Infants Born Large for Gestational Age and Developmental Attainment in Early Childhood.

OBJECTIVES: To investigate if an association exists between being born large for gestational age (LGA) and verbal ability or externalizing behaviour problems at ages 4-5 years. METHOD: A secondary analysis was conducted using the National Longitudinal Survey of Children and Youth, including singleton births in 2004-2005 followed till 4-5 years (n = 1685). LGA was defined as a birth weight > 90th percentile. Outcomes included poor verbal ability (scoring < 15th percentile on the Revised Peabody Picture Vocabulary Test) and externalizing behaviour problems (scoring > 90th percentile on externalizing behaviour scales). Multivariable logistic regression with longitudinal standardized funnel weights and bootstrapping estimation were used. RESULTS: Infants born LGA were not found to be at increased risk for poor verbal ability (aOR: 1.16 [0.49,2.72] and aOR: 0.83 [0.37,1.87] for girls and boys, resp.) or externalizing behaviour problems (aOR: 1.24 [0.52,2.93] and aOR: 1.24 [0.66,2.36] for girls and boys, resp.). Social factors were found to impact developmental attainment. Maternal smoking led to an increased risk for externalizing behaviour problems (aOR: 3.33 [1.60,6.94] and aOR: 2.12 [1.09,4.13] for girls and boys, resp.). CONCLUSION: There is no evidence to suggest that infants born LGA are at increased risk for poor verbal ability or externalizing behaviour problems.

Mild prematurity, proximal social processes, and development.

OBJECTIVE: To elucidate the role of gestational age in determining the risk of poor developmental outcomes among children born late preterm (34-36 weeks) and early term (37-38 weeks) versus full term (39-41 weeks) by examining the contribution of gestational age to these outcomes in the context of proximal social processes. METHODS: This was an analysis of the Canadian National Longitudinal Survey of Children and Youth. Developmental outcomes were examined at 2 to 3 (N= 15099) and 4 to 5 years (N= 12302). The sample included singletons, delivered at 34 to 41 weeks, whose respondents were their biological mothers. Multivariable modified Poisson regression was used to directly estimate adjusted relative risks (aRRs). We assessed the role of parenting by using moderation analyses. RESULTS: In unadjusted analyses, children born late preterm appeared to have greater risk for developmental delay (relative risk = 1.26; 95% confidence interval [CI], 1.01 to 1.56) versus full term. In adjusted analyses, results were nonsignificant at 2 to 3 years (late preterm aRR = 1.13; 95% CI, 0.90 to 1.42; early term aRR = 1.11; 95% CI, 0.96 to 1.27) and 4 to 5 years (late preterm aRR = 1.06; 95% CI, 0.79 to 1.43; early term aRR = 1.03; 95% CI, 0.85 to 1.25). Parenting did not modify the effect of gestational age but was a strong predictor of poor developmental outcomes. CONCLUSIONS: Our findings show that, closer to full term, social factors (not gestational age) may be the most important influences on development.

The validity and reliability of the neurogenic bladder symptom score.

PURPOSE: The neurogenic bladder symptom score is a tool to measure urinary symptoms and consequences in patients with acquired or congenital neurogenic bladder. We describe score validity and reliability. MATERIALS AND METHODS: Exploratory factor analysis was used to assess item variability and subscale structure. Reliability was assessed by the Cronbach α and correlation with retest data. Validity was assessed with a priori hypotheses specifying relationships with the AUASS (American Urological Association symptom score), ICIQ-UI (International Consultation on Incontinence-Urinary Incontinence) and urinary specific quality of life SF-Qualiveen questionnaires, and a self-assessed global bladder problem score. Known groups analysis was used to further assess construct validity. RESULTS: A cohort of 230 patients with spinal cord injury (35%), multiple sclerosis (59%) and congenital neurogenic bladder (6%) were included in study. Factor analysis suggested 3 neurogenic bladder symptom score domains, including incontinence, storage and voiding symptoms, and consequences. Overall internal consistency was high (Cronbach α=0.89). Test-rest reliability was also excellent with an ICC2,1 of 0.91. Validity was demonstrated by the confirmation of hypothesized correlations with the AUASS, ICIQ-UI and SF-Qualiveen, and significant differences in neurogenic bladder symptom score scores among known groups. Patients with a history of seeing a urologist had a significantly higher mean score, as did those with a higher global bladder problem score (22.1 vs 17.1 and 22.1 vs 12.6, respectively, each p<0.001). CONCLUSIONS: The neurogenic bladder symptom score, developed specifically to assess symptoms and consequences associated with neurogenic bladder dysfunction, has appropriate psychometric properties. Depending on the measurement need individual domains may be selected or it can be used as a comprehensive score.

