Binary logistic regression models
We assessed the association of chronotype with the risk of depressive status during infertility treatment, as shown inTable 2 . Compared to subjects in the evening chronotype group, neutral chronotype (OR = 0.45, 95% CI: 0.28-0.72, P trend <0.001) and morning chronotype (OR = 0.29, 95% CI: 0.18-0.49, P trend <0.001) were significantly associated with lower odds of depressive symptoms. Similarly, after adjusting for confounders, neutral chronotype (OR = 0.47, 95% CI: 0.28-0.77, P trend <0.001) and morning chronotype (OR = 0.32, 95% CI: 0.18-0.57, P trend <0.001) types were still associated with lower odds of depressive status, although this risk reduction was attenuated. For each standard deviation increase in MEQ-5 scores, the adjusted ORs (95% CIs) were 0.69 (0.59-0.79, P <0.001) for depressive symptoms.