Dose Correlation of and Koidz. Drug Pairs in the Chinese Medicine Prescription Based on the Copula Function.

OBJECTIVE

and Koidz. (AMK) are widely used in treating various diseases; however, research is insufficient on measuring the relationship that exists by combining this drug pair using the copula function.

METHODS

In this study, 279 traditional Chinese medicine prescriptions containing the and AMK drug pair were extracted from the prescription database for three types of screened indications, namely, diabetes mellitus, diarrhea, and insomnia. Following the principle of dose conversion, each dynasty unit was uniformly converted into a modern unit. Then, the kernel density distribution of and AMK was fitted with their empirical distribution functions. Finally, the optimal copula function was selected from the copula function family as a -copula function.

RESULTS

The empirical distribution and probability density functions of and AMK were obtained. From the results, their Kendall rank correlation coefficients with indications of diabetes mellitus, insomnia, and diarrhea were 0.8689, 0.7858, and 0.7403, whereas their Spearman rank correlation coefficients were 0.9563, 0.9276, and 0.8958. Results also indicated that the use of the -copula function can better reflect the correlation between and AMK doses.

CONCLUSION

From the three indications, the dose between and AMK was positively correlated. This study, therefore, confirms the medicinal principle of Chinese medicine "combining" from the perspective of mathematical statistics. Results from this study are practical to evaluate the correlation between the drug pair doses, and AMK, using the copula function model, which provides a new model for the scientific explanation of compatibility for Chinese medicines. This study also provides a methodological basis for more drug measurement studies and clinical medications.