Australian Health Promotion Association

Andrew J. Milat, Lesley King, Adrian Bauman and Sally Redman

As the chronic disease burden grows, government is increasingly investing in prevention.1-3. However, policy makers frequently report a scarcity of effective programs suitable for population-level implementation. Policy makers also seek information to aid decisions about whether programs found to be effective in small-scale studies can be implemented at the population level. To date, investigation of optimal ways to expand programs has not received adequate attention,4-6 and there is an urgent need for studies assessing mechanisms by which widespread intervention adoption and reach can be achieved.7-9

Transferring an intervention from controlled research settings into practical implementation studies usually involves a change of scale, or ‘scaling up’. While ‘scale’ seems an obvious concept, it hasn’t been widely discussed in health promotion. According to the WHO Health Promotion Glossary10 clarifying new terminology is important, as it facilitates effective communication within the field. In this spirit, we investigated how the terms ‘scaling up’ and ‘scalability’ are used in the literature, to inform future study in implementation science. A Medline keyword search of the terms ‘scaling up’ and ‘scalability’ was conducted from January 1990-October 2010. Abstracts of papers were categorised according to the field or content area in which these terms were discussed, with a subset pertaining to population health further analysed. Publication dates and conceptual elements in the use of the terms were collated. Full papers of the ‘population health’ subset were appraised for definitions of scaling up and scalability. The terms ‘scaling up’ and ‘scalability’ were reported in 208 publications between January 1990 and October 2010. Of these, 58 (28%) were population health -related, with none providing definitions of these terms after reviewing full papers.

‘Scaling up’ was consistently referred to in the context of increasing the size, reach or impact of health interventions (96%). Most papers using the term ‘scaling up’ were population health interventions (75%), followed  by health care interventions (22%). The majority were published between 2006 and 2010 (82%), with the earliest reference to ‘scaling up’ made in 2002, indicating it’s a relatively new concept. While the term ‘scalability’ was used in a variety of contexts, it most often referred to psychometric or measurement properties of health assessment tools or psychological scales (36%). In health information technology, it referred to the ability of systems to be enlarged (17%).

The term also described measurement characteristics in biological and biomedical testing (8%) and genetics (8%). Over this 20 year period, 12% of papers referred to ‘scalability’ in relation to population health (epidemiology, surveillance, interventions), with two of these specifically referring to increasing the reach of health promotion interventions (both in 2009). The majority of these papers (79%) were published between 2006 and 2010.

It is clear that these terms are simultaneously used in different ways in the literature, but are only beginning to be used in the context of population health. Encouragingly for policy makers, the more frequent application of these terms points to a greater focus on implementation science. In light of increasing policy interest in population-wide implementation of interventions, it would be valuable to define these concepts and terms and systematically examine the processes and issues associated with ‘scaling up’ in health promotion.

Health Promotion Journal of Australia 2011: 22(3)