Questioning assent: how are children's views included as families make decisions about clinical trials?

BACKGROUND: Assent is used to take children's wishes into account when they are invited into clinical trials, but the concept has attracted considerable criticism. We investigated children's accounts of decision-making with the aim of informing practice in supporting children when invited to join a clinical trial. METHODS: We audio-recorded qualitative, semi-structured interviews with 22 children aged 8-16 years about being invited to take part in a clinical trial. Most children were interviewed with their parents. Analysis of the transcribed interviews examined the content of participants' accounts thematically, whilst also drawing on principles of discourse analysis, which examines how individuals use talk to achieve certain effects or social practices. RESULTS: It was not possible to separate children's knowledge of the clinical trial, or their decision-making processes from that of their parents, with parents taking a substantial mediating role in producing their children's decisions. Decision-making gradually unfolded across time and events and was interwoven within the family context, rather than happening in one moment or in the clinical setting. Whilst children valued their parents' role, a case study of child-parent disagreement indicated how children can struggle to be heard. CONCLUSIONS: Decisions happen within a process of family dynamics, in contrast to ideas of assent that isolate it from this context. Parents have a substantial role in children's decisions, and thus how families come to provide consent. Reflecting this we argue that assent practices need to focus on supporting parents to support their children in learning and deliberating about trials. However, this needs to be accompanied by practitioners being alert to the possibility of divergence in child and parent views and enabling children's perspectives to be heard.

Pharmacogenetics of warfarin in a paediatric population: time in therapeutic range, initial and stable dosing and adverse effects.

Warfarin is used in paediatric populations, but dosing algorithms incorporating pharmacogenetic data have not been developed for children. Previous studies have produced estimates of the effect of polymorphisms in Cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex subunit 1 (VKORC1) on stable warfarin dosing, but data on time in therapeutic range, initial dosing and adverse effects are limited. Participants (n=97) were recruited, and routine clinical data and salivary DNA samples were collected from all participants and analysed for CYP2C9*2, *3 and VKORC1-1639 polymorphisms.VKORC1 -1639 was associated with a greater proportion of the first 6 months' treatment time spent within the target International Normalised Ratio (INR) range, accounting for an additional 9.5% of the variance in the proportion of time. CYP2C9*2 was associated with a greater likelihood of INR values exceeding the target range during the initiation of treatment (odds ratio (OR; per additional copy) 4.18, 95% confidence interval (CI) 1.42, 12.34). CYP2C9*2 and VKORC1-1639 were associated with a lower dose requirement, and accounted for almost 12% of the variance in stable dose. VKORC1-1639 was associated with an increased likelihood of mild bleeding complications (OR (heterozygotes vs homozygotes) 4.53, 95% CI 1.59, 12.93). These data show novel associations between VKORC1-1639 and CYP2C9*2 and INR values in children taking warfarin, as well as replicating previous findings with regard to stable dose requirements. The development of pharmacogenomic dosing algorithms for children using warfarin has the potential to improve clinical care in this population.

Respiratory syncytial virus infection of airway epithelial cells, in vivo and in vitro, supports pulmonary antibody responses by inducing expression of the B cell differentiation factor BAFF.

BACKGROUND: The mechanisms regulating antibody expression within the human lung during airway infection are largely unknown. In this study, our objectives were to determine if infection with respiratory syncytial virus (RSV) upregulates expression of the B cell differentiation factors A proliferation inducing ligand (APRIL) and B cell activating factor of the TNF family (BAFF), if this is a common feature of viral airway infection, and how this is regulated in human airway epithelial cells. METHODS: We measured BAFF and APRIL protein expression in bronchoalveolar lavage (BAL) fluid from infants with severe RSV disease, and healthy control children, and in nasopharyngeal aspirates from preschool children with other single respiratory viral infections. We also measured mRNA expression in bronchial brushings from RSV-infected infants, and in RSV-infected paediatric primary airway epithelial cell cultures (pAEC). Beas-2B cell cultures were used to examine mechanisms regulating BAFF expression. RESULTS: BAFF protein and mRNA were elevated (in marked contrast with APRIL) in BAL and bronchial brushings, respectively, from RSV-infected infants. BAFF protein was also found in upper airway secretions from children with human metapneumovirus, H1N1, bocavirus, rhinovirus, RSV and Mycoplasma pneumoniae infection. BAFF mRNA and protein were expressed following in vitro RSV infection of both pAEC and Beas-2B cultures, with mRNA expression peaking 12-h postinfection. BAFF induction was blocked by addition of a neutralising anti-interferon-ß antibody or palivizumab. CONCLUSIONS: BAFF, produced through an interferon-ß-dependent process, is a consistent feature of airway infection, and suggests a role for the airway epithelia in supporting protective antibody and B cell responses in the lung.

