Limitations: Information on causes of death was not available. Many patients did not continue their initial treatments after 1 month of therapy. Unmeasured confounders could affect associations.

• 研究局限性：研究中未获得死亡原因。许多患者在治疗1月后不能持续他们的初期治疗。无法预测的混杂因素可影响相关性。