Schonfeld D J, Rainey P M, Cullen M R, Showalter D R, Cicchetti D V
Department of Pediatrics, Yale University School of Medicine, New Haven, Conn., USA.
Arch Pediatr Adolesc Med. 1995 Apr;149(4):447-50. doi: 10.1001/archpedi.1995.02170160101015.
To assess the false-positive rate of blood lead determinations on samples obtained by fingerstick from children screened in private suburban and rural practices.
Screening capillary lead samples were obtained by fingerstick; children with capillary lead levels of 0.7 mumol/L (15 micrograms/dL) or greater were recalled for a confirmatory venous lead test that served as the criterion standard. Parents completed a five-question risk assessment questionnaire at the time of initial screening.
Four private suburban to rural practices that serve predominantly white, middle-class populations.
Children seen for routine care between August 1992 and February 1993 (N = 1085; 98% between 6 months and 6 years of age).
Capillary lead level was 0.7 mumol/L (15 micrograms/dL) or greater in 35 children (3% of total sample); venous lead samples were obtained in 30 patients. Nine of the elevated capillary lead results were true-positives (venous lead = 0.7, 0.8, 0.8, 0.9, 0.9, 0.9, 1.1, 1.1, and 1.7 mumol/L [15, 17, 17, 18, 18, 18, 22, 22, and 35 micrograms/dL]); parents of only two of these children answered yes to any question on the risk assessment questionnaire. Although the false-positive rate of the capillary lead screening test was 70% (21/30) in this setting, only 2% of the total sample had a false-positive screening test (an average of fewer than one false-positive per month per practice). Screening by fingerstick allowed phlebotomy to be avoided for 97% of the children.
Fingerstick screening for lead poisoning is a reasonable alternative to direct venous testing within private suburban and rural practices, provided that care is taken to avoid specimen contamination, that appropriate caution is used in the interpretation of screening test results, and that medical and environmental interventions are based on the results of confirmatory venous testing.
评估在郊区和农村私人诊所接受筛查的儿童中，通过手指采血获得的血铅检测结果的假阳性率。
通过手指采血获取筛查用的毛细血管血铅样本；毛细血管血铅水平达到或高于0.7微摩尔/升（15微克/分升）的儿童被召回进行确认性静脉血铅检测，该检测作为标准对照。家长在初次筛查时填写一份包含五个问题的风险评估问卷。
四家主要服务白人中产阶级人群的郊区至农村私人诊所。
1992年8月至1993年2月期间接受常规护理的儿童（N = 1085；98%年龄在6个月至6岁之间）。
35名儿童（占总样本的3%）的毛细血管血铅水平达到或高于0.7微摩尔/升（15微克/分升）；30名患者接受了静脉血铅样本检测。9例毛细血管血铅水平升高的结果为真阳性（静脉血铅水平分别为0.7、0.8、0.8、0.9、0.9、0.9、1.1、1.1和1.7微摩尔/升[15、17、17、18、18、18、22、22和35微克/分升]）；这些儿童中只有两名儿童的家长在风险评估问卷上对任何问题回答“是”。尽管在此环境下毛细血管血铅筛查试验的假阳性率为70%（21/30），但仅2%的总样本有假阳性筛查结果（平均每家诊所每月少于一例假阳性）。通过手指采血进行筛查使97%的儿童避免了静脉穿刺采血。
在郊区和农村私人诊所中，手指采血筛查铅中毒是直接静脉检测的合理替代方法，前提是注意避免样本污染，在解释筛查试验结果时适当谨慎，并且医疗和环境干预基于确认性静脉检测结果。