Primary airway epithelial cultures from children are highly permissive to respiratory syncytial virus infection.

BACKGROUND: Respiratory syncytial virus (RSV) infection of airway epithelial cells (AECs) is an important initial event in RSV bronchiolitis. AEC immunological responses are thought to be critical in driving the subsequent inflammation in the airway. This study examined viral replication, cytotoxicity and cytokine production in cultures of primary AECs from children compared with responses to RSV infection in an immortalised epithelial cell line and to those from infants with RSV bronchiolitis. METHODS: RSV replication, proinflammatory cytokine responses and cytotoxicity in RSV-infected primary AEC cultures derived from bronchial brushings from the lungs of children were compared with those seen in BEAS-2B cultures, as well as AECs and bronchoalveolar lavage fluid collected from children with and without RSV bronchiolitis. RESULTS: Viral replication, cytotoxicity and inflammatory cytokine production were greater in primary AEC cultures than in BEAS-2B cells. Different response patterns were observed, with RSV infection of primary AEC cultures causing distinct peaks of viral replication and matched cytotoxic responses. Some primary AEC culture immunological responses, such as interleukin 8, were similar in magnitude to those seen in clinical samples from the lungs of children with RSV bronchiolitis. Although variable amounts of RSV were detected by PCR in freshly isolated primary AECs, RSV was not detected by immunocytochemistry. CONCLUSION: This is one of the first studies to examine comprehensively the responses to RSV infection in primary AEC cultures from children and shows marked differences from those of a commercially available immortalised human cell line but reassuring similarities to results found in vivo. This suggests that future work investigating responses of AECs to RSV infection should use primary AEC cultures.

Adverse drug reactions causing admission to a paediatric hospital: a pilot study.

WHAT IS KNOWN AND OBJECTIVE: It is known that adverse drug reactions (ADRs) cause admission to hospital in adults and children. A recent adult study showed that ADRs are an important and frequent cause of hospital admission. The objective of this study is to develop methodology to ascertain the current burden of ADRs through a prospective analysis of all unplanned admissions to a paediatric hospital. METHODS: Prospective observational study over a 2-week period. RESULTS AND DISCUSSION: There were 19 admissions to the main hospital wards related to an ADR, giving an estimated incidence of 4%, with the ADR directly leading to the admission in 71% of cases. There were no deaths attributable to ADR. 33% of the reactions were possibly avoidable. The drugs most commonly implicated in causing admissions were anti-neoplastic agents. The most common reactions were neutropenia, vomiting and diarrhoea. The health burden of ADRs in the paediatric population is likely to be significant. This pilot study will be used to inform a much larger prospective study providing more detailed evidence of the burden of ill-health from ADRs in children. This larger study will add to a body of research aiming to identify drug-related problems within children to aid paediatric pharmacovigilance. WHAT IS NEW AND CONCLUSION: This study provides knowledge regarding the methodology to be used for a larger study investigating ADRs in children. The study will allow authors who wish to replicate the study in their own populations (internationally) to avoid some of the pitfalls in planning a large epidemiological study of paediatric ADRs. The study also provides an estimate of the incidence and problem of admissions caused by ADRs in a UK paediatric population.

Perspectives of normal child development in rural Malawi - a qualitative analysis to create a more culturally appropriate developmental assessment tool.

