Association of stigma, diabetes distress and self-efficacy with quality of life in adolescents with type 1 diabetes preparing to transition to adult care

AIMS

In type 1 diabetes (T1D), psychosocial factors may impact quality of life (QOL) and clinical outcomes, but remain understudied, particularly during late adolescence. Our aim was to determine whether stigma, diabetes distress and self-efficacy are associated with QOL in adolescents with T1D as they are preparing to transition to adult care.

METHODS

We conducted a cross-sectional study of adolescents (ages 16-17 years) with T1D participating in the Group Education Trial to Improve Transition (GET-IT) in Montreal, Canada. Participants completed validated questionnaires on stigma using the Barriers to Diabetes Adherence (BDA) stigma subscale, self-efficacy (Self-Efficacy for Diabetes Self-Management Measure [SEDM], score 1-10), diabetes distress (Diabetes Distress Scale for Adults with type 1 diabetes) and QOL (Pediatric Quality of Life Inventory [PedsQL] 4.0 Generic Core Scale and PedsQL 3.2 Diabetes Module). We examined associations of stigma, diabetes distress and self-efficacy with QOL using multivariate linear regression models adjusted for sex, diabetes duration, socioeconomic status and HbA1c.

RESULTS

Of 128 adolescents with T1D, 76 (59%) self-reported having the diabetes-related stigma and 29 (22.7%) reported experiencing diabetes distress. Those with stigma had lower diabetes-specific and general QOL scores compared with those without stigma, and stigma and diabetes distress were both associated with lower diabetes-specific QOL and lower general QOL. Self-efficacy was associated with higher diabetes-specific and general QOL.

CONCLUSIONS

Stigma and diabetes distress are associated with lower QOL, whereas self-efficacy is associated with higher QOL in adolescents with T1D preparing to transfer to adult care.

Diabetes duration, perceived comfort with self-management and glycaemic control in adolescents with type 1 diabetes: A cross-sectional study

AIMS

Evidence is lacking on whether diabetes duration is associated with type 1 diabetes (T1D) self-management during late adolescence before transfer from paediatric to adult care. We examined associations of diabetes duration with dimensions of perceived comfort with diabetes self-management (self-efficacy, transition readiness, diabetes distress) and glycaemic control in late adolescence.

METHODS

Using a cross-sectional design, we conducted a secondary analysis of baseline data of adolescents (ages 16-17 years) with T1D followed at paediatric diabetes academic hospitals in Montreal and enrolled in the Group Education Trial to Improve Transition (GET-IT-T1D). Participants completed validated questionnaires on self-efficacy (Self-Efficacy for Diabetes Self-Management Measure [SEDM], score 1 to 10), diabetes distress and transition readiness, as well as a haemoglobin (HbA1c) capillary blood test. Our primary outcome was self-efficacy. We examined associations of diabetes duration with self-efficacy, diabetes distress, transition readiness and HbA1c using linear and logistic regression models adjusted for sex, socioeconomic status, insulin pump use, glucose sensor use and psychiatric comorbidity.

RESULTS

Of 203 adolescents with T1D, mean diabetes duration (SD) was 7.57 (4.44) years. Mean SEDM score was 6.83 (SD 1.62). Diabetes duration was not associated with self-efficacy, diabetes distress or transition readiness. Each additional year of diabetes duration was associated with 0.11% (95% CI, 0.05 to 0.16) higher HbA1c.

CONCLUSIONS

Although diabetes duration is not associated with dimensions of perceived comfort with diabetes self-management, adolescents with longer diabetes duration are at risk for higher HbA1c and may need additional support to improve glycaemic control before transition to adult care.

Qualitative study exploring the perspectives of emerging adults with type 1 diabetes after transfer to adult care from a paediatric diabetes centre in Montreal, Canada

INTRODUCTION

Among youth living with type 1 diabetes (T1D), the increasing demands to diabetes self-care and medical follow-up during the transition from paediatric to adult care has been associated with greater morbidity and mortality. Inadequate healthcare support for youth during the transition care period could exacerbate psychosocial risks and difficulties that are common during emerging adulthood. The current investigation sought to explore the post-transfer perceptions of emerging adults living with T1D relating to their transition to adult care.

RESEARCH DESIGN AND METHODS

Thirty-three emerging adults living with T1D were recruited during paediatric care and contacted for a semistructured interview post-transfer to adult care (16.2±4.2 months post-transfer) in Montreal, Canada. We analysed data using thematic analysis.

RESULTS

We identified four key themes: (1) varied perceptions of the transition process from being quick and abrupt with minimal advice or information from paediatric healthcare providers (HCP) to more positive including a greater motivation for self-management and the transition being concurrent with the developmental period; (2) facilitators to the transition process included informational and tangible social support from HCPs and family or friends, a positive relationship with adult HCP and a greater ease in communicating with the adult care clinic or adult HCP; (3) barriers to adequate transition included lack of advice or information from paediatric HCPs, loss of support from HCPs and friends or family, the separation of healthcare services and greater difficulty in making appointments with adult clinic or HCP and (4) participants recommendations for improving the transition included increasing the length and frequency of appointments in adult care, having access to educational information, and better transition preparation from paediatric HCPs.

