P.J.E. Bindels

Use of uterine artery Doppler ultrasonography to predict pre-eclampsia and intrauterine growth restriction: a systematic review and bivariable meta-analysis

Background: Alterations in waveforms in the uterine artery are associated with the development of pre-eclampsia and intrauterine growth restriction. We investigated the predictive accuracy of all uterine artery Doppler indices for both conditions in the first and second trimesters. Methods: We identified relevant studies through searches of MEDLINE, EMBASE, the Cochrane Library and Medion databases (all records to April 2006) and by checking bibliographies of identified studies and consulting with experts. Four of us independently selected studies, extracted data and assessed study validity. We performed a bivariable meta-analysis of sensitivity and specificity and calculated likelihood ratios. Results: We identified 74 studies of pre-eclampsia (total 79 547 patients) and 61 studies of intrauterine growth restriction (total 41 131 patients). Uterine artery Doppler ultrasonography provided a more accurate prediction when performed in the second trimester than in the first-trimester. Most Doppler indices had poor predictive characteristics, but this varied with patient risk and outcome severity. An increased pulsatility index with notching was the best predictor of pre-eclampsia (positive likelihood ratio 21.0 among high-risk patients and 7.5 among low-risk patients). It was also the best predictor of overall (positive likelihood ratio 9.1) and severe (positive likelihood ratio 14.6) intrauterine growth restriction among low-risk patients. Interpretation: Abnormal uterine artery waveforms are a better predictor of pre-eclampsia than of intrauterine growth restriction. A pulsatility index, alone or combined with notching, is the most predictive Doppler index. These indices should be used in clinical practice. Future research should also concentrate on combining uterine artery Doppler ultrasonography with other tests.

Different definitions in childhood asthma: how dependable is the dependent variable?

There is abundant literature on how to select and statistically deal with predictors in prediction models. Less attention has been paid to the choice of the outcome. We assessed the impact of different asthma definitions on prevalence estimates and on the prediction models performances. We searched PubMed and extracted data of definitions used to diagnose childhood asthma (between 6 and 18 yrs) in cohort studies. Next, using data from an ongoing cohort study (n = 186), we constructed and compared four prediction models which all predict asthma at age 6 yrs, using a fixed set of predictors and four different definitions in turn. We defined an area of clinical indecision (posterior probability between 25% and 60%) and calculated the number of children who remained inside this area. 122 papers yielded 60 different definitions. Prevalence estimates varied between 15.1% and 51.1% depending on the asthma definition used. The percentage of children whose posterior asthma probability was in the area of clinical indecision varied from 14.9% to 65.3%. Variation in definitions and its effect on the performance of prediction models may be another source of otherwise inexplicable variation in daily clinical decision making. More uniformity of operational asthma definitions seems needed.

Adherence to inhaled corticosteroids in children with asthma and their parents

Poor adherence to inhaled corticosteroids (ICSs) may contribute to the recent rise in asthma morbidity. In general, appropriate adherence to ICSs is a complex process that is influenced by various determinants. The purpose of this study was to identify factors that were associated with adherence to ICSs in children with asthma and their parents in a multi-ethnic population in Amsterdam, the Netherlands. Two hundred and thirty-two children, aged 7-17 years, with paediatrician diagnosed asthma and their parents completed questionnaires examining socio-demographics, asthma control, knowledge of asthma and other determinants of adherence. Adherence to ICSs was assessed by self-report and pharmacy record data. We used logistic regression analyses to identify factors associated with adherence to ICSs in children and parents separately. We found no differences in adherence between the different ethnic groups. In the multivariate analysis for children, well-controlled asthma (OR: 4.12; CI: 1.50-11.3) was associated with poorer adherence, whereas positive subjective view of parents (OR: 0.45; CI:0.25-0.81) and self-efficacy (OR:0.51; CI: 0.35-0.75) were inversely associated with poorer adherence. A consistent result with the multivariate models for parents was the inversely significant association between poorer adherence and positive subjective view of parents to use ICSs (OR: 0.39; CI:0.19-0.77). Regardless of ethnic background, children positively stimulated by their parents to use ICSs showed a better adherence than children who experienced less positive influences. These results emphasise the importance of involving parents in the treatment of their childs asthma in order to enhance adherence to ICSs.

Antibiotic treatment is associated with reduced risk of a subsequent exacerbation in obstructive lung disease: an historical population based cohort study

