Luz Palacios-Derflingher

Estimated GFR and Fracture Risk: A Population-Based Study

BACKGROUND AND OBJECTIVES Although patients with ESRD have a higher fracture risk than the general population, there is conflicting evidence regarding fracture incidence in those with CKD. This study sought to determine the association between estimated GFR (eGFR) and fracture rates. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This study identified 1,815,943 community-dwelling adults who had at least one outpatient serum creatinine measurement between 2002 and 2008. Patients with eGFR <15 ml/min per 1.73 m(2) and those who required dialysis were excluded. Incident fractures of the hip, wrist, and vertebrae were identified using diagnostic and procedure codes. Poisson regression was used to determine adjusted rates of each fracture type by eGFR, age, and sex. RESULTS The median age of the cohort was 47 years (interquartile range, 24), and 7.1% had eGFR <60 ml/min per 1.73 m(2). Over a median follow-up of 4.4 years, fracture rates increased with age at all sites. Within each age stratum, unadjusted rates increased with declining eGFR; however, adjusted rates were similar across eGFR categories. For example, among women aged 65-74 years, adjusted hip fracture rates were 3.41 per 1000 person-years (95% confidence interval, 2.30 to 4.53) and 4.58 per 1000 person-years (95% confidence interval, 0.02 to 9.14) in those with eGFR ≥90 and 15-29 ml/min per 1.73 m(2), respectively. Similar results were observed for wrist and vertebral fractures. CONCLUSIONS In contrast to earlier studies, patients with eGFR<60 ml/min per 1.73 m(2) do not appear to have increased rates of hip, wrist, and vertebral fractures independent of age and sex.

Perinatal Care for South Asian Immigrant Women and Women Born in Canada: Telephone Survey of Users

BACKGROUND Previous research findings suggest that pregnant immigrant women receive less adequate perinatal care than pregnant non-immigrant women. This study was designed to assess the use of perinatal care services by newly immigrated South Asian women and Canadian-born women, and to determine any perceived barriers to receiving care. METHOD We conducted a telephone survey of women who delivered at an academic community hospital in Calgary, Alberta. Two groups of women were interviewed at seven weeks postpartum: South Asian women who had immigrated within the last three years, and Canadian-born women of any ethnicity. Women who spoke Hindi, Punjabi, and/or English were eligible. Interviews consisted mainly of closed-ended questions. The main outcomes we sought were the proportion of women receiving perinatal care (such as attending prenatal classes or fetal monitoring), and any perceived barriers to care. RESULTS Thirty South Asian and 30 Canadian-born women were interviewed. Most women in each group reported having pregnancy evaluations carried out. Fewer South Asian women than Canadian-born women understood the purpose of symphysis-fundal height measurement (60% vs. 90%, P = 0.015) and tests for Group B streptococcus (33% vs. 73%, P = 0.004). Thirteen percent of South Asian and 23% of Canadian-born women attended prenatal classes. Most women (87-97%) believed they had received all necessary medical care. Language barriers were most commonly reported by South Asian women (33-43% vs. 0 for Canadian-born women). CONCLUSION South Asian women considered language to be the most common barrier to receiving perinatal care. Such barriers may be overcome by wider availability of multilingual staff and educational materials in a variety of formats including illustrated books and videos.

Association Between GFR, Proteinuria, and Adverse Outcomes Among White, Chinese, and South Asian Individuals in Canada

BACKGROUND We investigated the association between proteinuria, estimated glomerular filtration rate (eGFR), and risk of mortality and kidney failure in white, Chinese, and South Asian populations. STUDY DESIGN Population-based cohort study. SETTING & PARTICIPANTS Participants from Alberta, Canada, with a serum creatinine and urine protein dipstick measurement from January 1, 2005, to December 31, 2005. PREDICTOR White, Chinese, or South Asian ethnicity. OUTCOMES Prevalence of proteinuria by level of eGFR (estimated using the MDRD [Modification of Diet in Renal Disease] Study equation) and the association between eGFR, proteinuria, and all-cause mortality and kidney failure. MEASUREMENTS Rates of all-cause mortality and kidney failure per 1,000 person-years were calculated using Poisson regression by ethnicity, eGFR level, and proteinuria level while adjusting for sociodemographic variables and comorbid conditions. RESULTS Of 491,729 participants, 5.3% were Chinese and 4.7% were South Asian. For participants with eGFR <60 mL/min/1.73 m(2), the prevalence of heavy proteinuria was higher in Chinese and South Asians compared with whites. Compared with whites, adjusted rates of death were significantly lower for Chinese and South Asian populations (rate ratios, 0.67 [95% CI, 0.56-0.80] and 0.73 [95% CI, 0.59-0.88], respectively); these rate ratios did not vary by eGFR and proteinuria levels. LIMITATIONS Using surname to identify ethnicity has the potential for misclassification due to name changes and identical last names from different ethnic groups. Also, to be eligible for inclusion, participants had to have a measurement of serum creatinine and urine dipstick proteinuria. CONCLUSIONS Although increasing proteinuria and lower eGFR predicted mortality and progression to kidney failure in all 3 ethnic groups, both Chinese and South Asian populations experienced a lower risk of death and similar risk of kidney failure compared with whites at all eGFR and proteinuria levels. Studies exploring this association further are required.

