Measurement Uncertainty in Clinical Validation Studies of Sensors.

Accurate clinical sensors and devices are essential to support optimal medical decision-making, and accuracy can be demonstrated through the conduct of clinical validation studies using validated reference sensors and/or devices for comparison. Typically unmeasurable, the true reference value can be substituted with an accepted physiological measurement with an associated uncertainty. We describe a basic model of measurement uncertainty that specifies the factors that may degrade the accuracy of an observed measurement value from a sensor, and we detail validation study design strategies that may be used to quantify and minimize these uncertainties. In addition, we describe a model that extends the observed measurement uncertainty to the resultant clinical decision and the factors that may impact the uncertainty of this decision. Clinical validation studies should be designed to estimate and minimize uncertainty that is unrelated to the sensor accuracy. The contribution of measurement observation uncertainty to clinical decision-making should be minimized but also acknowledged and incorporated into the clinical decision-making process.

Paediatric postdischarge mortality in developing countries: a systematic review.

OBJECTIVES: To update the current evidence base on paediatric postdischarge mortality (PDM) in developing countries. Secondary objectives included an evaluation of risk factors, timing and location of PDM. DESIGN: Systematic literature review without meta-analysis. DATA SOURCES: Searches of Medline and EMBASE were conducted from October 2012 to July 2017. ELIGIBILITY CRITERIA: Studies were included if they were conducted in developing countries and examined paediatric PDM. 1238 articles were screened, yielding 11 eligible studies. These were added to 13 studies identified in a previous systematic review including studies prior to October 2012. In total, 24 studies were included for analysis. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers extracted and synthesised data using Microsoft Excel. RESULTS: Studies were conducted mostly within African countries (19 of 24) and looked at all admissions or specific subsets of admissions. The primary subpopulations included malnutrition, respiratory infections, diarrhoeal diseases, malaria and anaemia. The anaemia and malaria subpopulations had the lowest PDM rates (typically 1%-2%), while those with malnutrition and respiratory infections had the highest (typically 3%-20%). Although there was significant heterogeneity between study populations and follow-up periods, studies consistently found rates of PDM to be similar, or to exceed, in-hospital mortality. Furthermore, over two-thirds of deaths after discharge occurred at home. Highly significant risk factors for PDM across all infectious admissions included HIV status, young age, pneumonia, malnutrition, anthropometric variables, hypoxia, anaemia, leaving hospital against medical advice and previous hospitalisations. CONCLUSIONS: Postdischarge mortality rates are often as high as in-hospital mortality, yet remain largely unaddressed. Most children who die following discharge do so at home, suggesting that interventions applied prior to discharge are ideal to addressing this neglected cause of mortality. The development, therefore, of evidence-based, risk-guided, interventions must be a focus to achieve the sustainable development goals.

A Multi-Week Assessment of a Mobile Exergame Intervention in an Elementary School.

BACKGROUND: Exergaming is potentially useful to promote physical activity in children; however, long-term effectiveness is unclear. MobileKids Monster Manor (MKMM) is a mobile exergame developed with the help of young advisors. The game wirelessly transmits physical activity data from an accelerometer to a mobile device. Players' steps are redeemed for in-game rewards, for example, new characters. OBJECTIVE: First, to evaluate whether increased physical activity previously observed in a 1-week intervention is sustained over a 2-week intervention and 1-week follow-up, and second, to compare impact in schools within different socioeconomic environments. METHODS: Thirty-seven elementary school students participated in a 4-week randomized controlled study (1-week baseline; 2-week intervention [with only the Game group receiving MKMM]; and 1-week follow-up). All participants wore a Tractivity® accelerometer throughout. Linear mixed models were applied to assess sustainability; a second 42-children-based dataset and age-/sex-adjusted linear regression models were used to compare effect across socioeconomic environments. RESULTS: In the first week of intervention, the Game group compared to the Control group showed a greater increase in physical activity (of 1,758 steps/day [95% confidence interval, CI = 133-3,385] and 31 active minutes/day [95% CI = 4-59]), relative to baseline (13,986 steps/day; 231 active minutes/day). However, this was not sustained in the second intervention week or follow-up. The school within a lower socioeconomic status environment showed lower baseline activity and the 1-week intervention resulted in a greater increase relative to baseline (3,633 steps/day more [95% CI = 1,281-5,985]). CONCLUSION: MKMM could be a useful short-term physical activity promotion tool; however, effectiveness may decrease as novelty diminishes.

