Background: As quality improvement (QI) programmes have become progressively larger scale, the risks of implementation having unintended consequences are increasingly recognised. More routine use of balancing measures to monitor unintended consequences has been proposed to evaluate overall effectiveness, but in practice published improvement interventions hardly ever report identification or measurement of consequences other than intended goals of improvement.Methods: We conducted 15 semistructured interviews and two focus groups with 24 improvement experts to explore the current understanding of balancing measures in QI and inform a more balanced accounting of the overall impact of improvement interventions. Data were analysed iteratively using the framework approach.Results: Participants described the consequences of improvement in terms of desirability/undesirability and the extent to which they were expected/unexpected when planning improvement. Four types of consequences were defined: expected desirable consequences (goals); expected undesirable consequences (trade-offs); unexpected undesirable consequences (unpleasant surprises); and unexpected desirable consequences (pleasant surprises). Unexpected consequences were considered important but rarely measured in existing programmes, and an improvement pause to take stock after implementation would allow these to be more actively identified and managed. A balanced accounting of all consequences of improvement interventions can facilitate staff engagement and reduce resistance to change, but has to be offset against the cost of additional data collection.Conclusion: Improvement measurement is usually focused on measuring intended goals, with minimal use of balancing measures which when used, typically monitor trade-offs expected before implementation. This paper proposes that improvers and leaders should seek a balanced accounting of all consequences of improvement across the life of an improvement programme, including deliberately pausing after implementation to identify and quantitatively or qualitatively evaluate any pleasant or unpleasant surprises.