Patient-reported outcomes in Alberta: rationale, scope, and design of a database initiative.

Background: The collection of patient reported outcomes (pros) is a standard of care in many cancer organizations. In Alberta, pros have been integrated into routine clinical practice since 2012. This longitudinal collection of pros provides a wealth of data and a unique research opportunity to improve cancer care. The goal of this pro data initiative is to establish a robust repository of information for ongoing clinical care and research focused on pros. In this paper, we describe the rationale, scope, and design of this initiative. Implementation: The initiative consists of pros and other administrative health data from the province of Alberta. Retrieval of health data from a variety of provincially governed sources will create a platform of information on pros, health outcomes, cancer data, other health conditions, and demographics. The aims of the initiative are to use the data to inform best practices at the point of care; to conduct health services research, particularly clinical epidemiology studies; and to evaluate a variety of pro-related outcomes. Discussion: Because this effort represents our first to integrate routinely collected pros with other administrative health data, a unique and robust data repository will be created. The ability to integrate various types of data will provide a comprehensive mechanism to evaluate a variety of outcomes. Because cancer care in Alberta is governed by a single health care system, the data linkages will include population health and psychosocial cancer data. We anticipate that research related to this initiative will ultimately help to inform more patient-centred care.

The association between sociodemographic and clinical characteristics and poor glycaemic control: a longitudinal cohort study.

AIMS: People with diabetes and poor glycaemic control are at higher risk of diabetes-related complications and incur higher healthcare costs. An understanding of the sociodemographic and clinical characteristics associated with poor glycaemic control is needed to overcome the barriers to achieving care goals in this population. METHODS: We used linked administrative and laboratory data to create a provincial cohort of adults with prevalent diabetes, and a measure of HbA1c that occurred at least 1 year following the date of diagnosis. The primary outcome was poor glycaemic control, defined as at least two consecutive HbA1c measurements ≥ 86 mmol/mol (10%), not including the index measurement, spanning a minimum of 90 days. We used multivariable Cox proportional hazards models to evaluate the association between baseline sociodemographic and clinical factors and poor glycaemic control. RESULTS: In this population-based cohort of 169 890 people, younger age was significantly associated with sustained poor glycaemic control, with a hazard ratio (HR) of 3.08, 95% CI (2.79-3.39) for age 18-39 years compared with age ≥ 75 years. Longer duration of diabetes, First Nations status, lower neighbourhood income quintile, history of substance abuse, mood disorder, cardiovascular disease, albuminuria and high LDL cholesterol were also associated with poor glycaemic control. CONCLUSIONS: Although our results may be limited by the observational nature of the study, the large geographically defined sample size, longitudinal design and robust definition of poor glycaemic control are important strengths. These findings demonstrate the complexity associated with poor glycaemic control and indicate a need for tailored interventions.

IgA nephropathy with early kidney disease is associated with increased arterial stiffness and renin-angiotensin system activity.

BACKGROUND: IgA nephropathy is associated with increased cardiovascular risk, though whether this is due to loss of kidney function or proteinuria is unclear. METHODS: For this study 10 normotensive IgA nephropathy subjects with early kidney disease (41±5 yrs, glomerular filtration rate (GFR) 87±9 ml/min, proteinuria 720±300 mg/d) and 10 gender- and blood pressure-matched healthy controls (36±1 yrs, estimated GFR 102±5 ml/min, proteinuria 70±6 mg/d) were studied in high-salt balance. Blood pressure and arterial stiffness, expressed as pulse wave velocity and aortic augmentation index, were measured at baseline and in response to 60 min of angiotensin II (AngII) infusion. RESULTS: At baseline, IgA nephropathy subjects demonstrated similar pulse wave velocity (8.6±0.7 vs. 8.0±0.4 m/s, p=0.5) but increased aortic augmentation index (12.6±3.1 vs. 1.8±4%, p=0.04) and a trend towards increased circulating renin-angiotensin system (RAS) components (plasma renin activity, 0.55±0.18 vs. 0.21±0.05 ng/l/s, p=0.08; angiotensin II, 25±5 vs. 16±1 ng/l, p=0.08) compared with controls. However, despite similar baseline blood pressure values (p=0.8), IgA nephropathy was associated with reduced arterial sensitivity to AngII challenge (Δmean arterial pressure: 19±4 vs. 29±1 mm Hg, p=0.05; Δpulse wave velocity: -0.06±0.6 vs. 1.5±0.3 m/s, p=0.07) compared with controls, even after multivariate analysis. CONCLUSION: Even in the setting of early kidney disease, IgA nephropathy is associated with increased arterial stiffness and decreased angiotensin II responsiveness, a marker of increased RAS activity.