BACKGROUND: Child development in developing countries is often evaluated using assessment tools created for 'Western' settings. Recent work has demonstrated that, for certain developmental milestones, 'Western' tools may be inaccurate as they include items unfamiliar to children of different cultural settings. METHODS: We used qualitative methods to gather information about normal development in an African setting. Ten village and two professional focus group discussions (FGDs) were conducted. We used purposive sampling methods to recruit groups of mothers, grandmothers and men in four areas of Southern Malawi for village FGDs. Separate FGDs were carried out with professionals working in areas relating to child development. A thematic content analysis established main patterns and themes and dissemination of results and continued feedback allowed for respondent validation and reflection of results. The information then gathered was used to create questions for a revised Malawian developmental assessment tool. RESULTS: Social and gross motor milestones were the main focus of interest for village and professional FGDs with the latter creating new language and fine motor concepts. Social milestones highlighted included 'duties and chores', 'sharing' and 'taking up leadership roles'. Language milestones included 'reporting events' and 'shrugging to indicate no' and fine motor milestones included 'peeling bananas', 'sorting maize' and 'making patterns with bottle tops'. Intelligence was described in relation to social and community integrity rather than 'Western' concepts of numeracy and literacy. CONCLUSIONS: Concepts, ideas and language relating to normal development in a sub-Saharan African setting have been gathered in this study. These have been used to create items for a more culturally appropriate developmental assessment tool.

Neutrophil TLR4 expression is reduced in the airways of infants with severe bronchiolitis.

BACKGROUND: In respiratory syncytial virus (RSV) bronchiolitis, neutrophils account for >80% of cells recovered from the airways in bronchoalveolar lavage (BAL) fluid. This study investigated neutrophil activation and Toll-like receptor (TLR) expression in the blood and lungs of infants with severe RSV bronchiolitis. METHODS: BAL fluid and (blood) samples were collected from 24 (16) preterm and 23 (15) term infants ventilated with RSV bronchiolitis, and 12 (8) control infants. Protein levels and mRNA expression of CD11b, myeloperoxidase (MPO) and TLRs 2, 4, 7, 8 and 9 were measured in neutrophils. RESULTS: Blood neutrophils had more CD11b in preterm and term infants with RSV bronchiolitis than control infants (p<0.025) but similar amounts of MPO. BAL fluid neutrophils from infants with RSV bronchiolitis had greater amounts of CD11b and MPO than blood neutrophils and BAL fluid neutrophils from controls (p<0.01). Blood neutrophils from term infants with RSV bronchiolitis had less total TLR4 protein than preterm infants with RSV bronchiolitis (p = 0.005), and both had less than controls (p<0.04). Total TLR4 for each group was greater in BAL fluid neutrophils than in blood neutrophils. Blood neutrophils from preterm infants with RSV bronchiolitis had greater TLR4 mRNA expression than term infants with RSV bronchiolitis (p = 0.005) who had similar expression to controls (p = 0.625). CONCLUSIONS: In infants with severe RSV bronchiolitis, neutrophil activation starts in the blood and progresses as they are recruited into the airways. Total neutrophil TLR4 remains low in both compartments. TLR4 mRNA expression is unimpaired. This suggests that neutrophil TLR4 expression is deficient in these infants, which may explain why they develop severe RSV bronchiolitis.

Reliability of calculating body mass index centile.

OBJECTIVE: Body mass index (BMI) centile is recommended for assessing body fatness in children. We compared the reliability of two methods of deriving BMI centile. METHOD: A total of 42 dietitians calculated the BMI centiles of six children, half using the Cole Calculator (a slide rule) and half calculating by hand and plotting on the BMI centile chart. RESULTS: The centile chart method was more reliable than the Cole Calculator, probably due to its greater familiarity.

Risk factors for obliterative bronchiolitis in heart-lung transplant recipients.