Neonatal morbidity associated with late preterm and early term birth: the roles of gestational age and biological determinants of preterm birth.

BACKGROUND: The aim of this study was to elucidate the role of gestational age in determining the risk of neonatal morbidity among infants born late preterm (34-36 weeks) and early term (37-38 weeks) compared with those born full term (39-41 weeks) by examining the contribution of gestational age within the context of biological determinants of preterm birth. METHODS: This was a retrospective cohort study. The sample included singleton live births with no major congenital anomalies, delivered at 34-41 weeks of gestation to London-Middlesex (Canada) mothers in 2002-11. Data from a city-wide perinatal database were linked with discharge abstract data. Multivariable models used modified Poisson regression to directly estimate adjusted relative risks (aRRs). The roles of gestational age and biological determinants of preterm birth were further examined using mediation and moderation analyses. RESULTS: Compared with infants born full term, infants born late preterm and early term were at increased risk for neonatal intensive care unit triage/admission [late preterm aRR=6.14, 95% confidence interval (CI) 5.63, 6.71; early term aRR=1.54, 95% CI 1.41, 1.68] and neonatal respiratory morbidity (late preterm aRR=6.16, 95% CI 5.39, 7.03; early term aRR=1.46, 95% CI 1.29, 1.65). The effect of gestational age was partially explained by biological determinants of preterm birth acting through gestational age. Moreover, placental ischaemia and other hypoxia exacerbated the effect of gestational age on poor outcomes. CONCLUSIONS: Poor outcomes among infants born late preterm and early term are not only due to physiological immaturity but also to biological determinants of preterm birth acting through and with gestational age to produce poor outcomes.

Hypertension in pregnancy after Escherichia coli O157:H7 gastroenteritis: a cohort study.

BACKGROUND: Escherichia coli O157:H7 is a common cause of bacterial gastroenteritis and may increase the risk of hypertension. We studied the risk of hypertension in pregnancy following a large E. coli O157:H7 outbreak that occurred in Walkerton, Canada, in the year 2000. METHODS: We linked data collected from Walkerton residents to provincial healthcare databases. We studied the pregnancies of three groups of women: two groups from Walkerton (those with and without acute gastroenteritis during outbreak) and a third group from neighboring rural communities unaffected by the outbreak. The primary outcome was a composite of gestational hypertension or preeclampsia. Secondary outcomes were gestational hypertension and preeclampsia examined separately. RESULTS: The median time to pregnancy after cohort entry was five years. The composite outcome was not significantly higher among women with gastroenteritis during the outbreak compared with residents of neighboring communities (8 of 117 (6.8%) versus 96 of 2166 (4.4%) pregnancies, respectively; adjusted relative risk 1.5 (95% confidence interval (CI) 0.8 to 3.2)). When examined separately the risk of preeclampsia was significantly higher among women with gastroenteritis (4 of 117 (3.4%) versus 17 of 2166 (0.8%) pregnancies; adjusted relative risk 3.8 (95% CI 1.3 to 11.6)). However, the risk of preeclampsia was lower than expected in the referent group and overall there were a small number of events in all the groups. CONCLUSION: There was no significant association between E. coli O157:H7 gastroenteritis and our primary assessment of hypertension in pregnancy.

