Our data collection forms will include the following items: study design, description of population, interventions, outcomes, characteristics of candidate instruments (eg, generic or disease specific), characteristics of independent anchor measures, critiques/commentary on methods to estimate MID s), and credibility criteria for method(s) to estimate MIDs.
For this comparative analysis we chose to focus on the following criteria: description of rigour in conduct, description of study context, description of the method of analysis, and credibility and depth and richness of findings (Table 1).
The meta-aggregative approach currently incorporates methods to assess dependability and credibility and therefore there was an added practicality when deciding upon these two elements.
This tool provided a structured method to evaluate rigor, research methods, credibility, and relevance (CRD, 2009).
Quality assessment of qualitative papers was carried out in accordance with the Critical Appraisal Skills Programme qualitative research appraisal tool, which covered rigour, key research methods used, credibility and relevance.
However, there is also strategic use of mixed methods research to gain funding and credibility, and concerns that this may hinder the utility of this approach.
Investigator triangulation is recognised as one method of strengthening the validity and credibility of qualitative findings [ 17].
A similar method was also adopted in another study that looked at the reliability and credibility of Angoff method in undergraduate medical examination using recent graduates as judges [ 9].
The concern with the rigour and credibility of qualitative methods has lead to the development of a number of checklist for assessing qualitative research.