Association between participation in a brief diabetes education programme and glycaemic control in adults with newly diagnosed diabetes.

AIMS: To determine the association between participation in a brief introductory didactic diabetes education programme and change in HbA1c among individuals with newly diagnosed diabetes. METHODS: We identified a population-based cohort of adults newly diagnosed with diabetes between October 2005 and June 2008 in Calgary, Canada, and conducted a retrospective cohort study by linking administrative and laboratory data with programme attendance data. We matched individuals who attended the programme within the first 6 months after diagnosis with those who did not attend, based on their propensity scores. We measured the change in HbA1c between time of diagnosis and 6-18 months later to determine the association between programme participation and change in HbA1c . RESULTS: HbA1c was measured at baseline and follow-up for 7793 individuals, including 803 programme participants. After propensity score matching, programme participation was associated with a significantly greater adjusted mean reduction in HbA1c between baseline and follow-up of 3.3 mmol/mol (95% CI 2.2-4.3) or 0.30% (95% CI 0.20-0.39). There was a significant interaction between baseline HbA1c and programme participation-the difference in adjusted mean reduction in HbA1c associated with programme participation ranged from 2.7 mmol/mol (0.25%) at baseline HbA1c of 53 mmol/mol (7%) to 6.2 mmol/mol (0.56%) at baseline HbA1c of 97 mmol/mol (11%). CONCLUSION: Despite its brevity, participation in a diabetes education programme was associated with an additional reduction in HbA1c in newly diagnosed people that was comparable with that reported in trials of programmes targeted at those with prevalent diabetes.

Sex influences the effect of body mass index on the vascular response to angiotensin II in humans.

OBJECTIVE: Sex influences the cardiorenal risk associated with body mass index (BMI). The role of the renin-angiotensin-aldosterone system in adiposity-mediated cardiorenal risk profiles in healthy, non-obese men and women was investigated. METHODS: Systemic and renal hemodynamic responses to angiotensin-II (AngII) as a function of BMI, waist and hip circumference, waist-hip ratio, as well as fat and lean mass were measured in 18 men and 25 women in high-salt balance, stratified by BMI (<25 kg/m2 (ideal body weight (IBW)) vs. ≥25 kg/m2 overweight)). RESULTS: In men (n = 7, BMI 23 ± 1 kg/m2) and women (n = 14, BMI 22 ± 2 kg/m2) of IBW, BMI was not associated with the systolic blood pressure (SBP) response to AngII. In contrast, overweight men (n = 11, 29 ± 2 kg/m2) demonstrated a progressively more blunted vasoconstrictor SBP response to AngII challenge as BMI increased (P = 0.007), even after adjustment for covariates. Women maintained the same relationship between BMI and the SBP response to AngII irrespective of weight status (P = 0.2, IBW vs. overweight women). Compared to BMI, other adiposity measures showed similar associations to systemic AngII responsiveness in men but not in women. Increasing BMI was associated with a blunted renovasoconstrictor response to AngII in all subjects, but was more pronounced in men. CONCLUSION: Sex influences the effect of adiposity on vascular angiotensin-responsiveness.

Non-linear relationship between serum 25-hydroxyvitamin D concentration and subsequent hip fracture.

