Patients referred to 11 independent treatment centres were included in the England-wide survey in November 2006.
But while outcomes for every PCT were included, no separate results were given for patients referred to a private provider.
‘The outcomes will be available when we undertake secondary analysis,’ said a DoH spokesman.
The fourth bi-monthly survey revealed a slow increase in the number of patients who remember their GP offering them more than one secondary care provider.
Out of almost 25 per cent of patients who returned questionnaires to Ipsos Mori in December 2006, more than four out of 10 recalled a choice of provider.
In the first choice survey in May, fewer than a third of patients recalled being offered choice.
Recall rates rose to 35 per cent in July and 38 per cent in September. The figures hide more than threefold local variations, with only 19 per cent of patients in Brighton and Hove and Mid-Essex PCTs recalling choice in December, compared with 64 per cent in Nottinghamshire.
Nine per cent of patients in Mid-Essex recalled being offered a choice booklet, compared with 48 per cent in Somerset.
Responses to the fourth survey fell sharply from 31 per cent in September to 25 per cent (56,928 responses) in December.
Kate Duxbury, Ipsos Mori project manager, blamed the drop on the Christmas period.
Ease of access to the hospital was important to almost 60 per cent of patients, as in previous surveys. Location and transport were important to four times as many patients as the quality of care provided by the hospital.