Useful pharmacodynamic endpoints in children: selection, measurement, and next steps.

Pharmacodynamic (PD) endpoints are essential for establishing the benefit-to-risk ratio for therapeutic interventions in children and neonates. This article discusses the selection of an appropriate measure of response, the PD endpoint, which is a critical methodological step in designing pediatric efficacy and safety studies. We provide an overview of existing guidance on the choice of PD endpoints in pediatric clinical research. We identified several considerations relevant to the selection and measurement of PD endpoints in pediatric clinical trials, including the use of biomarkers, modeling, compliance, scoring systems, and validated measurement tools. To be useful, PD endpoints in children need to be clinically relevant, responsive to both treatment and/or disease progression, reproducible, and reliable. In most pediatric disease areas, this requires significant validation efforts. We propose a minimal set of criteria for useful PD endpoint selection and measurement. We conclude that, given the current heterogeneity of pediatric PD endpoint definitions and measurements, both across and within defined disease areas, there is an acute need for internationally agreed, validated, and condition-specific pediatric PD endpoints that consider the needs of all stakeholders, including healthcare providers, policy makers, patients, and families.

Risk of bias in randomized trials of pharmacological interventions in children and adults.

OBJECTIVE: To determine whether randomized controlled trials of pharmacologic interventions in children are more likely to be biased than similar trials in adults. STUDY DESIGN: Trials involving only children and published in MEDLINE between January 2008 and October 2009 (n=100) were randomly selected and matched, by drug class and therapeutic area, with a similar trial completed in adults. The Cochrane risk of bias tool was used to compare the pediatric and adult trials. RESULTS: The characteristics of adult and pediatric trials included were similar, except that adult studies were more likely to be conducted in Europe and published in specialty journals. Two-thirds of all trials were single center, and 62% had 100 or fewer participants. Many trials had an unclear risk of bias for allocation concealment (65% adult, 52% pediatric). More pediatric trials had a low risk of bias for random sequence generation (59% pediatric, 41% adult, P=.002) and blinding of outcome assessment (63% pediatric, 48% adult, P=.04) than adult trials; however, a sensitivity analysis of trials published since 2008 (and so matched by year of publication) did not confirm this finding, suggesting year of publication was an important confounder. CONCLUSIONS: When randomized controlled trials are matched for drug class and therapeutic area, trials involving children display a similar risk of bias. Differences in the risk of bias between pediatric and adult trials are not caused by differences in the capacity of researchers to conduct and report trials of high quality.

A national study of the processes and outcomes of paediatric formulary applications in Australia.

OBJECTIVE: To evaluate the processes by which pharmaceuticals are added to the formularies of Australian paediatric hospitals. DESIGN: Descriptive study of the processes and outcomes of all submissions to Australian paediatric hospital drug and therapeutics committees from 1 July 2010 to 31 December 2011. SETTING: All eight tertiary paediatric hospitals in Australia. PARTICIPANTS: Interviews with committee secretaries or delegates and document analysis. MAIN OUTCOME MEASURES: Total number of formulary applications, stratified by therapeutic class, approval rates for each hospital and quality of supporting information. RESULTS: One hundred and twenty applications were considered during the study period, with most applications approved (range, 67%-100%). Neurological agents were the most common therapeutic class considered. A conflict of interest was declared for 10 applications (8%). Forty-five (38%) were independently reviewed by a statewide medicines advisory committee or hospital pharmacist. Several committees approved identical applications during the period of review and with different outcomes. For applications submitted for new drugs or new indications (95 applications), supporting data included randomised controlled trials (37/95), case series (36/95), product information (34/95) and narrative reviews (29/95). Few applications (14/95) included a systematic review or meta-analysis. No application included an evaluation of the risk of bias of supporting studies. CONCLUSIONS: There is limited high-quality evidence informing paediatric hospital-based drug approvals. Approval processes vary considerably among institutions with substantial duplication of effort and variable outcomes. Resources and training appear insufficient given the technical complexity of submissions. A national, standardised approach to hospital-based drug evaluation could reduce overlap and improve decision making.

Auditory integration training and other sound therapies for autism spectrum disorders (ASD).

