Preterm delivery was associated with maternal drug-treated hypertension and impaired renal function. A matched case-controlstudy showed no evidence of increased renal allograft loss after pregnancy.
This type of study design, known as "case-control," cannot prove cause-and-effect.
这种类型的研究被称为病例对照研究，它不能够证明两者之间的因果关系。
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DESIGN: Randomized casecontrolstudy to patients based on diagnosis SETTING: department of general diseases, rehabilitation room and ultrasound department of a university hospital.