OBJECTIVE:Individual patients with the same condition may respond differently to similar treatments. Our aim is to summarise the reporting of person-level heterogeneity of treatment effects (HTE) in multiperson N-of-1 studies and to examine the evidence for person-level HTE through reanalysis. STUDY DESIGN:Systematic review and reanalysis of multiperson N-of-1 studies. DATA SOURCES:Medline, Cochrane Controlled Trials, EMBASE, Web of Science and review of references through August 2017 for N-of-1 studies published in English. STUDY SELECTION:N-of-1 studies of pharmacological interventions with at least two subjects. DATA SYNTHESIS:Citation screening and data extractions were performed in duplicate. We performed statistical reanalysis testing for person-level HTE on all studies presenting person-level data. RESULTS:We identified 62 multiperson N-of-1 studies with at least two subjects. Statistical tests examining HTE were described in only 13 (21%), of which only two (3%) tested person-level HTE. Only 25 studies (40%) provided person-level data sufficient to reanalyse person-level HTE. Reanalysis using a fixed effect linear model identified statistically significant person-level HTE in 8 of the 13 studies (62%) reporting person-level treatment effects and in 8 of the 14 studies (57%) reporting person-level outcomes. CONCLUSIONS:Our analysis suggests that person-level HTE is common and often substantial. Reviewed studies had incomplete information on person-level treatment effects and their variation. Improved assessment and reporting of person-level treatment effects in multiperson N-of-1 studies are needed.

Background

Pediatric renal trauma is rare and lacks sufficient population-specific data to generate evidence-based management guidelines. A nonoperative approach is preferred and has been shown to be safe. However, bleeding risk assessment and management of collecting system injury are not well understood. We introduce the Multi-institutional Pediatric Acute Renal Trauma Study (Mi-PARTS), a retrospective cohort study designed to address these questions. This article describes the demographics and contemporary management of pediatric renal trauma at Level I trauma centers in the United States.

Methods

Retrospective data were collected at 13 participating Level I trauma centers on pediatric patients presenting with renal trauma between 2010 and 2019. Data were gathered on demographics, injury characteristics, management, and short-term outcomes. Descriptive statistics were used to report on demographics, acute management, and outcomes.

Results

In total, 1,216 cases were included in this study. Of all patients, 67.2% were male, and 93.8% had a blunt injury mechanism. In addition, 29.3% had isolated renal injuries, and 65.6% were high-grade (American Association for the Surgery of Trauma Grades III-V) injuries. The mean Injury Severity Score was 20.5. Most patients were managed nonoperatively (86.4%), and 3.9% had an open surgical intervention, including 2.7% having nephrectomy. Angioembolization was performed in 0.9%. Collecting system intervention was performed in 7.9%. Overall mortality was 3.3% and was only observed in patients with multiple injuries. The rate of avoidable transfer was 28.2%.

Conclusion

The management and outcomes of pediatric renal trauma lack data to inform evidence-based guidelines. Nonoperative management of bleeding following renal injury is a well-established practice. Intervention for renal trauma is rare. Our findings reinforce differences from the adult population and highlights opportunities for further investigation. With data made available through Mi-PARTS, we aimed to answer pediatric specific questions, including a pediatric-specific bleeding risk nomogram, and better understanding indications for interventions for collecting system injuries.

Level of evidence

Prognostic and Epidemiological; Level IV.