In a previous paper Coulter described HSR. He states:

HSR was defined by the Institute of Medicine, in a major report in 1979, as the investigation of the relationship between social structure, process and outcomes for personal health services. The last involves a transaction between a client and a provider to promote health. Andersen et al. (1994) state that this definition requires that HSR includes structure and/or process. The structural component includes personnel, facilities, services available, organizational features and financing. Process is the transaction that occurs between the provider and the patient. Under this definition of HRS the focus goes beyond the disease and interventions of clinical studies to include the total organization of the care delivery.

HSR involves four levels: (1) the clinical level; (2) the institutional level; (3) the systemic level; and (4) the contextual level (Andersen et al. 1994). The structure and process across organization types can affect effectiveness and clinical outcomes. At the systemic level the way in which health care is organized (e.g. a nationally funded and organized health care system) clearly has an impact on the patient–provider transaction. At the contextual level other policies (i.e. welfare policy) also have an impact.

A key structural component of HSR is finances. While HSR has made numerous contributions to understanding health care, its focus on outcomes and linking these to structure and process makes it a core consideration in any discussion of health services. Health policy should involve adopting the most efficacious, effective therapies with the best outcomes within real practices and within the resources available. Cost-effectiveness and cost–benefit analyses are an essential part of that determination (Clancy and Kamerow, 1996 and Kay and Blinkhorn, 1996). The ultimate objective of HSR is to improve the quality of care (Brown et al. 2000).

Steinwachs & Hughes (2008) note that it is largely HSR that is drawn upon by decision-makers and informs policy decisions and tends to be the primary source for information on how well health systems, at least in the USA, are functioning. This fact in itself should make it of prime interest to the CAM community.

The field was defined by the Academy of Health as follows:

Clearly then health services research covers a huge swathe of health concerns. In fact the challenge might be to identify what is not included. Herman et al. (2006) summarize HSR research by stating that it’s the ‘study of the effect of various components of healthcare system (e.g. social factors, financing systems, organizational structures and process, delivery of care, health technologies, personal behaviors) on healthcare outcomes (e.g. access, quality, cost, patient health and well-being)’(p. 79).

They also note that only three areas are excluded: (1) demonstration projects; (2) studies of efficacy done in laboratories or on animals; and (3) randomized controlled trials (RCTs) using strict protocols and defined patient groups. ‘In short, HSR is based on the assumption that efficacious treatments exist. It then evaluates the various components of treatment delivery (e.g. policy, structures, processes) with respect to outcomes to make healthcare more efficient, effective, and cost-effective’ (Herman et al. 2006, p. 79).

It is clear therefore why the CAM community might be interested in HSR. Firstly, its major concerns do dovetail very well with the types of concerns the CAM community is worried about, including access, utilization, funding, cost and outcomes. Secondly, because it is the field that is used by policy-makers it does have a significant role in shaping both the health care debates and health care delivery. Few other fields have as much potential to have an impact on the system organization and delivery of health as opposed to, say, impacting on specific therapy and treatment. Thirdly, but by no means least, it employs research methodologies that seem more appropriate to assessing CAM than the traditional RCTs so prevalent in biomedicine. There is therefore much for CAM to relate to in HSR.

Unfortunately, until quite recently, CAM has not very frequently been the subject in HSR. One feature that HSR does share with CAM is that, relatively speaking, in the USA it receives one of the lowest amounts of funding from the National Institutes of Health (NIH) (in 2005 about 5% of the budget) (Herman et al. 2006). Of course that greatly exceeds the budget for the National Center for Complementary and Alternative Medicine (NCCAM), which was 0.42% of the total NIH budget in 2006, which might help explain why investigating CAM has not constituted a large part of HSR (Coulter 2007).

The most dominant feature of HSR is that it is very multidisciplinary. It is done by statisticians, epidemiologists, sociologists, psychologists, anthropologists, economists, behavioural scientists, management/organizational studies, medicine, nursing, dentists, chiropractors, acupuncturists, and other health professions. Because of this it uses multimethods. The hierarchy of evidence that characterizes systematic reviews and meta-analysis does not make sense in this area (Coulter 2006).

While health planners may give more weight to economic factors such as cost, these may not be the most significant variables determining the outcomes of the health care. The relevance of any form of evidence in HSR will be dictated by both the purpose for which the information is being used and the context in which it is gathered. In the house of evidence, as outlined by Jonas (2005), HSR falls into the category he labels ‘use testing’. This is in contrast to what he terms ‘effects testing’. As Jonas notes, HSR research can provide information about the relevance and utility of practices whether they are proven or unproven in terms of efficacy. HSR represents a pluralistic approach to evidence.

There is no single methodology or research design for conducting HSR. This is a point also made by Walach et al. with regard to CAM: ‘More specifically we will argue that there is no such thing as an inherently ideal methodology. There are different methods to answer different questions’ (Walach et al. 2006 p. 2).

They suggest that instead of a hierarchical model of evidence the more appropriate model is a circular one. Under this approach there are a multiple of optimal methods and the most powerful method might be triangulation. This occurs when two distinct methodological and independent approaches are used to investigate the same phenomenon. So, for example, RCTs may need to be supplemented by long-term observational studies to see if therapies have the same effect in clinical practice that they have in controlled trials.