CONCLUSIONS

The experiences and perceptions of emerging adults are invaluable to guide the ongoing development and improvement of transition programmes for childhood-onset chronic illnesses.

Associations of Diabetes-related and Health-related Quality of Life With Glycemic Levels in Adolescents With Type 1 Diabetes Preparing to Transition to Adult Care

OBJECTIVES

As adolescents with type 1 diabetes (T1D) progress to adulthood, they assume responsibility for diabetes self-management while dealing with competing life demands, decreasing parental support, and the transfer to adult care. Lower perceived quality of life (QOL) may hamper diabetes management, which is associated with suboptimal glycemic levels. Our objective was to determine associations of diabetes- and health-related QOL with glycemic management (glycated hemoglobin [A1C]) in adolescents with T1D before their transfer to adult care.

METHODS

We conducted a cross-sectional analysis of baseline data from the Group Education Trial to Improve Transition (GET-IT- T1D) in adolescents with T1D (16 to 17 years of age). Participants completed validated questionnaires measuring diabetes-related QOL (PedsQL 3.2 Diabetes Module) and health-related QOL (PedsQL 4.0 Generic Core Scales). Associations of QOL Total and subscale scores with A1C were assessed using linear regression models adjusted for sex, diabetes duration, socioeconomic status, insulin pump use, and mental health comorbidity.

RESULTS

One hundred fifty-three adolescents with T1D were included (mean age, 16.5 [standard deviation, 0.3] years). Diabetes-related QOL Total scores (adjusted β=-0.04; 95% confidence interval [CI], -0.05 to -0.02) as well as subscale scores for Diabetes Symptoms (adjusted β=-0.02; 95% CI, -0.04 to -0.00) and Diabetes Management (adjusted β=-0.04; 95% CI, -0.05 to -0.02) were inversely associated with A1C. Health-related QOL Total scores were not associated with A1C, but Psychosocial Health subscale scores were (adjusted β=-0.01; 95% CI, -0.03 to -0.00).

CONCLUSION

Our results suggest that strategies focussing on diabetes-related QOL and psychosocial health may help prepare adolescents for the increasing responsibility of diabetes self-care.

Text message-based intervention, Keeping in Touch (KiT), to support youth as they transition to adult type 1 diabetes care: a protocol for a multisite randomised controlled superiority trial

INTRODUCTION

Transition from paediatric to adult care can be challenging for youth living with type 1 diabetes (T1D), as many youth feel unprepared to transfer to adult care and are at high risk for deterioration of glycaemic management and acute complications. Existing strategies to improve transition experience and outcomes are limited by cost, scalability, generalisability and youth engagement. Text messaging is an acceptable, accessible and cost-effective way of engaging youth. Together with adolescents and emerging adults and paediatric and adult T1D providers, we co-designed a text message-based intervention, Keeping in Touch (KiT), to deliver tailored transition support. Our primary objective is to test the effectiveness of KiT on diabetes self-efficacy in a randomised controlled trial.

METHODS AND ANALYSIS

We will randomise 183 adolescents with T1D aged 17-18 years within 4 months of their final paediatric diabetes visit to the intervention or usual care. KiT will deliver tailored T1D transition support via text messages over 12 months based on a transition readiness assessment. The primary outcome, self-efficacy for diabetes self-management, will be measured 12 months after enrolment. Secondary outcomes, measured at 6 and 12 months, include transition readiness, perceived T1D-related stigma, time between final paediatric and first adult diabetes visits, haemoglobin A1c, and other glycaemia measures (for continuous glucose monitor users), diabetes-related hospitalisations and emergency department visits and the cost of implementing the intervention. The analysis will be intention-to-treat comparing diabetes self-efficacy at 12 months between groups. A process evaluation will be conducted to identify elements of the intervention and individual-level factors influencing implementation and outcomes.

ETHICS AND DISSEMINATION

The study protocol version 7 July 2022 and accompanying documents were approved by Clinical Trials Ontario (Project ID: 3986) and the McGill University Health Centre (MP-37-2023-8823). Study findings will be presented at scientific conferences and in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT05434754.

Association of accelerometry-derived social jetlag and sleep with temperament in children less than 6 years of age

STUDY OBJECTIVES

Social jetlag (SJL) measures the discrepancy between circadian and social clocks. Using accelerometry-derived data, our objective was to assess the prevalence of SJL in young healthy children and determine the association of SJL and sleep with temperament.

METHODS

Of 117 children participating in TARGet Kids!, a Canadian cohort of healthy preschool-aged children, 78 children (39 girls (50%)); mean age [SD]: 35.1[20.5] months) were included. Sleep was measured objectively using accelerometry. Temperament dimensions (surgency, negative affectivity, and effortful control) were assessed with the very short forms of Rothbart's child and infant behavior questionnaires. We examined associations of SJL and sleep with temperament using multivariable linear regression models adjusted for sex, age, ethnicity, and preschool/daycare attendance.

