Links to SAGE readings have been provided, non-SAGE readings are suggested and you may be able to find these via your university’s library.
For two different views on the issue of quality appraisal in qualitative research, see:
Some examples of different ways of synthesizing qualitative research are suggested here. They take different approaches: see Smith and Anderson for a good example, and why they choose not to assess quality according to structured critieria:
O'Connell R and Downe S. (2009) ‘A metasynthesis of midwives' experience of hospital practice in publicly funded settings: compliance, resistance and authenticity’ Health (London);13(6): 589–609. doi: 10.1177/1363459308341439.
Blacklock, C., Ward, A. M., Heneghan, C. and Thompson, M. (2014) ‘Exploring the migration decisions of health workers and trainees from Africa: a meta-ethnographic synthesis’, Social Science & Medicine, 100: 99–106.