This important book examines issues affecting the sustainability and spread of new working practices. The question of why good ideas do not spread, 'the best practices puzzle', has been widely recognized. But the 'improvement evaporation effect', where successful changes are discontinued, has attracted less attention. Keeping things the way they are has been seen as an organizational problem to be resolved, not a condition to be achieved. This is one of the first major studies of the sustainability of change focusing on the example of the NHS, by a unique team of health service and...