Longer duration of initial invasive mechanical ventilation is still a crucial risk factor for moderate-to-severe bronchopulmonary dysplasia in very preterm infants: a multicentrer prospective study.

"Declarations Conflict of interestNo financial or non-financial benefits have been received or will be received from any party related directly or indirectly to the subject of this article. The authors have no conflict of interest to declare. Ethical approvalThe research protocol has been registered in the Chinese Clinical Trial Registration Center (ID: ChiCTR1900025234) and has been ethically reviewed by the Ethics Committee of the Provincial Hospital Affiliated to Shandong First Medical University (LCYJ: No. 2019-132). Informed consent to participate in the study have been obtained from participants’ parent. Conflict of interest No financial or non-financial benefits have been received or will be received from any party related directly or indirectly to the subject of this article. The authors have no conflict of interest to declare."

"Funding This work was supported by the Project of “2021 Shandong Medical Association Clinical Research Fund (Qilu Special Project, YXH2022DZX0200X) and Shandong Key Research and Development Project (2018GSF118163)."

"Declarations: Conflict of interestNo financial or non-financial benefits have been received or will be received from any party related directly or indirectly to the subject of this article. The authors have no conflict of interest to declare.: Ethical approvalThe research protocol has been registered in the Chinese Clinical Trial Registration Center (ID: ChiCTR1900025234) and has been ethically reviewed by the Ethics Committee of the Provincial Hospital Affiliated to Shandong First Medical University (LCYJ: No. 2019-132). Informed consent to participate in the study have been obtained from participants’ parent. Ethical approval: The research protocol has been registered in the Chinese Clinical Trial Registration Center (ID: ChiCTR1900025234) and has been ethically reviewed by the Ethics Committee of the Provincial Hospital Affiliated to Shandong First Medical University (LCYJ: No. 2019-132). Informed consent to participate in the study have been obtained from participants’ parent."