In constant currency terms, revenue for the four months was 2 per cent below the prior comparable period, which was a period of high demand during the initial surges of Covid-19 in North America and Europe.
Forsyth Barr, in a research note said: "We expect to see the first signs of the earnings decline when F&P Healthcare reports its first-half result on Thursday.
"Our key focus areas are; (1) any insights into the remainder of full-year 2022 and the demand profile post Covid-19, (2) gross margins and the impact from increased freight costs, and (3) selling, general, and administrative expenses (SG&A) cost control in light of likely declining revenue.
"While we don't expect quantitative guidance we look for any insights into expectations for the remainder of 2021 and the demand profile thereafter," Forsyth Barr said.
America's ResMed, which like F&P Healthcare makes devices for the treatment of sleep apnea, last month reported a 20 per cent lift in first-quarter revenue to US$904m ($1.3b), with net income rising 14 per cent to US$204m.
In the same space, Netherlands-based Philips in June announced a €250m ($404m) global product recall after discovering a fault in its "DreamStation" sleep offering.