The ascertainment of the outcome will be evaluated from three items: assessment of outcome, duration of follow-up and completeness of follow-up.
Table 2 shows the meta-analysis' overall results (pooled sensitivities and specificities), the results according to STARD score (high/low quality) and the results for specific STARD items (comparison of outcome "yes" vs. "no").
The two main items of the outcome chapter refer to the overall and disease-free survival.
All items of the outcome measures extracted from the systematic review will be translated into categories of the ICF following a standardized approach [ 27].
Items of the outcome measures used in the study retrieved by the recent systematic review by Gnass et al. (2010) will be identified using a standardized procedure [ 27].
Evidence to suggest that retrospective items of treatment outcome have construct validity has been reported from studies of hip replacement (THR) surgery [ 59], lower back pain [ 47, 60], and diabetes [ 5, 30].
The 25-item 'Measurement of Outcome Measures' that considered a measures characteristics under four categories: methodological, practical, distributional and general.
Furthermore, polychoric correlations were calculated between 2 single-item measures of outcome and the 12 safety culture sub-dimensions.
An extra appraisal item, 'Sensitivity of outcome tool' was added to the published tool since the use of an insensitive outcome tool may have meant that differences in posture between conditions were not measured, significantly impacting on study outcomes [ 28].
In addition, to verify construct validity, an ordered probit analysis was conducted between the 2 single-item measures of outcome (Patient Safety Grade and Number of Events Reported, which are the ordinal variables) and the 12 safety culture sub-dimensions.
What emerges as an important finding, and which is not so much an item of other outcome studies, is that patients do not assess outcome predominately as a change of symptoms.