Urine volume and change in estimated GFR in a community-based cohort study.

BACKGROUND AND OBJECTIVES: The effect of increased fluid intake on kidney function is unclear. This study evaluates the relationship between urine volume and renal decline over 6 years in a large community-based cohort. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This prospective cohort study was undertaken in Canada from 2002 to 2008. We obtained 24-hour urine samples from adult participants with an estimated GFR (eGFR) ≥60 ml/min per 1.73 m(2) at study entry. Percentage annual change in eGFR from baseline was categorized as average decline <1% per year, between 1% and 4.9% (mild-to-moderate decline) or ≥5% (rapid decline). RESULTS: 2148 participants provided valid 24-hour urine samples, grouped as <1 L/d (14.5%); 1 to 1.9 L/d (51.5%); 2 to 2.9 L/d (26.3%); and ≥3 L/d (7.7%). Baseline eGFR for each category of urine volume was 90, 88, 84, and 87 ml/min per 1.73 m(2), respectively. Overall, eGFR declined by 1% per year, with 10% demonstrating rapid decline and 40% demonstrating mild-to-moderate decline. An inverse, graded relationship was evident between urine volume and eGFR decline: For each increasing category of 24-hour urine volume, percentage annual eGFR decline was progressively slower, from 1.3%, 1.0%, 0.8%, to 0.5%, respectively; P = 0.02. Compared with those with urine volume 1 to 1.9 L/d, those with urine volume ≥3 L/d were significantly less likely to demonstrate mild-to-moderate decline (adjusted odds ratio 0.66; 95% confidence interval 0.46 to 0.94) or rapid decline (adjusted odds ratio 0.46; 95% confidence interval 0.23 to 0.92); adjusted for age, gender, baseline eGFR, medication use for hypertension (including diuretics), proteinuria, diabetes, and cardiovascular disease. CONCLUSIONS: In this community-based cohort, decline in kidney function was significantly slower in those with higher versus lower urine volume.

Dipstick proteinuria as a screening strategy to identify rapid renal decline.

Rapid kidney function decline (RKFD) predicts cardiovascular morbidity and mortality, but serial assessment of estimated GFR (eGFR) is not cost-effective for the general population. Here, we evaluated the predictive value of albuminuria and three thresholds of dipstick proteinuria to identify RKFD in 2,574 participants in a community-based prospective cohort study with a median of 7 years follow-up. Median change in eGFR was -0.78 ml/min per 1.73 m(2) per year; with 8.5% experiencing RKFD, defined as a >5% annual eGFR decline from baseline. Of those with RKFD, 65% advanced to a new CKD stage compared with 19% of those without RKFD. Dipstick protein ≥ 1 g/L was a stronger predictor of RKFD than albuminuria. Overall, 2.5% screened positive for dipstick protein ≥ 1 g/L at baseline; one of every 2.6 patients would have RKFD if all were followed with serial eGFR measurement. Overall, the screening strategy correctly identified progression status for 90.8% of patients, mislabeled 1.5% as RKFD, and missed 7.7% with eventual RKFD. Among those with risk factors (cardiovascular disease, age >60, diabetes, or hypertension), the probability of identifying RKFD from serial eGFR measurements increased from 13 to 44% after incorporating dipstick protein (≥ 1 g/L threshold). In summary, inexpensive screening with urine dipstick should allow primary care physicians to follow fewer patients with serial eGFR assessment but still identify those with rapid decline of kidney function.

Controlling quality in CME/CPD by measuring and illuminating bias.

