Table 5.

Agreement between informants’ reports of twin with concurrent self-report of co-twin.

Gambling Behavior	Ever	Monthly	Weekly	Problem (1+)	Pathological (5+)
Kappa	0.28 (.19 – .37)	0.30 (.26 – .35)	0.22 (.14 – .31)	0.16 (.10 – .22)	0.26 (.12 – .40)
Yule’s Y	0.67 (.57 – .76)	0.34 (.30 – .39)	0.24 (.15 – .32)	0.59 (.47 – .71)	0.65 (.50 – .77)
Sensitivity	0.95 (.94 – .96)	0.50 (.47 – .53)	0.74 (.69 – .79)	0.11 (.07 – .16)	0.28 (.13 – .44)
Specificity	0.59 (.44 – .74)	0.81 (.78 – .84)	0.48 (.41 – .54)	0.99 (.99 – 1.00)	0.98 (.98 – .99)
PPV	0.99 (.99 – .99)	0.74 (.71 – .78)	0.68 (.63 – .73)	0.66 (.50 – .82)	0.27 (.13 – .42)
NPV	0.21 (.14 – .28)	0.59 (.56 – .62)	0.56 (.49 – .63)	0.89 (.87 – .90)	0.99 (.98 – .99)

Note: PPV = positive predictive value, NPV = negative predictive value