Browsing by Subject "Child Health"

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    Open Access
    A comparison of the accuracy of various methods of postnatal gestational age estimation; including Ballard score, foot length, vascularity of the anterior lens, last menstrual period and also a clinician's non-structured assessment
    (2020) Stevenson, Alexander Graham; Tooke, Lloyd; Joolay, Yaseen
    Rationale Gestational age is a strong determinant of neonatal mortality and morbidity. Early obstetric ultrasound is the clinical reference standard, but is not widely available in many developing countries. There is a well recognised need to identify reliable and simple methods of postnatal gestational age estimation. Methods A prospectively designed methods comparison study in a tertiary referral hospital in a developing country. Early ultrasound (<20 weeks) was the clinical reference standard. Methods evaluated included anthropometric measurements (including foot-length), vascularity of the anterior lens, the New Ballard Score and Last Menstrual Period. Clinicians' non-structured global impression “End of Bed” Assessment was also evaluated. Results 106 babies were included in the study. Median age at birth was 34 weeks (IQR 29-36). Ballard Score and “End of Bed” Assessment had a mean bias of -0.14 and 0.06 weeks respectively but wide 95% limits of agreement. The physical component of the Ballard score, the total Ballard score and Foot-length's ability to discriminate between term and preterm infants gave an AUROC of 0.97, 0.96 and 0.95 respectively. Discussion Although “End of Bed” Assessment and Ballard score had small mean biases, the wide confidence intervals render the methods irrelevant in clinical practice. Foot-length was particularly poor in Small for Gestational Age infants. None of the methods studied were superior to a non-structured clinician's informal “End of Bed” Assessment. Conclusion None of the methods studied met the a priori definition of clinical usefulness. Improving access to early ultrasound remains a priority. Instead of focusing on chronological accuracy, future research should compare the ability of early ultrasound and Ballard score to predict morbidity and mortality.
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    Open Access
    Evaluation of a knemometer
    (1996) Zöllner, Ekkehard Werner Arthur; Bonnici, Francois
    Knemometry is a sensitive technique to measure lower leg length. It has been utilised in the assessment of short-term growth. Knemometry is compared to other indicators of early growth. Its uses and limitations are highlighted. 11 The acquisition of a knemometer necessitated a study to establish the reliability and the validity of its measurements, to compare two different recommended measuring procedures and to establish whether repositioning the child between readings is necessary. Forty-four healthy children ranging in age from 5,2 - 10,9 years were enrolled. Measurements were done by a single observer. The lower leg of each child was measured by a series of 3x3 readings called "measuring procedure 1" (MP1), followed by a series of 4 readings, the child being repositioned between each reading, called "measuring procedure 2" (MP2). Ten metal rods were measured at the start of each measuring day (314,90 - 449,90mm) to assess validity of the measurements. The mean standard deviation (SD) of the measurements performed on children was 0,4mm and the coefficient of variation (CV) 0,1%, irrespective of the measuring procedure. Rod measurements yielded corresponding values of0,13mm and 0,03%. The SD tended to increase with increasing length of rods (rod size 404,90 to 449,90mm). The measurement bias was -0,26mm, except for rod size 345mm (+0,07mm). The standard error of the mean when measuring children was lower for MP2 (0,20mm) than for MP1 (0,25mm). Outliers were distributed at random among the readings. Data analysis by one way ANOVA showed that it may be advantageous to reposition the subject in between readings. The results confirm that the knemometer is a sensitive instrument. Most of the variation in the measurements was attributable to the subjects, rather than the instrument. This could be explained by unidentified minor movements and by the relative "elasticity" of the children compared to the rods. The knemometer is less reliable in the upper range of measurement when rods are measured. The bias is not consistent, reflecting a possible weakness in the construction. Inspection identified the coupling arm of the knee plate as a possible source. Because outliers cannot be excluded while performing routine measurements, the 95th percentile for SD affords reasonable protection against their inclusion. It is recommended that 4 independent readings should be taken to establish a measurement and that the first reading should not be excluded. The whole series of readings should be repeated if the SD is >0,65mm. Users need to be aware of the construction flaw in the make of the instrument tested.