UNLABELLED: Serum 25-OH vitamin D levels were compared in 254 hip fracture subjects and 2,402 matched control subjects. There was a significant inverse association between 25-OH vitamin D and hip fracture only between 0 and 70 nmol/L. INTRODUCTION: Vitamin D is integral to bone metabolism, however the utility of serum 25-OH vitamin D as a risk marker for hip fractures is controversial. METHODS: We conducted a case-control study of patients admitted to the hospitals with hip fractures in Calgary, Alberta, (catchment population 1.4 million) between January 1, 2007 and August 31, 2011. We searched the laboratory information system of Calgary Laboratory Services for serum 25-OH vitamin D levels within 6 months prior to admission on patients admitted to hospital with hip fractures. Cases were identified through the Calgary Laboratory Services laboratory information system and were matched to controls for age, sex, and month of testing. The hip fracture-25-OH vitamin D association was examined using multiple linear and spline regression. RESULTS: Of 305 subjects initially identified with hip fractures, serum 25-OH vitamin D levels were available for 254 (83 %). These were matched to 2,402 control subjects. We observed a significant (p < 0.01) non-linear relationship such that 25-OH vitamin D was inversely associated with hip fracture only below 70 nmol/L (odds ratio = 0.81 per 10 nmol/L increase; 95 % CI 0.86-0.93). CONCLUSIONS: The utility of 25-OH vitamin D level as a risk marker for hip fracture depends on the cut-off level used and was of potential use only for lower levels of 25-OH vitamin D.

Impact of gender on the cardiac autonomic response to angiotensin II in healthy humans.

Premenopausal women have a lower risk of cardiovascular disease (CVD) compared with men of a similar age. Furthermore, the regulation of factors that influence CVD appears to differ between the sexes, including control of the autonomic nervous system (ANS) and the renin-angiotensin system. We examined the cardiac ANS response to angiotensin II (Ang II) challenge in healthy subjects to determine whether differences in women and men exist. Thirty-six healthy subjects (21 women, 15 men, age 38 ± 2 years) were studied in a high-salt balance. Heart-rate variability (HRV) was calculated by spectral power analysis [low-frequency (LF) sympathetic modulation, high-frequency (HF) parasympathetic/vagal modulation, and LF:HF as a measure of overall ANS balance]. HRV was assessed at baseline and in response to graded Ang II infusions (3 ng·kg(-1)·min(-1) × 30 min; 6 ng·kg(-1)·min(-1) × 30 min). Cardiac ANS tone did not change significantly in women after each Ang II dose [3 ng·kg(-1)·min(-1) mean change (Δ)LF:HF (mean ± SE) 0.5 ± 0.3, P = 0.8, vs. baseline; 6 ng·kg(-1)·min(-1) ΔLF:HF (mean ± SE) 0.5 ± 0.4, P = 0.4, vs. baseline], whereas men exhibited an unfavorable shift in overall cardiac ANS activity in response to Ang II (ΔLF:HF 2.6 ± 0.2, P = 0.01, vs. baseline; P = 0.02 vs. female response). This imbalance in sympathovagal tone appeared to be largely driven by a withdrawal in cardioprotective vagal activity in response to Ang II challenge [ΔHF normalized units (nu), -5.8 ± 2.9, P = 0.01, vs. baseline; P = 0.006 vs. women] rather than an increase in sympathetic activity (ΔLF nu, -4.5 ± 5.7, P = 0.3, vs. baseline; P = 0.5 vs. women). Premenopausal women maintain cardiac ANS tone in response to Ang II challenge, whereas similarly aged men exhibit an unfavorable shift in cardiovagal activity. Understanding the role of gender in ANS modulation may help guide risk-reduction strategies in high-risk CVD populations.

Motivational interviewing to improve weight loss in overweight and/or obese patients: a systematic review and meta-analysis of randomized controlled trials.

