Welsh councils and health care trusts have been urged to stop masking the levels of bed blocking.
Welsh councils and health trusts should stop using local deals that mask the level of bed blocking, auditor general Jeremy Colman has warned.
Mr Colman said delays in discharging patients from hospital to receive social care in their homes cost£69m in 2006-07.
He said the scale of the problem is distorted when councils and the NHS have an agreed period after a patient is declared fit for discharge but remain in hospital and that time is not counted as a delayed transfer into care.
“This masks the extent of the problem and underestimates the impact on the independence of vulnerable people,” Mr Colman says in an overview report.
He urged the Welsh Assembly to develop a patient choice policy, “which includes how long it is reasonable for a vulnerable elderly person to remain in a hospital bed awaiting the placement of their choice”.
The Welsh Local Government Association said fewer than a third of delayed discharges were the fault of social care.
And Moyna Wilkinson, joint lead director on older people for the Association of Directors of Social Services Wales, said: “It is important that delayed transfers of care are not seen as a problem solely at the point of discharge. “Factors such as confidence, isolation, family contacts and community involvement can be important determinants in health.”