血清铁蛋白诊断铁缺乏临界值研究的Meta分析

目的探讨血清铁蛋白(SF)诊断铁缺乏的适宜临界值。方法通过计算机检索及手工查阅收集以骨髓铁染色为金标准,探讨SF诊断铁缺乏临界值的国内外相关文献,按照纳入与排除标准筛选文献并提取数据,将纳入研究依据阈值效应异质性检验结果按SF临界值12～20、25和30、36～60μg/L分组,根据异质性检验结果选择相应的效应模型对各组进行加权定量合并,计算各组的综合诊断效能参数及其95%CI,绘制综合受试者工作特征(SROC)曲线并计算曲线下面积和Q*指数,并进行敏感性分析。结果 14篇纳入文献分为三组进行合并效应值分析发现,SF临界值12～20μg/L组的汇总灵敏度最低(0.767,95%CI 0.705～0.821),但汇总特异度最高(0.959,95%CI 0.934～0.976),25和30μg/L组的汇总灵敏度最高(0.877,95%CI 0.799～0.933),汇总特异度为(0.944,95%CI 0.888～0.977),36～60μg/L组的汇总灵敏度(0.836,95%CI 0.797～0.870)和特异度(0.876,95%CI 0.846～0.901)都较低。综合诊断效能指标诊断比值比属SF 25、30μg/L组最高(101.42,95%CI 36.137～284.64),SROC曲线下面积最大(0.9497±0.039),Q*指数也最接近1(0.8901±0.052)。分别剔除样本量<50的文献和中文文献后,各项诊断效能参数仍以SF 25和30μg/L组为最佳,与剔除研究前的结论一致。结论 SF检测以25或30μg/L为临界值判断铁缺乏时其准确性和综合效能较高。

Meta-analysis of studies on cut-off value of serum ferritin for identifying iron deficiency

Objective To synthesize evidence to discuss the appropriate cut-off value of serum ferritin(SF) for identifying iron deficiency.Methods A comprehensive electronic search and manual tracking were performed to collect potential studies on cut-off value of SF for identifying iron deficiency.Most relevant studies were identified according to the inclusion and exclusion criteria and data were extracted.All included studies were divided into three groups according to the cutoff value of SF: 12-20 μg/L group,25μg/L or 30μg/L group and 36-60μg/L group.Heterogeneity of the included studies was tested to select proper efficacy model for calculating pooled weighted diagnostic indicators and their 95% CI.Summary receiver operating characteristic(SROC) curve was made and the area under the curve(AUC) and Q* index were calculated respectively for the three groups.Finally,sensitivity analysis were performed.Results A total of 14 studies were included and were divided into three groups.After the pooled efficacy analysis,we found that the 12-20μg/L group showed the lowest pooled sensitivity(0.767,95CI 0.705-0.821) but highest specificity(0.959,95CI 0.934-0.976).Compared with the other two groups,the pooled sensitivity of 25,30μg/L group(0.877,95CI 0.799-0.933) was highest,its pooled specificity was(0.944,95CI 0.888-0.977),the pooled sensitivity and pooled specificity of 36-60μg/L group(0.836,95CI 0.797-0.870),(0.876,95CI 0.846-0.901)]were both relatively low.In terms of the integrated diagnostic capabilities,the 25,30μg/L group showed the highest diagnostic odds ratio(101.42,95CI 36.137-284.64),the largest AUC(0.9497±0.039) and the Q* index nearest 1(0.8901±0.052)among the three groups.After we removed the studies with samples less than 50 and the studies from Chinese authors,the 25,30μg/L group still showed the best diagnostic efficiency.Conclusion 25 or 30μg/L of SF as the cut-off value of identifying iron deficiency shows high accuracy and good integrated diagnostic capability.