Single dose oral diclofenac for acute postoperative pain in adults

Data managementData were extracted by two review authors and recorded on a standarddata extraction form. Data suitable for pooling were enteredinto RevMan 5.0.16.Data analysisQUOROM guidelines were followed (Moher 1999). For efficacyanalyses we used the number of participants in each treatmentgroup who were randomised, received medication, and providedat least one post-baseline assessment. For safety analyses we usednumber of participants who received study medication in eachtreatment group. Analyses were planned for different doses. Sensitivityanalyses were planned for pain model (dental versus otherpostoperative pain), trial size (39 or fewer versus 40 or more pertreatment arm), and quality score (two versus three or more), saltpreparation (Na versus K salt), and formulation (tablet versus dispersible).A minimum of two studies and 200 participants wererequired for any analysis (Moore 1998).Primary outcome:Number of participants achieving at least 50% pain reliefFor each study, mean TOTPAR (total pain relief) or SPID(summed pain intensity difference) for active and placebo groupswere converted to %maxTOTPAR or %maxSPID by divisioninto the calculated maximum value (Cooper 1991). The proportionof participants in each treatment group who achieved atleast 50%maxTOTPAR was calculated using verified equations(Moore 1996; Moore 1997a; Moore 1997b). These proportionswere then converted into the number of participants achieving atleast 50%maxTOTPAR by multiplying by the total number ofparticipants in the treatment group. Information on the numberof participants with at least 50%maxTOTPAR for active treatmentand placebo was then used to calculate relative benefit (RB)and number needed to treat to benefit (NNT).Pain measures accepted for the calculation of TOTPAR or SPIDwere:• five-point categorical pain relief (PR) scales withcomparable wording to “none, slight, moderate, good orcomplete”;• four-point categorical pain intensity (PI) scales withcomparable wording to “none, mild, moderate, severe”;• VAS for pain relief;• VAS for pain intensity.If none of these measures were available, numbers of participantsreporting “very good or excellent” on a five-point categorical globalscale with the wording “poor, fair, good, very good, excellent” weretaken as those achieving at least 50% pain relief (Collins 2001).Further details of the scales and derived outcomes are in the glossary(Appendix 4).Secondary outcomes:1. Use of rescue medication. Numbers of participantsrequiring rescue medication were used to calculate relative riskand numbers needed to treat to prevent (NNTp) use of rescuemedication for treatment and placebo groups. Median (or mean)time to use of rescue medication was used to calculate theweighted mean of the median (or mean) for the outcome.Weighting was by number of participants.2. Adverse events. Numbers of participants reporting adverseevents for each treatment group were used to calculate relativerisk and numbers needed to treat to harm (NNH) estimates for:i) any adverse event;ii) any serious adverse event (as reported in the study);iii) withdrawal due to an adverse event.3. Withdrawals. Withdrawals for reasons other than lack ofefficacy (participants using rescue medication - see above) andadverse events were noted, as were exclusions from analysis wheredata were presented.Relative benefit or risk estimates were calculated with 95% confidenceintervals (CI) using a fixed-effect model (Morris 1995).NNT, NNTp and NNH with 95% CI were calculated using thepooled number of events by the method of Cook and Sackett(Cook 1995). A statistically significant difference from control wasassumed when the 95% CI of the relative benefit did not includethe number one.Homogeneity of studies was assessed visually (L’Abbé 1987). The ztest (Tramèr 1997) was used to determine if there was a significantdifference between NNTs for different doses of active treatment,or between groups in the sensitivity analyses.R E S U L T SDescription of studiesSee: Characteristics of included studies; Characteristics of excludedstudies.The earlier review included seven studies (Ahlstrom 1993; Bakshi1992; Bakshi 1994; Herbertson 1995; Mehlisch 1995; Nelson1994; Olson 1997). The new searches identified an additionalnine potentially relevant studies. One (Tam 2001) was excludedafter reading the full paper, and eight were included (Chang2002; Cooper 1996; Desjardins 2004; Hersh 2004; Hofele 2006;Kubitzek 2003; Torres 2004; Zuniga 2004). In total 15 studieswere included in this review update. Details are in the relevant’Characteristics of studies’ tables.Single dose oral diclofenac for acute postoperative pain in adults (Review)Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.5