A total of 24 studies was included in the review: 17 had a high quality rating, six had an average rating and one a low rating.
Five evaluations reported interventions that were successful: four evaluated Health Action Zones (HAZs) and the fifth the construction of a supermarket in a food desert. Successful interventions employed a number of different strategies, but all included improvements to management systems with increased strategic partnerships and a degree of partnership with government and community organisations.
Eleven papers evaluated UK HAZ, three of which were considered at least mostly successful, four partly successful, three were unclear and one was unsuccessful. Eight of these studies were rated as being of high quality and three as average.
Each aspect of the quality criteria were discussed individually; few papers discussed ethical issues associated with area-based interventions.
There was some evidence that area-based interventions reduced inequalities. Seven studies found substantial effects and nine found partial effects. Such interventions tended to produce beneficial results when there was a change in the physical environment, adequate funding, good leadership and liaison with local communities, and the size of area was appropriate to the inequality.