Collaboration between local health and local government agencies for health improvement.

Background: In many countries, national, regional and local inter- and intra-agency collaborations have been introduced in order to improve health outcomes. Evidence is needed on the effectiveness of locally-developed partnerships which target changes in individual health outcomes and behaviours.

Objectives: To evaluate the effects of interagency collaboration between local health and local government agencies on health outcomes.

Search Strategy: Twenty-five databases were searched using a highly sensitive search strategy. 'Snowballing' methods were also used, including expert contact, website searching and reference list follow up.

Selection Criteria: Randomized controlled trials (RCTs), controlled clinical trials (CCTs), controlled before-and-after studies (CBAs) and interrupted time series (ITS) where the study reported on interagency collaboration between health and local government agencies. Studies were selected independently in duplicate by two of five authors.

Data Collection And Analysis: From the team of five review authors, two authors independently conducted data extraction and assessed risk of bias for each study.

Main Results: Eleven studies were identified, presenting information on a total of 26,686 participants. Owing to the heterogeneity between studies a narrative synthesis was undertaken. The included studies covered a range of topics. Six studies examined mental health initiatives, of which one study showed health benefit; four showed modest improvement in one or more of the outcomes measured, but no clear overall health gain; and one study showed no evidence of health gain. Two studies were related to lifestyle improvements of which one failed to show health gains for the intervention population, while the other showed more unhealthy lifestyle behaviours persisting in the intervention population. Three studies were related to chronic disease management and all three failed to demonstrate health gains.

Authors' Conclusions: Collaboration between local health and local government is commonly considered best practice. However, the review did not identify any reliable evidence that inter‑agency collaboration, compared to standard services, leads to health improvement. A few studies identified component benefits but these were not reflected in overall outcome scores and could have resulted from the use of significant additional resources. Although agencies appear enthusiastic about collaboration, methodological flaws in the primary studies and incomplete implementation of initiatives have prevented the development of a strong evidence base. If these flaws are addressed in future studies (for example by providing greater detail on the implementation of programs, using more robust designs, with integrated process evaluations and measurement of health outcomes) it could provide a better understanding of what might work and why.When updating this review, we will analyse any partnership or process evaluations of our included studies to try to identify markers of success in local collaborative partnerships that could inform policy developments in the future.