Steinwachs & Hughes (2008) note that the report Crossing the Quality Chasm: A New Health Care Systems for the 21st Century (Committee on the Quality of Care in America 2001) identified six critical elements: (1) patient safety; (2) effectiveness; (3) timeliness; (4) patient-centred care; (5) efficiency; and (6) equity. It is HSR that provides the measurement tools for evaluating these goals.

In two recent articles by Herman et al., 2006 and Coulter and Khorsan, 2008, the merits of the match between CAM and HSR have been examined. In their paper Herman et al. (2006) identify 355 studies in the field of HSR and CAM therapies. But this represented only 2% of studies identified in the search (up to 2005) as HSR. Of those with abstracts that clearly identified the nature of the study, the bulk was surveys of CAM users which often included their reasons for using CAM. The next most frequent were descriptive surveys of providers ‘to obtain their characteristics, the characteristics of their patients, and the specific therapies they prescribe’ (p. 80). There was one study looking at the economic impacts of CAM, eight on research needs and five on research methods. Their paper therefore is more focused on what HSR research can bring to CAM (and the reverse). They suggest that studies of integrative medicine (IM), health insurance coverage, effectiveness, cost-effectiveness, practice guidelines and whole-systems research are all areas of potential work for HSR in CAM. Because of the way the literature search was conducted (and that only those studies with abstracts were reviewed), the number of studies probably represents a very incomplete list. In two earlier papers focusing just on chiropractic, the number of studies listed in HSR and social sciences was 105 (Mootz et al. 1997) and 81, respectively (Mootz et al. 2006).

Coulter & Khorsan (2008) for their part make the case that one of the significant contributions of HSR to CAM is in the area of descriptive studies. Despite the fact we now have numerous studies on the utilization of CAM we still have very little good empirical data on what is done in CAM practices. From the studies we can tell you the percentage of the population using various CAM professionals but not what they are being treated for, what they are being treated with, what it costs and what the outcomes are. As they note, until we know more about the practice, the scope of practice, patient characteristics, utilization rates, patient numbers, patient health problems, therapies being used, cost and funding, it is difficult to design appropriate studies, including whole-systems research. ‘The studies on epidemiology, insurance, and cost effectiveness can all contribute to our understanding of CAM’ (Coulter & Khorsan 2008 p. 40). In the case of chiropractic there is now a large body of descriptive studies as well as other HSR studies. The latter has included studies on workman’s compensation, comparisons of chiropractic and medical care, evaluation by patients, the testing of various hypotheses about chiropractic utilization using empirical data, studies of the efficacy of chiropractic in clinical trials, meta-analysis of studies on manipulation, field studies on the appropriateness of chiropractic manipulation and the economic cost of chiropractic. Therefore, there exists for chiropractic ‘an extensive body of data that describes the practice, the patients, and the providers of chiropractic’ (Coulter & Khorsan 2008 p. 42).

Because HSR focuses on existing practices and programmes in the real world as opposed to the artificial world created under RCTs, it speaks to a major concern of CAM – effectiveness. As Coulter & Khorsan note, ‘in this way HSR introduces a badly needed dose of realism into the evidence-based practice movement’ (Coulter & Khorsan 2008 p. 41). Steinwachs & Hughes (2008) observe that effectiveness research is undertaken in community settings and with patients who are not subjected to inclusion or exclusion criteria and who can be given multiple interventions.

Steinwachs & Hughes (2008) identify key areas where they feel HSR can make major contributions to CAM: studies evaluating the quality of health care; studies of the structure of health care; studies of the process of health care; studies of the outcomes of care; and public health studies focusing on preventive health services.

Coulter & Khorsan (2008) add to this list two other major areas: studies on the health-related quality of life and studies on the appropriateness of care.

However we wish to focus on its potential in another area – whole-systems research and programme evaluation.

Numerous commentators have noted that, in studying CAM, and more recently IM, we need to move away from the reductionist model used in RCT to study the whole system. The favoured theoretical models for doing this have been systems theory (Beckman et al., 1996, Bell et al., 2002 and Verhoef et al., 2005) and/or complexity theory (Kernick 2006).

Originally systems theory grew out of work in biology but was later applied in the field of cybernetics, information theory and computers. Beckman et al. (1996) identify the following features of systems theory. First, it posits a multilevelled structure in which the whole cannot be reduced to its parts or the sum of its parts. A change in any subpart has an impact on all the other parts. Second, it posits an ecological view of systems in which a system interacts constantly with its environment and where the results are processes rather than final structures so that health becomes a process, not an endproduct. Third, it posits non-linear causality. Fourth, it sees systems as self-organizing and with emergent properties which cannot be found in the constituent parts. Fifth, the systems are therefore self-transcendent, meaning they can transcend any one state and create new structures and processes. Sixth, the mind represents the dynamics of self-organization and is characteristic not only of individuals but also of social, cultural and ecological systems.

For Bell et al., systems theory provides a ‘rational conceptual framework within which to evaluate CAM systems, integrative medicine’ (Bell et al. 2002 p. 13