Policy change eliminating body checking in non-elite ice hockey leads to a threefold reduction in injury and concussion risk in 11- and 12-year-old players

Background In ice hockey, body checking is associated with an increased risk of injury. In 2011, provincial policy change disallowed body checking in non-elite Pee Wee (ages 11–12 years) leagues. Objective To compare the risk of injury and concussion between non-elite Pee Wee ice hockey players in leagues where body checking is permitted (2011–12 Alberta, Canada) and leagues where policy change disallowed body checking (2011–12 Ontario, Canada). Method Non-elite Pee Wee players (lower 70%) from Alberta (n=590) and Ontario (n=281) and elite Pee Wee players (upper 30%) from Alberta (n=294) and Ontario (n=166) were recruited to participate in a cohort study. Baseline information, injury and exposure data was collected using validated injury surveillance. Results Based on multiple Poisson regression analyses (adjusted for clustering by team, exposure hours, year of play, history of injury/concussion, level of play, position and body checking attitude), the incidence rate ratio (IRR) associated with policy allowing body checking was 2.97 (95% CI 1.33 to 6.61) for all game injury and 2.83 (95% CI 1.09 to 7.31) for concussion. There were no differences between provinces in concussion [IRR=1.50 (95% CI 0.84 to 2.68)] or injury risk [IRR=1.22 (95% CI 0.69 to 2.16)] in elite levels of play where both provinces allowed body checking. Conclusions The rate of injury and concussion were threefold greater in non-elite Pee Wee ice hockey players in leagues where body checking was permitted. The rate of injury and concussion did not differ between provinces in elite levels, where body checking was allowed.

The Effect of the “Zero Tolerance for Head Contact” Rule Change on the Risk of Concussions in Youth Ice Hockey Players

Background: Ice hockey is a popular winter sport in Canada. Concussions account for the greatest proportion of all injuries in youth ice hockey. In 2011, a policy change enforcing “zero tolerance for head contact” was implemented in all leagues in Canada. Purpose: To determine if the risk of game-related concussions and more severe concussions (ie, resulting in >10 days of time loss) and the mechanisms of a concussion differed for Pee Wee class (ages 11-12 years) and Bantam class (ages 13-14 years) players after the 2011 “zero tolerance for head contact” policy change compared with players in similar divisions before the policy change. Study Design: Cohort study; Level of evidence, 3. Methods: The retrospective cohort included Pee Wee (most elite 70%, 2007-2008; n = 891) and Bantam (most elite 30%, 2008-2009; n = 378) players before the rule change and Pee Wee (2011-2012; n = 588) and Bantam (2011-2012; n = 242) players in the same levels of play after the policy change. Suspected concussions were identified by a team designate and referred to a sport medicine physician for diagnosis. Incidence rate ratios (IRRs) were estimated based on multiple Poisson regression analysis, controlling for clustering by team and other important covariates and offset by game-exposure hours. Incidence rates based on the mechanisms of a concussion were estimated based on univariate Poisson regression analysis. Results: The risk of game-related concussions increased after the head contact rule in Pee Wee (IRR, 1.85; 95% CI, 1.20-2.86) and Bantam (IRR, 2.48; 95% CI, 1.17-5.24) players. The risk of more severe concussions increased after the head contact rule in Pee Wee (IRR, 4.12; 95% CI, 2.00-8.50) and Bantam (IRR, 7.91; 95% CI, 3.13-19.94) players. The rates of concussions due to body checking and direct head contact increased after the rule change. Conclusion: The “zero tolerance for head contact” policy change did not reduce the risk of game-related concussions in Pee Wee or Bantam class ice hockey players. Increased concussion awareness and education after the policy change may have contributed to the increased risk of concussions found after the policy change.

