Postnatal growth in VLBW infants: significant association with neurodevelopmental outcome

OBJECTIVE: To study the significance of growth status at birth and postnatal growth on neurodevelopmental outcome in very low birth weight (VLBW) infants. STUDY DESIGN: Growth and neurodevelopment were examined in 219 VLBW (<1250 g) children, 94 small for gestational age (SGA) (<10th percentile) and 125 appropriate for gestational age (AGA) (>10th percentile). Outcome at age 2 was assessed with the Bayley Scales of Infant Development (Mental Developmental Index [MDI], Psychomotor Developmental Index [PDI]) and a standardized neurologic examination. RESULTS: SGA status was not associated with poor neurodevelopmental outcome. However, after adjustment for covariables including cerebral palsy (CP), SGA children with weight <10th percentile at age 2 had lower mean PDI than SGA children with catch-up growth to weight >10th percentile (mean [SD], 89.9 [17.4] versus 101.8 [14.5]; P<.001). AGA children with catch-down growth (weight <10th percentile at age 2) were, independent of CP, more likely to have lower mean MDI (94.9 vs 101.7, P=.05) and PDI (81.9 vs 95.1; P<.001) than AGA children remaining >10th percentile at age 2. They also more frequently had severe CP (22.9% vs 1.2%; P=.008). CONCLUSIONS: In VLBW children, the course of postnatal growth rather than the appropriateness of weight for gestational age at birth determines later neurodevelopmental outcome.     

Comparison of clinical prediction rules for management of pharyngitis in settings with limited resources

OBJECTIVE: To compare the effectiveness of several clinical prediction rules for culture-positive streptococcal pharyngitis in a single group of patients in a setting in which clinicians routinely treat all cases of pharyngitis presumptively, without laboratory data. STUDY DESIGN: A MEDLINE search identified clinical prediction rules for streptococcal pharyngitis in children. Each rule was applied analytically to data from 410 children in Cairo, Egypt with clinical pharyngitis, in whom throat cultures were performed. The diagnostic effectiveness of these rules for predicting a positive culture were assessed and compared. RESULTS: Seven prediction rules were identified. Of these 7 rules, 4 were developed in North American children, 1 was recommended by the World Health Organization (WHO), and 2 were developed in Egypt. In the Cairo children, the WHO rule was the least sensitive, at 12%. The 6 other rules had sensitivities ranging from 81% to 99% and specificities ranging from 4% to 40%; 2 rules seemed to be effective, with diagnostic odds ratios of 5.2 and 6.1. CONCLUSIONS: The prediction rules demonstrated variable diagnostic effectiveness in the Egyptian children. Without laboratory testing, 2 clinical rules detected > 90% of cases of pharyngitis with positive culture for group A streptococcus and reduced overtreatment of culture-negative cases by approximately 40%. Selected clinical prediction rules have useful characteristics in settings of limited resources and need further validation.     

Understanding diagnostic tests 1: sensitivity, specificity and predictive values

The usefulness of diagnostic tests, that is their ability to detect a person with disease or exclude a person without disease, is usually described by terms such as sensitivity, specificity, positive predictive value and negative predictive value. In this article, the first of the series, a simple, practical explanation of these concepts is provided and their use and misuse discussed. It is explained that while sensitivity and specificity are important measures of the diagnostic accuracy of a test, they are of no practical use when it comes to helping the clinician estimate the probability of disease in individual patients. Predictive values may be used to estimate probability of disease but both positive predictive value and negative predictive value vary according to disease prevalence. It would therefore be wrong for predictive values determined for one population to be applied to another population with a different prevalence of disease. CONCLUSION: Sensitivity and specificity are important measures of the diagnostic accuracy of a test but cannot be used to estimate the probability of disease in an individual patient. Positive and negative predictive values provide estimates of probability of disease but both parameters vary according to disease prevalence.     

