I am looking to find 1 or more papers published by reputable
independent organizations that show that

a)  doctors have minimal impact on changing people?s lifestyle &
behaviour.  The behaviour change I would be most interested in would
be the maintainance of ideal testing frequency for blood sugar for
diabetics.  Others behaviours that would be good proxies would be
stopping smoking, weight loss, condom use (HIV prevention).

b) greater, and longer term change can be brought about by educating
Influencers in the target segment  so they can use their peer to peer
influencer through word of mouth.

I have read one such article a while ago which described visiting gay
bars in San Francisco, interviewing people there to identify the key
influentials in those groups, educating them and then seeing a
remarkable increase in the rate of condom usage across all the bars 
(I cant find that article now)

$5