Demystification of commonly used measurements in paediatrics

Dit proefschrift gaat over een aantal metingen die vaak gedaan worden binnen mijn vakgebied, de kindergeneeskunde. Dokters worden opgevoed met het adagium “meten is weten”. In dit proefschrift probeer ik deze stelling aan een kritisch oordeel te onderwerpen: Is meten wel weten?In dit proefschrift onderzoek ik de betrouwbaarheid en het nut van vijf veelgebruikte metingen of procedures binnen de kindergeneeskunde, namelijk het meten van glucose in de urine uit luiers van pasgeborenen met behulp van test-strips, de diagnostische waarde van klinische symptomen (inclusief glucosurie) bij het opsporen van ernstige infecties bij prematuren, de vochtbalans bij zieke pasgeborenen, de beoordeling van de mate van benauwdheid bij kinderen en het gebruik van virale testen bij bronchiolitis.Alleen de meting van glucosurie met behulp van test-strips bleek in de door ons uitgevoerde studies (onder enkele voorwaarden) betrouwbaar, de overige metingen of procedures waren onvoldoende precies of bleken onvoldoende nuttig te zijn in de klinische praktijk.Samenvattend klopt het adagium “meten is weten” dus lang niet altijd; eigenlijk klopt het alleen onder de voorwaarde dat je weet wat, hoe, wie en waarom je meet! Meten is weten , maar met onzekerheid! Daarnaast blijkt uit dit proefschrift dat het nuttig kan zijn om veel gebruikte, routinematige metingen onder de loep te nemen. We willen benadrukken dat onze evidence-based practice een belangrijke rol heeft gespeeld bij het creëren van een een zelf-kritische en nieuwsgierige houding een belangrijke rol heeft gespeeld bij het tot stand komen van dit proefschrift.Measurements are essential In medical practice. Throughout their training, doctors are taught the adage “meten is weten” (the knowledge is in the numbers). In this thesis we evaluated various diagnostic measurements in paediatrics – across a wide age range, from neonates to older children – aimed at clarifying (demystifying) these commonly used procedures. We discuss the general aspects of uncertainty in medicine, since uncertainty is a major reason for performing diagnostic tests in the first place. Furthermore we explain the way evidence-based medicine (EBM) may help doctors to deal with this feeling of uncertainty.The measurements investigated in this thesis are: 1) test strips for measurement of glucosuria in neonates, 2) diagnostic value of various clinical signs, including glucosuria, in identifying late-onset sepsis in premature neonates, 3) fluid-balance charts in neonates, 4) clinical assessment of severity of dyspnoea in children and 5) viral tests to identify and isolate RSV-infected infants hospitalised for bronchiolitis, for the purpose of reducing nosocomial cross-infection.Apart from the test strips for measurement of glucosuria, all measurements or procedures we have investigated appeared to be too imprecise or of insufficiently useful in clinical practice.In general we conclude that the adage “meten is weten” (the knowledge is in the numbers) still holds true, provided that one knows what is being measured, how the measurement is performed, by whom, and for what reason. Furthermore we would like to emphasize the importance of investigating common or routine procedures, and the role EBM has played when investigating this theme

Clinical Scores for Dyspnoea Severity in Children:A Prospective Validation Study

In acute dyspnoeic children, assessment of dyspnoea severity and treatment response is frequently based on clinical dyspnoea scores. Our study aim was to validate five commonly used paediatric dyspnoea scores.Fifty children aged 0-8 years with acute dyspnoea were clinically assessed before and after bronchodilator treatment, a subset of 27 children were videotaped and assessed twice by nine observers. The observers scored clinical signs necessary to calculate the Asthma Score (AS), Asthma Severity Score (ASS), Clinical Asthma Evaluation Score 2 (CAES-2), Pediatric Respiratory Assessment Measure (PRAM) and respiratory rate, accessory muscle use, decreased breath sounds (RAD).A total of 1120 observations were used to assess fourteen measurement properties within domains of validity, reliability and utility. All five dyspnoea scores showed overall poor results, scoring insufficiently on more than half of the quality criteria for measurement properties. The AS and PRAM were the most valid with good values on six and moderate values on three properties. Poor results were mainly due to insufficient measurement properties in the validity and reliability domains whereas utility properties were moderate to good in all scores.This study shows that commonly used dyspnoea scores show insufficient validity and reliability to allow for clinical use without caution

Glucosuria as an early marker of late-onset sepsis in preterms:a prospective cohort study

Background: Early and accurate diagnosis of late-onset sepsis (LONS) in preterm infants is difficult since presenting signs are subtle and non-specific. Because neonatal sepsis may be accompanied by glucose intolerance and glucosuria, we hypothesized that glucosuria may be associated with LONS in preterms, in an early stage. We aim to evaluate the association of glucosuria and late-onset neonatal sepsis (LONS) in preterm infants, in an attempt to improve early and accurate diagnosis of LONS. Methods: We performed a prospective observational cohort study in 316 preterms ( Results: Glucosuria was found in 65.8 % of 316 preterm patients, and sepsis was suspected 157 times in 123 patients. LONS was found in 47.1 % of 157 suspected episodes. The presence of glucosuria was associated with LONS (OR 2.59, 95 % CI 1.24-5.43, p = 0.012) with sensitivity 69.0 % and specificity 53.8 % (Likelihoodratio 1.49). After adjustment for gestational age, birth weight, and postnatal age, this association weakened and was no longer significant (adjusted OR 2.16; 95 % CI 0.99-1.85, p = 0.055). An increase in glucosuria 48-24 h before onset of symptoms was not associated with LONS. Conclusion: In preterms glucosuria is associated with LONS within 24 h, however this association is too weak to be of diagnostic value

