evidence of impact of integrating programming

Intuitively, we know that integrating programmes across sectors (e.g. nutrition with health, WASH, food secutity and livelihoods, etc) will have a greater positive impact on a number of outcomes (e.g. maintaining GAM rates, preventing disease outbreaks etc) than just doing single sector responses. However there seems to be very little quantiative evidence out there that this is in fact the case. Does anyone know of any good data that provides evidence that this is the case, for programmes or responses that have involved two or more sectors closely working together?