Motivational interviewing, a directive, patient-centred counselling approach focused on exploring and resolving ambivalence, has emerged as an effective therapeutic approach within the addictions field. However, the effectiveness of motivational interviewing in weight-loss interventions is unclear. Electronic databases were systematically searched for randomized controlled trials evaluating behaviour change interventions using motivational interviewing in overweight or obese adults. Standardized mean difference (SMD) for change in body mass, reported as either body mass index (BMI; kg m(-2) ) or body weight (kg), was the primary outcome, with weighted mean difference (WMD) for change in body weight and BMI as secondary outcomes. The search strategy yielded 3540 citations and of the 101 potentially relevant studies, 12 met the inclusion criteria and 11 were included for meta-analysis. Motivational interviewing was associated with a greater reduction in body mass compared to controls (SMD = -0.51 [95% CI -1.04, 0.01]). There was a significant reduction in body weight (kg) for those in the intervention group compared with those in the control group (WMD = -1.47 kg [95% CI -2.05, -0.88]). For the BMI outcome, the WMD was -0.25 kg m(-2) (95% CI -0.50, 0.01). Motivational interviewing appears to enhance weight loss in overweight and obese patients.

A description of the costs of living and standard criteria deceased donor kidney transplantation.

Kidney transplantation improves quality of life and survival and is associated with lower health care costs compared with dialysis. We described and compared the costs of living and standard criteria for deceased donor kidney transplantation. Patients included adult recipients of a first kidney-only transplant between April 1, 1998, and March 31, 2006, as well as their donor information. All costs (outpatient care, diagnostic imaging, inpatient care, physician claims, laboratory tests and transplant medications) for 2 years after transplant for recipients and transplant-related costs prior to transplant (donor workup and management) were included. Complete cost information was available for 357 recipients. The mean total 2-year cost of transplantation, including donor costs, for recipients of living and deceased donors was $118 347 (95% confidence interval [CI], 110 395-126 299) and $121 121 (95% CI 114 287-127 956), respectively (p = 0.7). The mean cost for a living donor was $18 129 (95% CI 16 845-19 414) and for a deceased donor was $36 989 (95% CI 34 421-39 558). Living donor kidney transplantation has similar costs at 2 years compared with deceased donor transplantation. These results can be used by health care decision makers to inform strategies to increase donation.

Obstructive sleep apnoea is associated with diabetes in sleepy subjects.

BACKGROUND: Although obstructive sleep apnoea (OSA) has been linked to insulin resistance and glucose intolerance, it is unclear whether there is an independent association between OSA and diabetes mellitus (DM) and whether all patients with OSA are at risk. The objective of this study was to determine the association between OSA and DM in a large cohort of patients referred for sleep diagnostic testing. METHODS: A cross-sectional analysis of participants in a clinic-based study was conducted between July 2005 and August 2007. DM was defined by self-report and concurrent use of diabetic medications (oral hypoglycaemics and/or insulin). Sensitivity analysis was performed using a validated administrative definition of diabetes. OSA was defined by the respiratory disturbance index (RDI) using polysomnography or ambulatory monitoring. Severe OSA was defined as an RDI > or = 30/h. Subjective sleepiness was defined as an Epworth Sleepiness Scale score > or = 10. RESULTS: Complete data were available for 2149 patients. The prevalence of DM increased with increasing OSA severity (p<0.001). Severe OSA was associated with DM following adjustment for patient demographics, weight and neck circumference (odds ratio (OR) 2.18; 95% CI 1.22 to 3.89; p<0.01). Following a stratified analysis, this relationship was observed exclusively in sleepy patients (OR 2.59 (95% CI 1.35 to 4.97) vs 1.16 (95% CI 0.31 to 4.37) in non-sleepy patients). CONCLUSIONS: Severe OSA is independently associated with DM in patients who report excessive sleepiness. Future studies investigating the impact of OSA treatment on DM may wish to focus on this patient population.

Mortality of Canadians treated by peritoneal dialysis in remote locations.