Association between First Nations ethnicity and progression to kidney failure by presence and severity of albuminuria

Background: Despite a low prevalence of chronic kidney disease (estimated glomerular filtration rate [GFR] < 60 mL/min per 1.73 m2), First Nations people have high rates of kidney failure requiring chronic dialysis or kidney transplantation. We sought to examine whether the presence and severity of albuminuria contributes to the progression of chronic kidney disease to kidney failure among First Nations people. Methods: We identified all adult residents of Alberta (age ≥ 18 yr) for whom an outpatient serum creatinine measurement was available from May 1, 2002, to Mar. 31, 2008. We determined albuminuria using urine dipsticks and categorized results as normal (i.e., no albuminuria), mild, heavy or unmeasured. Our primary outcome was progression to kidney failure (defined as the need for chronic dialysis or kidney transplantation, or a sustained doubling of serum creatinine levels). We calculated rates of progression to kidney failure by First Nations status, by estimated GFR and by albuminuria category. We determined the relative hazard of progression to kidney failure for First Nations compared with non–First Nations participants by level of albuminuria and estimated GFR. Results: Of the 1 816 824 participants we identified, 48 669 (2.7%) were First Nations. First Nations people were less likely to have normal albuminuria compared with non–First Nations people (38.7% v. 56.4%). Rates of progression to kidney failure were consistently 2- to 3-fold higher among First Nations people than among non–First Nations people, across all levels of albuminuria and estimated GFRs. Compared with non–First Nations people, First Nations people with an estimated GFR of 15.0–29.9 mL/min per 1.73 m2 had the highest risk of progression to kidney failure, with similar hazard ratios for those with normal and heavy albuminuria. Interpretation: Albuminuria confers a similar risk of progression to kidney failure for First Nations and non–First Nations people.

Pneumatic compression devices during hemodialysis: a randomized crossover trial

BACKGROUND Maintenance of central blood volume (CBV) is essential for hemodynamic stability during hemodialysis (HD), though preservation of CBV is poorly understood. Pneumatic compression devices (PCDs) during HD may help maintain CBV. METHODS We performed a randomized, crossover trial to determine the effect of PCDs on CBV during HD. Patients underwent two consecutive mid-week HD sessions, randomized to begin the first session either with or without PCDs [stratified by intradialytic hypotension (IDH)-prone status]. The primary outcome was change in CBV during HD. The secondary outcomes were change in other hemodynamic and volume status parameters. RESULTS Fifty-one patients (median age 65 years, 75% male, 22% IDH-prone) were randomized; forty-six completed the study. During HD, the median change in CBV for PCD and control sessions was -0.08 versus -0.05 L (P = 0.62). There was no difference in the change in cardiac output (CO) (-0.63 versus -0.49 L/min, P = 0.78) or systemic vascular resistance (SVR) (+1.30 versus +1.55 mmHg/L/min, P = 0.67) for PCDs versus control. Based on the bioimpedance measurements, patients were not volume overloaded pre-dialysis. There was a greater reduction in total body water (TBW) (-2.6 versus -2.3 L, P = 0.05) and intracellular fluid (ICF) volume (-1.3 versus -1.1 L, P = 0.03), and no difference in change in the extracellular fluid (ECF) volume (1.3 versus 1.2 L, P = 0.09) with PCDs versus control. Similar results were observed in IDH-prone patients. CONCLUSIONS Compared with standard of care, PCDs have no effect on intradialytic hemodynamic parameters, including CBV, although they may allow greater capacity for fluid removal. Further studies are required to better understand physiological and hemodynamic changes in patients during HD.

The risk of injury associated with body checking among Pee Wee ice hockey players: an evaluation of Hockey Canada’s national body checking policy change

