Here’s your sentence with corrected grammar and improved clarity:
Revised:
Given that average postal invitation response rates in general population health research are 27.9%—with a minimum of 17.1%—and considering that participation in this research requires an overnight polysomnography (PSG) session, a lower response rate threshold of 17.1% will be adopted. This accounts for the documented trend of declining survey participation over recent decades, as noted by Guo et al. (2016).