Background: Healthcare systems worldwide are concerned with strengthening board-level governance of quality. We applied Lozeau, Langley and Denis' typology (transformation, customisation, loose coupling and corruption) to describe and explain the organisational response to an improvement intervention in six hospital boards in England.

Methods: We conducted fieldwork over a 30-month period as part of an evaluation in six healthcare provider organisations in England. Our data comprised board member interviews (n=54), board meeting observations (24 hours) and relevant documents.

Results: Two organisations transformed their processes in a way that was consistent with the objectives of the intervention, and one customised the intervention with positive effects. In two further organisations, the intervention was only loosely coupled with organisational processes, and participation in the intervention stopped when it competed with other initiatives. In the final case, the intervention was corrupted to reinforce existing organisational processes (a focus on external regulatory requirements). The organisational response was contingent on the availability of 'slack' - expressed by participants as the 'space to think' and 'someone to do the doing' - and the presence of a functioning board.

Conclusions: Underperforming organisations, under pressure to improve, have little time or resources to devote to organisation-wide quality improvement initiatives. Our research highlights the need for policy-makers and regulators to extend their focus beyond the choice of intervention, to consider how the chosen intervention will be implemented in public sector hospitals, how this will vary between contexts and with what effects. We provide useful information on the necessary conditions for a board-level quality improvement intervention to have positive effects.