Poststroke Care Pathways and Spasticity Treatment: A Retrospective Study in Alberta

BACKGROUND

Limited evidence exists regarding care pathways for stroke survivors who do and do not receive poststroke spasticity (PSS) treatment.

METHODS

Administrative data was used to identify adults who experienced a stroke and sought acute care between 2012 and 2017 in Alberta, Canada. Pathways of stroke care within the health care system were determined among those who initiated PSS treatment (PSS treatment group: outpatient pharmacy dispensation of an anti-spastic medication, focal chemo-denervation injection, or a spasticity tertiary clinic visit) and those who did not (non-PSS treatment group). Time from the stroke event until spasticity treatment initiation, and setting where treatment was initiated were reported. Descriptive statistics were performed.

RESULTS

Health care settings within the pathways of stroke care that the PSS (n = 1,079) and non-PSS (n = 22,922) treatment groups encountered were the emergency department (86 and 84%), acute inpatient care (80 and 69%), inpatient rehabilitation (40 and 12%), and long-term care (19 and 13%), respectively. PSS treatment was initiated a median of 291 (interquartile range 625) days after the stroke event, and most often in the community when patients were residing at home (45%), followed by "other" settings (22%), inpatient rehabilitation (18%), long-term care (11%), and acute inpatient care (4%).

CONCLUSIONS

To our knowledge, this is the first population based cohort study describing pathways of care among adults with stroke who subsequently did or did not initiate spasticity treatment. Areas for improvement in care may include strategies for earlier identification and treatment of PSS.

Benzodiazepine use in medical cannabis authorization adult patients from 2013 to 2021: Alberta, Canada

BACKGROUND

Benzodiazepines are a class of medications that are being frequently prescribed in Canada but carry significant risk of harm. There has been increasing clinical interest on the potential "sparing effects" of medical cannabis as one strategy to reduce benzodiazepine use. The objective of this study as to examine the association of medical cannabis authorization with benzodiazepine usage between 2013 and 2021 in Alberta, Canada.

METHODS

A propensity score matched cohort study with patients on regular benzodiazepine treatment authorized to use medical cannabis compared to controls who do not have authorization for medical cannabis. A total of 9690 medically authorized cannabis patients were matched to controls. To assess the effect of medical cannabis use on daily average diazepam equivalence (DDE), interrupted time series (ITS) analysis was used to assess the change in the trend of DDE in the 12 months before and 12 months after the authorization of medical cannabis.

RESULTS

Over the follow-up period after medical cannabis authorization, there was no overall change in the DDE use in authorized medical cannabis patients compared to matched controls (- 0.08 DDE, 95% CI: - 0.41 to 0.24). Likewise, the sensitivity analysis showed that, among patients consuming ≤5 mg baseline DDE, there was no change immediately after medical cannabis authorization compared to controls (level change, - 0.04 DDE, 95% CI: - 0.12 to 0.03) per patient as well as in the month-to-month trend change (0.002 DDE, 95% CI: - 0.009 to 0.12) per patient was noted.

CONCLUSIONS

This short-term study found that medical cannabis authorization had minimal effects on benzodiazepine use. Our findings may contribute ongoing evidence for clinicians regarding the potential impact of medical cannabis to reduce benzodiazepine use.

HIGHLIGHTS

• Medical cannabis authorization had little to no effect on benzodiazepine usage among patients prescribed regular benzodiazepine treatment in Alberta, Canada. • Further clinical research is needed to investigate the potential impact of medical cannabis as an alternative to benzodiazepine medication.

Disease-modifying therapy use and health resource utilisation associated with multiple sclerosis over time: A retrospective cohort study from Alberta, Canada

BACKGROUND

Estimating multiple sclerosis (MS) prevalence and incidence, and assessing the utilisation of disease-modifying therapies (DMTs) and healthcare resources over time is critical to understanding the evolution of disease burden and impacts of therapies upon the healthcare system.