INTRODUCTION: There has been a surge of interest in the area of bias in industry-supported continuing medical education/continuing professional development (CME/CPD) activities. In 2007, we published our first study on measuring bias in CME, demonstrating that our assessment tool was valid and reliable. In light of the increasing interest in this area, and building on our experience, we wanted to further understand the application of this tool in different environments. We invited other CME/CPD providers from multiple sites in Canada to participate in a second CME bias study. METHODS: A new steering committee was established with representatives from 5 academic CME/CPD offices nationally, the Royal College of Physicians and Surgeons, and the College of Family Physicians of Canada to outline the project in terms of review of the literature, refining items on the tool, updating the training guide for implementation, and establishing a resource Web site for reviewers. Training involved a train-the-trainer session with the event coordinators at each of the 5 participating centers via videoconferencing. RESULTS: The content reviews from the study showed moderate inter-rater reliability (ICC = 0.54), and the live reviews showed poor overall inter-rater reliability; however, one center achieved substantial inter-rater reliability (ICC = 0.68). DISCUSSION: The analysis from this study suggests that the tool can be used as a part of a multistage process to introduce quality control mechanisms to help raise standards for CME/CPD. It is imperative to develop a cost-effective standardized training protocol that can be implemented at all sites to maximize the reliability of the tool.

Performance of the creatinine-based and the cystatin C-based glomerular filtration rate (GFR) estimating equations in a heterogenous sample of patients referred for nuclear GFR testing.

Cystatin C may be a more accurate marker of the glomerular filtration rate (GFR) than creatinine. We evaluated the performance of the creatinine-based abbreviated modification of diet in renal disease (MDRD), the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, and 6 cystatin C-based equations in estimating GFR (eGFR) in a heterogeneous sample of patients. Measured GFR (mGFR) was obtained from the plasma clearance of 99mtechnetium Diethylenetriaminepentaacetic acid in 42 adult patients referred for nuclear GFR testing (January to March 2008). We evaluated the bias, precision, and accuracy of the abbreviated MDRD, CKD-EPI, Filler, Grubb, Hoek, Larsson, Le Bricon, and Rule eGFR equations. Participants had a mean mGFR of 70.9 mL/min/1.73 m2 (range: 22-125 mL/min/1.73 m2), a median age of 57 years (interquartile range: 45, 66), were 62% male, and were 38% liver transplant recipients. Correlation coefficients between eGFRs and mGFR ranged from 0.65 to 0.87 (each P<0.001). The cystatin C-based Hoek equation had the best overall performance with a low bias (-1.4 mL/min/1.73 m2), good precision (13.3 mL/min/1.73 m2), and greatest accuracy, with 93% of values within 30% of mGFR. Although the CKD-EPI equation had the lowest bias (-0.6 mL/min/1.73 m2), it had poor precision (20.7 mL/min/1.73 m2) and low accuracy, with only 69% of values within 30% of mGFR. The Hoek equation remained accurate and had the least bias when patients were grouped according to the history of liver transplantation and the mGFR above or below 60 mL/min/1.73 m2. In this heterogeneous sample, the cystatin C-based Hoek equation performed the best overall, regardless of mGFR level or history of liver transplantation.

Patient attitudes towards the arteriovenous fistula: a qualitative study on vascular access decision making.

BACKGROUND: The use of arteriovenous fistulas (AVFs) among hemodialysis (HD) patients has been consistently associated with lower rates of morbidity and mortality; however, up to 30% of eligible patients refuse the creation or cannulation of an AVF. We aimed to understand the attitudes, beliefs, preferences and values of patients who refused creation or use of an AVF. METHODS: With qualitative methodology, we conducted semi-structured interviews with 13 HD patients (Canada, 2009), who previously refused creation or use of an AVF. Three independent analysts reviewed interview transcripts. RESULTS: We discovered three main themes that impacted the decision to refuse a fistula: (i) poor previous personal or vicarious experiences with the fistula, including cannulation, bleeding, time commitment and appearance; (ii) knowledge transfer and informed decision making. Patients identified information from other patients to be as important as information from health care workers, that information on vascular access (VA) was presented but not understood and that timing of information was crucial with information overload at the start of dialysis and (iii) maintenance of status quo and outlook on life. Some patients stated they live day-to-day without being influenced by the mortality risks with a catheter. CONCLUSIONS: AVF refusal is multifactorial and depends on individual patients. Although nephrologists consider the fistula to be the optimal VA, patients do not think in the same terms of reducing infection rates but focus on the practical day-to-day use of their VA and its influence on their quality of life and future outlook.