RESULTS

20 out of 78 (25.6%) experienced SJL of greater than 30 minutes. SJL was greater in children who attended preschool/daycare compared with children who did not (26.3[18.8]min vs. 17.6[14.8]min; p<0.05). There was no evidence of an association between SJL and any temperament dimension. We found evidence of an association between increased sleep duration and increased negative affectivity scores (longer 24h sleep (ß:0.347, 95% CI:0.182,0.512, p<0.0001); longer nighttime sleep duration (ß:0.413, 95% CI:0.163,0.663, p=0.002)).

CONCLUSIONS

In our cohort, 1 in 4 preschool-aged children experienced SJL. Increased sleep duration was associated with increased negative affect, which could have implications for children developing internalizing behavior such as depression or low-self-esteem. We found that sleep duration, but not SJL, was associated with temperament and may impact daytime behavior of young children.

Association of Self-Efficacy, Transition Readiness and Diabetes Distress With Glycemic Control in Adolescents With Type 1 Diabetes Preparing to Transition to Adult Care

OBJECTIVES

Adolescence and emerging adulthood are associated with inadequate medical follow up, suboptimal glycemic control and higher risk for adverse outcomes. Our aim in this study was to determine whether self-efficacy, transition readiness or diabetes distress is associated with glycemic control (glycated hemoglobin [A1C]) among adolescents with type 1 diabetes (T1D) preparing to transition to adult care.

METHODS

We conducted a cross-sectional study of adolescents (age 17 years) with T1D followed at the Montreal Children's Hospital Diabetes Clinic 1 year before transferring to adult care. Participants completed validated questionnaires on self-efficacy (Self-Efficacy for Diabetes Self-Management Measure [SEDM], score 1 to 10), transition readiness (Am I ON TRAC? For Adult Care questionnaire [TRAC], score ≥8 indicates readiness) and diabetes distress (Diabetes Distress Scale for Adults with Type 1 Diabetes [T1-DDS], score ≥3 indicates distress). The primary outcome was A1C (%) 1 year before transfer. We examined associations of self-efficacy, transition readiness and diabetes distress with A1C using multivariate linear and logistic regression models adjusted for sex, age at diagnosis and socioeconomic status.

RESULTS

Of 74 adolescents with T1D (29 males, 39.1%), 27 (36.4%) had suboptimal glycemic control (A1C ≥9.0%). Less than half were transition-ready (TRAC questionnaire score ≥8) and 14% had diabetes distress (T1-DDS score ≥3). SEDM was not associated with A1C. Adolescents considered ready for transition were less likely to have suboptimal glycemic control (odds ratio, 0.30; 95% confidence interval, 0.09 to 0.99), whereas adolescents with diabetes distress were more likely to have suboptimal glycemic control (odds ratio, 6.24; 95% confidence interval, 1.06 to 36.75).

CONCLUSIONS

Improving health-care transition within pediatric care should focus on both transition readiness and diabetes distress to help improve adolescents' glycemic control and prepare them for adult care.

Adipokines and the risk of active TB: a nested case-control study

BACKGROUND: Adipokines are emerging mediators of immune response, and may affect susceptibility to active TB.OBJECTIVE: To examine the associations between adipokines and the risk of active TB.METHODS: In a case-control study nested within a prospective cohort of middle-aged and older adults in Singapore, 280 incident active TB cases who donated blood for research before diagnosis were matched with 280 controls. Serum levels of adiponectin, resistin, leptin and ghrelin were measured. Multivariable logistic regression models were used to compute the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between adipokines and the risk of active TB.RESULTS: Higher levels of leptin and resistin were associated with reduced risk of TB in a dose-dependent manner. Compared to those in the lowest quartile of leptin levels, those in the highest quartile had an OR of 0.46 (95%CI 0.26-0.82; P for trend = 0.009). Similarly, compared to those in the lowest quartile of resistin levels, those in the highest quartile had an OR of 0.46 (95%CI 0.24-0.90; P for trend = 0.03). Adiponectin and ghrelin levels were not associated with TB risk.CONCLUSION: Increased serum levels of leptin and resistin may be associated with reduced susceptibility to active TB infection.

Behavioral difficulties, sleep problems, and nighttime pain in children with cerebral palsy

BACKGROUND

Children with cerebral palsy (CP) may be at risk of behavioral difficulties.

AIMS

1) Determine the prevalence of behavioral difficulties in preschool- and school-aged children with CP and 2) Assess the association between behavioral difficulties and a) sleep problems, b) nighttime pain and c) child characteristics (age, CP phenotype, comorbidities).

METHODS AND PROCEDURES

Caregivers of 113 children with CP aged 4-12 years [mean (SD) age = 7.4 (2.5) years; 61.9% male] completed the Strengths and Difficulties Questionnaire, Sleep Disturbance Scale for Children and a sleep quality questionnaire to assess child behavior, sleep and nighttime pain, respectively.