METHODS

A retrospective population-based study was used to determine MS prevalence and incidence (2003-2019), and describe utilisation of DMTs (2009-2019) and healthcare resources (1998-2019) among people living with MS (pwMS) using administrative data in Alberta.

RESULTS

Prevalence increased from 259 (95% confidence interval [CI]: 253-265) to 310 (95% CI: 304, 315) cases per 100,000 population, and incidence decreased from 21.2 (95% CI: 19.6-22.8) to 12.7 (95% CI: 11.7-13.8) cases per 100,000 population. The proportion of pwMS who received ≥1 DMT dispensation increased (24% to 31% annually); use of older platform injection therapies decreased, and newer oral-based, induction, and highly-effective therapies increased. The proportion of pwMS who had at least one MS-related physician, ambulatory, or tertiary clinic visits increased, and emergency department visits and hospitalizations decreased.

CONCLUSIONS

Alberta has one of the highest rates of MS globally. The proportion of pwMS who received DMTs and had outpatient visits increased, while acute care visits decreased over time. The landscape of MS care appears to be rapidly evolving in response to changes in disease burden and new highly-effective therapies.

The impact of the Starting dialysis on Time, At home on the Right Therapy (START) project on the use of peritoneal dialysis

BACKGROUND

Peritoneal dialysis (PD) is actively promoted, but increasing PD utilisation is difficult. The objective of this study was to determine if the Starting dialysis on Time, At Home, on the Right Therapy (START) project was associated with an increase in the proportion of dialysis patients receiving PD within 6 months of starting therapy.

METHODS

Consecutive patients over age 18, with end-stage kidney failure, who started dialysis between 1 April 2015 and 31 March 2018 in the province of Alberta, Canada. Programmes were provided with high-quality data about the individual steps in the process of care that drive PD utilisation that were used to identify problem areas, design and implement interventions to address them, and then evaluate whether those interventions had impact. The primary outcome was the proportion of patients receiving PD within 6 months of starting dialysis. Secondary outcomes included hospitalisation, death or probability of transfer to haemodialysis (HD). Interrupted time series methodology was used to evaluate the impact of the quality improvement initiative on the primary and secondary outcomes.

RESULTS

A total of 1962 patients started dialysis during the study period. Twenty-seven per cent of incident patients received PD at baseline, and there was a 5.4% (95% confidence interval: 1.5-9.2) increase in the use of PD in the province immediately after implementation. There were no changes in the rates of hospitalisation, death or probability of transfer to HD after the introduction of START.

CONCLUSIONS

The approach used in the START project was associated with an increase in the use of PD in a setting with high baseline utilisation.

Trajectory of health care resources among adults stopping or reducing treatment frequency of botulinum toxin for chronic migraine treatment in Alberta, Canada

OBJECTIVE

Understand health resource, medication use, and cost of adults with chronic migraine who received guideline-recommended onabotulinumtoxinA (botulinum toxin) treatment frequency and then continued or reduced/stopped.

BACKGROUND

Botulinum toxin may be a beneficial treatment for chronic migraine; the trajectory of health resources utilization among those with continued or reduced/stopped use is unclear.

METHODS

A retrospective population-based cohort study utilizing administrative data from Alberta, Canada (2012-2020), was performed. A cohort of adults who received ≥5 botulinum toxin treatment cycles for chronic migraine over 18 months (6-month run-in; 1-year pre-index period) were grouped into those who (1) continued use (≥3 treatments/year), or (2) stopped or reduced use (stopped for 6 months then received 0 or 1-2 treatments/year, respectively) over a 1-year post-index period. Health resources and medication use were described, and pre-post costs were assessed. A second cohort that received ≥3 treatments/year immediately followed by 1 year of stopped or reduced use was considered in sensitivity analysis.

