It is disorientating to find Niall Dickson sitting behind a mammoth desk and folded around the phone. For years, the public has seen him standing - be it outside Whitehall, in a hospital corridor or a neighbourhood of controversy - glaring steelily at BBC Ten O'Clock news viewers. By day, his hint-of-Scot voice woke Radio 4's Today programme listeners on issues as diverse as foundation hospitals and child poverty. And then he was gone. He left journalism at the beginning of the year to head the King's Fund, the country's most influential health policy thinktank.

Reactions to his appointment say perhaps more about relations between the media and academics than Dickson himself. Among social affairs journalists, he is the real thing: "a genuine expert", "not your bog-standard reporter", "always asked the sharp question", say his former peers. Among medical academics, however, there has been some sniffiness about whether a mere hack has knowledge enough. There is consensus, however, on how the fund will benefit from Dickson's rock solid impartiality and sparkling communication skills.

When the headhunters called, Dickson says, new pastures were already on his mind. He was approaching 50 and had been at the BBC for 15 years, first as health correspondent for BBC radio news, then as chief social affairs correspondent before taking up the editorship, responsible for 80 journalists, in 1995. He still had an appetite for the unpredictable, but not like before. "I think most people would describe me," he laughs mischievously, "as being pretty hungry for stories. But there is a slight tendency with these jobs to see things again and again. I didn't want to get into that situation."

His predecessor (the Guardian's Polly Toynbee) had done the job for six years - "the right time" - and he wanted to make change in "a specific and tangible" way.

"I'm not saying that journalists don't make a difference, but it's not the same as running an organisation that has social goals that you can help shape. I wanted to get back into more hands- on management and I wanted to take on a new challenge," Dickson says.

To its detractors and cheerleaders alike, the King's Fund is no easy ride. Dickson takes the chief executive baton from Rabbi Julia Neuberger, the social campaigner credited with lifting the charity's profile while steering it through stockmarket falls of almost a quarter of its income in 2002, which plummeted the fund's value to £120m. Staff cuts and reshaping have bequeathed Dickson a sound but not laurel-resting base. In addition, some believe he should sharpen the fund's focus; that it is a jack of all healthcare.

The real challenge, argue some, is whether Dickson is tough enough to chop out "the dead wood" in the organisation. "The King's Fund has gone down the pan," says Roy Lilley, the outspoken healthcare commentator, former NHS trust chairman and self-confessed friend of Dickson. Niall has got to get some sharp thinking in there. I think he knows that that's the job he's got to do. It was a brave step to leave the glitterati of the BBC, and he knows that even more courageous things are needed of him."

Dickson is sanguine about his staff. At the moment, he's not contemplating shedding anyone, saying: "We've got some fantastic stars." Those who claim the fund isn't what it was are "looking back to halcyon days that probably didn't exist". But the fact that Dickson chose to move his office into a spacious corner of the fund's policy and grants department - "the engine room" - of the grand, £18m Regency premises in London's Cavendish Square is some testament to where his priorities lie.

How does the prospect of reducing numbers appeal? "Well, reducing numbers, if that were what I was about to do, would not appeal. And of course, there's an an aspect of management that is not pleasant - about how you manage underperformance and financial difficulties." In the next year, the fund will have to "save a bit of money or generate more income. We'll do it."

To summarise, Dickson's wish-list for the charity is to tie its thinking more closely to its doing: to integrate research and policy with training and education. "With that model, we become the thinktank that does." He plans to examine the mix of what the fund provides. It's relationship with the government is "delicate". But, "if you're totally in the tent and never criticise them publicly, you kid yourself if you believe you're hugely influential. I think government will take people seriously who criticise in a measured way when it's justified."

He wants more action research, using London as "a laboratory". He also wants to develop close relationships with the capital's health service. "It puts our finger on the pulse, understanding the anxieties in a way that senior managers can't," he says. "I think being on the side of the service, understanding where they're at, is part of what we need to do."

The approach is arguably a hallmark of Dickson's career. Jane Salvage, international nursing consultant and former colleague at Nursing Times, recalls how he won over journalists at the magazine and doubters within the "introverted" profession who were sceptical about how a man who had never been a nurse could properly steer the high-profile magazine. "He rapidly acquired nursing politics and nursing issues and brought a fresh approach and new ideas," she says.

Left and right have long tussled over the hot electoral issue of health policy, but Dickson argues that he is in neither camp. Years at the BBC have imbued impartiality - without eroding his interest in politics. He left the Labour party in the late 1970s - "when the Trots were dominant"- but now doesn't describe himself as a supporter of any party. "I do have values, principles about the importance of free healthcare," he says. But - ever the reporter- he believes his objectivity enables him to assess the strength of argument. Equally, the fund earns respect by "not having strong ideological views but on having very sound evidence for what it says".

Tackling health inequality is central to the fund's work, "but we don't subscribe to a particular ideology". Anticipating the next question, he says: "So if you ask me, 'Are we pro or anti markets?', the answer is we are neither. Markets are a mechanism by which you develop health. I don't believe in absolutes. We recognise that markets can fail." The King's Fund is pro-choice, but, says Dickson, "there's no point having a choice between three care homes that are not very good".

Could the same argument apply to the BBC - has its increased output decreased quality? Dickson pauses, then says firmly: "I think I'd prefer not to comment. I remain hugely loyal to the BBC. I wish it terribly well." He did express views about the direction of social affairs coverage in the privacy of his exit interview, which is why he calls it "the most extraordinary exit interview of all time".

Within the media more generally, he worries about the "increasing negativity" in the reporting of public sector issues. While it is right and natural that news is predisposed towards the negative, he is concerned that there's a failure to give context and balance. "We've moved into a culture where there's a feeding frenzy on individuals. I think the public does thirst for a more grown-up, less 'goodies and baddies' approach. 'Fewer primary colours' I think is the phrase Richard Sambrook [director of BBC news] used to describe Andrew Gilligan's journalism."

Does he feel well out of the BBC at this moment? He laughs heartily. "Well the words rat and sinking ship have been used." But the debacle had no bearing on his decision to leave. "I'm genuinely upset about what it's going through." But he believes the BBC will eventually be strengthened by the affair. "It is important that the corporation looks at procedures and protocols about who it employs, about the parameters that are set for editors, and what it means to be BBC news."

An action plan, in fact, that those wanting the fund's future success may hope will not be altogether dissimilar from Dickson's own.

The CV

Age 50
Status Married, one son, two daughters
Education Glasgow Academy, Edinburgh Academy, Edinburgh University
Career Teacher in Edinburgh comprehensive from 1976-78 before becoming a press officer at the policy and research body, the National Corporation for the Care of Old People (now the Centre for Policy on Ageing); then head of publishing at Age Concern, 1979-81; editor of Therapy Weekly, 1981-83; editor of Nursing Times, 1983-88; BBC news health correspondent, 1988-90; BBC chief social affairs correspondent, 1990-95; BBC social affairs editor, 1995-2003
Interests Golf, tennis, history, current affairs