Evaluation of a Novel Mobile Exergame in a School-Based Environment.

Physical inactivity is increasing among children globally and has been directly linked to the growing problems of overweight and obesity. We aim to assess the impact of a new mobile exergame, MobileKids Monster Manor (MKMM), in a school-based setting. MKMM, developed with input from youth to enhance physical activity, is wirelessly connected to an accelerometer-based activity monitor. Forty-two healthy students (11.3 ± 1.2 years old and 0.28 ± 1.29 body-mass index [BMI] z-score) participated in a randomized 4-week crossover study to evaluate the game intervention. The two study arms consisted of week-long baseline, game intervention/control, washout, and control/game intervention phases. All participants were required to wear an activity monitor at all times to record steps and active minutes for the study duration. MKMM was used during each arm's respective intervention week, during which children were asked to play the game at their convenience. When children were exposed to the game, an increase compared with the control phase of 2,934 steps per day (p = 0.0004, 95% CI 1,434-4,434) and 46 active minutes per day (p = 0.001, 95% CI 20-72) from baseline (12,299 steps/day and 190 active minutes/day) was observed. A linear regression model showed that MKMM yielded a greater increase in steps and active minutes per day among children with a higher BMI z-score, showing 10 percent more steps per day and 14 percent more active minutes per day relative to baseline, per unit increase in BMI z-score. In conclusion, MKMM increased steps and active minutes in a school-based environment. This suggests that mobile exergames could be useful tools for schools to promote physical activity and combat obesity in adolescents.

The PAediatric Risk Assessment (PARA) Mobile App to Reduce Postdischarge Child Mortality: Design, Usability, and Feasibility for Health Care Workers in Uganda.

BACKGROUND: Postdischarge death in children is increasingly being recognized as a major contributor to overall child mortality. The PAediatric Risk Assessment (PARA) app is an mHealth tool developed to aid health care workers in resource-limited settings such as Sub-Saharan Africa to identify pediatric patients at high risk of both in-hospital and postdischarge mortality. The intended users of the PARA app are health care workers (ie, nurses, doctors, and clinical officers) with varying levels of education and technological exposure, making testing of this clinical tool critical to successful implementation. OBJECTIVE: Our aim was to summarize the usability evaluation of the PARA app among target users, which consists of assessing the ease of use, functionality, and navigation of the interfaces and then iteratively improving the design of this clinical tool. METHODS: Health care workers (N=30) were recruited to participate at Mbarara Regional Referral Hospital and Holy Innocents Children's Hospital in Mbarara, Southwestern Uganda. This usability study was conducted in two phases to allow for iterative improvement and testing of the interfaces. The PARA app was evaluated using quantitative and qualitative measures, which were compared between Phases 1 and 2 of the study. Participants were given two patient scenarios that listed hypothetical information (ie, demographic, social, and clinical data) to be entered into the app and to determine the patient's risk of in-hospital and postdischarge mortality. Time-to-completion and user errors were recorded for each participant while using the app. A modified computer system usability questionnaire was utilized at the end of each session to elicit user satisfaction with the PARA app and obtain suggestions for future improvements. RESULTS: The average time to complete the PARA app decreased by 30% from Phase 1 to Phase 2, following user feedback and modifications. Participants spent the longest amount of time on the oxygen saturation interface, but modifications following Phase 1 cut this time by half. The average time-to-completion (during Phase 2) for doctors/medical students was 3 minutes 56 seconds. All participants agreed they would use the PARA app if available at their health facility. Given a high PARA risk score, participants suggested several interventions that would be appropriate for the sociocultural context in southwestern Uganda, which involved strengthening discharge and referral procedures within the current health care system. CONCLUSIONS: Through feedback and modifications made during this usability study, the PARA app was developed into a user-friendly app, encompassing user expectations and culturally intuitive interfaces for users with a range of technological exposure. Doctors and medical students had shorter task completion times, though all participants reported the usefulness of this tool to improve postdischarge outcomes.

