Medical centre owner Primary Health Care has lifted its first-half profit by 50 per cent and forecast a rise in its full-year earnings of up to eight per cent.

Primary Health Care made a net profit of $69.5 million in the six months to December 31, up from $46.3 million in the same period in the previous year.

Earnings and profit margins continued to grow in the six months to December, despite GP patient numbers remaining weak due to the cautious economic mood, Primary Health Care said.

The company also operates pathology and imaging centres, where earnings and margins also improved over the six months to December 31, it said.

The company's earnings before interest, tax, depreciation and amortisation (EBITDA) in the six months to December 31 were $186.1 million, up 12 per cent on the previous corresponding period.

It expects EBITDA for the year to June 30 to be in the range of $370 million and $380 million, which compares to the previous year's $351.1 million.

"Strong underlying demand and a high quality, extensive infrastructure footprint should continue to provide revenue growth, while further benefits from economies of scale and operating efficiencies are expected to result in EPS (earnings per share) growth for the year to 30 June 2013 of 20 to 25 per cent," Dr Bateman said in a statement.