OUTCOMES AND RESULTS

25.6% of children (17.6% preschool-aged; 29.1% school-aged) had behavioral difficulties. Sleep problems (odds ratio [OR] 9.1, 95% confidence interval [CI] 3.4-24.4) and nighttime pain (OR 4.1, 95% CI 1.5-11.5) were associated with behavioral difficulties. Sleep problems remained significantly associated with behavioral difficulties (adjusted OR 7.5, 95% CI 2.6-21.4) when adjusted for nighttime pain, age and non-ambulatory status.

CONCLUSIONS AND IMPLICATIONS

Behavioral difficulties were reported in one in four children with CP and were associated with sleep problems and nighttime pain. Identifying and treating behavioral difficulties, sleep problems or nighttime pain is important in the care of children with CP.

Group education for adolescents with type 1 diabetes during transition from paediatric to adult care: study protocol for a multisite, randomised controlled, superiority trial (GET-IT-T1D)

INTRODUCTION

Transition from paediatric to adult care is challenging for adolescents and emerging adults (ages 18 to 30 years) with type 1 diabetes (T1D). This transition is characterised by a deterioration in glycaemic control (haemoglobin A1c (HbA1c)), decreased clinical attendance, poor self-management and increased acute T1D-related complications. However, evidence to guide delivery of transition care is lacking. Given the effectiveness of group education in adult diabetes glycaemic control and improvements in qualitative measures in paediatric diabetes, group education is a potentially feasible and cost-effective alternative for the delivery of transition care. In emerging adults with T1D, we aim to assess the effectiveness of group education visits compared with usual care on HbA1c, T1D-related complications, psychosocial measures and cost-effectiveness after the transfer to adult care.

METHODS AND ANALYSIS

In a multisite, assessor-blinded, randomised, two-arm, parallel-group, superiority trial, 212 adolescents with T1D (ages 17 years) are randomised to 12 months group education versus usual T1D care before transfer to adult care. Visits in the active arm consist of group education sessions followed by usual T1D care visits every 3 months. Primary outcome is change in HbA1c measured at 24 months. Secondary outcomes are delays in establishing adult diabetes care, T1D-related hospitalisations and emergency department visits, severe hypoglycaemia, stigma, self-efficacy, diabetes knowledge, transition readiness, diabetes distress, quality of life and cost-effectiveness at 12 and 24 months follow-up. Analysis will be by intention-to-treat. Change in HbA1c will be calculated and compared between arms using differences (95% CI), along with cost-effectiveness analysis. A similar approach will be conducted to examine between-arm differences in secondary outcomes.

ETHICS AND DISSEMINATION

The study was approved by McGill University Health Centre Research Ethics Board (GET-IT/MP-37-2019-4434, version 'Final 1.0 from November 2018). Study results will be disseminated through peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03703440.

Sleep and quality of life of patients with glycogen storage disease on standard and modified uncooked cornstarch

BACKGROUND

Glycemic control in hepatic glycogen storage diseases (GSDs) relies on specific nutritional recommendations, including strict avoidance of a fasting period. Uncooked cornstarch (UCCS) is an important therapeutic component. A new modified UCCS, Glycosade™, was created with the objective of prolonging euglycemia. We aimed to determine the length of euglycemia on Glycosade™ using a continuous glucose monitor (CGM) and to evaluate whether longer euglycemia and thus less nighttime interruptions would improve sleep and quality of life (QoL) after the introduction of the modified cornstarch.

METHODS

We conducted a prospective cohort study to assess quality and quantity of sleep and quality of life (QoL) in patients with GSDs on standard UCCS and after the introduction of Glycosade™. Sleep and QoL evaluation was done for patients using validated questionnaires, a standardized sleep diary and actigraphy. Length of fast and glucose variability were determined with CGM.

RESULTS

Nine adults with GSD Ia took part in the study. Glycosade™ introduction was done under close supervision during a hospital admission. Comparison of sleep in 9 patients showed sleep disturbances on standard UCCS that were improved with Glycosade™. QoL was normal both pre and post Glycosade™. The CGM confirmed maintenance of a longer fasting period with Glycosade™ at home.

CONCLUSION

Glycosade™ represents an alternative option for GSD patients. We showed possible benefits in terms of sleep quality. We also confirmed the longer length of fast on Glycosade™.

SYNOPSIS

A new modified form of uncooked starch for patients with glycogen storage disease represents an alternative option as it showed a longer length of fast and improvements in sleep quality.

Point-of-care lung ultrasound in young children with respiratory tract infections and wheeze

OBJECTIVE

Characterise lung ultrasound (LUS) findings, diagnostic accuracy and agreement between novice and expert interpretations in young children with respiratory tract infections and wheeze.