Cardiorespiratory events detected by home memory monitoring and one-year neurodevelopmental outcome

OBJECTIVE: To determine if infants with cardiorespiratory events detected by home memory monitoring during early infancy have decreased neurodevelopmental performance. STUDY DESIGN: Infants (n = 256) enrolled in the Collaborative Home Infant Monitoring Evaluation also completed the Bayley Scales of Infant Development II at 92 weeks' postconceptional age. Infants were classified as having 0, 1 to 4, or 5+ cardiorespiratory events. Events were defined as apnea >or=20 seconds or heart rate <60 to 80 bpm or <50 to 60 bpm, for >or=5 to 15 seconds, depending on age. RESULTS: For term infants, having 0, 1 to 4, and 5+ cardiorespiratory events was associated with unadjusted mean Mental Developmental Index (MDI) values (+/-SD) of 103.6 (10.6), 104.2 (10.7), and 97.7 (10.9), respectively, and mean Psychomotor Developmental Index (PDI) values of 109.5 (16.6), 105.8 (16.5), and 100.2 (17.4). For preterm infants, having 0, 1 to 4, and 5+ cardiorespiratory events was associated with unadjusted mean MDI values of 100.4 (10.3), 96.8 (11.5), and 95.8 (10.6), respectively, and mean PDI values of 91.7 (19.2), 93.8 (15.5), and 94.4 (17.7). The adjusted difference in mean MDI scores with 5+ events compared with 0 events was 5.6 points lower in term infants ( P = .03) and 4.9 points lower in preterm infants ( P = .04). CONCLUSIONS: Having 5+ conventional events is associated with lower adjusted mean differences in MDI in term and preterm infants.     

早期预测食物过敏高风险儿童方法探讨

目的探讨联合多种危险因素获得的过敏风险评分预测食物过敏高风险儿童的价值。方法采用问卷调查方式获得≤3岁婴幼儿的过敏危险因素信息,以多元logistic逐步回归分析婴幼儿食物过敏危险因素,计算各危险因素对食物过敏的阳性预测值,依据回归方程计算过敏风险评分,通过ROC曲线评价过敏风险评分在筛查食物过敏高风险儿童中的价值。结果获得78例确诊为食物过敏及156例非过敏性疾病的≤3岁婴幼儿的回顾性调查信息。其中过敏性疾病家族史、剖宫产、孕期使用抗生素或解热镇痛药、孕期吸烟或接触吸烟环境、孕期接触杀虫剂或驱蚊剂、家中饲养宠物均是婴幼儿发生食物过敏的危险因素(P0.05)。过敏家族史预测食物过敏的阳性预测值为63.2%,ROC曲线下面积(AUC)为0.696(95%CI:0.620～0.771)。当联合多因素获得的过敏风险评分≥2.85时,其预测食物过敏的AUC为0.804(95%CI:0.746～0.863),灵敏度为0.526,特异度为0.910,尤登指数为0.436。结论多危险因素联合指标筛查食物过敏高风险儿童的预测价值高于过敏家族史。     

Need for quantitative assessment of transglutaminase autoantibodies for celiac disease in screening-identified children

OBJECTIVES: To assess several transglutaminase autoantibody (TGAA) assays in their ability to distinguish celiac disease (CD) in screening-identified children with abnormal intestine biopsy specimens from those with normal biopsy specimens. STUDY DESIGN: Children at risk for CD (n = 54) composed of type 1 diabetics, first-degree relatives of type 1 diabetics or CD, and HLA-DQ2+ individuals followed from birth received intestine biopsy. Sera obtained at the time of biopsy were tested for TGAA, using the radioimmunoassay and 5 other commercially available enzyme-linked immunosorbent assays. RESULTS: False-positive rates ranged from 28% to 80%. The positive predictive value (PPV) of the tests ranged from 63% to 84% (lower than reported for symptomatic children). Setting a higher cutoff for each assay maximized PPV. CONCLUSIONS: There are significant quantitative differences among all TGAA assays that could affect interpretation of a positive test for CD. The overall false-positive rate for all assays was high in this population. Using the assay as a quantitative rather than qualitative tool by increasing the cutoff of positivity to indicate biopsy increases PPV. Multicenter workshops are needed to identify critical differences and to standardize TGAA assays among laboratories.