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Table 6 Internal consistency and test–retest reliability

From: Development and validation of behavioral intention measures of an E-vapor product: intention to try, use, dual use, and switch

Scale Sub-Group Validation sample Cross-validation sample
Test–retest reliability Internal consistency reliability Test–retest reliability Internal consistency reliability
n ICC (p) n α n ICC (p) n α
ITT Full sample 279 .886 (< .001) 1495 .958 283 .930 (< .001) 1448 .962
ASPQ 48 .790 (< .001) 260 .938 53 .806 (< .001) 248 .953
ASNPQ 58 .745 (< .001) 333 .923 49 .929 (< .001) 315 .922
EV Users 54 .650 (< .001) 277 .876 50 .885 (< .001) 283 .899
Former Users 57 .672 (< .001) 302 .948 61 .893 (< .001) 275 .957
Never Users 62 .858 (< .001) 323 .945 70 .861 (< .001) 327 .950
ITU Full sample 279 .886 (< .001) 1495 .973 283 .911 (< .001) 1448 .973
ASPQ 48 .838 (< .001) 260 .968 53 .781 (< .001) 248 .966
ASNPQ 58 .761 (< .001) 333 .946 49 .910 (< .001) 315 .939
EV Users 54 .796 (< .001) 277 .935 50 .862 (< .001) 283 .952
Former Users 57 .715 (< .001) 302 .972 61 .816 (< .001) 275 .983
Never Users 62 .741 (< .001) 323 .985 70 .908 (< .001) 327 .978
ITDU Full sample 115 .759 (< .001) 109 .798 (< .001)
ASPQ 42 .817 (< .001) 46 .721 (< .001)
ASNPQ 49 .742 (< .001) 39 .684 (< .001)
EV Usersa 24 .395 (.026) 24 .755 (< .001)
ITS Full sample 115 .813 (< .001) 742 .965 109 .834 (< .001) 701 .973
ASPQ 42 .858 (< .001) 260 .972 46 .746 (< .001) 248 .978
ASNPQ 49 .687 (< .001) 333 .964 39 .880 (< .001) 315 .963
EV Users 24 .739 (< .001) 149 .920 24 .857 (< .001) 138 .964
  1. Reliability coefficients for the Intention scales among the full validation and cross-validation samples, as well as among the 5 study sub-groups
  2. ASPQ, Adult Smokers Planning to Quit; ASNPQ, Adult Smokers Not Planning to Quit; EV, e-vapor; ICC, Intraclass correlation coefficient
  3. aTest retest reliability among the full sample (n = 48) was ICC = .544, p < .001