BACKGROUND: Auditory integration therapy was developed as a technique for improving abnormal sound sensitivity in individuals with behavioural disorders including autism spectrum disorders. Other sound therapies bearing similarities to auditory integration therapy include the Tomatis Method and Samonas Sound Therapy. OBJECTIVES: To determine the effectiveness of auditory integration therapy or other methods of sound therapy in individuals with autism spectrum disorders. SEARCH METHODS: For this update, we searched the following databases in September 2010: CENTRAL (2010, Issue 2), MEDLINE (1950 to September week 2, 2010), EMBASE (1980 to Week 38, 2010), CINAHL (1937 to current), PsycINFO (1887 to current), ERIC (1966 to current), LILACS (September 2010) and the reference lists of published papers. One new study was found for inclusion. SELECTION CRITERIA: Randomised controlled trials involving adults or children with autism spectrum disorders. Treatment was auditory integration therapy or other sound therapies involving listening to music modified by filtering and modulation. Control groups could involve no treatment, a waiting list, usual therapy or a placebo equivalent. The outcomes were changes in core and associated features of autism spectrum disorders, auditory processing, quality of life and adverse events. DATA COLLECTION AND ANALYSIS: Two independent review authors performed data extraction. All outcome data in the included papers were continuous. We calculated point estimates and standard errors from t-test scores and post-intervention means. Meta-analysis was inappropriate for the available data. MAIN RESULTS: We identified six randomised comtrolled trials of auditory integration therapy and one of Tomatis therapy, involving a total of 182 individuals aged three to 39 years. Two were cross-over trials. Five trials had fewer than 20 participants. Allocation concealment was inadequate for all studies. Twenty different outcome measures were used and only two outcomes were used by three or more studies. Meta-analysis was not possible due to very high heterogeneity or the presentation of data in unusable forms. Three studies (Bettison 1996; Zollweg 1997; Mudford 2000) did not demonstrate any benefit of auditory integration therapy over control conditions. Three studies (Veale 1993; Rimland 1995; Edelson 1999) reported improvements at three months for the auditory integration therapy group based on the Aberrant Behaviour Checklist, but they used a total score rather than subgroup scores, which is of questionable validity, and Veale's results did not reach statistical significance. Rimland 1995 also reported improvements at three months in the auditory integration therapy group for the Aberrant Behaviour Checklist subgroup scores. The study addressing Tomatis therapy (Corbett 2008) described an improvement in language with no difference between treatment and control conditions and did not report on the behavioural outcomes that were used in the auditory integration therapy trials. AUTHORS' CONCLUSIONS: There is no evidence that auditory integration therapy or other sound therapies are effective as treatments for autism spectrum disorders. As synthesis of existing data has been limited by the disparate outcome measures used between studies, there is not sufficient evidence to prove that this treatment is not effective. However, of the seven studies including 182 participants that have been reported to date, only two (with an author in common), involving a total of 35 participants, report statistically significant improvements in the auditory intergration therapy group and for only two outcome measures (Aberrant Behaviour Checklist and Fisher's Auditory Problems Checklist). As such, there is no evidence to support the use of auditory integration therapy at this time.

The Pharmaceutical Benefits Scheme and implications for paediatric prescribing.

AIMS: To evaluate the impact of the Pharmaceutical Benefits Advisory Committee (PBAC) decisions on access to medicines listed on the Pharmaceutical Benefits Scheme (PBS) for children. METHODS: We analysed all public summary documents from PBAC meetings from July 2005 to November 2006 and compared these with the Therapeutic Goods Administration (TGA) recommendations for children for the same medicine. Main outcome measures stratified by age, the total number of medicines for specific indications (accepted and rejected) by therapeutic class; estimated cost to the PBS per annum for each medicine recommended for listing; comparison of TGA-approved product information and PBS listing for recommended medicines. RESULTS: Of the 102 medicines for specific indications considered by the PBAC, 7% (7/102) of submissions were for new paediatric indications. Most submissions (60%, 61/102) did not specify age for the PBS recommendation and were for conditions which only affect adults. Listings which specifically included children were more likely to have a positive PBAC recommendation. Of the six recommended medicines for children, four were estimated to cost between $10-30 million per year. There was fair concordance between PBS- and TGA-approved product information for age (kappa 0.21) but in 46%, PBAC recommendations were for age-unrestricted listing compared with adults-only use in the TGA-approved product information. CONCLUSION: Access to new subsidised medicines for children in Australia lags behind adults because most applications to the PBAC for new medicines are for conditions which only affect adults. PBS processes facilitate access for children to new medicines by avoiding age restrictions.

How to use medicines in children: principles of paediatric clinical pharmacology.

Knowledge of drug administration in children and infants has significantly lagged behind that of adults. Despite several paediatric therapeutic mishaps that have been a catalyst for major regulatory reform, the majority of registered medicines do not have indications or dosing for children. This paper will briefly summarise key issues in paediatric pharmacology, including differences in prescribing for children, off-label and unlicensed prescribing and conduct of paediatric clinical trials. A particular emphasis will placed on the situation in Australia.

Prescribing safely for children.

This paper is the second in a series of two and will attempt to highlight important issues in prescribing for children, including principles of safe prescribing, adverse drug reaction assessment and common drugs including paracetamol and ibuprofen. A list of drug information resources is included, which may be useful for clinicians.