Ashley P Jones

Meta-analysis of individual patient data versus aggregate data from longitudinal clinical trials

Background In clinical trials following individuals over a period of time, the same assessment may be made at a number of time points during the course of the trial. Our review of current practice for handling longitudinal data in Cochrane systematic reviews shows that the most frequently used approach is to ignore the correlation between repeated observations and to conduct separate meta-analyses at each of a number of time points. Purpose The purpose of this paper is to show the link between repeated measurement models used with aggregate data and those used when individual patient data (IPD) are available, and provide guidance on the methods that practitioners might use for aggregate data meta-analyses, depending on the type of data available. Methods We discuss models for the meta-analysis of longitudinal continuous outcome data when IPD are available. In these models time is included either as a factor or as a continuous variable, and account is taken of the correlation between repeated observations. The meta-analysis of IPD can be conducted using either a one-step or a two-step approach: the latter involves analysing the IPD separately in each study and then combining the study estimates taking into account their covariance structure. We discuss the link between models for use with aggregate data and the two-step IPD approach, and the problems which arise when only aggregate data are available. The methods are applied to IPD from 5 trials in Alzheimers disease. Results Two major issues for the meta-analysis of aggregate data are the lack of information about correlation coefficients and the effect of missing data at the patient-level. Application to the Alzheimers disease data set shows that ignoring correlation can lead to different pooled estimates of the treatment difference and their standard errors. Furthermore, the amount of missing data at the patient level can affect these estimates. Limitations The models assume fixed treatment effects across studies, and that any missing data is missing at random, both at the patient-level and the study level. Conclusions It is preferable to obtain IPD from all studies to correctly account for the correlation between repeated observations. When IPD are not available, the ideal aggregate data are model-based estimates of treatment difference and their variance and covariance estimates. If covariance estimates are not available, sensitivity analyses should be undertaken to investigate the robustness of the results to different amounts of correlation. Clinical Trials 2009; 6: 16—27. http:// ctj.sagepub.com

Melatonin for sleep problems in children with neurodevelopmental disorders: randomised double masked placebo controlled trial.

Objective To assess the effectiveness and safety of melatonin in treating severe sleep problems in children with neurodevelopmental disorders. Design 12 week double masked randomised placebo controlled phase III trial. Setting 19 hospitals across England and Wales. Participants 146 children aged 3 years to 15 years 8 months were randomised. They had a range of neurological and developmental disorders and a severe sleep problem that had not responded to a standardised sleep behaviour advice booklet provided to parents four to six weeks before randomisation. A sleep problem was defined as the child not falling asleep within one hour of lights out or having less than six hours’ continuous sleep. Interventions Immediate release melatonin or matching placebo capsules administered 45 minutes before the child’s bedtime for a period of 12 weeks. All children started with a 0.5 mg capsule, which was increased through 2 mg, 6 mg, and 12 mg depending on their response to treatment. Main outcome measures Total sleep time at night after 12 weeks adjusted for baseline recorded in sleep diaries completed by the parent. Secondary outcomes included sleep onset latency, assessments of child behaviour, family functioning, and adverse events. Sleep was measured with diaries and actigraphy. Results Melatonin increased total sleep time by 22.4 minutes (95% confidence interval 0.5 to 44.3 minutes) measured by sleep diaries (n=110) and 13.3 (−15.5 to 42.2) measured by actigraphy (n=59). Melatonin reduced sleep onset latency measured by sleep diaries (−37.5 minutes, −55.3 to −19.7 minutes) and actigraphy (−45.3 minutes, −68.8 to −21.9 minutes) and was most effective for children with the longest sleep latency (P=0.009). Melatonin was associated with earlier waking times than placebo (29.9 minutes, 13.6 to 46.3 minutes). Child behaviour and family functioning outcomes showed some improvement and favoured use of melatonin. Adverse events were mild and similar between the two groups. Conclusions Children gained little additional sleep on melatonin; though they fell asleep significantly faster, waking times became earlier. Child behaviour and family functioning outcomes did not significantly improve. Melatonin was tolerable over this three month period. Comparisons with slow release melatonin preparations or melatonin analogues are required. Trial registration ISRCT No 05534585.

