Michael West, from Aston business school, told managers at the NHS Confederation conference that better employer practices could save up to 12 per cent more patients.
Carrying out appraisals, training and placing workers in teams could improve mortality figures, Healthcare Commission ratings and patient satisfaction, Mr West said.
'If you could improve appraisals, you could reduce 12 per cent of deaths in hip fracture patients.
'With 25 per cent more staff working in teams, you have seven per cent fewer patients dying in emergency surgery,' he said.
Mr West said staff should leave their appraisals feeling respected by their employer and more able to do their job, in order to get the most out of the process.
His research is based on interviews, questionnaires and data from 61 hospitals around the country.
Steve Barnett, director of NHS Employers, said the study showed 'it would be absolutely nuts not to take workforce management seriously'.
Happy staff meant satisfied patients, he said, but it is not enough to rely on the staff survey to measure this.
'There has to be an ongoing assessment. Good management is about using data in a real-time way that indicates what the workforce is feeling on a particular issue at one time,' Mr Barnett said.
University College London Hospitals foundation trust workforce director David Amos.admitted that the number of appraisals being carried out in his trust was comparatively low.
He revealed that the trust.compiles league tables on the number of staff having appraisals and publishes the results broken up into 'divisions'. Managers in the third division have to provide a chart to show exact dates of when they plan to appraise each member of staff.
However, Mr Barnett said he felt that compulsory appraisals did not work as it was just about 'ticking boxes'.
He said: 'There have to be incentives, articulating to managers and employers what the business case is for doing these things properly. Rather than an edict from the chief executive, which makes everyone feel in a farm.'