Figures obtained by the Guardian have shown the most complete picture yet of the reliance by the NHS and community health services in England on foreign nationals, with people from more than 200 countries employed.

The statistics, produced by the Health and Social Care Information Centre (HSCIC), show that 11% of all staff for whom data was available and who work for the NHS and in community health services are not British.

The proportion of foreign nationals increases for professionally qualified clinical staff (14%) and even more so for doctors (26%), prompting the British Medical Association (BMA) to observe that without the contribution of non-British staff, "many NHS services would struggle to provide effective care to their patients".

Tim Finch, from the Institute for Public Policy Research thinktank, said the statistics held lessons for immigration policy.

"People are still attracted to work in the NHS," he said. "Without them we'd clearly be short – it would be very hard to replace that number overnight.

"If the single thread of immigration policy is just to get the overall figure down by any means, you've got to look at the consequences of that on the NHS."

Finch said that while the NHS benefited from foreign nationals, health services in the countries they had left could suffer.

He added that as the economic fortunes of some countries providing large numbers of staff to the NHS improved, people might become less inclined to leave, potentially creating problems for Britain, albeit not in the near future.

Finch downplayed the prospect of foreign nationals preventing British people getting a job in health services, saying that under the government's points system for non-EU migrants, workers would not gain entry unless there was a vacant post they were needed to fill.

EU countries, English-speaking countries, those with ties to Britain through the Commonwealth, countries targeted by the NHS for employees and those that have experienced wars all figure prominently in the list of those supplying the most employees.

India provided the highest number after Britain, with 18,424 out of a total of 1,052,404 workers whose identity was known.

India also provided the highest number of professionally qualified clinical staff, doctors and consultants, after Britain. The number of Indian consultants was 2,708, 7% of the total whose nationality was known.

GPs are not included in the HSCIC figures because they are not employed by the NHS.

The Philippines provided the highest number of qualified nursing, midwifery and health visiting staff after Britain, with 8,094 out of a total of 309,529 for whom data was available, reflecting the fact that there was a recruitment drive in the country under Tony Blair's government to attract people to such posts.

The Philippines also provides the third highest number of NHS staff overall with 12,744.

Ireland had the fourth highest number of staff in the NHS, followed by Poland, Nigeria, Zimbabwe, Portugal, Pakistan, Spain and Germany.

A BMA spokeswoman said: "Overseas doctors have for many years made a valuable and important contribution to the NHS, especially in key services where there has been a historic shortage of UK-trained doctors.

"This includes consultant posts in emergency care, haematology and old-age psychiatry. Without the support of these doctors many NHS services would struggle to provide effective care to their patients."

She said the figures reflected the fact that for many years the NHS actively encouraged overseas doctors to move to the UK.

The spokeswoman added that doctors were subject to strict criteria set by the GMC and that if they were from outside the European Economic Area they had to take additional language tests to ensure that they spoke English to a good standard.

While the figures help illustrate the contribution of migrants, they do not paint the whole picture, as many will have taken British nationality since arriving.

Nationality statistics of NHS staff have never been published but figures on where doctors qualified are made available by the General Medical Council, which include GPs in its data.

Mirroring the HSCIC statistics, India is the second most common country of qualification after Britain, according to the council, which says 25,122 doctors registered in the UK were trained in the world's second most populous nation.

The HSCIC figures are provisional as of September last year. The nationalities of 136,624 staff were not recorded and, due to use of different staff record systems, data was not available from two NHS trusts, Moorfields Eye Hospital NHS foundation trust and Chesterfield Royal Hospital foundation trust.