METHODS

Prospective cross-sectional study in a paediatric ED. Patients ≤2 years with a respiratory tract infection and wheeze at triage were recruited unless in severe respiratory distress. Prior to clinical management, a novice sonologist performed the LUS using a six-zone scanning protocol. The treating physician remained blinded to ultrasound findings; final diagnoses were extracted from the medical record. An expert sonologist, blinded to all clinical information, assessed the ultrasound video clips at study completion. Positive LUS was defined as the presence of ≥1 of the following findings: ≥3 B-lines per intercostal space, consolidation and/or pleural abnormalities.

RESULTS

Ninety-four patients were enrolled (median age 11.1 months). LUS was positive in 42% (39/94) of patients (multiple B-lines in 80%, consolidation in 64%, pleural abnormalities in 23%). The proportion of positive LUS, along with their diagnostic accuracy (sensitivity (95% CI), specificity (95% CI)), were as follows for children with bronchiolitis, asthma, pneumonia and asthma/pneumonia: 46% (45.8% (34.0% to 58.0%), 72.7% (49.8% to 89.3%)), 0% (0% (0.0% to 23.3%), 51.3% (39.8% to 62.6%)), 100% (100% (39.8% to 100.0%), 61.1% (50.3% to 71.2%)), 50% (50% (6.8% to 93.2%), 58.9% (48.0% to 69.2%)), respectively. There was good agreement between the novice and expert sonographers for a positive LUS (kappa 0.68 (95% CI 0.54 to 0.82)).

CONCLUSIONS

Among children with respiratory tract infections and wheeze, a positive LUS seems to distinguish between clinical syndromes by ruling in pneumonia and ruling out asthma. If confirmed in future studies, LUS may emerge as a point-of-care tool to guide diagnosis and disposition in young children with wheeze.

Quality assurance evaluation of a simple linear protocol for the treatment of impending status epilepticus in a pediatric emergency department 2 years postimplementation

Objective:

To evaluate the efficacy and safety of a simple linear midazolam-based protocol for the management of impending status epilepticus in children up to 18 years of age.

Methods:

This is a descriptive, quality assessment, retrospective chart review of children presenting with the chief complaint of seizure disorder in the emergency department (ED) of a tertiary care pediatric hospital and a triage category of resuscitation or urgent from April 1, 2009, to August 31, 2011. In children with at least one seizure episode in the ED treated according to the linear protocol, three main outcomes were assessed: compliance, effectiveness, and complications.

Results:

Of the 128 children meeting the above study criteria, 68 had at least one seizure episode in the ED, and treatment was required to terminate at least one seizure episode in 46 of 68 patients (67.6%). Fifty-five seizure episodes were treated in the 46 patients: 51 of 55 seizure episodes were treated with midazolam (92.7%) and 4 of 55 with lorazepam or diazepam (7.3%). Of those treated with midazolam, 86.3% (44 of 51) were successfully treated with one or two doses of midazolam. The median seizure duration for all treated patients was 6 minutes. Of the 42 patients treated with midazolam, 7 required either continuous positive airway pressure or intubation, and two patients were treated for hypotension. One patient died of pneumococcal meningitis.

Conclusion:

This simple linear protocol is an effective and safe regimen for the treatment of impending status epilepticus in children.

Accuracy of ultrasonography for determining successful realignment of pediatric forearm fractures

STUDY OBJECTIVE

The primary objective of this study is to assess the accuracy of point-of-care ultrasonography compared with blinded orthopedic assessment of fluoroscopy in determining successful realignment of pediatric forearm fractures. The secondary objective is to determine the rate of agreement of ultrasonography and fluoroscopy in real-time by the treating physician.

METHODS

A cross-sectional study was conducted in children younger than 18 years and presenting to an academic emergency department with forearm fractures requiring realignment of a single bone. Physicians performed closed reductions with ultrasonographic assessment of realignment until the best possible reduction was achieved. Fluoroscopy was then immediately performed and images were saved. A positive test result was defined as an inadequately reduced fracture on fluoroscopy by a blinded pediatric orthopedic surgeon (reference standard) and on ultrasonography (index test) and fluoroscopy in real-time by the treating physician.

RESULTS

One hundred patients were enrolled (median age 12.1 years; 74% male patients); the radius was involved in 98%, with 27% involving the growth plate. The sensitivity, specificity, positive predictive value, and negative predictive value were 50% (95% confidence interval [CI] 15.4% to 84.6%), 89.1% (95% CI 82.8% to 95.5%), 28.6% (95% CI 4.9% to 52.2%), and 95.3% (95% CI 90.9% to 99.8%), respectively. The treating physicians' agreement rate of the real-time images was 98%.

CONCLUSION

Point-of-care ultrasonography can help emergency physicians determine when pediatric forearm fractures have been adequately realigned, but inadequate reductions should be confirmed by other imaging modalities.

Attitudes and knowledge regarding health care policy and systems: a survey of medical students in Ontario and California

BACKGROUND

Canada and the United States have similar medical education systems, but different health care systems. We surveyed medical students in Ontario and California to assess their knowledge and views about health care policy and systems, with an emphasis on attitudes toward universal care.

