And you do understand what a meta study is?
What is the deal with the derisive commentary? First it was baselessly jumping to an absurd conclusion I was reading a news article and now this. Why? Do you think shitting on people makes your statements more believable?
You have to go through all 32 analyzed studies to look how they corrected for other factors (of which age is just one).
Is this my job or the job of those who did the analysis?
What they did is, they accessed how those 32 studies corrected for possible bias (not only selection bias). But for you, here a relevant quote:
Simply asserting they corrected for possible bias therefore there is no possible bias is not a useful statement. Where is the evidence of corrections responsive to my concern?
Appendix 1 (pp 65â"75) provides a summary of each study. In 34 (67%) of 51 studies, the minimum age of participants was 55, 60, or 65 years. The maximum reported age of a participant was 115 years and the minimum reported was 37 years, although not all studies recorded minimum and maximum age. For studies that recorded information on the distribution of sex, the proportion of female participants was between 43% and 72%. Three studies were exclusively in female participants6,64,67 and one study was exclusively in male participants.29 Reported follow-up periods ranged from 3 to 23 years, although many studies reported follow-up either as a median or mean. 20 (39%) studies were done in Europe, 17 (33%) in North America, 12 (24%) in Asia, and two (4%) in Oceania (both in Australia). Several studies reported on different dementia subtypes. 43 (84%) studies reported on dementia (including one study on non-Alzheimerâ(TM)s dementia55), 24 (47%) on Alzheimerâ(TM)s disease, 16 (31%) on vascular dementia, one (2%) on frontotemporal dementia, and one (2%) on mixed vascular dementia and Alzheimerâ(TM)s disease. The studies reported on one or more pollutant exposures, with 40 (78%) reporting on PM25, 28 (55%) on NO2, 17 (33%) on PM10, 12 (24%) on NOx, ten (20%) on black carbon (BC)/PM25 absorbance, ten (20%) on annual O3 (O3 was reported on as warm-season or annual exposure, with two [4%] studies reporting on warm-season O3), six (12%) on PM25â"10, five (10%) on carbon monoxide, five (10%) on sulphur dioxide, and three (6%) on nitrogen oxide. Additional pollutants were reported in two or fewer studies. 48 (94%) studies were cohort studies, two (4%) were cohort studies with a nested caseâ"control analysis, and one (2%) was a caseâ"control study.
None of the above addresses the issue. Knowing min / max ages is irrelevant and the rest is not responsive to the issue I outlined. If you look at the underlying protocol they were at least supposed to look at those under and over 65 years of age yet there is no age stratification whatsoever in the figures provided.