observed Spearman correlation observed probit correlation Z transform deattenuated Spearman correlation deattenuatedprobit correlation Z transform ICCs

2 weeks of room temperature pre-shipping plus 4 weeks of freezer (X)

0.952 0.956 1.896 0.979 0.98 2.31 0.946

4 weeks of room temperature pre-shipping plus 12 weeks of freezer (Y)

0.711 0.727 0.922 0.776 0.79 1.072 0.835

difference

0.241 0.229 0.974 0.203 0.19 1.238

se

0.348 0.827

V statistic

2.797 1.497

p-value (large sample)

0.005 0.134

p-value (exact)

0.021 0.056
The V statistics are based on (7) and (5) using the probit transformation.
Table 7: Spearman Correlations between HbA1c levels determined immediately vs. HbA1c levels determined after 2 delay periods, N= NICC =12.