METHODS

A web-based survey was administered during the 2010-2011 academic year to students in 5 medical schools in Ontario and 4 in California. The survey collected demographic data and evaluated attitudes and knowledge regarding broad health care policy issues and health care systems. An index of support for universal health care was created, and logistic regression models were used to examine potential determinants of such support.

RESULTS

Responses were received from 2241 students: 1354 from Ontario and 887 from California, representing 42.9% of eligible respondents. Support for universal health care coverage was higher in Ontario (86.8%) than in California (51.1%), p < 0.001. In California, females, self-described nonconservatives, students with the intent to be involved in health care policy as physicians and students with a primary care orientation were associated with support for universal coverage. In Ontario, self-described liberals and accurate knowledge of the Canadian system were associated with support. A single-payer system for practice was preferred by 35.6% and 67.4% of students in California and Ontario, respectively. The quantity of instruction on health care policy in the curriculum was judged too little by 73.1% and 57.5% of students in California and Ontario, respectively.

INTERPRETATION

Medical students in Ontario are substantially more supportive of universal access to health care than their California counterparts. A majority of students in both regions identified substantial curricular deficiencies in health care policy instruction.

Volumetric-modulated arc radiotherapy for skull-base and non-skull-base head and neck cancer: a treatment planning comparison with fixed Beam IMRT

The purpose of this study is to compare the dose distribution, monitor units (MUs) and radiation delivery time between volumetric-modulated arc (VMAT) and fix-beam intensity modulated radiotherapy (FB-IMRT) in skull-base and non-skull-base head and neck cancer (HNC). CT datasets of 8 skull-base and 7 non-skull-base HNC were identified. IMRT and VMAT plans were generated. The prescription dose ranged 45-70 Gy (1.8-2.2 Gy/fraction). The VMAT delivery time was measured when these plans were delivered to the patients. The FB-IMRT delivery time was generated on a phantom. Comparison of dose-volume histogram data, MUs, and delivery times was performed using T-test. Our results show that both plans yield similar target volume coverage, homogeneity, and conformity. In skull-base cases, compared to FB-IMRT, VMAT generated significantly smaller hot-spot inside PTV (2.0% vs. 4.5%, p = 0.031), lower maximum chiasm dose (32 ± 11 Gy vs. 41 ± 15 Gy, p = 0.026), lower ipsilateral temporal-mandibular joint dose (D33: 41.4 Gy vs. 46.1 Gy, p = 0.016), lower mean ipsilateral middle ear dose (43 ± 9 Gy vs. 38 ± 10 Gy, p = 0.020) and a trend for lower optic nerve, temporal lobe, parotid, and oral cavity dose. In non-skull-base cases, doses to normal tissues were similar between the two plans. There was a reduction of 70% in MUs (486 ± 95 vs. 1614 ± 493, p < 0.001) and 73% in delivery times (3.0 ± 0.6 vs. 11.0 ± 3.3 min, p < 0.001) favoring VMAT. We conclude that VMAT appears to spare more normal tissues from high radiation dose for the tested skull-base tumors. Dosimetrically, both approaches were equivalent for non-skull-base tumor with VMAT using fewer MUs and shorter delivery time.

Effect of glutamine on glucose metabolism in children with Duchenne muscular dystrophy

BACKGROUND & AIMS

Glutamine is a potent gluconeogenic precursor and stimulates insulin secretion. Glutamine's effect on glucose metabolism in Duchenne muscular dystrophy (DMD) has never been studied. To determine plasma glucose and insulin concentrations measured during and after glutamine administration in DMD boys. We hypothesized that glutamine can modulate whole body glutamine-glucose metabolism in DMD, a genetically determined disease.

METHODS

As secondary endpoints of a randomized crossover trial in 30 prepubertal DMD boys, we measured fasting blood glucose, insulin and the Homeostasis Model Assessment (HOMA) index after daily oral glutamine (0.5 g kg(-1) d(-1)) for 4 months versus placebo. In a separate time series trial in 6 prepubertal DMD boys, we measured the same endpoints as well as plasma glutamine and whole body glucose turnover (Ra,glc) (primed continuous i.v. infusion of d-[6,6-(2)D]glucose), while participants received acute oral glutamine (0.5 g kg(-1) d(-1)) continuously for 5 h.

RESULTS

In the randomized trial, baseline measurements of HOMA correlated with age (r = 0,51, p = 0.007) and percent fat estimated by bioelectrical impedance analysis (BIA) (r = 0.39, p = 0.047). After 4 months glutamine supplementation, we observed no treatment or order effect on HOMA or insulin. During acute glutamine for 5 h (time series trial), plasma glutamine doubled and was associated with increased plasma insulin concentration (10.42 ± 2.54 vs 7.32 ± 1.86, p = 0.05) with no effect on plasma glucose, HOMA or Ra,glc.

CONCLUSIONS

Acute glutamine transiently stimulates insulin secretion in DMD boys, which could be mediated by plasma glutamine concentrations. Fasting insulin concentration and HOMA might provide quantifiable indices of disease progression.

