Placebo doesn't affect objective outcomes anyway.
Elaborate? I'm pretty sure that's not correct, at the very least when it comes to pain, immune system things, autonomic stuff, and possibly some musculoskeletal stuff.
Only few people are interested in studying placebos. However, there are a few papers (Gotzsche is one of the few).
Pain (or nausea) isn't an objective outcome anyway.
Very interesting decision from the one of the leading scientific publications to publish an article about Reiki therapy.
http://www.nature.com/news/consider-all-the-evidence-on-alternative-therapies-1.18547
[Edit: should be Nature publishes an article about alternative therapy]