4.4 Limitations
(1) A total of 19 literatures were included in this study, all of which
were in English, and only Su et al., Li et al., Xu et al., Tao et al.,
Guo et al., Wei et al. performed baseline Feature description. Xu et
al., Shao et al., Deng et al. did not describe the blinding of
performance bias. And the vast majority of literature, including Hu et
al., reported on the existence of incomplete outcome data. (2) In the
Egger’s test for the main indicators, although the results did not
report the existence of publication bias, many hidden results will still
affect the results of meta-analysis. (3) There is heterogeneity in the
results of meta-analysis. After exploring the heterogeneity by means of
subgroup analysis, the heterogeneity of some subgroups has been
improved, but the rest of the subgroups still show some heterogeneity.
The sources of these heterogeneities are very extensive, including but
not limited to the experimental habits of researchers, laboratory light
temperature environment, geographical latitude and magnetic field, etc.
(4) Although the interpretability of the machine learning model has
reached a high quality, the lack of sample data may still cause some
trouble to the feature screening results.