Dynamics of Disease Progression and Gastrostomy Tube Placement in Children and Adolescents with Cystic Fibrosis: Application of Joint Models for Longitudinal and Time-to-Event Data

Percutaneous Endoscopic Gastrostomy in Children: An Update to the ESPGHAN Position Paper

BACKGROUND

The European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) position paper from 2015 on percutaneous endoscopic gastrostomy (PEG) required updating in the light of recent clinical knowledge and data published in medical journals since 2014.

METHODS

A systematic review of medical literature from 2014 to 2020 was carried out. Consensus on the content of the manuscript, including recommendations, was achieved by the authors through electronic and virtual means. The expert opinion of the authors is also expressed in the manuscript when there was a lack of good scientific evidence regarding PEGs in children in the literature.

RESULTS

The authors recommend that the indication for a PEG be individualized, and that the decision for PEG insertion is arrived at by a multidisciplinary team (MDT) having considered all appropriate circumstances. Well timed enteral nutrition is optimal to treat faltering growth to avoid complications of malnutrition and body composition. Timing, device choice and method of insertion is dependent on the local expertise and after due consideration with the MDT and family. Major complications such as inadvertent bowel perforation should be avoided by attention to good technique and by ensuring the appropriate experience of the operating team. Feeding can be initiated as early as 3 hours after tube placement in a stable child with iso-osmolar feeds of standard polymeric formula. Low-profile devices can be inserted initially using the single-stage procedure or after 2-3 months by replacing a standard PEG tube, in those requiring longer-term feeding. Having had a period of non-use and reliance upon oral intake for growth and weight gain-typically 8-12 weeks-a PEG may then safely be removed after due consultation. In the event of non-closure of the fistula the most successful method for closing it, to date, has been a surgical procedure, but the Over-The-Scope-Clip (OTSC) has recently been used with considerable success in this scenario.

CONCLUSIONS

A multidisciplinary approach is mandatory for the best possible treatment of children with PEGs. Morbidity and mortality are minimized through team decisions on indications for insertion, adequate planning and preparation before the procedure, subsequent monitoring of patients, timing of the change to low-profile devices, management of any complications, and optimal timing of removal of the PEG.

Harnessing repeated measurements of predictor variables for clinical risk prediction: a review of existing methods

BACKGROUND

Clinical prediction models (CPMs) predict the risk of health outcomes for individual patients. The majority of existing CPMs only harness cross-sectional patient information. Incorporating repeated measurements, such as those stored in electronic health records, into CPMs may provide an opportunity to enhance their performance. However, the number and complexity of methodological approaches available could make it difficult for researchers to explore this opportunity. Our objective was to review the literature and summarise existing approaches for harnessing repeated measurements of predictor variables in CPMs, primarily to make this field more accessible for applied researchers.

METHODS

MEDLINE, Embase and Web of Science were searched for articles reporting the development of a multivariable CPM for individual-level prediction of future binary or time-to-event outcomes and modelling repeated measurements of at least one predictor. Information was extracted on the following: the methodology used, its specific aim, reported advantages and limitations, and software available to apply the method.

RESULTS

The search revealed 217 relevant articles. Seven methodological frameworks were identified: time-dependent covariate modelling, generalised estimating equations, landmark analysis, two-stage modelling, joint-modelling, trajectory classification and machine learning. Each of these frameworks satisfies at least one of three aims: to better represent the predictor-outcome relationship over time, to infer a covariate value at a pre-specified time and to account for the effect of covariate change.

CONCLUSIONS

The applicability of identified methods depends on the motivation for including longitudinal information and the method's compatibility with the clinical context and available patient data, for both model development and risk estimation in practice.