An audit of pain management following pediatric day surgery at British Columbia Children's Hospital.

A prospective audit of 225 children was conducted to evaluate current pain management strategies both in-hospital and at home following day surgery at British Columbia Children's Hospital (Vancouver, British Columbia). Anesthetic, postanesthetic care unit and surgical day care unit records were collected to generate in-hospital data. A telephone questionnaire was administered 48 h postdischarge for at home data. Pain reports and scores were significantly higher (P<0.01) at home compared with in-hospital. Children undergoing certain procedures were more likely to experience significant pain. Although good pain control was commonly achieved after surgery, improvements may be possible by increasing the use of multimodal analgesia, providing standardized written discharge instructions and using surgery-specific pediatric analgesia guidelines.

Two-stage vs mixed-effect approach to pharmacodynamic modeling of propofol in children using state entropy.

OBJECTIVES: To compare the population pharmacodynamic (PD) models of propofol in children derived using two-stage and mixed-effect modeling approaches. METHODS: Fifty-two ASA 1 and 2 children aged 6-15 years presenting for gastrointestinal endoscopy were administered a loading dose of 4 mg·kg(-1) of propofol intravenously at an infusion rate determined by a randomization schedule. Using the plasma concentration predicted by the Paedfusor pharmacokinetic (PK) model, the propofol effect on state entropy (SE) was modeled using the two-stage and the mixed-effect modeling approaches, and the final population PD models were compared with each other in terms of their prediction performance, using median percentage and absolute percentage errors as well as mean absolute weighted error as metrics. The effects of age and body weight as prospective covariates were examined. RESULTS: The final population models were comparable with each other; the two-stage and the mixed-effect approaches resulted in a k(e0) of 2.38 and 2.66 min(-1), γ of 5.29 and 5.68, and EC(50) of 4.73 and 4.84 µg·ml(-1), respectively. The bootstrap estimates of the PD parameters were mean (SD) k(e0) = 2.38 (0.10), γ = 5.30 (0.30), and EC(50) = 4.73 (0.14). The PD parameters did not exhibit dependence on age and body weight. The parameters reported in this study in children were different from their adult counterparts reported in previous studies. CONCLUSIONS: Models derived using different mathematical approaches produced consistent model parameters. By virtue of its relative computational efficiency, the two-stage approach can serve as an attractive alternative to the mixed-effect approach in situations where data are not sparse.

Spontaneous respiration during intravenous anesthesia in children.

PURPOSE OF REVIEW: Maintaining spontaneous respiration during intravenous anesthesia for investigative and surgical procedures may avoid the need for airway instrumentation and reduce the risk of desaturation. In addition, when performing airway endoscopic procedures in children, maintaining spontaneous respiration while using intravenous anesthesia can reduce the need for endotracheal intubation. This facilitates improved access to the smaller airway, allows assessment of the dynamic function of the airway, and reduces exposure of personnel to inhaled anesthetic agents. RECENT FINDINGS: Anesthetic hypnotic and analgesic agents are potent dose-dependent depressants of respiration. Infants have historically been considered to be at a higher risk of respiratory depression, especially from opioid analgesics. However, recent evidence suggests that infants and younger children outside the neonatal period are more resistant to the effects of remifentanil, even when combined with propofol. Spontaneous respiration can be maintained at doses adequate to suppress somatic responses to painful procedures. The large inter-individual variation in respiratory depressant effects necessitates individualized dose titration. The drug dose is more linearly related to variation in the respiratory rhythm and respiratory rate than to minute volume or end-tidal carbon dioxide. Apneic episodes are less likely when respiratory depressant drugs are administered slowly, as this allows time for the end-tidal carbon dioxide level to rise to a new apneic threshold. Hypnotic anesthetics and opioid analgesics act synergistically to cause respiratory depression and suppression of the somatic response. SUMMARY: Spontaneous respiration can be maintained when anesthetizing children using intravenous anesthesia.