Association between estimated glomerular filtration rate at initiation of dialysis and mortality.

BACKGROUND: Recent studies have reported a trend toward earlier initiation of dialysis (i.e., at higher levels of glomerular filtration rate) and an association between early initiation and increased risk of death. We examined trends in initiation of hemodialysis within Canada and compared the risk of death between patients with early and late initiation of dialysis. METHODS: The analytic cohort consisted of 25 910 patients at least 18 years of age who initiated hemodialysis, as identified from the Canadian Organ Replacement Register (2001-2007). We defined the initiation of dialysis as early if the estimated glomerular filtration rate was greater than 10.5 mL/min per 1.73 m². We fitted time-dependent proportional-hazards Cox models to compare the risk of death between patients with early and late initiation of dialysis. RESULTS: Between 2001 and 2007, mean estimated glomerular filtration rate at initiation of dialysis increased from 9.3 (standard deviation [SD] 5.2) to 10.2 (SD 7.1) (p < 0.001), and the proportion of early starts rose from 28% (95% confidence interval [CI] 27%-30%) to 36% (95% CI 34%-37%). Mean glomerular filtration rate was 15.5 (SD 7.7) mL/min per 1.73 m² among those with early initiation and 7.1 (SD 2.0) mL/min per 1.73 m² among those with late initiation. The unadjusted hazard ratio (HR) for mortality with early relative to late initiation was 1.48 (95% CI 1.43-1.54). The HR decreased to 1.18 (95% CI 1.13-1.23) after adjustment for demographic characteristics, serum albumin, primary cause of end-stage renal disease, vascular access type, comorbidities, late referral and transplant status. The mortality differential between early and late initiation per 1000 patient-years narrowed after one year of follow-up, but never crossed and began widening again after 24 months of follow-up. The differences were significant at 6, 12, 30 and 36 months. INTERPRETATION: In Canada, dialysis is being initiated at increasingly higher levels of glomerular filtration rate. A higher glomerular filtration rate at initiation of dialysis is associated with an increased risk of death that is not fully explained by differences in baseline characteristics.

Long term risk for hypertension, renal impairment, and cardiovascular disease after gastroenteritis from drinking water contaminated with Escherichia coli O157:H7: a prospective cohort study.

OBJECTIVES: To evaluate the risk for hypertension, renal impairment, and cardiovascular disease within eight years of gastroenteritis from drinking water contaminated with Escherichia coli O157:H7 and Campylobacter. DESIGN: A prospective cohort study. Setting Walkerton, Ontario, Canada. PARTICIPANTS: 1977 adult participants in the Walkerton Health Study recruited between 2002 and 2005 after an outbreak of gastroenteritis in May 2000, when a municipal water system was contaminated, with no pre-outbreak history of outcome measures. OUTCOME MEASURES: Information was collected annually via survey, physical examination, and laboratory assessment. Primary measures were acute gastroenteritis (diarrhoeal illness lasting >3 days, bloody diarrhoea, or >3 loose stools/day), hypertension (blood pressure ≥140/90 mm Hg), and renal impairment (microalbuminuria or estimated glomerular filtration rate <60 ml/min/1.73 m(2)). Self reported physician diagnosis of cardiovascular disease (myocardial infarction, stroke, or congestive heart failure) was a secondary outcome. RESULTS: Acute gastroenteritis at the time of the outbreak was reported by 1067 (54%) of participants. Incident hypertension was detected in 697 (35%) (294 (32%) of group not exposed to acute gastroenteritis v 403 (38%) of exposed group). While 572 (29%) had at least one indicator of renal impairment (266 (29%) of unexposed v 306 (29%) of exposed), only 30 (1.5%) had both (8 (0.9%) of unexposed v 22 (2.1%) of exposed). Cardiovascular disease was reported by 33/1749 (1.9%). The adjusted hazard ratios for hypertension and cardiovascular disease after acute gastroenteritis were 1.33 (95% confidence interval 1.14 to 1.54) and 2.13 (1.03 to 4.43) respectively. The adjusted hazard ratio for the presence of either indicator of renal impairment was 1.15 (0.97 to 1.35) and was 3.41 (1.51 to 7.71) for the presence of both. CONCLUSION: Gastroenteritis from drinking water contaminated with E coli O157:H7 and Campylobacter was associated with an increased risk for hypertension, renal impairment, and self reported cardiovascular disease. Annual monitoring of blood pressure and periodic monitoring of renal function may be warranted for individuals who experience E coli O157:H7 gastroenteritis.

