The heterogeneity of the papers reviewed in this study precluded the description or synthesis of a definitive or universal set of core PHC services thus limiting our ability to answer our original research question. The variability in published material was a result of the different purposes, diverse methods, different terminology, and different settings of the studies undertaken. These differences are highlighted in Additional file 1: Table S1. The literature was also characterised by variation in the methodological rigour underpinning the studies analysed.
These features of the available literature were limitations in the context of our research objective. One reason that a definitive set of core services was not evident from the literature was because of the idiosyncratic nature with which different authors defined different sets of core services using different terminology with different methods and for different purposes. Also, the purpose of defining core services was not always explicit. Reasons for defining core services varied enormously, and included: documenting lessons learnt from case studies of successful services; to form a basis for discussion of workforce, education, and training needs; for service planning, monitoring, and evaluation; to document services mandated by legislation; planning and advocacy; maximising cost-effectiveness, and; defining the responsibilities of resident and visiting teams. Thus, the starting point for any initiative that seeks to develop a set of core services is to agree on an explicit purpose. This may vary depending on the intended audience, be they policymakers, consumers, researchers, practitioners, or health service planners. Another limitation of the literature in the context of this study was that different purposes resulted in different methods used. Thus, in future, explicitly defining a specific purpose will also provide a guide as to an appropriate method. Possible methods include: literature reviews; consultations and expert opinion; consensus methods; empirical methods; and combinations of these. Whatever method adopted, the critical factor is the need to ensure the validity and reliability of the method in relation to the stated purpose.
In managing these characteristics of the literature which, in the context of this study, were exposed as limitations, the study was able to produce a creative and perhaps more useful solution to the difficult problem of defining “core” services. Despite the considerable variability in the results from the diverse studies we encountered, we were able to synthesise common PHC dimensions across the 19 papers and the demarcations within each of these dimensions (Table 4).
In relation to context and scope, available evidence about “core” services related to widely different geographical, demographic, and epidemiological environments. These included: both developed and developing countries; regional, state, national, and global reach; as well as for specific population groups such as Indigenous populations. The dimensions and demarcations summarised in Table 4 provide an excellent starting point or checklist with which to consider the appropriate response for any given context. For example, a life span approach may be useful in a population with high needs in children and older people that are to be prioritised. This framework thus provides a valuable platform for health service providers to use in their decisions relating to how best to meet the PHC needs of their jurisdictions.
Most importantly, the critical task is to ensure that all residents (regardless of where they live) should be able to readily access the “core” services, however defined, in times of need. Recognising that many rural and remote communities cannot depend on market forces to deliver these services equitably or on the basis of need, it is clear that the way in which access to these “core” PHC services is realised will also vary from context to context. For example, some services (such as emergency retrieval and evacuation) must be available in situ, while others may need to be accessed by alternative models of delivery such as visiting services provided through a “hub-and-spoke” arrangement, fly in/fly out services, or telehealth. Additionally, the need to move people to services rather than services to people may require significant patient-assisted travel schemes. Any consideration of what services should be provided must also be accompanied by strategic thinking about how the services may be provided most efficiently and effectively. Past research undertaken describes a number of different models ranging from fixed services, through visiting services, and telehealth
[25, 26]. Arguably, not all services must be provided in situ. Unfortunately, there exist few rigorous evaluations of health service models comparing the cost efficiency and health effectiveness of different rural and remote health care services to help guide decisions about which services should be provided locally and which services can be just as effective in meeting health care needs through different modes of access.
Overarching this key decision about “how” to provide “which” services is the need to recognise the fiscal constraints within which every health service and funding authority operates. Financial resources are not ubiquitously available in unlimited supply, and a delimitation of the package or suite of “core” PHC services in a given context could assist decision-making in this regard. Hence the quanta of services and the provision model need to be prioritised according to community needs and context, and matched against the availability of financial resources. Furthermore, in order to ensure relevance and sustainability of service provision, it will be important for PHC health services to be responsive to changes in community needs that result from changing demography, population mobility, and ageing. Using the matrix of PHC dimensions and demarcations outlined in this paper which is based on the best available evidence, the issue of what services and how they might be accessed most effectively and efficiently can now be explored more systematically.