Visibility of the urethral meatus and risk of urinary tract infections in uncircumcised boys

BACKGROUND

Uncircumcised boys are at higher risk for urinary tract infections than circumcised boys. Whether this risk varies with the visibility of the urethral meatus is not known. Our aim was to determine whether there is a hierarchy of risk among uncircumcised boys whose urethral meatuses are visible to differing degrees.

METHODS

We conducted a prospective cross-sectional study in one pediatric emergency department. We screened 440 circumcised and uncircumcised boys. Of these, 393 boys who were not toilet trained and for whom the treating physician had requested a catheter urine culture were included in our analysis. At the time of catheter insertion, a nurse characterized the visibility of the urethral meatus (phimosis) using a 3-point scale (completely visible, partially visible or nonvisible). Our primary outcome was urinary tract infection, and our primary exposure variable was the degree of phimosis: completely visible versus partially or nonvisible urethral meatus.

RESULTS

Cultures grew from urine samples from 30.0% of uncircumcised boys with a completely visible meatus, and from 23.8% of those with a partially or nonvisible meatus (p = 0.4). The unadjusted odds ratio (OR) for culture growth was 0.73 (95% confidence interval [CI] 0.35-1.52), and the adjusted OR was 0.41 (95% CI 0.17-0.95). Of the boys who were circumcised, 4.8% had urinary tract infections, which was significantly lower than the rate among uncircumcised boys with a completely visible urethral meatus (unadjusted OR 0.12 [95% CI 0.04-0.39], adjusted OR 0.07 [95% CI 0.02-0.26]).

INTERPRETATION

We did not see variation in the risk of urinary tract infection with the visibility of the urethral meatus among uncircumcised boys. Compared with circumcised boys, we saw a higher risk of urinary tract infection in uncircumcised boys, irrespective of urethral visibility.

TU-E-BRA-03: Real-Time Fiducial Detection and Prostate Movement Assessment with Cine MV Images in RapidArc Treatments

PURPOSE

To develop an algorithm for detection of metallic fiducial markers in cine MV images, and to assess the prostate movement during RapidArc treatment.

METHODS

A Varian TrueBeam linear accelerator (LINAC) was used to deliver RapidArc treatment for prostate patients. Cine images were acquired with the onboard electronic portal imaging device (EPID) using the MV therapeutic beam. Three metallic fiducial markers were implanted inside the prostate. To detect the fiducial position, we explicitly account for the possible marker blockage by MLC during beam modulation. If the marker is not blocked, we employ the planning coordinates of the marker centroids projected onto the cine MV images and perform template matching in the vicinity of its projection to localize the actual position of the marker. Displacements of the fiducial markers are assessed by comparing the actual and planned positions.

RESULTS

We analyzed ∼280 cine MV images acquired during a 55-sec RapidArc treatment for a prostate patient. The three markers were visible in about 46%, 52%, and 48% of the images, and at least one fiducial was visible during almost entire treatment (97% of the time). The marker detection algorithm agrees well with manual detection (< 0.2 mm). The mean displacement for each fiducial was 0.40 ± 0.42, 0.27 ± 0.29, and 0.46 ± 0.34 mm. The maximum displacement was 2.33, 1.75, and 2.23 mm.

CONCLUSIONS

An algorithm for automatic detection of fiducial markers in cine MV images has been developed. The prostate movement during a RapidArc treatment has been analyzed for a patient with implanted markers. Accurate target positioning is achieved at all times during treatment. In light of the random nature of intrafraction prostate motion, this work represents an important step toward real-time image-guided prostate radiation therapy.

SU-E-T-499: Validation of the Varian Generic Phase Space Files for Monte Carlo Calculations of Dose Distributions for the TrueBeam Linac Head

PURPOSE

To validate the generic phase space files for Varian TrueBeam linac head simulations.

METHODS

The generic phase space files include the simulation results of 6MV, 10MV, 6MV FFF, and 10MV FFF (flattening-filter free) operating modes of TrueBeam for patient-independent linac head components. Using the generic phase space files as the radiation sources, the BEAMnrc Monte Carlo codes are used to simulate the patient-dependent parts of the TrueBeam linac and the resulting phase space files are generated at a plane just before entering a water phantom for 4 different field sizes (5×5, 10×10, 20×20, and 40×40 cm² ). Dose distributions are calculated by DOSXYZnrc in the water phantom of size 50×50×40 cm³ . The percentage-depth-dose (PDD) curves and lateral dose profiles at three different depths (dmax, 10cm, 20cm) are obtained. Comprehensive comparisons have been made for a total of 64 dose profiles (including PDDs) between the Monte Carlo calculations and the measured data. The gamma index analysis is performed for all the comparisons.