Impact of deliberate practice on evidence-based medicine attitudes and behaviours of health care professionals

Introduction Although evidence-based medicine (EBM) teaching activities may improve short-term EBM knowledge and skills, they have little long-term impact on learners' EBM attitudes and behaviour. This study examined the effects of learning EBM through stand-alone workshops or various forms of deliberate EBM practice. Methods We assessed EBM attitudes and behaviour with the evidence based practice inventory questionnaire, in paediatric health care professionals who had only participated in a stand-alone EBM workshop (controls), participants with a completed PhD in clinical research (PhDs), those who had completed part of their paediatric residency at a department (Isala Hospital) which systematically implemented EBM in its clinical and teaching activities (former Isala residents), and a reference group of paediatric professionals currently employed at Isala's paediatric department (current Isala participants). Results Compared to controls (n = 16), current Isala participants (n = 13) reported more positive EBM attitudes (p < 0.01), gave more priority to using EBM in decision making (p = 0.001) and reported more EBM behaviour (p = 0.007). PhDs (n = 20) gave more priority to using EBM in medical decision making (p < 0.001) and reported more EBM behaviour than controls (p = 0.016). Discussion Health care professionals exposed to deliberate practice of EBM, either in the daily routines of their department or by completing a PhD in clinical research, view EBM as more useful and are more likely to use it in decision making than their peers who only followed a standard EBM workshop. These findings support the use of deliberate practice as the basis for postgraduate EBM educational activities

Reliability of Reagent Strips for Semi-quantitative Measurement of Glucosuria in a Neonatal Intensive Care Setting

Background: Glucosuria in preterm infants is often measured using a visually readable reagent strip, e.g., when monitoring total parenteral nutrition or during sepsis or when treating with corticosteroids. However, the specific circumstances in a neonatal intensive care unit (NICU), such as the use of diapers and the high temperature in incubators, could affect its reliability. Objectives: To evaluate the reliability of the semi-quantitative measurement of glucosuria under the specific circumstances of a NICU setting. Methods: Nine hundred assessments of artificially supplemented (contrived) urine samples, intended to simulate pathological specimens, were performed under the following varying conditions: environmental temperature (21 degrees C and 34 degrees C); different times of contact of the urine with the diaper; and using two different methods of collecting urine from the diaper. Each reagent strip was read independently by three observers. The test strips scores were categorized as 0, 1+, 2+, 3+, or 4+ in ascending degree of glucosuria. Results: Agreement was excellent under all the different conditions (temperature, weighted kappa (kappa(w)) = 0.92; method of urine collection, kappa(w) = 0.88; time, p = 0.266). Inter-observer reliability was very good (multi-rater kappa = 0.81). The deviation between the different conditions was seldom larger than one category (2.94 The reagent strip readings were concordant with the true urinary glucose concentrations in 79.0% of assessments. The discordance was never larger than one category. Conclusion: The reliability of the semi-quantitative measurement of glucosuria in newborn infants using reagent strips is good, even under the conditions of a NICU. Changes in the rating of reagent strips of more than one category are most likely to be beyond measurement error

Inborn Errors of Metabolism That Cause Sudden Infant Death:A Systematic Review with Implications for Population Neonatal Screening Programmes

BACKGROUND: Many inborn errors of metabolism (IEMs) may present as sudden infant death (SID). Nowadays, increasing numbers of patients with IEMs are identified pre-symptomatically by population neonatal bloodspot screening (NBS) programmes. However, some patients escape early detection because their symptoms and signs start before NBS test results become available, they even die even before the sample for NBS has been drawn or because there are IEMs which are not included in the NBS programmes. OBJECTIVES AND METHODS: This was a comprehensive systematic literature review to identify all IEMs associated with SID, including their treatability and detectability by NBS technologies. Reye syndrome (RS) was included in the search strategy because this condition can be considered a possible pre-stage of SID in a continuum of aggravating symptoms. RESULTS: 43 IEMs were identified that were associated with SID and/or RS. Of these, (1) 26 can already present during the neonatal period, (2) treatment is available for at least 32, and (3) 26 can currently be identified by the analysis of acylcarnitines and amino acids in dried bloodspots (DBS). CONCLUSION: We advocate an extensive analysis of amino acids and acylcarnitines in blood/plasma/DBS and urine for all children who died suddenly and/or unexpectedly, including neonates in whom blood had not yet been drawn for the routine NBS test. The application of combined metabolite screening and DNA-sequencing techniques would facilitate fast identification and maximal diagnostic yield. This is important information for clinicians who need to maintain clinical awareness and decision-makers to improve population NBS programmes