I may going to get flamed for this - but JAMA has turned out to be a political mouthpiece for the feminists. They have, in the past, published misleading "findings" that where the sole purpose was to support the feminist dogma.
JAMA claims do not do well when held to scrutiny.
Flamed hell, as a FORMER member of the AMA; you nailed it on the head. I would only expand your thesis to include any leftist fringe group with an ax to grind as the one's pulling the AMA's strings.