Department of Anaesthesia, Zealand University Hospital, Koege, Denmark.
Department of Anaesthesia, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark.
Acta Anaesthesiol Scand. 2018 May;62(5):666-676. doi: 10.1111/aas.13072. Epub 2018 Jan 22.
Bias (systematic error) and small trial sample size (random error) may induce imprecise and exaggerated treatment effects in randomised controlled trials (RCTs). To avoid this, SPIRIT- and CONSORT-guidelines, and Cochrane Collaboration bias recommendations were developed. We investigated risk of bias and trial sample size development over time in postoperative pain trials.
This study was based on data from two systematic reviews regarding pain management after total hip arthroplasty (THA) or total knee arthroplasty (TKA). RCTs of analgesic interventions with a comparator control group were included. Primary outcomes were risk of bias and trial sample size developments over time. We calculated cumulated bias scores ranging from 0 to 14 based on Cochrane's seven bias domains (0 = low; 1 = unclear, 2 = high). Developments were evaluated with run and control charts. Further, we compared data from trials published between 1990-1999 and 2010-2016.
We included 171 trials published between 1989 and 2016. Overall, the summarised risk of bias decreased, mainly due to better randomization and allocation concealment. Visual inspection suggested an on-going improvement that started around 2007. Trial sample size did not change significantly. For trials published between 1990-1999 and 2010-2016 adequate reporting increased from 36% to 75% for random sequence generation, from 9% to 38% for allocation concealment and from 27% to 52% for blinding of participants/personnel.
Risk of bias for RCTs regarding postoperative pain management after THA and TKA has decreased from 2007 to 2016, mainly due to better randomization and allocation concealment. Deficiencies remain. Thus, reporting according to validated guidelines is essential. Sample sizes did not change significantly.
偏倚（系统误差）和小样本量（随机误差）可能导致随机对照试验（RCT）中治疗效果不精确和夸大。为了避免这种情况，制定了 SPIRIT 和 CONSORT 指南以及 Cochrane 协作偏倚建议。我们调查了术后疼痛试验中偏倚风险和试验样本量随时间的发展情况。
本研究基于两项关于全髋关节置换术（THA）或全膝关节置换术（TKA）后疼痛管理的系统评价数据。纳入了具有对照对照组的镇痛干预措施的 RCT。主要结局是随时间推移的偏倚风险和试验样本量发展情况。我们根据 Cochrane 的七个偏倚领域（0 = 低；1 = 不清楚，2 = 高）计算了从 0 到 14 的累积偏倚评分（0 = 低；1 = 不清楚，2 = 高）。使用运行和控制图评估发展情况。此外，我们比较了 1990-1999 年和 2010-2016 年发表的试验数据。
我们纳入了 1989 年至 2016 年发表的 171 项试验。总体而言，总结的偏倚风险降低，主要是由于随机化和分配隐藏的改善。视觉检查表明，这种改善始于 2007 年左右。试验样本量没有明显变化。对于 1990-1999 年和 2010-2016 年发表的试验，随机序列生成的充分报告从 36%增加到 75%，分配隐藏的充分报告从 9%增加到 38%，参与者/人员的盲法从 27%增加到 52%。
THA 和 TKA 术后疼痛管理的 RCT 偏倚风险从 2007 年到 2016 年有所降低，主要是由于随机化和分配隐藏的改善。仍然存在缺陷。因此，根据验证过的指南进行报告至关重要。样本量没有明显变化。
