Four more NHS Direct contracts, worth a total of £2.9m, have gone to market leader HBOC.

The company appears to be gaining a stranglehold on the NHS telephone triage market following its takeover of one of its main rivals, Access Health, in December.

The new contracts - with Greater Manchester, Essex, West Country and West Yorkshire Metropolitan ambulance services - follow the piloting of HBOC's software at the Two Shires ambulance service.

HBOC's approach has been to supply systems for ambulance trusts to run by themselves. Access's alternative approach is to manage the NHS Direct call centre as well as equip it - it runs the pilots at the Northumbria and Hampshire ambulance trusts.

HBOC's takeover of Access means that it can now supply either option, though all four of the new NHS Direct pilots will be using the company's telephone triage package, Centramax.

The contracts last until the pilot periods end on 31 March next year. The schemes will then be expanded to the entire ambulance trust operations - Essex, covering a population of 1.6 million, West Yorkshire (2.1 million), Greater Manchester (2.8 million), and Westcountry (2.2 million). At that point, the contracts are due to be re-tendered. The largest in cash terms, Westcountry, also includes a geographical mapping system supplied by Global Mapping Solutions.

The Two Shires pilot has been running since March 1998 covering a population of 250,000 in the Milton Keynes area. It is now being expanded to cover 1.8 million people across Buckinghamshire, Northamptonshire and Oxfordshire.

During the first 10 months at Two Shires, 20,000 calls were received. HBOC expects the number of calls to increase considerably. Experience in the US suggests that it takes two years to achieve public awareness and full capacity of telephone triage services, says HBOC (now known as McKesson-HBOC following its acquisition last October by a US pharmaceuticals distributor).

During one three-month period, 290 callers said they intended going to accident and emergency. Of these, only 79 were advised that this was the right choice. The other 221 were given self-care advice or advised to see their GP. In the same period, 308 out of 1,142 callers who said they intended to see their GPs were re-directed to A&E.

The cost impact on A&E is unclear, but A&E departments are saving 60 hours a week in nursing time. Previously, callers were transferred by the switchboard to an unofficial helpline in the department, answered by any nurse available at the time.