Patients residing in remote locations may be more likely to initiate peritoneal dialysis when starting renal replacement therapy to avoid relocation. These patients may have reduced access to medical care, however. To examine the hypothesis that patients residing some distance from their nephrologists would be more likely to select peritoneal dialysis but have an increased risk of mortality, we used prospectively collected data in a random sample of 26,775 patients initiating dialysis in Canada between 1990 and 2000. The distance between the patient's residence at dialysis inception and the practice location of their nephrologists was calculated. We used Cox proportional hazard models to determine the adjusted relation between this distance and clinical outcomes over a mean follow-up period of 2.5 years up to 14 years. Remote-dwelling patients were more likely than urban dwellers to commence peritoneal dialysis in distances ranging from 50 to greater than 300 km than those residing within 50 km. The adjusted rates of death and the adjusted hazard ratio among patients initiating peritoneal dialysis was significantly higher in those living further from the nephrologists than those living within 50 km. Further study into the quality of care delivered to remote-dwelling patients on peritoneal dialysis is needed.

Patient and allograft survival of Indo Asian and East Asian dialysis patients treated in Canada.

Kidney failure is relatively common among Canadians of Asian origin. However, little is known about the health outcomes after initiation of renal replacement therapy in this population. Our study evaluates differences in the likelihood of renal transplantation and graft loss among Asian and white patients. We studied 21 523 adults of East Asian, Indo Asian or white ethnicity who had initiated dialysis in Canada from 1990-2000. Subjects were followed until death, loss to follow-up or end of study (2004). The proportion of the eligible subjects who were East Asian, Indo Asian, or white was 6, 3, and 91%, respectively. Compared to white patients, East Asian and Indo Asian patients were significantly less likely to receive a renal transplant after adjusting for potential confounding factors. This disparity is greater for transplants from living donors as compared to those from deceased donors. The adjusted death censored graft loss in transplant recipients was not significantly different between ethnic groups. The adjusted risk of death following transplantation, however, was significantly lower in Indo Asian than in white patients. Our findings show that in a Canadian population, patients of East Asian or Indo Asian origin had lower rates of renal transplantation than white patients, especially for living donor transplantation. These findings warrant further study, especially given the good graft outcomes in these individuals.

Derivation and validation of a clinical index for prediction of rapid progression of kidney dysfunction.

BACKGROUND: Chronic kidney disease is common among the elderly, and these patients are at risk of progressive kidney dysfunction. AIM: To develop an index to predict rapid progression of kidney dysfunction. DESIGN: Community-based cohort divided into derivation (n = 6789) and validation (n = 3395) subsets. METHODS: We identified 10 184 subjects aged >/=66 years from computerized laboratory data. Prescription drug data was used to define disease categories and medication exposure, and an index for predicting rapid progression of kidney dysfunction (> or =25% decline in glomerular filtration rate over a 2-year period) was obtained from a logistic regression model in the derivation cohort. The risk score for each subject was calculated by summing the component variables together, which were subsequently categorized into five risk classes. RESULTS: Five predictors of rapid progression were identified: age >75 years, cardiac disease, diabetes mellitus, gout, and use of anti-emetic medications. Rates of rapid progression for risk classes I through V were 8.6%, 10.9%, 13.9%, 15.6%, and 24.1%, respectively, for the derivation cohort, and 8.4%, 11.6%, 15.5%, 17.3%, 21.9%, respectively, for the validation cohort. The risk index distinguished between low and high risk of rapid progression, with a 2.5-fold greater risk for the highest, compared to the lowest, risk decile. DISCUSSION: Readily available clinical data can be used to identify most elderly at risk of rapid progression of kidney dysfunction. This simple index could help clinicians to identify patients at risk, and implement strategies to slow the progression of kidney dysfunction.

The 2006 Canadian Hypertension Education Program recommendations for the management of hypertension: Part I--Blood pressure measurement, diagnosis and assessment of risk.

