It appears to provide a level of discrimination comparable to the NG-MAST typing scheme [ 15], although this has not been formally validated as different datasets have been used.
While the GIS is a self-administered questionnaire designed to improve patient-doctor communication and furnish information on treatment outcomes, it has not been formally validated as a tool for monitoring the response of GERD symptoms and quality of life to proton pump inhibitor (PPI) treatment [ 19].
Finally, IMAI has yet to be formally validated, particularly in low-HIV prevalence settings such as Rwanda, which represents an important next step in establishing a standard of general adult and adolescent primary care delivery.
Further, an assessment of local impact probability can be formally validated through experiments or be grounded on commonsense.
Moreover, none of the measures has been formally validated, and as such unknown levels of measurement bias and random error can bias the estimates.
As none of the questionnaires from any of the previous studies had been formally validated, an initial validation pilot was conducted in accordance with current recommendations (Sudman and Bradburn, 1982; Oppenheim, 1992; Peterson, 2000; McColl et al, 2001).
The 5-second head-lift test may be considered insensitive [ 10] and inappropriate for the detection of residual block [ 11], and the test for general muscle weakness has not been formally validated and was intended more as a clinical measurement tool for overall well being.
Only the QHES instrument was formally validated in terms of construct validity [ 21].
Secondly, while the questionnaire used has obvious face validity, it has not been formally validated for our local population.