Obliterative bronchiolitis is the major cause of death of long-term survivors of heart-lung transplantation. Of our first 75 patients who have received heart-lung transplantation, 38 have been followed for a year or longer. Eight patients developed clinical evidence of obliterative bronchiolitis within 15 months of transplantation, of whom four died with postmortem confirmation of extensive obliterative bronchiolitis, interstitial and pleural fibrosis, and vascular sclerosis in the heart and lungs. One further patient died before one year after chronic rejection. All nine patients had evidence on transbronchial biopsy of submucosal fibrosis and vascular sclerosis. Twelve of our remaining patients have shown similar areas of lung fibrosis on transbronchial biopsy, and the other eighteen are well and without fibrosis on transbronchial biopsy. Studies of the 274 biopsies obtained from 38 patients confirmed rejection on 182 occasions with more frequent, more persistent, and more severe rejection in the chronic rejection group than in the without-fibrosis or lung fibrosis groups. Opportunistic infection resulted in pneumonia on 19 occasions, and were most commonly found in lung fibrosis patients. We conclude that obliterative bronchiolitis is the likely outcome in patients with early, poorly controlled, severe rejection.

Infection and reactivation with cytomegalovirus strains in lung transplant recipients.

Cytomegalovirus pneumonia is a major cause of morbidity and death following lung transplantation (LT) (1). The case fatality rate is highest in the CMV-seronegative recipients (R-) of organs from seropositive donors (D+), which suggests that transmission of CMV may occur with the graft (1), but in seropositive recipients (R+) the comparative importance of reactivation of endogenous virus and reinfection with donor virus is poorly understood.

Herpes simplex virus infection in heart-lung transplant recipients.

We report our experience of herpes simplex virus infection in a series of 51 recipients of heart lung transplantation (HLT). Nine patients, all of whom were seropositive for the virus preoperatively, developed HSV infection. Seven episodes of culture-proved mucocutaneous HSV infection without evidence of pulmonary involvement occurred in four patients. Six episodes of HSV pneumonia were seen in a further five patients, one of whom died. Diagnosis of HSV pneumonia was by histological appearances on transbronchial biopsy, together with culture of lung tissue or bronchoalveolar lavage. Concomitant cytomegalovirus infection occurred in four patients. All patients who developed HSV pneumonia did so within the first two postoperative months; in four patients following augmented immunosuppression. We now suggest that HLT recipients who are HSV antibody-positive should receive prophylactic acyclovir for the first two months after surgery and at times of augmented immunosuppression.

Transbronchial biopsies in children after heart-lung transplantation.

Sixty transbronchial biopsies have been performed in eight children after heart-lung transplantation. The selection of fiber-optic bronchoscope or a small (4 mm; 30 cm) rigid bronchoscope was made according to the size of endotracheal tube required at surgery. If the endotracheal tube was size 7.5 or greater, a fiber-optic bronchoscope was used, whereas if the endotracheal tube size was below 7, a rigid bronchoscope was used. For the diagnosis of lung rejection, the histology of biopsies revealed a sensitivity of 91% and specificity of 69% (similar to the result in adults). The histology also distinguished lung infection from rejection. Complications included three pneumothoraces and two clinically significant episodes of hemorrhage, one of which led to a cardiorespiratory arrest, which may have been caused by hypoxia. As a result, arterial oxygen saturation is now monitored during the procedure using a pulse oximeter.

Acute pulmonary hypertensive crisis in a patient with primary pulmonary hypertension treated by both epoprostenol (prostacyclin) and nitroprusside.

A 19-year-old girl was diagnosed as having primary pulmonary hypertension that was confirmed by right heart catheterization. Acute right heart failure was associated with syncope. Stabilization, while not achieved with intravenous epoprostenol (Prostacyclin) alone, was achieved with intravenous prostacyclin and nitroprusside.

Prospective study of transbronchial biopsies in the management of heart-lung and single lung transplant patients.

