2.4.2.1 Reliability: Internal consistency and Test-retest
reliability
To measure the internal consistency, Cronbach-α values per dimensions
were calculated and also a total Cronbach-α value was computed.
Cronbach-α with values of 0.60 to 0.80 is regarded as evidence of good
reliability and those above 0.80 indicating excellent
reliability.17, 18 The parent and teens reports
Tr-PedsQL™ 3.0 EoE module were applied for twice at one week interval.
Test-retest reliability was determined by using the intraclass
correlation coefficient (ICC). ICCs with values of 0.60 to 0.80 regarded
as evidence of good reliability and those above 0.80 indicating
excellent reliability.17