Variable observed Spearman correlation observed probit correlation Z transform deattenuated Spearman correlation deattenuatedprobit correlation Z transform
NAPAP, 1968 (o.d.) 0.155 0.162 0.163 0.212 0.221 0.225
salicylates, 1968 (mg%) 0.081 0.085 0.085 0.127 0.133 0.134
Difference between correlations 0.074 0.077 0.078 0.085 0.088 0.091
 (95% CI) (0.013, 0.134) (-0.005, 0.174)
se 0.033 0.049
V statistic 2.395 1.849
p-value 0.017 0.064
The V statistic for the observed and deattenuated probit correlations is based on (7) and (5), respectively.
Table 6: Spearman Correlations between serum creatinine at baseline (1968) vs. each of NAPAP and salicylates at the baseline clinic visit (1968), Swiss Analgesic Study, n=168.