Can Western developmental screening tools be modified for use in a rural Malawian setting

Objective: To create a more culturally relevant developmental assessment tool for use in children in rural Africa. Design: Through focus groups, piloting work and validation, a more culturally appropriate developmental tool, based on the style of the Denver II, was created. Age standardised norms were estimated using 1130 normal children aged 0–6 years from a rural setting in Malawi. The performance of each item in the tool was examined through goodness of fit on logistic regression, reliability and interpretability at a consensus meeting. The instrument was revised with removal of items performing poorly. Results: An assessment tool with 138 items was created. Face, content and respondent validity was demonstrated. At the consensus meeting, 97% (33/34) of gross motor items were retained in comparison to 51% (18/35) of social items, and 86% (69/80) of items from the Denver II or Denver Developmental Screening Test (DDST) were retained in comparison to 69% (32/46) of the newly created items, many of these having poor reliability and goodness of fit. Gender had an effect on 23% (8/35) of the social items, which were removed. Items not attained by 6 years came entirely from the Denver II fine motor section (4/34). Overall, 110 of the 138 items (80%) were retained in the revised instrument with some items needing further modification. Conclusions: When creating developmental tools for a rural African setting, many items from Western tools can be adapted. The gross motor domain is more culturally adaptable, whereas social development is difficult to adapt and is culturally specific.

The use of systematic reviews in the planning, design and conduct of randomised trials: a retrospective cohort of NIHR HTA funded trials

BackgroundA systematic review, with or without a meta-analysis, should be undertaken to determine if the research question of interest has already been answered before a new trial begins. There has been limited research on how systematic reviews are used within the design of new trials, the aims of this study were to investigate how systematic reviews of earlier trials are used in the planning and design of new randomised trials.MethodsDocumentation from the application process for all randomised trials funded by the National Institute for Health Research Health Technology Assessment (NIHR HTA) between 2006 and 2008 were obtained. This included the: commissioning brief (if appropriate), outline application, minutes of the Board meeting in which the outline application was discussed, full application, detailed project description, referee comments, investigator response to referee comments, Board minutes on the full application and the trial protocol. Data were extracted on references to systematic reviews and how any such reviews had been used in the planning and design of the trial.Results50 randomised trials were funded by NIHR HTA during this period and documentation was available for 48 of these. The cohort was predominately individually randomised parallel trials aiming to detect superiority between two treatments for a single primary outcome. 37 trials (77.1%) referenced a systematic review within the application and 20 of these (i.e. 41.7% of the total) used information contained in the systematic review in the design or planning of the new trial. The main areas in which systematic reviews were used were in the selection or definition of an outcome to be measured in the trial (7 of 37, 18.9%), the sample size calculation (7, 18.9%), the duration of follow up (8, 21.6%) and the approach to describing adverse events (9, 24.3%). Boards did not comment on the presence/absence or use of systematic reviews in any application.ConclusionsSystematic reviews were referenced in most funded applications but just over half of these used the review to inform the design. There is an expectation from funders that applicants will use a systematic review to justify the need for a new trial but no expectation regarding further use of a systematic review to aid planning and design of the trial. Guidelines for applicants and funders should be developed to promote the use of systematic reviews in the design and planning of randomised trials, to optimise delivery of new studies informed by the most up-to-date evidence base and to minimise waste in research.

The use of MElatonin in children with Neurodevelopmental Disorders and impaired Sleep: a randomised, double-blind, placebo-controlled, parallel study (MENDS).