Background In 2013, Hockey Canada introduced an evidence-informed policy change delaying the earliest age of introduction to body checking in ice hockey until Bantam (ages 13–14) nationwide. Objective To determine if the risk of injury, including concussions, changes for Pee Wee (11–12 years) ice hockey players in the season following a national policy change disallowing body checking. Methods In a historical cohort study, Pee Wee players were recruited from teams in all divisions of play in 2011–2012 prior to the rule change and in 2013–2014 following the change. Baseline information, injury and exposure data for both cohorts were collected using validated injury surveillance. Results Pee Wee players were recruited from 59 teams in Calgary, Alberta (n=883) in 2011–2012 and from 73 teams in 2013–2014 (n=618). There were 163 game-related injuries (incidence rate (IR)=4.37/1000 game-hours) and 104 concussions (IR=2.79/1000 game-hours) in Alberta prior to the rule change, and 48 injuries (IR=2.16/1000 game-hours) and 25 concussions (IR=1.12/1000 game-hours) after the rule change. Based on multivariable Poisson regression with exposure hours as an offset, the adjusted incidence rate ratio associated with the national policy change disallowing body checking was 0.50 for all game-related injuries (95% CI 0.33 to 0.75) and 0.36 for concussion specifically (95% CI 0.22 to 0.58). Conclusions Introduction of the 2013 national body checking policy change disallowing body checking in Pee Wee resulted in a 50% relative reduction in injury rate and a 64% reduction in concussion rate in 11-year-old and 12-year-old hockey players in Alberta.

Perceived Usefulness of Learning Strategies by Children with Tourette Syndrome Plus, Their Parents and Their Teachers.

Objective: Children with Tourette syndrome and other co-morbidities (abbreviated hereafter to TS+) experience significant learning difficulties. We wished to identify educational strategies that these students, their parents and teachers considered useful. Design: An ‘educational toolkit’ was compiled of 84 strategies identified by teachers of TS+ children. Setting: Children attending the TS+ clinic of a university hospital in Edmonton, Alberta. Method: The educational toolkit was administered to 30 randomly selected TS+ children attending the clinic, their teachers, and their parents. Results: 13 strategies were endorsed by ≥ 50% of the students, 53 by ≥ 50% of parents, and 42 by ≥ 50% of teachers. The 10 strategies students most strongly endorsed were: (1) computers; (2) calculators; (3) spell-checkers; (4) extra time in class; (5) less homework; (6) information from the teacher; (7) feedback on how to improve work; (8) printed assignments; (9) TS+ explained to their teacher; and (10) not being punished or suspended because of TS+ behaviours. The 10 strategies most frequently endorsed by parents were: (1) the student paying attention and being informed; (2) computers; (3) the teacher telling the whole class ‘listen carefully’ when discussing important ideas; (4) providing ideas about organizing work; (5) providing printed assignments; (6) telling students when they are being helpful; (7) encouraging students for good behaviour and signaling incorrect behaviour; (8) checking students understand each idea the teacher presents; (9) outside experts explaining TS+ to the teacher; and (10) exchanging notes with the teacher. The 10 items most strongly endorsed by teachers were: (1) providing information and direction; (2) feedback on how to improve work; (3) checking students wrote down homework assignments; (4) helping students start work assignments; (5) computers; (6) spell-checkers; (7) monitoring time and work; (8) extra time; (9) feedback about the student’s behaviour and advice if misbehaving; and (10) the teacher explaining to the class how students can help students with learning challenges. Conclusions: There is considerable agreement among parents and teachers about how to help children with TS+ with their schoolwork and behaviours.

The effect of a national body checking policy change on concussion risk in youth ice hockey players

Objective To determine if the risk of game-related concussion differs for Pee Wee (11–12 years) ice hockey players in the season following a national policy change disallowing body checking (2013/2014) when compared to a season (2011/2012) when body checking was allowed. Design Historical cohort study. Setting Community ice hockey rinks. Participants Pee Wee players were recruited from 59 teams in all divisions of play in Alberta (n=883) in 2011/12 prior to the rule change and from 73 teams in 2013/14 following the rule change (n=617). Assessment of risk factors Pee Wee ice hockey players before and after a national body checking policy change. Outcome measures Suspected concussions were identified by a team therapist/safety designate and referred to a sport medicine physician. Concussions were included if they met the Zurich 2013 Consensus definition of concussion. Main results There were 104 game-related concussions (IR=2.79/1000 game-hours) in Alberta prior to the rule change and 24 concussions (IR=1.08/1000 game-hours) after. Based on a multivariable Poisson regression model adjusting for player size, age, body checking attitudes, previous injury, level of play, and position, accounting for clustering by team, the rate of concussion declined following the policy change [IRR=0.34 (95% CI; 0.21 – 0.56)]. Overall, a physician diagnosed 67.3% and 79.1% of suspected game concussions in 2011/2012 and 2013/2014, respectively. Conclusions Introduction of the national policy change disallowing body checking in Pee Wee resulted in a 66% reduction in the Alberta Pee Wee ice hockey concussion rate. These findings have important implications for youth ice hockey policy. Competing interests None.