For how we live.
Two large re-analyses of the same public datasets found the association is real, negative and very small. A third review found the association is not even consistent between the Global North and South.
The same audit found high-performance female athletes well represented in the field — and that the studies generating prevalence figures lean on self-reported food records and MET lookup tables.
The Pittsburgh Sleep Quality Index global score is the field's default outcome. Tested in a large South African cohort, its single-factor structure fit poorly and internal consistency was modest.
Analgesic trials keep failing, and one reason is that the comparison arm keeps improving. Where a trial recruits, how long it runs and how big it is all move the placebo response — and none of that is about the drug.
A systematic review in Cell called that rate implausible and said it overstates the gut microbiome's role in human disease. A separate audit found the statistical tools themselves disagree.
Two datasets report an age-independent fall in men's testosterone across birth cohorts. A separate study of nine thousand men found much of the variation between cohorts came from the tests themselves.
A 223-study meta-regression reports sperm concentration falling 51.6% since 1973. Two published critiques argue the method cannot support that reading. Both sides are peer-reviewed.
The first large replication project in the field found effect sizes shrank substantially on repeat, and reports that many original authors declined to engage with the attempt.