BACKGROUND Difficulties in initiating and maintaining sleep are common in children with neurodevelopmental disorders. Melatonin is unlicensed in children yet widely prescribed for sleep problems. OBJECTIVE To determine whether or not immediate-release melatonin is beneficial compared with placebo in improving total duration of night-time sleep in children with neurodevelopmental problems. DESIGN Randomised, double-blind, placebo-controlled, parallel study. SETTING Hospitals throughout England and Wales recruited patients referred by community paediatricians and other clinical colleagues. PARTICIPANTS Children with neurodevelopmental problems aged from 3 years to 15 years 8 months who did not fall asleep within 1 hour of lights out or who had < 6 hours of continuous sleep. Before randomisation, patients meeting eligibility criteria entered a 4- to 6-week behaviour therapy period in which a behaviour therapy advice booklet was provided. Sleep was measured using sleep diaries and actigraphy. After this period the sleep diaries were reviewed to determine if the sleep problem fulfilled the eligibility criteria. Eligible participants were randomised and followed for 12 weeks. INTERVENTIONS Melatonin or placebo capsules in doses of 0.5 mg, 2 mg, 6 mg and 12 mg for a period of 12 weeks. The starting dose was 0.5 mg and the dose could be escalated through 2 mg and 6 mg to 12 mg during the first 4 weeks, at the end of which the child was maintained on that dose. MAIN OUTCOME MEASURES The primary outcome was total night-time sleep time (TST) calculated using sleep diaries at 12 weeks compared with baseline. Secondary outcome measures included TST calculated using actigraphy data, sleep-onset latency (SOL) (time taken to fall asleep), sleep efficiency, Composite Sleep Disturbance Index score, global measure of childs sleep quality, Aberrant Behaviour Checklist, Family Impact Module of the Pediatric Quality of Life Inventory (PedsQL™), the Epworth Sleepiness Scale, number and severity of seizures and adverse events. Salivary melatonin concentrations and association of genetic variants with abnormal melatonin production were also investigated. RESULTS A total of 275 children were screened to enter the trial; 263 (96%) children were registered and completed the 4- to 6-week behaviour therapy period and 146 (56%) children were randomised, of whom 110 (75%) contributed data for the primary outcome. The difference in TST time between the melatonin and placebo groups adjusted for baseline was 22.43 minutes [95% confidence interval (CI) 0.52 to 44.34 minutes; p = 0.04] measured using sleep diaries. A reduction in SOL, adjusted for baseline, was seen for melatonin compared with placebo when measured by sleep diaries (-37.49 minutes, 95% CI -55.27 to -19.71 minutes; p < 0.0001) and actigraphy (-45.34 minutes, 95% CI -68.75 to -21.93 minutes; p = 0.0003). There were no significant differences between the two groups in terms of the reporting of adverse events. The results of other secondary outcomes favoured melatonin but were not statistically significant. CONCLUSIONS On average, the children treated with melatonin slept 23 minutes longer than those in the placebo group; however, the upper limit of the confidence interval was less than 1 hour, the minimum clinically worthwhile difference specified at the outset of the trial. Melatonin is effective in reducing SOL in children with neurodevelopmental delay by a mean of 45 minutes; a value of 30 minutes was specified a priori to be clinically important. Future studies should be conducted over longer periods and directly compare different formulations of melatonin with conventional hypnotic and sedative medications. It would also be important to study groups of children with specific neurological disorders. TRIAL REGISTRATION Current Controlled Trials ISRCTN05534585. FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 16, No. 40. See the HTA programme website for further project information.

A predominantly anti-inflammatory cytokine profile is associated with disease severity in meningococcal sepsis

ObjectiveThis study aimed to determine whether an anti-inflammatory profile in meningococcal disease is associated with an increased risk of severe disease or septic shock.Design and settingProspective observational study in a tertiary care children’s hospital.Patients and participants63 children with confirmed meningococcal disease.InterventionsPlasma concentrations of interleukin-1 receptor antagonist (IL-1Ra), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor-α (TNF) were assayed on admission. Receiver operator characteristic curve analysis was used to determine optimum thresholds for IL-1Ra:TNF, IL-1Ra:IL-6 and IL-1Ra:IL-8 ratios.Measurements and resultsMedian IL-1Ra:TNF and IL-1Ra:IL-6 ratios were significantly higher in severe disease with septic shock than in severe disease without septic shock and in non severe disease (IL-1Ra:TNF 263 vs. 185 vs. 108; IL-1Ra:IL-6 139 vs. 23 vs. 17). Median IL-1Ra:IL-8 ratios were not significantly different in the three groups. A significantly larger proportion of children with high IL-1Ra:TNF-α and IL-1Ra:IL-6 ratios developed severe disease with septic shock than those with a low ratios (95.2% vs. 4.8%; 76.2% vs. 23.8%).ConclusionsAn anti-inflammatory profile appears to be associated with the development of severe disease and septic shock in meningococcal sepsis. This may imply that experimental new therapies of pro-inflammatory cytokine inhibition and anti-inflammatory cytokines in meningococcal disease could be detrimental.

