The FTSE 250-listed private healthcare group saw its adjusted underlying earnings (EBITDA) fall by 8% to £213mln for the six months to September 30, down from £232mln a year earlier.
The London and Johannesburg-quoted firm posted a pre-tax loss of £150mln in the first half, against a £10mln loss a year earlier, as revenue fell by 1.4% to £1.39bn from £1.41bn.
In Switzerland, the company’s adjusted EBITDA fell by 17% to SFr118mln despite revenue in the country rising by 1% to SFr826mln.
Mediclinic’s chief executive Ronnie van der Merwe commented: "The poor performance in Switzerland more than outweighed the revenue growth and margin expansion delivered by the Southern Africa and the Middle East divisions."
The group kept its interim dividend unchanged at 3.20p per share.
In early morning trading, Mediclinic shares were 3.9% lower at 341.40p.
In a separate announcement, Mediclinic also announced that its senior independent non-executive director Desmond Smith will retire from the board at the end of its annual general meeting expected to take place on 24 July 2019.