Relationships between Pathological Patterns and Quality of Life: Pathway Analysis

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.

A group of serum proteins as potential diagnostic biomarkers for Yin-deficiency-heat syndrome

Yin-deficiency-heat (YDH) syndrome is a very common subhealth status in Traditional Chinese Medicine. However, currently, there is no unified standard for diagnosing YDH syndrome. We applied the iTRAQ-2D LC-MS/MS method to explore the potential of serum protein profiles as biomarker for YDH syndrome. A total of 120 differentially expressed proteins (79 downregulated and 41 upregulated) were identified by the proteomic profiling. The results of KEGG pathway analysis showed that the functions of the differentially expressed proteins were mainly involved in complement and coagulation cascades. The clinical data showed that YDH syndrome was closely related to inflammation and coagulation, compared with the healthy controls. The ELISA validation results indicated that the expression levels of ALB, CFI, and KLKB1 were downregulated in the YDH syndrome group (p < .05). Moreover, we established a decision tree model based on the combination of these three proteins and achieved a sensitivity of 87.5%, a specificity of 84.4%, and AUC of 0.891. The results indicated that the combination of ALB, CFI, and KLKB1 may serve as potential biomarkers for diagnosing YDH syndrome. Our study can provide a new method for YDH syndrome diagnosis, and may also provide an experimental basis to understand the molecular mechanism of YDH syndrome.