OBJECTIVE: To provide updated, evidence-based recommendations for the diagnosis and assessment of adults with high blood pressure. OPTIONS AND OUTCOMES: For persons in whom a high blood pressure value is recorded, a diagnosis of hypertension is dependent on the appropriate measurement of blood pressure, the level of the blood pressure elevation, the approach used to monitor blood pressure (office, ambulatory or home/self), and the duration of follow-up. In addition, the presence of cardiovascular risk factors and target organ damage should be assessed to determine the urgency, intensity and type of treatment. For persons diagnosed as having hypertension, estimating the overall risk of adverse cardiovascular outcomes requires an assessment for other vascular risk factors and hypertensive target organ damage. EVIDENCE: MEDLINE searches were conducted from November 2004 to October 2005 to update the 2005 recommendations. Reference lists were scanned, experts were polled, and the personal files of the authors and subgroup members were used to identify other studies. Identified articles were reviewed and appraised using prespecified levels of evidence by content and methodological experts. As per previous years, the authors only included studies that had been published in the peer-reviewed literature and did not include evidence from abstracts, conference presentations or unpublished personal communications. RECOMMENDATIONS: The present document contains recommendations for blood pressure measurement, diagnosis of hypertension, and assessment of cardiovascular risk for adults with high blood pressure. These include the accurate measurement of blood pressure, criteria for the diagnosis of hypertension and recommendations for follow-up, assessment of overall cardiovascular risk, routine and optional laboratory testing, assessment for renovascular and endocrine causes, home and ambulatory blood pressure monitoring, and the role of echocardiography for those with hypertension. Key features of the 2006 recommendations include continued emphasis on an expedited diagnosis of hypertension, an in-depth review of the role of global risk assessment in hypertension therapy, and the use of home/self blood pressure monitoring for patients with masked hypertension (subjects with hypertension who have a blood pressure that is normal in clinic but elevated on home/self measurement). VALIDATION: All recommendations were graded according to the strength of the evidence and were voted on by the 45 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported herein received at least 95% consensus. These guidelines will continue to be updated annually.

The 2006 Canadian Hypertension Education Program recommendations for the management of hypertension: Part II - Therapy.

OBJECTIVE: To provide updated, evidence-based recommendations for the management of hypertension in adults. OPTIONS AND OUTCOMES: For lifestyle and pharmacological interventions, evidence from randomized, controlled trials and systematic reviews of trials was preferentially reviewed. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. For lifestyle interventions, blood pressure (BP) lowering was accepted as a primary outcome given the lack of long-term morbidity/mortality data in this field. For treatment of patients with kidney disease, the development of proteinuria or worsening of kidney function was also accepted as a clinically relevant primary outcome. EVIDENCE: MEDLINE searches were conducted from November 2004 to October 2005 to update the 2005 recommendations. In addition, reference lists were scanned and experts were contacted to identify additional published studies. All relevant articles were reviewed and appraised independently by content and methodological experts using prespecified levels of evidence. RECOMMENDATIONS: Lifestyle modifications to prevent and/or treat hypertension include the following: perform 30 min to 60 min of aerobic exercise four to seven days per week; maintain a healthy body weight (body mass index of 18.5 kg/m2 to 24.9 kg/m2) and waist circumference (less than 102 cm for men and less than 88 cm for women); limit alcohol consumption to no more than 14 standard drinks per week in men or nine standard drinks per week in women; follow a diet that is reduced in saturated fat and cholesterol and that emphasizes fruits, vegetables and low-fat dairy products; restrict salt intake; and consider stress management in selected individuals. Treatment thresholds and targets should take into account each individual's global atherosclerotic risk, target organ damage and comorbid conditions. BP should be lowered to less than 140/90 mmHg in all patients, and to less than 130/80 mmHg in those with diabetes mellitus or chronic kidney disease (regardless of the degree of proteinuria). Most adults with hypertension require more than one agent to achieve these target BPs. For adults without compelling indications for other agents, initial therapy should include thiazide diuretics. Other agents appropriate for first-line therapy for diastolic hypertension with or without systolic hypertension include beta-blockers (in those younger than 60 years), angiotensin-converting enzyme (ACE) inhibitors (in nonblack patients), long-acting calcium channel blockers or angiotensin receptor antagonists. Other agents for first-line therapy for isolated systolic hypertension include long-acting dihydropyridine calcium channel blockers or angiotensin receptor antagonists. Certain comorbid conditions provide compelling indications for first-line use of other agents: in patients with angina, recent myocardial infarction or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with diabetes mellitus, ACE inhibitors or angiotensin receptor antagonists (or in patients without albuminuria, thiazides or dihydropyridine calcium channel blockers) are appropriate first-line therapies; and in patients with nondiabetic chronic kidney disease, ACE inhibitors are recommended. All hypertensive patients should have their fasting lipids screened, and those with dyslipidemia should be treated using the thresholds, targets and agents recommended by the Canadian Hypertension Education Program Working Group on the management of dyslipidemia and the prevention of cardiovascular disease. Selected patients with hypertension, but without dyslipidemia, should also receive statin therapy and/or acetylsalicylic acid therapy. VALIDATION: All recommendations were graded according to strength of the evidence and voted on by the 45 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 95% consensus. These guidelines will continue to be updated annually.

