Shorter stays in hospital do not appear to have led to an increase in avoidable readmissions, Department of Health research has found.

The research followed concerns over the recent increase in the proportion of patients being readmitted within 28 days of discharge. For over-75 year olds, the rate increased by 40 per cent between 1998-99 and 2006-07, from 10 to 14 per cent of patients.

Critics claimed the increase was due to the impact of payment by results, under which hospitals get paid a standard amount for each patient, potentially incentivising them to discharge some earlier than clinically necessary.

Avoidable readmissions

But the report said: "We consistently found extremely small correlations, providing no evidence for the hypothesis that decreases in the length of stay have led to a higher rate of [avoidable] readmissions."

More research is needed to get at the real cause in the increasing readmissions, it said. Some of it may be because of changes in patient expectations and the four hour waiting target in accident and emergency, which could lead to more patients being admitted.

The researchers also said that variation in the quality of care provided by community and social care services tasked with looking after discharged patients could distort the overall trends.