There is now a good understanding and knowledge of the types of quality improvement (QI) interventions that are undertaken in healthcare  but less understanding of how to increase their effectiveness .
Studies on healthcare quality increasingly point to understanding organisational issues in health service delivery as central to explaining variations in care and making progress towards sustained quality improvement. The Institute of Medicine's watershed To Err is Human  and Crossing the Quality Chasm  reports specifically identified organisational failings as one of the root causes of poor quality, with the latter devoting an entire chapter to analysing healthcare organisations as complex, adaptive systems and the implications of this perspective for implementing change. As elaborated by others [5–7] this perspective includes recognising the multiple levels of the healthcare system. High-level influences such as policy, payment rules, regulation and accreditation are strongly mediated by dynamics and responses not only at the levels of hospitals, but also the smaller care delivery units within hospitals that deliver services directly to patients.
A rigorous, if relatively small, body of research does exist in the health services literature which specifically attempts to unravel this 'black box' of organisation at the hospital level and its impact on the quality of care [8, 9]. This work has focused on identifying hospital predictors of successful implementation of quality improvement, typically using multivariate statistical methods and quasi-experimental data, and has highlighted a number of factors that appear to be associated with successfully implementing change in hospitals . The factors that predict successful quality improvement implementation include leadership support , particular dimensions of organisational culture and climate [12, 13], and team-based structures and composition , as well as investing in the measurement of quality and making quality projects 'do-able' [15, 16]. As noted previously , there is also an increasing evidence-base relating to the factors that influence how 'improving quality' can be successfully implemented and assimilated into the routine practice of frontline clinical teams. Such work has been heavily influenced by the micro-systems focus in the work of researchers from Dartmouth-Hitchcock in the United States [18, 19].
There has been a traditional preference for broad, survey-based research to explore factors associated with successful quality improvement (for example the recent EU-funded MARQuIS project  and the work of the European Observatory on Health Systems and Policies). However, as Øvretveit and Staines  have pointed out: 'Apart from a few projects, the details of which interventions were actually made are often not presented, and there are few adequate or independent research descriptions of actual implementations of organisational and system wide programs over time'. Given the paucity of in-depth studies to date, it is hardly surprising that the minutiae of quality improvement programs and processes remain largely shrouded in mystery. This is not to argue that large-scale surveys of national policies across large numbers of countries are not important; it is simply to say that without further detailed investigation of the findings of such surveys, health care leaders-whilst being aware of broad trends and directions-will remain uninformed as to the detailed 'how to'-or implementation-of successful quality improvement at the hospital level.
The predominant focus in the majority of studies in healthcare quality has been solely on technical factors that are thought to influence the quality of care (despite the socio-technical systems perspective in which information technology and deeper, cultural processes are studied symmetrically). As a consequence it has been all too easy to forget (or simply fail to acknowledge) the fact that every aspect of care is accomplished through people in their everyday actions and interactions with and for each other-a social process. If quality is viewed in this way issues such as identity, politics, leadership, value systems, organisational 'slack', and learning, can begin to receive the same attention as the technical factors that have dominated the research field to date.
Furthermore, most studies have rarely taken the time to construct theories or explanations for what they observe or find in their analyses . This is particularly true of the organisational and cultural dimensions of quality improvement. Unfortunately the existing evidence-base has also been less adept at shedding light on how factors at different levels of a healthcare system relate to one another, and how in practice hospitals should go about influencing and setting 'key success factors' in motion.
The European Union-funded QUASER study will seek to extend recent research that has addressed these theoretical and methodological issues. Bate, Mendel and Robert  undertook a three-year international study that was explicitly designed to help practitioners and researchers understand the factors and processes that enable hospitals in the US and Europe (England and the Netherlands) to achieve-and sustain-high quality services for their patients. This original study took as its starting point that whilst technical factors, such as information systems, do play a major role in accounting for the quality 'gap', organisational and cultural factors are crucial in understanding how quality and safety improvement occurs.
Based on in-depth, multi-level case studies of seven leading hospital, this research found that high-performing hospitals were able to achieve, and then sustain, high levels of quality because they recognised and had been extremely successful in addressing-on an ongoing basis-six common challenges. The six common challenges that were identified from the case studies were:
structural-organising, planning and co-ordinating quality efforts
political-addressing and dealing with the politics of change surrounding any QI effort
cultural-giving 'quality' a shared, collective meaning, value and significance within the organisation
educational-creating a learning process that supports improvement
emotional-engaging and mobilizing people by linking QI efforts to inner sentiments and deeper commitments and beliefs
physical and technological-the designing of physical systems and technological infrastructure that supports and sustains quality efforts
The researchers represented these common challenges by means of a 'codebook' which took the form of a checklist that practitioners can use to identify where the organisational gaps in their local improvement efforts may lie and what they may need to do to address them. Based on the systematic review and coding of the organisational case studies, multiple illustrations of the different types of challenges and solutions were extracted from the individual case study narratives and assigned to the different challenges. In total, the codebook includes 56 such solutions spread across the six challenges, all derived inductively from the organisational cases themselves.
The QUASER study will extend and apply this original research in several important ways:
by studying a range of hospitals at different stages on their quality 'journeys' (as opposed to just high performing hospitals)
by explicitly including clinical effectiveness, patient safety and patient experience as key components of what we mean by 'quality' (as opposed to focusing just on service improvement)
by incorporating available qualitative and quantitative measures of quality into a cross-case, comparative analysis (as opposed to a purely qualitative analysis)
by including a much broader range of countries (England, the Netherlands, Norway, Portugal and Sweden)
by providing context-specific guidance to (a) hospitals depending on where they are on their quality journey, and (b) payers and those assessing the quality of hospital care
Finally, given that each of the macro (national healthcare system), meso (hospital) and micro (frontline clinical team) levels, separately and in interaction with each other, affects clinical effectiveness, patient safety and patient experience the QUASER study will retain a particular focus on the dynamics and interactions between these different levels [23–25] as possible key determinants of sustained quality in healthcare.
A favourable ethical opinion for this research study was granted by NRES Committee South East Coast-Surrey in April 2011, REC reference: 11/LO/0348.