Objectives
Best Start is an area-based early childhood intervention where projects are developed and implemented through a community partnership. A core tenet of the initiative is that implementing projects through a partnership generates greater value than would be expected if projects were undertaken independently by partner members. In this study we examine whether: (1) Best Start is effective in increasing the proportion of infants being fully breastfed at 3 months and 6 months. (2) The quality of community partnerships is a potential mechanism for change.

Methods
Best Start was implemented in Victoria, Australia. The study examined breastfeeding rates before and after Best Start in sites with Best Start breastfeeding projects compared to the rest of state. The relationship between partnership quality scores and breastfeeding percentages was also examined. Both analyses controlled for socioeconomic and demographic differences and clustering by area.

Results
Best Start targeted some of the most socially disadvantaged communities in Victoria. In the 3 years of its operation, the rates of fully breastfeeding at 3 months (OR 1.30, 95% CI 1.14–1.47) and 6 months (OR 1.33, 95% CI 1.1–1.61) increased in Best Start sites compared to the rest of the state. Quality of partnership scores was positively associated with increased percentages of fully breastfeeding (3 months = OR 1.03, 95% CI 1.01–1.06; 6 months = OR 1.03, 95% CI 0.98–1.08).

Conclusions
These results suggest that area-based interventions are effective in increasing percentages of fully breastfeeding. The study also supported the idea that developing quality community partnerships had a positive influence on their success.