RESULTS

The matching of the calculated dose distributions to the measured ones is analyzed by the gamma index method with a criterion of 2% dose tolerance and 2 mm distance-to-agreement. Of the 64 comparisons, the minimum gamma index passing rate is at least 92%, after taking into account the statistical nature of the Monte Carlo calculated dose values. Despite the existence of latent variance of phase space files, the phantom dose calculation uncertainty can be less than 1% for field sizes as small as 5×5 cm² . The computing time saved by using phase space files could be a factor of 5-10.

CONCLUSIONS

The Varian generic phase space files are accurate and efficient radiation sources for Monte Carlo calculations of radiation dose distributions for TrueBeam linac head. This work was supported in part by Varian Medical Systems and the NIH (1R01 CA104205 and 1R21 CA153587).

SU-E-T-485: Validation of Acuros XB Dose Calculations in SBRT Lung Planning with Monte Carlo Methods

PURPOSE

The Acuros XB (AXB) Advanced Dose algorithm (Varian Medical Systems) represents a dramatic shift in clinical photon dose calculation methodology from pencil-beam superposition/convolution methods. Early studies evaluating the accuracy of the algorithm in lung have found good agreement with both measurement and Monte Carlo based dose calculations. In this study, a dosimetric validation of Acuros is performed for clinical SBRT lung planning cases using Monte Carlo (MC) calculations as a benchmark.

METHODS

MC simulations using BEAMnrc/DOSXYZnrc were carried out for 8 AXB calculated 6/10 MV arc plans delivered on a TrueBeamTM STx linac in high-dose-rate flattening filter free mode. Clinical planning constraints were applied in each case with plans normalized to achieve 95% PTV coverage. Metrics used in the evaluation include: maximum and minimum GTV/PTV dose, PTV isodose coverage, conformity and dose profile comparisons. To understand the impact of moving toward to AXB calculations in SBRT lung planning, calculations using the Analytical Anisotropic Algorithm (AAA) are presented for each plan.

RESULTS

For both 6 and 10MV energies, consistent mean GTV dose and PTV isodose coverage was observed for AXB and MC calculations. GTV mean dose was observed to deviate by <2% for all cases. Isodose coverage for MC simulations ranged from 92%-98%. AAA was also in agreement with MC simulations within the GTV to within 2%. AXB and MC maximum and minimum PTV dose differences were larger (up to 9%) but not of clinical concern. In several cases, AXB exhibited a significant improvement in dose calculation accuracy in the lung region surrounding the GTV over AAA, particularly with lung densities < 0.1 g/cc.

CONCLUSION

AcurosXB provides increased accuracy in modelling dose deposition for SBRT lung over AAA and is found to be in good agreement with MC calculations.

Glutamine supplementation in sick children: is it beneficial?

The purpose of this review is to provide a critical appraisal of the literature on Glutamine (Gln) supplementation in various conditions or illnesses that affect children, from neonates to adolescents. First, a general overview of the proposed mechanisms for the beneficial effects of Gln is provided, and subsequently clinical studies are discussed. Despite safety, studies are conflicting, partly due to different effects of enteral and parenteral Gln supplementation. Further insufficient evidence is available on the benefits of Gln supplementation in pediatric patients. This includes premature infants, infants with gastrointestinal disease, children with Crohn's disease, short bowel syndrome, malnutrition/diarrhea, cancer, severe burns/trauma, Duchenne muscular dystrophy, sickle cell anemia, cystic fibrosis, and type 1 diabetes. Moreover, methodological issues have been noted in some studies. Further mechanistic data is needed along with large randomized controlled trials in select populations of sick children, who may eventually benefit from supplemental Gln.

Risk compensation in children's activities: A pilot study

BACKGROUND

The intent of protective equipment (PE) in sports and leisure activities is to reduce injuries. However, some postulate that any safety measure prompts riskier behaviour, a phenomenon known as 'risk homeostasis' or 'risk compensation.' This study explores one approach to examining this in children. The rationale for this pilot study was to establish if children between six and 16 years old could answer questions about risk-taking sensibly and which questions, if any, could be eliminated; to establish the reliability of response; and to determine the numbers needed for a definitive study.

METHODS

Sixty-three children with nonsevere injuries, ages six to 16 years, were interviewed while waiting to be seen at the Montreal Children's Hospital emergency department. An interviewer administered a questionnaire comprising three sections. The first part only applied to those who were injured in an activity for which some form of PE was available (n=19). The second part examined customary risk-taking behaviour using the thrill and adventure seeking scales of a standardized questionnaire (Zuckerman) (n=63). The third section posed hypothetical questions about likely risk-taking when using PE to those who had engaged in such activities (n=58).

RESULTS

The approach and questionnaire proved feasible with this age group. The responses suggest that children wearing PE were more likely to report increased risk-taking than those who did not wear PE. For most of the hypothetical questions, the majority also reported changes toward riskier behaviour when using PE. However, those wearing PE scored lower on the thrill and adventure seeking scale, suggesting that they are, by nature, less venturesome.

CONCLUSION

The results indicate that risk compensation may modify the effectiveness of PE for children engaged in sports and leisure activities. Conversely, the findings also suggest that those wearing PE may be a cautious subgroup.