A prospective study of 219 bronchoscopies in 54 heart-lung and in 2 single lung transplant recipients was undertaken over a 12-month period by a single operator. For histologic study, an average of 17.3 transbronchial biopsy specimens (range, 6 to 56) were taken from three lobes (or from two lobes and lingula of one lung). A further two specimens were taken for culture. The average procedure time was 14.4 minutes (SE 0.31). An estimate of the probability of rejection being missed, depending on the number of specimens taken and based on the method of Gilman and Wang, suggests 18 biopsy specimens are required to have 95% confidence of diagnosing rejection. Sensitivity for diagnosing rejection by histologic study of transbronchial biopsy specimens was 94%, and specificity was 90%. The simple grading of severity of rejection that was used was related both to the number of specimens demonstrating rejection and to the severity of graft airway mucosal inflammation seen at bronchoscopy. The major complication encountered, on 27 occasions, was bleeding of more than 100 ml. On no occasion did bleeding result in any long-term complication. Extensive transbronchial biopsy is a simple, relatively safe, and quick procedure, with a high sensitivity and specificity for diagnosing rejection and lung infection.

Epstein-Barr virus infection in heart and heart-lung transplant recipients: incidence and clinical impact.

BACKGROUND: A retrospective serologic study was made of 67 heart-lung and 295 heart transplant recipients (with transplantations at Papworth Hospital, Cambridge, England) to determine the incidence and clinical impact of Epstein-Barr virus infection. METHODS: Epstein-Barr virus capsid antigen immunofluorescence tests were performed, and the antibody avidity was determined by modifying the washing procedure to include a mild reducing agent (8M urea). RESULTS: This testing showed that 6.0% of the patients had primary Epstein-Barr virus infections, whereas 17.4% had the reactivation of a past infection. Primary infections were only detected in patients who were Epstein-Barr virus antibody-negative before transplantation, who had received an organ from an Epstein-Barr virus antibody-positive donor. Of the patients with serologically proven Epstein-Barr virus infections, 52.9% had symptoms. Although these were generally mild, five heart and two heart-lung transplant recipients had malignant lymphoma and one heart and one heart-lung transplant recipient had lymphoproliferative disease after Epstein-Barr virus infection. Additional four heart transplant recipients had lymphoma after transplantation. None of these four patients had evidence of active Epstein-Barr virus infection; one was Epstein-Barr virus antibody-negative during the study period and three had stable Epstein-Barr virus virus capsid antigen immunoglobulin G titers throughout. CONCLUSIONS: Epstein-Barr virus infection in organ transplant recipients may lead on to life-threatening lymphoproliferative disease or lymphoma. For this reason it may be beneficial to monitor patients after transplantation for evidence of Epstein-Barr virus infection and to follow the progress of those affected.

Creon 10,000 Minimicrospheres vs. Creon 8,000 microspheres--an open randomised crossover preference study.

Creon 10,000 Minimicrospherestrade mark (Creon) 10,000 MMS) is a pancreatic enzyme formulation that contains smaller spheres of pancreatin in a 50% smaller capsule than conventional microspheres (Creon) 8,000). This three-centre study investigated the preference of cystic fibrosis (CF) patients for these products. In one centre, 72 h stool fat excretion and coefficient of fat absorption (CFA) were also compared. Fifty-nine patients with a mean age 10 years (range 3-17) took Creon 8,000 ms for 14 days and were then randomised to 28 days of Creon 8,000 ms followed by 28 days of Creon 10,000 MMS, or vice versa. Dosing was lipase for lipase according to the labelled declaration. At the end of the second treatment period, 51 of 54 patients who completed the study expressed a preference, with a statistically significant preference in favour of Creon 10,000 MMS (47/51; 87%) vs. Creon 8,000 ms (4/51; 7.4%; P<0.0001). Stool fat (g/day) and CFA (%) were measured in 24 patients at the end of each treatment period: the products were therapeutically equivalent (Creon 10,000: 8.4 g/day, 91.3% CFA; Creon 8,000: 6.7 g/day, 93.5% CFA). Both products were well tolerated. In conclusion, in CF children we found a clear preference for Creon 10,000 MMS compared with Creon 8,000 ms with no difference in fat absorption between the two products. Creon 10,000s smaller capsules are easier to take and should aid patient compliance.

Evidence-based pediatric pulmonary medicine: how can it help?

