Statistics is not my field and I freely admit that, so I can't comment on Marvin's data and methods.
However as someone who has researched this subject for 20+ years, and worked in a med lab, several issues stand out as items Marvin can't possibly account for which would make his figures conservative. In no particular order, they are:
Primary vs. Contributory causes of death
This is a distinction that Jehovah's Witnesses take advantage of and which Dr. Aryeh Shander briefly explains in the video, No Blood: Medicine Meets The Challenge. When a patient with leukemia dies, they die from their disease. Period. End of story. Transfusion is not thearpy for leukemia, or any of the related and/or similar illnesses. Transfusion is administered to counteract the effects of intense chemo and/or radiation treatment, or in the event of a bone marrow transplant, to keep the patient alive while the grafted marrow 'takes.'
When blood products are not an option, these treatments are often simply unavailable and alternative treatments are employed. Why induce severe anemia as a side effect in an attempt to treat a disease that might or might not work when you know in advance that you can't administer blood to counteract it?
Yet contributory causes of death are still important. To dismiss them out of hand, because they can't rightly be included in a statistical study is to distort the issue. The survival rate of Witnesses leukemia patients is so bad that The Oncologist ran an article in 2002 entitled "Faith Identity And Leukemia: When Blood Products Are Not An Option" to help medical professionals deal with the feelings of guilt, frustration and anger over the loss of Witness patients.
As a nurse who had witnessed the death of a female JW patient put it, "She wanted everything done, but would not consent to the one essential thing that would save her life."
Red Cells are only one component
Blood does a lot of things in the body and most of them are vital for life. My youngest child was hospitalized when a common perscription medication attacked the platelets in her blood. Her count was so low that the ER physicians hands were shaking when he showed me the lab report. Acute thrombocytopenia is every bit as dangerous as acute anemia, if not more so. A sneeze can set off a fatal brain hemorrhage and the patient will be dead in seconds.
Obviously then, there are other transfusion types besides the tradtional red cell transfusion. Whole plasma is often administered when physicans are not entirely sure what exactly is wrong, but do know that it is a plasma function, as in atypical bleeding, cases involving liver impairment and other plasma specific disfunctions. Platelets are administered in cases like I mentioned above with my child. Witnesses are not supposed to accept any of this stuff.
Differering standards of care
I've already quoted a letter from BMJ on this thread which (IMHO) poignantly shows the plight of a JW patient when bloodless medicine is either unavailable or too expensive. Even today, this is still the case in many parts of the word.
Evolution of the doctrine
The JW parent organization has made many adjustments over the years to blunt the sheer human cost of adherence to this doctrine. Nobody thinks twice about accepting gamma globulin today. It's the basis of most post-exposure vaccines. It's the basis for antivenins for snake and other poisonous bites. It's used to treat acyte thrombocytopenic purpura, Kawasaki's syndrome, etc. Yet there was a time when JW's were not supposed to accept gamma globulin.
Similar observations could be made about albumin, factor specific concentrates for bleeding disorders, Anti-D, (Which despite being a gamma family globulin was treated differently by the JW parent organization for some strange reason.) Transfusion of gamma globulin (Which again was treated differently than simple injection by the JW parent organizaiton for some strange reason.) etc. All of these were forbidden at one time. If we're talking about the human cost since the inception of the doctrine, these things are relevant, because they all represent potential (I would actually say probable) areas where JW patients experienced higher mortality in decades past than they do today.
I don't know how Marvin (Or anybody else) could statistically account for these types of things, but if they could be accounted for, they would inflate rather than deflate his numbers.