Risk of pregnancy-related hypertension within 5 years of exposure to drinking water contaminated with Escherichia coli O157:H7.

The authors evaluated the risk for pregnancy-related hypertension among previously healthy women who conceived within 5 years of exposure to drinking water contaminated with Escherichia coli O157.H7 in Walkerton, Canada (2000). Chronic hypertension was defined as systolic/diastolic blood pressure >/=140/90 mm Hg before 20 weeks gestation; gestational hypertension was defined as new onset systolic/diastolic blood pressure >/=140/90 mm Hg >/=20 weeks gestation. The incidence of hypertension was compared between women who were asymptomatic during the outbreak to those who experienced acute gastroenteritis. Blood pressure data were available for 135 of 148 eligible pregnancies. The adjusted relative risks for chronic and gestational hypertension were 1.5 (95% confidence interval [CI]: 0.3-7.7) and 1.0 (95% CI: 0.4-2.5), respectively. Mean arterial pressure before 20 weeks gestation was 2.7 mm Hg higher in women who had acute gastroenteritis (95% CI: 0.05-5.4). A trend toward higher chronic hypertension and mean arterial pressure in early pregnancy was observed among women who experienced gastroenteritis after exposure to bacterially-contaminated drinking water.

Who should be referred for a fistula? A survey of nephrologists.

BACKGROUND: There is marked variation in the use of the arteriovenous fistula (AVF) across programmes, regions and countries not explained by differences in patient demographics or comorbidities. The lack of clear criteria of who should or should not get a fistula may contribute to this, as well as barriers to creating AVFs. METHODS: We conducted a survey of Canadian and American nephrologists to assess the patient variables considered to determine the timing and type of access requested. Perceived barriers and absolute contraindications to access were also collected. RESULTS: An immediate referral for a fistula was more highly preferred when patients are <65 years old, have minimal comorbidities or have no history of failed accesses. In older patients, and in those with increased comorbidities or a previously failed fistula, US nephrologists selected arteriovenous grafts as an alternative to the fistula, while Canadian nephrologists selected primarily catheters. Referral for vascular mapping was more common in the USA than in Canada. Gender did not influence the timing or the type of access. Perceived barriers to establishing a mature fistula included patient refusal for creation (77%) or cannulation (58%), delay in decision regarding dialysis modality (71%), wait time for surgical creation (55%) and high failure-to-mature rate (52%). We found that 27% of Canadian and 43% of American nephrologists indicated no absolute contraindications for permanent vascular access. CONCLUSIONS: This study demonstrated marked variability in timing and criteria used to select patients for referral for a vascular access between nephrologists practicing within Canada and the USA. Establishing minimal eligibility criteria for fistulae is an important area of future research.

Risk of pregnancy-related hypertension within five years of exposure to bacteria-contaminated drinking water.