Adalimumab plus Methotrexate for Uveitis in Juvenile Idiopathic Arthritis

BACKGROUND Adalimumab, a fully human anti–tumor necrosis factor α monoclonal antibody, is effective in the treatment of juvenile idiopathic arthritis (JIA). We tested the efficacy of adalimumab in the treatment of JIA‐associated uveitis. METHODS In this multicenter, double‐blind, randomized, placebo‐controlled trial, we assessed the efficacy and safety of adalimumab in children and adolescents 2 years of age or older who had active JIA‐associated uveitis. Patients who were taking a stable dose of methotrexate were randomly assigned in a 2:1 ratio to receive either adalimumab (at a dose of 20 mg or 40 mg, according to body weight) or placebo, administered subcutaneously every 2 weeks. Patients continued the trial regimen until treatment failure or until 18 months had elapsed. They were followed for up to 2 years after randomization. The primary end point was the time to treatment failure, defined according to a multicomponent intraocular inflammation score that was based on the Standardization of Uveitis Nomenclature criteria. RESULTS The prespecified stopping criteria were met after the enrollment of 90 of 114 patients. We observed 16 treatment failures in 60 patients (27%) in the adalimumab group versus 18 treatment failures in 30 patients (60%) in the placebo group (hazard ratio, 0.25; 95% confidence interval [CI], 0.12 to 0.49; P<0.0001 [the prespecified stopping boundary]). Adverse events were reported more frequently in patients receiving adalimumab than in those receiving placebo (10.07 events per patient‐year [95% CI, 9.26 to 10.89] vs. 6.51 events per patient‐year [95% CI, 5.26 to 7.77]), as were serious adverse events (0.29 events per patient‐year [95% CI, 0.15 to 0.43] vs. 0.19 events per patient‐year [95% CI, 0.00 to 0.40]). CONCLUSIONS Adalimumab therapy controlled inflammation and was associated with a lower rate of treatment failure than placebo among children and adolescents with active JIA‐associated uveitis who were taking a stable dose of methotrexate. Patients who received adalimumab had a much higher incidence of adverse events and serious adverse events than those who received placebo. (Funded by the NIHR Health Technology Assessment Programme and Arthritis Research UK; SYCAMORE EudraCT number, 2010–021141–41.)

Does Deworming Improve Growth and School Performance in Children

Background The World Bank ranks soil-transmitted helminth infection as causing more ill health in children aged 5–15 years than any other infection. In light of this ranking, global agencies recommend regular, mass treatment with deworming drugs to children in developing countries. The World Health Organization (WHO) argues that “deworming helps meet the Millennium Development Goals”, in particular the six health-related goals:eradicate extreme poverty and hunger;achieve universal primary education;promote gender equality and empower women;reduce child mortality and improve maternal health; and combat HIV/AIDS, malaria, and other diseases. However, deworming campaigns cost money to deliver, and so we must be clear that WHO statements about the impact of these programmes are based on reliable evidence. In 2000, we systematically reviewed the reliable evidence from relevant controlled trials about the effects of anthelminth drugs for soil-transmitted helminth infection on child growth and cognition. This systematic review, published in The Cochrane Database and the BMJ, demonstrated uncertainty around the assumed benefit and concluded that it may be a potentially important intervention, but needed better evaluation. The BMJ published a large number of letters that criticised the findings, including from authors at the World Bank, the WHO, the United States Centers for Disease Control and Prevention, and the Pan American Health Organization. We do not feel that these criticisms were scientifically substantive enough to undermine the method or the conclusion. For example, several critics commented on the fact that the systematic review could not make any conclusions about the long-term effects of treatment—but, as we argued in our reply to these criticisms, “we were unable to find any randomised controlled trials that evaluated long term benefit, and the evidence of short term benefit was not, for us, convincing.” The research community quite correctly carried out further randomised controlled trials (RCTs) of repeated doses in community trials with longer follow-up compared with no intervention or placebo. In light of this additional research, we have now updated the original Cochrane review. An author of one of the trials included in the 2000 review, Ed Cooper, criticised the review for not taking into account heterogeneity in parasite burdens. Therefore, in the recently updated review, we conducted an additional subgroup analysis at trial level stratified by worm intensity and prevalence.

