Health services research: rethinking the quest to be useful.

Health services research (HSR) is conceived as an applied discipline and studies are expected to be useful. Yet some of the most justly famous and important HSR has no tangible short-term impact. This raises the question of what constitutes 'useful' and whether it is possible to predict which studies will influence policy or practice. Attribution is also a constant issue: elements of health care systems change all the time and changes consistent with research findings may not signal causation but mere correlation. It is possible to make good changes in the absence of solid research evidence and it is also possible to make good changes while unaware of supportive research. Given these contingencies, it is worthwhile reflecting on the extent to which it is reasonable to expect HSR to affect policy or practice. Herein lies a paradox: the easier it is to act on research evidence, the more likely the change may have taken place regardless, while the more original and potentially game-changing the research, the greater the challenge of responding to it. It is nonetheless possible to design health services research more effectively to increase the likelihood of applicability (usually by broadening its scope and examining contextual issues that decision-makers must take into account). For their part, funders of HSR should take note of the historical fact that uptake of the most important work may take decades and may manifest in unforeseeable ways. The Royal Society of Medicine Press Ltd 2011.