2.7 Data extraction
Data from each included paper were extracted using an extraction form.
Two authors independently extracted data from each eligible paper and
recorded all the extracted data in the data extraction table. Any
variation in the extracted data between the authors were identified and
settled through discussion. Regarding the trials’ characteristics,
extracted data included population, the intervention, type of
expectations, measure of expectations, timing of measuring PEs,
outcomes, outcome measurement tool and follow-up points of outcomes. The
primary outcomes of interest considered in the systematic review were
pain intensity, levels of function and quality of life. Follow-up
periods were divided into three subdivisions; short (≤ 6 weeks), medium
(> 6 weeks - ≤ 6 months), and long (> 6
months) respectively from a previously published protocol (2).