Feasibility study to inform the design of a randomised controlled trial to eradicate Pseudomonas aeruginosa infection in individuals with Cystic Fibrosis

BackgroundThere are controversies about the most effective treatment to eradicate first growth of Pseudomonas aeruginosa (P aeruginosa) from the lower airways of patients with cystic fibrosis (CF). UK guidelines recommend oral treatment, but some advocate intravenous (IV) treatment. The objective of this study was to assess the feasibility of conducting a randomised controlled trial comparing two treatment strategies to eradicate P aeruginosa in CF patients.Methods/Principal FindingsTwo surveys were conducted. Survey [1] included clinicians who were responsible for the treatment of individuals with CF, to assess their clinical practice, opinions and numbers of potentially eligible patients. Survey [2] included adults and young people aged 13 years or more with CF and parents of children with CF aged less than 13 years, identified at six UK CF centres, who fulfilled eligibility criteria for the proposed clinical trial, to assess their views about the interventions and their willingness to participate in the trial. Generally clinicians treat first or new growth of P aeruginosa with oral antibiotics, but 90% reported that they would consider IV treatment of first isolation of P aeruginosa. 74% of clinicians would consider recruiting their patients and 45% of consumers would consider entry for themselves or their children into a trial comparing oral with intravenous antibiotics. The median rate per annum for first or new growths of P aeruginosa in adults was 3% (range 1% to 9%) and in children was 10% (range 3% to 23%). If the trial was conducted across the UK, with a consent rate of 45%, then the number of eligible patients per annum who would be willing to take part in a study would be approximately 41 adults and 203 children.ConclusionsThis work demonstrates the importance of feasibility studies in preparation for multicentre clinical trials. It confirmed the uncertainty amongst clinicians and patients about the clinical question, enabled assessment of the number of potentially eligible patients, the proportion of patients and clinicians prepared to participate and aspects of trial design which might encourage this. It showed that a clinical trial was feasible, but only if patients were recruited from across United Kingdom.

Risk-proportionate clinical trial monitoring: an example approach from a non-commercial trials unit

BackgroundSome level of monitoring is usually required during a clinical trial to protect the rights and safety of trial participants and to safeguard the quality and reliability of trial results. Although there is increasing support for the use of risk-proportionate approaches to achieve these aims, the variety of methods and lack of an empirical evidence base can present challenges for clinical trial practitioners.MethodsThis paper describes the monitoring methods and procedures that are utilised by a non-commercial clinical trials unit which coordinates a range of clinical trials across a variety of clinical areas with different associated risks.ResultsMonitoring activities and approaches should be selected to be proportionate to the risks identified within a trial. A risk-proportionate approach to monitoring is described giving details of methods that may be considered by clinical trial practitioners during the development of a trial monitoring plan. An example risk assessment and corresponding monitoring plan for a low risk (type A in the Medicines and Healthcare Products Regulatory Agency (MHRA) classification system) pediatric trial is provided for illustration.ConclusionWe present ideas for developing a monitoring plan for a clinical trial of an investigational medicinal product based on our experience. Alternative approaches may be relevant or preferable in other settings based on inherent risk.