Table 1.

Reasons for exclusion.

Reason for exclusion	Number of papers
Not empirical study/not published in peer reviewed journal/full text unavailable	296
Not mixed method report/both data sets not presented or retrievable	287
Not healthcare research	88
Analysis/findings not clearly describeda	4

^aDue to lack of clarity in these papers method and/or result presentations it was not possible to determine what analysis technique had been used.