Exposure to Escherichia coli O157:H7 may result in subclinical kidney injury manifesting as hypertension during pregnancy. We evaluated the risk of pregnancy-related hypertension (PRH) among previously healthy females from the Walkerton Health Study, Canada (2002-6), who conceived within five years of exposure to bacteria-contaminated drinking water. Ontario Ministry of Health Antenatal forms were used to determine outcomes and risk factors. PRH was defined as any systolic or diastolic blood pressure (BP) > or =140 mm Hg and > or =90 mm Hg, respectively. Chronic and gestational hypertension were defined, respectively, as elevated BP observed prior to or at > or =20 weeks gestation. Risk of PRH was evaluated using a modified Poisson regression model that controlled for known risk factors. Of 148 eligible pregnancies, antenatal audits with blood pressure data were available for 135. PRH was detected in 20.7% pregnancies, of which 6.7% were chronic hypertension and 14.1% gestational hypertension. Although nonsignificant, we observed a consistent trend toward higher rates of PRH and mean arterial pressure, particularly prior to 20 weeks gestation, among women who reported symptomatic gastroenteritis compared to asymptomatic women. BP should be monitored closely in women after exposure to contaminated water.

Elevated blood pressure in relation to overweight and obesity among children in a rural Canadian community.

OBJECTIVE: Childhood overweight and obesity may result in premature onset of cardiovascular risk factors such as hypertension. Rural populations in North America may be at increased risk for overweight. We evaluated whether overweight and obesity were associated with prehypertension and hypertension in a well-characterized population of children in rural Canada. METHODS: The study population for this cross-sectional study was composed of children (aged 4-17 years) who were participants of the Walkerton Health Study (Canada) in 2004. Prehypertension and hypertension were defined on the basis of percentiles from the average of 3 blood pressure measures taken on a single occasion. Percentiles for BMI and blood pressure were calculated by using the 2000 Centers for Disease Control and Prevention growth charts. Multinomial logistic regression was used to evaluate the odds for prehypertension and hypertension resulting from overweight and obesity. RESULTS: Of 675 children (98.7% white), 122 (18.1%) were overweight and 77 (11.4%) were obese. Prehypertension and hypertension were detected in 51 (7.6%) and 50 (7.4%), respectively. After adjustment for family history of hypertension and kidney disease, obesity was associated with both prehypertension and hypertension. Overweight was associated with hypertension but not prehypertension. These associations were observed across the genders and children aged <13 and >or=13 years, except that overweight was not associated with hypertension among girls. CONCLUSIONS: In this population of children who lived in a rural community in Canada, overweight and obesity were strongly associated with elevated blood pressure. Whether blood pressure normalizes with improvements in diet, physical activity, and environment is an area for additional study.

Treating TTP/HUS with plasma exchange: a single centre's 25-year experience.

Thrombotic thrombocytopenic purpura/Haemolytic uremic syndrome (TTP/HUS) is a thrombotic microangiopathy with a 6-month mortality rate of 16-29%. The present study described the clinical features, treatment regime and 6-month all-cause mortality rate of TTP/HUS patients at the London Health Sciences Centre (LHSC), Canada. Data for this retrospective cohort study were obtained from inpatient and outpatient records for all patients referred for plasma exchange therapy at LHSC, Canada between 1981 and 2006. Patients (n = 110) were categorized as: idiopathic primary (38%) or relapsed (16%), and secondary responsive (30%) or non-responsive (16%). Mortality data were available for all but three patients. The all-cause 6-month mortality rate was 19% overall and was 12% and 26% among idiopathic and secondary TTP/HUS patients, respectively. No mortality events occurred among the 17 idiopathic patients who relapsed. Relapsed patients had the least severe presenting characteristics, the fastest response time, and experienced significant improvement in the severity of clinical features between the first and final presentation. These findings suggest an excellent outcome for relapsed TTP/HUS patients. Patient education, surveillance, and aggressive plasma exchange therapy are hypothesized to improve the likelihood of survival: these hypotheses should be tested in a randomized controlled trial.

