The Scottish Patient Safety Programme was established with the aim of reducing hospital mortality rates by 15% by December 2012, and then by 20% by the end of 2015.
But by the period October to December 2013, the rate for Scotland as a whole had fallen by 14.2%, official figures from the NHS revealed.
A report revealed that while there had been "a sustained reduction in hospital mortality between 2009 and 2011, the level thereafter has remained relatively constant".
Mortality rates fell in 29 of the 31 hospitals taking part in the Scottish Patient Safety Programme - with 12 hospitals meeting the target with reductions of 15% or more.
There were four hospitals where death rates fell by more than 20% - Crosshouse Hospital in Kilmarnock achieved a reduction of 32.9% by the last three months of last year, Glasgow's Southern General Hospital recorded a fall of 22.7%, Ninewells Hospital in Dundee reduced mortality by 21% and Raigmore Hospital in Inverness had a fall of 20.8% when compared to October to December 2007.
Only two hospitals saw their mortality rates increase - the Golden Jubilee National Hospital in Clydebank and Stracathro Hospital in Brechin, Angus.
At the Golden Jubilee the mortality rate increased by 71.4% between October to December 2007 and October to December 2013 - but the report points out heart and lung transplant surgery was moved to this hospital in 2008.
At Stracathro the mortality rate increased by 6.3% over the period, with the report noting the hospital treats a "disproportionately aged patient population as compared to Scotland, a sizeable proportion of which have suffered strokes".
About 60% of the total of 54,937 deaths in Scotland in 2012 happened in hospital, according to the research.
The hospital standardised mortality rate takes account of those patients who die within 30 days of being admitted to hospital, and therefore includes some deaths that take place in the community.
But the rate does not include patients who die in hospital more than 30 days after they were admitted for treatment.