What is a question about this article? If the question is unanswerable, say "unanswerable".

One way to decrease stigma may be through the promotion of "TB clubs", where those infected may share experiences and offer support, or through counseling. Some studies have shown TB education programs to be effective in decreasing stigma, and may thus be effective in increasing treatment adherence. Despite this, studies on relationship between reduced stigma and mortality are lacking as of 2010, and similar efforts to decrease stigma surrounding AIDS have been minimally effective. Some have claimed the stigma to be worse than the disease, and healthcare providers may unintentionally reinforce stigma, as those with TB are often perceived as difficult or otherwise undesirable. A greater understanding of the social and cultural dimensions of tuberculosis may also help with stigma reduction.

Who have been performing studies on the relationship between stigma and mortality?
unanswerable