I can’t even follow this. I admire you math minded people.https://onlinelibrary.wiley.com/doi/epdf/10.1111/andr.13209
Title of the article is "Covid-19 Vaccination BNT162b2 Temporarily Impairs Semen Concentration and Total Motile Count among Semen Donors"
In the paper, the authors say their research shows the impairment is temporary. I'm having trouble with their math.
Specifically, taking Table 2. If there is no significant change between T1 and T0 (as the paper says in words), when the sperm concentration is -14.5. And there is a significant decrease in the sperm concentration between T2 and T0 (as the paper says in words), when the change in sperm concentration is -15.4. Then why does the change in sperm concentration of -15.9 show no statistical significance (as the paper says in words)?
And, also Table 2. If there is no significant change between T0 and T1 (as the paper says in words), when the total motile count is -2%. And there is significant decrease from T0 to T2 when the total motile count is -22.1%. Then why is the change in total motility count of -19.4% from T0 to T3 not significant?
Actually, after I wrote the above it, I called someone who works with statistics all the time. He said, is because the confidence level (that 95% CI column) has both numbers negative for the T0 to T2 rows so there is a 95% confidence that the number really is a negative number. The T0 to T1 and the T0 to T3 rows have both negative and positive numbers so there is a statistical chance that actual reality is no change (zero) or more sperm or increased motile count (positive number)... they are 95% sure that the actual reality is between a 30% lower sperm concentration and a 1.7% higher sperm count. And they are 95% sure that the actual reality is between 35% fewer total motile sperm and 0.6% greater total motile sperm.
Edit to fix a typo