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.     

Medullary Nuclear Dysplasia (Möbius Syndrome) in an Infant with Recurrent Apnea and Jsoelectric Eeg

From birth, an infant girl had repeated episodes of loss of consciousness, apnea and bradycardia, aphonia, and severe pharyngeal-esophageal discoordination. These functional deficits correlated with a gross and microscopic malformation of the medulla oblongata, which is characterized by profound deficits of motor and sensory nuclei and of the reticular formation. We have classified this as an example of Mobius syndrome. No etiology was suggested from the history. Histopathologic findings are compatible with an early massive insult to developing structures in the tegmentum of the medulla oblongata.     

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.     

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.     

The Parkland Memorial Hospital experience in ensuring compliance with Universal Newborn Hearing Screening follow-up

OBJECTIVE: Reduce false-positive results and loss to follow-up through systematic modifications in Universal Newborn Hearing Screening at a large public hospital. STUDY DESIGN: During a pilot program, neonates who failed technician-performed automated auditory brain stem response were scheduled for diagnostic evaluation. In year 1, audiologists rescreened neonates who failed, and those who did not pass were screened as outpatients. For years 2 through 4, neonates who failed were rescreened by technicians before inpatient audiology rescreening. RESULTS: For the pilot, 3759 neonates were screened; 1% (n = 43) failed and 44% (n = 19) were lost to follow-up. In year 1, 15,297 neonates were screened and 2% (n = 365) failed; audiology rescreening reduced this to <1% (n = 129). Outpatient rescreening yielded 0.5% (n = 70) who failed; 17% (n = 12) were lost to follow-up. In year 2, 16,384 neonates were screened, 3% (n = 456) failed, and 1% (n = 167) failed after technician rescreen; audiology rescreening reduced inpatient fails to 0.6% (n = 108), and 0.4% (n = 61) failed outpatient rescreening; 11% (n = 7) were lost to follow-up. Results for years 3 and 4 were similar to year 2, with further reduction in loss to follow-up to 11% (n = 6) and 1.7% (n = 1). CONCLUSIONS: Successful Universal Newborn Hearing Screening with reduced false-positive results and loss to follow-up can be accomplished with a planned schedule of inpatient rescreens and outpatient rescreening at the birthing facility.     

Reversible changes in cerebral activity associated with acidosis in preterm neonates

Murdoch Eaton DG, Wertheim D, Oozeer R, Dubowitz LMS, Dubowitz V. Reversible changes in cerebral activity associated with acidosis in preterm neonates. Acta Paediatr 1994;83:486–92. Stockholm. ISSN 0803–5253
Computerized online EEG monitoring in ventilated preterm infants less than 32 weeks' gestation enabled evaluation of the effect of acidosis on cerebral function. All episodes of acidosis were found to be associated with changes in the levels of cerebral activity. In 21 of the 32 episodes, EEG activity returned to pre-acidosis levels after therapeutic intervention. The duration of EEG abnormality was related to the severity of acidosis. However, the time to recovery of the EEG after therapeutic procedures was not related to duration of the EEG change.