Association between residence location and likelihood of kidney transplantation in Aboriginal patients treated with dialysis in Canada.

For reasons that are not well understood, Aboriginal people with end-stage renal disease (ESRD) have lower rates of kidney transplantation. We hypothesized that distance between residence location and the closest transplant center was greater in Aboriginal dialysis patients and would partially explain the lower rate of transplantation in this population. We studied a random sample of 9905 patients initiating dialysis in Canada between 1990 and 2000. We calculated the distance between residence location at dialysis inception and the closest transplant center. Cox proportional hazards models were used to examine the relation between residence location and the likelihood of transplantation over a median period of 2.3 years. The proportion of Aboriginal participants living 300 km from the closest transplant center was 25, 18, 18, and 39% respectively, compared with 55, 19, 11, and 15% among white subjects. The relative likelihood of transplantation was significantly lower for Aboriginal compared to white participants across all four distance strata, with no apparent effect of residence location. For example, the relative likelihood of transplantation was hazard ratio (HR) 0.47, 95% confidence interval (CI) (0.31-0.72) in Aboriginal participants residing 300 km from the closest transplant center. Results were similar for transplants from deceased donors and living donors, and in all seven regions studied. In conclusion, remote location of residence does not explain the lower rate of kidney transplantation among Aboriginal people treated for ESRD in Canada.

Progression of kidney dysfunction in the community-dwelling elderly.

Despite the high prevalence of chronic kidney disease among the elderly, few studies have described their loss of kidney function. We sought to determine the progression of kidney dysfunction among a community-based cohort of elderly subjects. The cohort included 10 184 subjects 66 years of age or older, who had one or more outpatient serum creatinine measurements during each of two time periods: 1 July to 31 December 2001 and 1 July to 31 December 2003. A mixed effects model, including covariates for age, gender, diabetes mellitus, and comorbidity, was used to determine the rate of decline in estimated glomerular filtration rate (eGFR, in ml/min/1.73 m2) per year over a median follow-up of 2.0 years. Subjects with diabetes mellitus had the greatest decline in eGFR of 2.1 (95% CI 1.8-2.5) and 2.7 (95% CI 2.3-3.1) ml/min/1.73 m2 per year in women and men, respectively. The rate of decline for women and men without diabetes mellitus was 0.8 (95% CI 0.6-1.0) and 1.4 (95% CI 1.2-1.6) ml/min/1.73 m2 per year. Subjects with a study mean eGFR<30 ml/min/1.73 m2, both those with and without diabetes mellitus, experienced the greatest decline in eGFR. In conclusion, we found that the majority of elderly subjects have no or minimal progression of kidney disease over 2 years. Strategies aimed at slowing progression of kidney disease should consider underlying risk factors for progression and the negligible loss of kidney function that occurs in the majority of older adults.

