Evaluating a community-based public health intervention using a complex systems approach.

Background: This article outlines the methods being used to evaluate a community-based public health intervention. This evaluation approach recognizes that not only is the intervention, Healthy Families NZ, complex, but the social systems within which it is being implemented are complex. Methods: To address challenges related to complexity, we discuss three developing areas within evaluation theory and apply them to an evaluation case example. The example, Healthy Families NZ, aims to strengthen the prevention system in Aotearoa/New Zealand to prevent chronic disease in 10 different geographic areas. Central to the evaluation design is the comparative case method which recognizes that emergent outcomes are the result of 'configurations of causes'. 'Thick', mixed-data, case studies are developed, with each case considered a view of a complex system. Qualitative Comparative Analysis is the analytical approach used to systematically compare the cases over time. Conclusions: This article describes an approach to evaluating a community-based public health intervention that considers the social systems in which the initiative is being implemented to be complex. The evaluation case example provides a unique opportunity to operationalize and test these methods, while extending their more frequent use within other fields to the field of public health.

Building a systems-thinking community workforce to scale action on determinants of health in New Zealand.

This article describes findings from the evaluation of Healthy Families NZ (HFNZ), an equity-driven, place-based community health initiative. Implemented in nine diverse communities across New Zealand, HFNZ aims to strengthen the systems that can improve health and well-being. Findings highlight local needs and priorities including the social mechanisms important for reorienting health and policy systems towards place-based communities. Lessons encompass the importance of local lived experience in putting evidence into practice; the strength of acting with systems in mind; the need for relational, learning, intentional, and well-resourced community organisation; examples of how to foster place-based 'community-up' leadership; and how to enable responsiveness between communities and local and national policy systems. A reconceptualisation of scaling in the context of complexity and systems change is offered, which recognises that relationships and agency are key to making progress on the determinants of health.

Adherence to daily dietary and activity goals set within a Maori and Pacific weight loss competition.

BACKGROUND: New Zealand Pacific and Maori populations measure disproportionately high on the international body mass index (BMI). Information is needed on what behavioural weight loss goals to recommend and how to attract and retain them in interventions. Our team weight loss competition trial for participants with a BMI ≥30 used cash prizes to incentivise completion of nine daily behaviour goals. This paper evaluates the theoretical merit of and adherence to these goals. METHODS: A qualitative component evaluation methodology was used. Trial data on team activity, demographics and anthropometric outcome data were extracted to determine frequency of daily goal completion by teams throughout the competition and to describe participant characteristics. T-tests were used to compare completion rates of the challenges, challenge completion by day of week and between weekdays and weekends. To examine adherence to the daily challenge activity over 24 weeks the total amount of completed challenges adjusted for number of active teams was plotted by week. A Body Shape Index (ABSI) was used to determine individual anthropometric change from baseline to 8, 16 and 24 weeks. Program documents were analysed to identify barriers to adherence and retention of participants. RESULTS: Of 19 teams (N = 130) who began only five teams performed daily goals across the whole 24 weeks. Adherence was highest during the first 8 weeks. No difference in performance between goals was found suggesting they were equally viable, though tasks worth less points were performed more frequently. Goal completion was higher on weekdays. The behaviour goals appeared to have theoretical merit in that more members of high performing teams experienced a positive change in their ABSI. CONCLUSIONS: Incentives offer a promising strategy for encouraging retention in weight loss interventions. This study suggests that participants in a competition will perform incentivised tasks. The findings however, are limited by missing data and high drop out of individuals and whole teams. Further research is needed on how to increase retention.