This is a specific study that will be misapplied by the Watchtower to unrelated scenarios and operations. I find it somewhat irresponsible, as it will be used to help justify avoiding blood in areas that do not have these same survival rates.
The comparision is somewhat irrelevant, as too different types of groups are being compared. To make an accurate assessment, the article should have shown survival rates of non-jws that did not have blood transfusions, and also survival of the entire group.
The other factor not mentioned is that the preparation done on JWs and operations are far more costly and intensive in order to reduce the need for blood. If such level of care was taken for all patients, then survival rates are likely to have been higher across the board.