Study designs of evaluations included in the review
Double-blinded randomised controlled trials (RCTs) were included.
Specific interventions included in the review
Paracetamol, codeine and caffeine.
Participants included in the review
Partici[ants were in the age range 13 to 87 years with a mean weight ranging from 46 to 81 kg. All had severe pain before taking the study drug or placebo (mean baseline pain score 0.54 to 0.87%); pain could originate from episiotomy, postpartum uterine cramp, dental or miscellaneous post-operative pain.
Outcomes assessed in the review
Total pain relief (TOTPAR) and pain intensity difference (SPID). The higher the recorded value of the outcome measure, the greater the pain relief. Response rate ratio (ResRR), and the re-medication rate (RemRR) were also assessed.
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the authors performed the selection. All studies had to be RCTs; those using formulations for non-oral routes, or where paracetamol was administered prior to surgery, were excluded. All included studies had to deal with post-operative acute pain including dental pain and postpartum pain. Studies involving orthopaedic surgery, general surgery, rectal surgery, hysterectomy, mastectomy, osteotomy and Caesarean section were included for comparative purposes.