In my experience, the Hmong do not resist blood test or blood transfusion as a rule. I have not experience or heard of any case during my 15 years practicing as a medical doctor. If the procedure is for the benefit of their health and it is explained fully, I see no reason for their resistance.
I think that the main problem relating to blood test and transfusion is lack of explanation. For example, many Hmong ladies are reluctant to attend a local hospital for antenatal care due to the simple fact that it is a hospital policy to do routine glucose tolerance test on all pregnant ladies. These Hmong ladies are happy to have one blood test but they cannot understand why they have to have blood taken more than once in one visit. Many choose to attend a different hospital.
On one extreme, some Hmong like to have blood test to check for "everything". In Australia, we have many Hmong underwent major surgeries including open heart surgery and blood tests and blood transfusion were never an issue.
One recurrent complain is about the way the patient was treated at some collection center and the inexperience of venipuncture but many nurse. This is the reason I do almost all my venipuncture (as doctor can mess thing up but still acceptable!).
In summary, there is no one rule to deal with a Hmong patient. As long as we have an open mind and understand that we are dealing with a group of people who tend to look at life in totality - so we may require to use all our six senses to deal with them. Traditionally, they are very much family oriented with a century-old network of support extending across the globe. For example,a patient is in St Paul may have his family/clan leader in Melbourne, Australia and before he can made any major decision, he may want to consult with his leader first. Even many Hmong have become Christians, the majority (80%+) of them still practice animism/ancestor worship. This has implication in their illness perception and some form of treatment. They also resist autopsy as part of their religious belief.
By seeking to understand the individual patient and ensure that the family/clan leader understood ...dealing with a Hmong patient can be a pleasant experience.
Pao Saykao
http://www.lexicon.net/drpao/