Our results confirm the earlier findings of Perneger and Burnand with the SF-12 [ 4] and of Vercherin et al. with the SF-36 [ 8], that older age, female sex, and to a lesser extent low education and low economic status (blue collar workers and non-nationals), are major determinants of item missingness in QoL questionnaires.
Psychometric indices were not the only determinant of item quality.
The selection of the task features used to scale CCER was made in the light of the characteristics which had turned out to be significant determinants of the item's difficulty in previous studies on measuring situation-specific skills by using stage-oriented models, drawing notably on Blum et al. (2003), Kauertz and Fischer (2008), Winther and Achtenhagen (2009).
Logistic regression models [ 20] were constructed to identify the type and determinants of missingness for each item of the SF-36 (except for HT).
The first subscale (10 items) comprises determinants of frailty, such as sociodemographic data and data about life events and chronic diseases; the second subscale (15 items), which we used in this study, determines the level of frailty according to physical (eight items), social (three items), and psychological (four items) factors, including one item about cognition.
In the few studies that have compared the determinants of global and comparative SRH items, the global measure has been found to be the most inclusive measure of subjective health in terms of its associations with other factors of health [ 37, 39].
Remember, the number of items is not the determinant, so don't be tempted to purchase unnecessary things.
One determinant of dwell times might be the similarity of items to the to-be-searched for target.
▪ Determinants of behavioral change: A 41-item questionnaire, based on existing TPB questionnaires, will be used to assess lifestyle-specific behavior with regard to the constructs attitude, social norm, self-efficacy and intention to change.
The participants responded to items about several determinants of drinking behaviour at each wave.
Also, as the researcher may be assessing other determinants of mortality, the length of the questionnaire should be considered to avoid patient burden ('Number of items').
