three factors (heat sensation-pain, discharge-breath, and cold preference-thirst factors) from the HP items. Tongue temperature was negatively correlated with the discharge-complexion factor of CP and the discharge-breath factor of HP (r: -0.171 to -0.203), indicating that a lower tongue temperature may be a consequence of emission of excessive heat in HP and a lower blood perfusion in CP. Body temperature did not correlate with the CHPQ factor scores. In conclusion, tongue temperatures measured using IRT may be a partial indicator of CHPPs.

Objective research on tongue manifestation of patients with eczema

BACKGROUND

Tongue observation often depends on subjective judgment, it is necessary to establish an objective and quantifiable standard for tongue observation.

OBJECTIVE

To discuss the features of tongue manifestation of patients who suffered from eczema with different types and to reveal the clinical significance of the tongue images.

METHODS

Two hundred patients with eczema were recruited and divided into three groups according to the diagnostic criteria. Acute group had 47 patients, subacute group had 82 patients, and chronic group had 71 patients. The computerized tongue image digital analysis device was used to detect tongue parameters. The L*a*b* color model was applied to classify tongue parameters quantitatively.

RESULTS

For parameters such as tongue color, tongue shape, color of tongue coating, and thickness or thinness of tongue coating, there was a significant difference among acute group, subacute group and chronic group (P< 0.05). For Lab values of both tongue and tongue coating, there was statistical significance among the above types of eczema (P< 0.05).

CONCLUSIONS

Tongue images can reflect some features of eczema, and different types of eczema may be related to the changes of tongue images. The computerized tongue image digital analysis device can reflect the tongue characteristics of patients with eczema objectively.