Evidence-based medicine aims to identify, critically appraise, and apply the best available evidence in making decisions about the care of patients. These aims are similar to those conscientious clinicians have always sought to achieve, but an evidence-based approach applies a systematic and rigorous methodology to this process to ensure that the evidence applied is relevant and of high quality. Because of the volume of potentially relevant information that needs to be accessed from the medical literature, many clinicians rely on reviews of the evidence. Systematic reviews provide summaries of the results of evidence-based healthcare, which can be made available to clinicians, healthcare administrators, and patients. The use of explicit, systematic methods in reviews limits bias (systematic errors) and reduces random errors (simple mistakes), thus providing reliable results on which to draw conclusions and make decisions. Meta-analysis is the use of statistical methods to summarize the results of independent studies. When used appropriately, meta-analysis can provide more precise estimates of the effects of healthcare than those derived from the individual studies included in a review. Childhood respiratory diseases can be a challenging area in which to undertake clinical research. These challenges include diagnostic uncertainty, lack of objective endpoints, and aspects of generalizability of randomized controlled trials. Despite these difficulties, there are now many examples of systematic reviews and evidence-based approaches in pediatric pulmonology. If applied appropriately, they can ensure that management of patients is based on clinically useful diagnostic tests and treatments that have been shown to be effective and not harmful.

Randomized controlled trials in cystic fibrosis (1966-1997) categorized by time, design, and intervention.

The improved prognosis of cystic fibrosis (CF) over the last three decades has been associated with an increased use of a range of treatments, but it is important that the use of an individual treatment is based on evidence. Well-designed randomized controlled trials (RCTs) are a robust method for evaluating the effectiveness of such treatments. We have developed a register of RCTs in CF and have studied when they were performed, their design, and what interventions were investigated. We identified 506 RCTs; 37.5% were identified solely as abstract reports in conference proceedings. There has been about a 30-fold increase in the number of RCTs in CF since 1966. A high proportion of the RCTs (72.7%) had a sample size of 30 or less, and only 8.7% were multicenter trials. Reporting of study design was poor: in 51.4% the report did not state whether there was any blinding in the trial design; 53.6% of studies were of crossover design. The most common interventions studied were antibiotic treatments and physiotherapy, but a number of commonly used therapies had been evaluated only in a small number of patients. Although the number of RCTs of interventions in CF patients has increased over the last 25 years, the sample sizes of these trials are generally too small to indicate whether the intervention was effective, and very few were multicenter. Future RCTs in CF are more likely to provide clinically useful answers if higher numbers of patients are recruited into large, well-designed multicenter trials. This should be a priority of the organization of future research in CF.

Time to publication as full reports of abstracts of randomized controlled trials in cystic fibrosis.

OBJECTIVES: To determine 1) what proportion of abstracts of randomized controlled trials (RCTs) presented at international conferences on cystic fibrosis (CF) are published as full reports, 2) time to publication, and 3) factors that might delay or prevent publication. METHODS: At the end of 1995, the Cochrane CF Group's register of RCTs contained 199 abstracts describing 180 RCTs. Abstracts were identified by handsearching 44 abstract books of three international CF conferences over a 30-year period. We searched the register for subsequent full reports of these RCTs and used survival analysis to investigate time to publication. Using the log-rank test, we examined 1) whether there is a difference in time to publication between reports where the investigators concluded that the test treatment was as effective as or better than the control treatment, and reports where it was not, and 2) whether there is a difference in time to publication according to sample size. RESULTS: Thirty-two percent of the 178 abstracts analyzed were subsequently published in full. Survival analysis indicated that the proportions published before 12 months, 2 years, and 5 years were 8.1%, 29%, and 40% respectively. No difference in time to publication was identified when the abstracts were stratified according to conclusions or sample size; no significant association (P > 0.05) existed between time to publication and both sample size and conclusions together. CONCLUSION: Only a small proportion of abstracts of RCTs presented at international conferences on CF are followed by full publication, and usually only after several years. Therefore, many potentially valuable studies do not reach a wide audience. However, we found no consistent factors which might delay or prevent publication.