Okay, the user sent "co-variates". Let me check the translation rules again. First, I need to translate all content into Japanese. The term "co-variates" is an English word. I should translate it into Japanese. The correct translation for "co-variates" in Japanese is "共変量" (kōhenryō). I need to make sure that there's no existing Japanese content here. Since the input is in English, I don't need to leave it unchanged. Just provide the translation. No explanations, just the result. So the answer should be "共変量".