The big differences emerge when third-party money is used for items in contracts described as supplements, talent fees or appearance fees.
A seven-point Likert scale was used for items in the questionnaire ranging from (1) "strongly disagree" to (7) "strongly agree".
Ethylene Oxide (EtO) is used for items that are moisture and heat sensitive, such as devices with plastic or electrical components that cannot withstand high temperatures.
From February to March 2012, a four-step Delphi process was used for item selection.
The first subsample included 3,326 cases, and it was used for item analysis and EFA.
In addition to the confirmatory factor analyses, Cronbach's alphas and item-to-total correlations were used for item reduction.
For 58 instruments (55.8%), patient input was used for item reduction, and for 12 instruments (11.5%) the items were selected by expert input only.
Where patient input was used for item selection (n = 58), the methods were predominantly quantitative (n = 31, 53.4%) and conducted by factor analysis (17 of 31 instruments).
The focus groups and literature review that were conducted in 2001 were used for item generation in the development of the ITP-PAQ in the absence of a conceptual model [ 17].
A formal structured examination of content validity; a statistical analysis of test-retest reliability, factor structure, and construct validity were used for item reduction and evaluation of the final instrument.