Objectives: The risk of a subsequent exacerbation after treatment of an exacerbation with oral corticosteroids without (OS) or with (OSA) antibiotics was evaluated in a historical population based cohort study comprising patients using maintenance medication for obstructive lung disease. Methods: The Pharmo database includes drug dispensing records of more than 2 million subjects in The Netherlands. Eligible were patients ⩾50 years who in 2003 were dispensed ⩾2 prescriptions of daily used inhaled β2 agonists, anticholinergics and/or corticosteroids, and experienced at least one exacerbation before 1 January 2006. Exacerbation was defined as a prescription of OS or OSA. The times to the second and third exacerbations were compared using Kaplan–Meier survival analysis. Independent determinants of new exacerbations were identified using multivariable Cox recurrent event survival analysis. Results: Of 49 599 patients using maintenance medication, 18 928 had at least one exacerbation; in 52%, antibiotics had been added. The OS and OSA groups were comparable for potential confounding factors. Median time to the second exacerbation was 321 days in the OS group and 418 days in the OSA group (p<0.001); and between the second and third exacerbation 127 vs 240 days (p<0.001). The protective effect of OSA was most pronounced during the first 3 months following treatment (hazard ratio (HR) 0.62; 99% CI 0.60 to 0.65). In the OSA group, mortality during follow-up was lower (HR 0.82; 99% CI 0.66 to 0.98). Conclusion: Treatment with antibiotics in addition to oral corticosteroids was associated with a longer time to the next exacerbation, and a decreased risk of developing a new exacerbation.

Residential exposure to mould and dampness is associated with adverse respiratory health

Background Indoor exposure to mould and dampness is frequently associated with asthma symptoms with and without lung function changes. However, the mechanisms contributing to this threat to respiratory health are only partly understood.

Validation of a Single Concentration Methacholine Inhalation Provocation Test (SCIPT) in Children

A new method to assess bronchial hyperresponsiveness (BHR) using a single concentration methacholine has already been validated in adults with asthma. Because the geometrical dimensions of the airways in children are different, the results from studies in adults cannot be extrapolated to children. In this study, we validated the single concentration methacholine inhalation provocation test (SCIPT) in children. Twenty-two children performed three methacholine inhalation challenge tests in random order. Two challenges were performed according to the SCIPT: doubling doses (0.03–1.8 mg; maximal cumulated dose 3.6 mg) were administered with an Aerosol Provocation System (Masterscope, Jaeger). The third challenge was performed according to a standard dosimeter method (SDM): doubling doses (0.002–1.8 mg; maximal cumulative dose 3.5 mg) were administered with a DeVillbiss 646 nebulizer. The degree of BHR is expressed as a PD20. A difference of < 1.5 dose step was assumed to be due to intraindividual variation. We found an intraclass correlation of 0.91 between both tests according to the SCIPT and of 0.80 between the SCIPT and SDM. We found, according to the method of Bland and Altman, good agreement when comparing these two challenge tests. The single concentration inhalation provocation test is reproducible and shows good agreement with a standard dosimeter method to test bronchial responsiveness in children.

Health-Related Quality of Life in Children with Asthma from Different Ethnic Origins

This study aimed to identify and explain differences in health-related quality of life (QoL) between immigrant and non-immigrant children with asthma. In 274 children (7–17 years of age) generic and asthma-related QoL were assessed. The association between ethnicity and QoL was studied in linear regression model analyses. For the asthma-related QoL, unadjusted analyses showed significant ethnic differences. The non-immigrant children had the highest scores, which implies a better QoL. After adjusting for asthma control and socioeconomic status (SES), ethnic differences disappeared. These results suggest that immigrant children have a similar QoL to that of non-immigrant children from a comparable SES, when their asthma is under control.

Betekenis van klachten en symptomen voor de diagnostiek van acute infectieuze conjunctivitis: een systematisch literatuuronderzoek

SamenvattingRietveld RP, Van Weert HCPM, Ter Riet G, Bindels PJE. Betekenis van klachten en symptomen voor de diagnostiek van acute infectieuze conjunctivitis: een systematisch literatuuronderzoek. Huisarts Wet 2004;47(5):227-9.Inleiding Om bij een ‘pusoog’ selectiever antibiotica te kunnen voorschrijven, moet men een bacteriële van een virale conjunctivitis kunnen onderscheiden. Klachten en symptomen, zoals purulente afscheiding, worden verondersteld van diagnostische betekenis te zijn voor de oorzaak van acute infectieuze conjunctivitis. Wij doorzochten de literatuur naar bewijzen voor deze veronderstellingen.Methoden In PubMed, Embase, CINAHL, het Cochrane Controlled Trial Register, de literatuurlijst van de NHG-Standaard Het rode oog en van oogheelkundige leerboeken werd gezocht naar relevante artikelen. Wij sloten artikelen in waarin klachten of symptomen werden vergeleken met het resultaat van een bacteriële kweek.Resultaten Wij vonden geen artikelen waarin de betekenis van klachten en symptomen voor het onderscheid tussen een virale en bacteriële conjunctivitis werd onderzocht.Beschouwing Er is geen bewijs dat de huidige diagnostische criteria bruikbaar zijn voor het onderscheid tussen een virale en bacteriële conjunctivitis. Diagnostisch onderzoek is nodig om selectiever antibiotica voor te kunnen schrijven.Dit artikel is een bewerking van: Rietveld RP, Van Weert HCPM, Ter Riet G, Bindels PJE. Diagnostic impact of signs and symptoms in acute infectious conjunctivitis: systematic literature search (BMJ 2003;327:789). Publicatie gebeurt met toestemming van de uitgever.