Abstract：
BACKGROUND: Fragility analysis is a method of further characterizing outcomes in terms of the stability of statistical findings. This study assesses the statistical fragility of recent randomized controlled trials (RCTs) evaluating robotic-assisted versus conventional total knee arthroplasty (RA-TKA versus C-TKA).
METHODS: We queried PubMed for RCTs comparing alignment, function, and outcomes between RA-TKA and C-TKA. Fragility index (FI) and reverse fragility index (RFI) (collectively, \"FI\") were calculated for dichotomous outcomes as the number of outcome reversals needed to change statistical significance. Fragility quotient (FQ) was calculated by dividing the FI by the sample size for that outcome event. Median FI and FQ were calculated for all outcomes collectively as well as for each individual outcome. Subanalyses were performed to assess FI and FQ based on outcome event type and statistical significance, as well as study loss to follow-up and year of publication.
RESULTS: The overall median FI was 3.0 (interquartile range, [IQR] 1.0 to 6.3) and the median reverse fragility index was 3.0 (IQR 2.0 to 4.0). The overall median FQ was 0.027 (IQR 0.012 to 0.050). Loss to follow-up was greater than FI for 23 of the 38 outcomes assessed.
CONCLUSIONS: A small number of alternative outcomes is often enough to reverse the statistical significance of findings in RCTs evaluating dichotomous outcomes in RA-TKA versus C-TKA. We recommend reporting FI and FQ alongside P values to improve the interpretability of RCT results.
METHODS: We queried PubMed for RCTs comparing alignment, function, and outcomes between RA-TKA and C-TKA. Fragility index (FI) and reverse fragility index (RFI) (collectively, \"FI\") were calculated for dichotomous outcomes as the number of outcome reversals needed to change statistical significance. Fragility quotient (FQ) was calculated by dividing the FI by the sample size for that outcome event. Median FI and FQ were calculated for all outcomes collectively as well as for each individual outcome. Subanalyses were performed to assess FI and FQ based on outcome event type and statistical significance, as well as study loss to follow-up and year of publication.
RESULTS: The overall median FI was 3.0 (interquartile range, [IQR] 1.0 to 6.3) and the median reverse fragility index was 3.0 (IQR 2.0 to 4.0). The overall median FQ was 0.027 (IQR 0.012 to 0.050). Loss to follow-up was greater than FI for 23 of the 38 outcomes assessed.
CONCLUSIONS: A small number of alternative outcomes is often enough to reverse the statistical significance of findings in RCTs evaluating dichotomous outcomes in RA-TKA versus C-TKA. We recommend reporting FI and FQ alongside P values to improve the interpretability of RCT results.
摘要：
背景：脆弱性分析是一种根据统计结果的稳定性进一步表征结果的方法。这项研究评估了最近的随机对照试验（RCT）的统计脆弱性，该试验评估了机器人辅助与常规全膝关节置换术（RA-TKA与C-TKA）。
方法：我们向PubMed查询了比较对齐的RCT，函数,RA-TKA和C-TKA之间的结果。脆弱性指数(FI)和反向脆弱性指数(RFI)(统称，计算“FI”）作为改变统计显著性所需的结果逆转次数。通过将FI除以该结果事件的样本大小来计算脆性商(FQ)。计算所有结果以及每个单独结果的平均FI和FQ。根据结局事件类型和统计学意义进行分分析以评估FI和FQ，以及随访和发表年份的研究损失。
结果：总体中位数FI为3.0（四分位距，[IQR]1.0至6.3），中位数RFI为3.0（IQR2.0至4.0）。总体中位数FQ为0.027（IQR0.012至0.050）。在评估的38项结果中，有23项随访损失大于FI。
结论：少量的替代结果通常足以逆转RA-TKA与C-TKA中评估二分结果的RCT结果的统计学意义。我们建议报告FI和FQ以及P值，以提高RCT结果的可解释性。
方法：我们向PubMed查询了比较对齐的RCT，函数,RA-TKA和C-TKA之间的结果。脆弱性指数(FI)和反向脆弱性指数(RFI)(统称，计算“FI”）作为改变统计显著性所需的结果逆转次数。通过将FI除以该结果事件的样本大小来计算脆性商(FQ)。计算所有结果以及每个单独结果的平均FI和FQ。根据结局事件类型和统计学意义进行分分析以评估FI和FQ，以及随访和发表年份的研究损失。
结果：总体中位数FI为3.0（四分位距，[IQR]1.0至6.3），中位数RFI为3.0（IQR2.0至4.0）。总体中位数FQ为0.027（IQR0.012至0.050）。在评估的38项结果中，有23项随访损失大于FI。
结论：少量的替代结果通常足以逆转RA-TKA与C-TKA中评估二分结果的RCT结果的统计学意义。我们建议报告FI和FQ以及P值，以提高RCT结果的可解释性。
