| Study | Reason for exclusion |
|---|---|
| Alhashemi 2006 | Pain not patient‐reported |
| Alhashemi 2007 | Pain not patient‐reported |
| Alimian 2014 | Paracetamol administered via continuous infusion |
| Anand 2013 | Outcomes assessed over 75 minutes only |
| Ang 1990 | Propacetamol administered intramuscularly |
| Ashrafnejad 2012 | Available as abstract only with no usable data |
| Aydogan 2008 | No pain or analgesic outcome |
| Caliskan 2013 | Preoperative administration of interventions |
| Candiotti 2010 | Not all participants had postoperative pain, efficacy outcomes were assessed at 24 hour intervals, not clear when drugs were administered |
| Cok 2011 | Preemptive administration of interventions |
| Dowling 2014 | Appears that control group did not receive placebo. Pain data only presented up to 1 hour. |
| Elseify 2011 | First dose received after induction of anesthesia, no 4‐ or 6‐hour pain data |
| Fijalkowska 2006 | Compares laparotomy to laparoscopy |
| Fourcade 2005 | No data provided on 4‐ or 6‐hour intervals |
| Garcia 1999 | Participants received propacetamol 30 minutes before operation |
| Gehling 2010 | Paracetamol administered via continuous infusion and no data at 4 or 6 hours |
| Ghaffaripour 2012 | Available as abstract only with no usable data |
| Gousheh 2013 | Interventions administered 10 minutes after induction of anesthesia. Operations were at least 1 hour long; therefore administration > 30 minutes before end of surgery. |
| Granry 1997 | Multiple dose study without data for first dose |
| Grundmann 2006 | Study drug administered more than 30 minutes before the end of surgery |
| Hernandez Palazon 2001 | No data provided for either 4‐ or 6‐hour intervals |
| Irct2012062410102N | All patients initially receive IV paracetamol |
| Ko 2010 | Preoperative administration of interventions |
| Kocum 2013 | Pain not patient‐reported, unclear if interventions within 30 minutes of end of surgery |
| Memis 2010 | Multiple dose study without data for first dose |
| Murat 2005 | Some pain assessments investigator‐reported. Unable to ascertain numbers of participants self reporting pain. |
| NCT01691690 | Pain not patient‐reported |
| NCT01721486 | Pain not patient‐reported |
| Nikoda 2006 | Not randomized |
| Olonisakin 2012 | No data beyond 3 h |
| Pernia 2000 | Received paracetamol in both arms to evaluate efficacy of drug metamizol |
| Rashwan 2013 | No pain data until 8 h post interventions |
| Silvanto 2007 | Study drug administered more than 30 minutes before the end of surgery |
| Topal 2009 | Control group did not receive active control or placebo |
| Toygar 2008 | One control group had intervention administered before induction, and the other control group received no intervention (no placebo was administered) |
| Turner 2014 | Interventions administered 30 minutes before surgical incision |
| Uvarov 2008 | Control group received no intervention |
| Uzun 2010 | Paracetamol plus placebo versus paracetamol plus metamizole, versus no treatment |
| Verchere 2002 | Interventions administered 1 hour before the end of surgery |
| Zeidan 2014 | Dose finding study with outcomes reported at 45 minutes |
| Ziolkowski 2008 | All groups received paracetamol |
IV: intravenous