A case study of hospital closure and centralization of coronary revascularization procedures.

BACKGROUND: Despite nation-wide efforts to reduce health care costs through hospital closures and centralization of services, little is known about the impact of such actions. We conducted this study to determine the effect of a hospital closure in Calgary and the resultant centralization of coronary revascularization procedures from 2 facilities to a single location. METHODS: Administrative data were used to identify patients who underwent coronary artery bypass grafting (CABG), including those who had combined CABG and valve procedures, and patients who underwent percutaneous transluminal angioplasty (PTCA) in the Calgary Regional Health Authority from July 1994 to March 1998. This period represents the 21 months preceding and the 24 months following the March 1996 hospital closure. Measures, including mean number of discharges, length of hospital stay, burden of comorbidity and in-hospital death rates, were compared before and after the hospital closure for CABG and PTCA patients. Multivariate analyses were used to derive risk-adjustment models to control for sociodemographic variables and comorbidity. RESULTS: The number of patients undergoing CABG was higher in the year following than in the year preceding the hospital closure (51.6 per 100,000 before v. 67.3 per 100,000 after the closure); the same was true for the number of patients undergoing PTCA (129.8 v. 143.6 per 100,000). The burden of comorbidity was significantly higher after than before the closure, both for CABG patients (comorbidity index 1.3 before v. 1.5 after closure, p < 0.001) and for PTCA patients (comorbidity index 1.0 before v. 1.1 after, p = 0.04). After adjustment for comorbidity, the mean length of hospital stay was significantly lower after than before the closure for CABG patients (by 1.3 days) and for PTCA patients (by 1.0 days). The adjusted rates of death were slightly lower after than before the closure in the CABG group. The adjusted rates of death or CABG in the PTCA group did not differ significantly between the 2 periods. INTERPRETATION: Hospital closure and the centralization of coronary revascularization procedures in Calgary was associated with increased population rates of procedures being performed, on sicker patients, with shorter hospital stays, and, for CABG patients, a trend toward more favourable short-term outcomes. Our findings indicate that controversial changes to the structure of the health care system can occur without loss of efficiency and reduction in quality of care.

Poor long-term survival after coronary angiography in patients with renal insufficiency.

Cardiovascular disease is common among dialysis patients, but much less is known regarding non-dialysis-dependent renal insufficiency (NDDRI) and its association with cardiac disease. We undertook a study to assess the impact of renal insufficiency on survival post-coronary angiography by comparing three groups of patients: dialysis-dependent patients, patients with NDDRI (creatinine > 2.3 mg/dL), and a reference group with creatinine levels less than 2.3 mg/dL and not on dialysis therapy. We used a prospective cohort that consisted of all patients undergoing coronary angiography in Alberta, Canada, from January 1, 1995, to December 31, 1997. Of the 16,989 patients, 196 patients (1.2%) were on dialysis therapy, 262 patients (1.5%) had NDDRI, and 16,531 patients (97.3%) formed the reference group. Mortality rates 1 year after angiography were 30.2% for patients with NDDRI, 15.8% for dialysis patients, and 4.1% for the reference group. Compared with the reference group, crude 4-year survival was significantly worse for dialysis patients and those with NDDRI, with hazard ratios of 4.05 (95% confidence interval, 3.02 to 5.42) and 7.32 (95% confidence interval, 5.97 to 8.97), respectively. Even after adjusting for clinical risk factors, survival remained worse for dialysis patients and those with NDDRI, with hazard ratios of 2.59 (95% confidence interval, 1.92 to 3.49) and 2.51 (95% confidence interval, 2.02 to 3.12), respectively. We conclude that renal insufficiency, both dialysis dependent and non-dialysis dependent, is an independent risk factor for increased mortality and poor long-term survival among patients undergoing coronary angiography.