Developing an instrument to measure bias in CME.

INTRODUCTION: The pharmaceutical industry, by funding over 60% of programs in the United States and Canada, plays a major role in continuing medical education (CME), but there are concerns about bias in such CME programs. Bias is difficult to define, and currently no tool is available to measure it. METHODS: Representatives from industry and academia collaborated to develop a tool to illuminate and measure bias in CME. The tool involved the rating of 14 statements (1 = strongly disagree, 4 = strongly agree) and was used to evaluate 17 live CME events. Cronbach's alpha was used to assess the internal consistency of the scale. RESULTS: Cronbach's alpha for the total score was 0.82, indicating excellent internal consistency. Incomplete or biased data, data presented in an unbalanced manner, and experience not integrated with evidence-based medicine were found to correlate strongly with the total score. Use of trade names showed a low correlation with the total, and nondeclaration of conflict of interest correlated negatively with the total. These associations suggest that whereas sponsor companies may declare conflicts of interest, such a declaration may not ensure an unbiased presentation. DISCUSSION: The tool and the data from this study can be used to raise awareness about bias in CME. Policymakers can use this tool to ensure that CME providers meet the standards for education, and CME providers can use the tool for conducting random audits of events they have accredited.

Advancing rehabilitation research: an interactionist perspective to guide question and design.

The purpose of this position statement is to propose an interactionist framework to bring together the existing literature and provide a unifying direction for rehabilitation research. The framework comprises three components: the conceptual model, the research question, and the research design. The interactionist conceptual model has been adapted from the World Health Organization International Classification of Functioning, Disability, and Health. The model forms the starting point that guides the specification of the research question, which, in turn, guides the selection of research design. This approach demands that the question takes precedence and that there be an extensive repertoire of research designs, each of which is valued for its 'goodness-of-fit' with the question, rather than an a priori, single hierarchical ordering of designs. Research designs must be appropriate for questions that examine the disability experience, development over the lifespan, multifaceted interventions, low incidence conditions, and development of new interventions. Analytical challenges include dealing with confounding, mediating, and moderating variables. Rehabilitation researchers--and those who fund their work--should consider and value the use of diverse research methods to best answer the questions posed from the interactionist perspective.

A gradient of acute gastroenteritis was characterized, to assess risk of long-term health sequelae after drinking bacterial-contaminated water.

OBJECTIVE: A municipal water system became contaminated with Escherichia coli O157:H7 and Campylobacter spp. Beginning 2 years after an outbreak, all residents from the region were invited to participate in a cohort study assessing the risk of long-term sequelae. We aimed to develop a method to grade the accuracy and severity of self-reported acute symptoms. STUDY DESIGN AND SETTING: We corroborated participant survey responses with health records at the time of the outbreak. Of the 4,135 participants, 1,388 were asymptomatic during the outbreak, 1,752 had symptoms of acute self-limited gastroenteritis that could neither be confirmed nor refuted by prior health records, and 995 had symptoms that necessitated medical attention (and thus were confirmed by prior health records). RESULTS: The gradient related to the severity of acute symptoms. Compared to those with unconfirmed gastroenteritis, participants with confirmed gastroenteritis were more likely to describe fever, bloody diarrhea, and prolonged diarrhea (all P < .03). The gradient also correlated with long-term plausible outcomes, including chronic gastrointestinal symptoms, chronic symptoms of arthritis or depression, and the avoidance of municipal water ingestion after the outbreak (P for trend consistently < .03). Conversely, for the outcome of chronic tinnitus, an association was neither expected nor observed (P for trend = .26). CONCLUSION: We successfully characterized a gradient to be used in future primary analyses assessing the risk of long-term health sequelae after an outbreak.