I suspect the fairness could be compromised because CNA could manipulate the test to bias the Canada educated testers. Even worse the CNA has the statistic info of the tester's educated country.
NCLEX is more fair since it's knowledge based and score was determined not based on statistic.
You can read the following doc for how CNA use the question in CRNE and statics number of 2008 CRNE.
Pay attention to 2) Marking exams and statistical analysis of exam questions
http://www.cna-nurses.ca/CNA/documents/pdf/publications/CRNE_Bulletin_June_2005_e.pdf
Pay attention to Performance section, success rates.
NCLEX is more fair since it's knowledge based and score was determined not based on statistic.
You can read the following doc for how CNA use the question in CRNE and statics number of 2008 CRNE.
Pay attention to 2) Marking exams and statistical analysis of exam questions
http://www.cna-nurses.ca/CNA/documents/pdf/publications/CRNE_Bulletin_June_2005_e.pdf
Pay attention to Performance section, success rates.