Second, differences in interview techniques may also influence responses.
Interviews lasted between 35-120 minutes, with no major differences in interview lengths between countries.
Consequently, differences in interview style and experience could have influenced the flow and content of the interviews.
Most Clinical Directors had met J.K.S. previously and so that any differences in interview content are considered to be a function of personality rather than methodology.
Performing these analyses without the zero-traders resulted in larger and significant median differences in interview TTO scores between worse and better outcomes for the physical component summary of the SF-36 (difference in mean rank = 5.50), the NRS measuring pain (difference in mean rank = 5.83) and the SF-6D (difference in mean rank = 4.85).
Of interest that project identified lower UMAT scores in all 3 components for those who indicated a strong interest in general practice at exit from the course [ 32], but with no identifiable differences in interview scores or grade point average from prior university achievement.
De Leeuw provides a good illustration of how the internal consistency (psychometric reliability) of summary scales may be varied by mode features through (i) differences in interview pace and (ii) the opportunity for respondents to relate their responses to scale items to each other [ 38].
Nevertheless, we left the 'country' (coded as: Spain, 3 centres; France, 2 centres; Italy, 5 centres; Germany/Denmark, 2 centres) as an adjustment parameter to take into account a potential residual confounding effect due to the possible differences in interview methods and cultural settings.
However, variation in measurement methods may also explain differing prevalence and predictors, such as differences in interviewing techniques of SCOPE midwives across centres.
6 Potential reasons why GUI and MCS estimates are not compatible include differences in interviewing techniques and administration of surveys which would easily influence reporting of socially undesirable behaviours such as gestational alcohol use.
