On 2017 Aug 03, David Mage commented:

The authors have performed a thorough study of SUID rates in the entire U.S. for years 1995-1997 and 2011-2013 and test for significant differences (at P<0.05) in Table 2.

However, they neglected to make the finite population correction (fpc) that adjusts for the sample size n of independent probability samples without replacement from a finite population of size N.

Given that they sampled the entire U.S. infant populations for SUID during those years so that n = N, the fpc = 0 as shown below because there is no sampling error.

Consequently footnote 'a' and related discussion could be removed.

fpc = Sqrt[(N - n)/(N - 1)] = 0 for n = N.

On 2017 Aug 03, David Mage commented:

The authors have performed a thorough study of SUID rates in the entire U.S. for years 1995-1997 and 2011-2013 and test for significant differences (at P<0.05) in Table 2.

However, they neglected to make the finite population correction (fpc) that adjusts for the sample size n of independent probability samples without replacement from a finite population of size N.

Given that they sampled the entire U.S. infant populations for SUID during those years so that n = N, the fpc = 0 as shown below because there is no sampling error.

Consequently footnote 'a' and related discussion could be removed.

fpc = Sqrt[(N - n)/(N - 1)] = 0 for n = N.