RESULTS

Pre-post health resource, medication use, and costs were similar among those with continued use (n = 3336). Among those who stopped or reduced use (n = 1099; 756 stopped, 343 reduced), health resource, medication use, and costs were lower in the post- (total median per-person cost [IQR]: all-cause $4851 [$8090]; migraine-related $835 [$1915]) versus pre- (all-cause $6096 [$7207]; migraine-related $2995 [$1950]) index period (estimated cost ratios [95% CI]: total all-cause 0.86 [0.79, 0.95]; total migraine-related 0.44 [0.40, 0.48]). In the second cohort (n = 3763), return to continued use (≥3 treatments/year) occurred in up to 70.4% in those with reduced use.

CONCLUSIONS

Of adults treated with botulinum toxin for chronic migraine, 75.2% had continued use, stable health resource and medication use, and costs over a 2 year period. In those that stopped/reduced use, the observed lower health resource and migraine medication use may indicate improved symptom control, but the resumption of guideline-recommended treatment intervals after reduced use was common.

Incidence and prevalence, and medication use among adults living with dermatomyositis: an Alberta, Canada population-based cohort study

Dermatomyositis is a rare disease characterized by progressive muscle weakness and skin rashes. Estimates of incidence and prevalence are fundamental measures in epidemiology, but few studies have been conducted on dermatomyositis. To address this knowledge gap, we conducted a population-based study to determine the contemporary incidence (between 2013 and 2019) and prevalence (2019) of adults living with dermatomyositis using administrative health data in Alberta, Canada. We also described disease-related medication use, as there are very few approved medications for the treatment of dermatomyositis, and no Canadian therapeutic guidelines. The average age- and sex-standardized annual incidence of dermatomyositis was 2.8-3.0 cases per 100,000 adults, and prevalence was 28.6 cases per 100,000 adults, which is greater than reported in other cohorts. Dermatomyositis-related medication use decreased from 73% in the first year to 46% in the eighth year after diagnosis. Glucocorticoids were the most commonly used drug class, often taken concurrently with various immunomodulatory agents; this medication use aligns with empirically-based recommendations and the few therapeutic guidelines for dermatomyositis. Considering that Alberta may have one of the highest rates of dermatomyositis among adults, further research on the burden of disease is warranted for planning within the health care system.

Health care cost of severe obesity and obesity-related comorbidities: A retrospective cohort study from Alberta, Canada

BACKGROUND

Estimates of health care costs associated with severe obesity, and those attributable to specific health conditions among adults living with severe obesity are needed.

METHODS

Administrative data was used to identify adults who previously received a procedure, and had (investigational cohort) or did not have (control cohort) a body mass index ≥ 35 kg/m2. Two-part models were used to estimate the incremental health care cost of severe obesity and related health conditions during a 1-year observation period.

RESULTS

Adjusting for potential confounders, the total health care cost ratio was higher in the investigational (n = 220,190) versus control (n = 1,955,548) cohort (1.32 [95 % CI: 1.32, 1.33]) with a predicted incremental cost of $2221 (95 % CI $2184, $22,265) per person-year; costs were less when obesity-related health conditions were controlled for (1.13 [95 % CI: 1.13, 1.14]; $1097 [95 % CI: $1084, $1110] per person-year). Among those living with severe obesity, incremental costs associated with specific health conditions ranged from $737 (95 % CI: $747, $728) lower (dyslipidemia) to $12,996 (95 % CI: $12,512, $13,634) higher (peripheral vascular disease) per person-year.

CONCLUSIONS

Adults living with severe obesity had greater costs than those without, largely driven by obesity-related health conditions. For the Alberta adult population with a severe obesity prevalence of 11 %, severe obesity may account for an estimated additional $453-918 million in health care costs per year. Findings of this study provide rationale for resources and strategies to prevent and manage obesity and its complications.

Analgesic Use Among Adults with a Trauma-Related Emergency Department Visit: A Retrospective Cohort Study from Alberta, Canada

INTRODUCTION

A better understanding of current acute pain-driven analgesic practices within the emergency department (ED) and upon discharge will provide foundational information in this area, as few studies have been conducted in Canada.

METHODS

Administrative data were used to identify adults with a trauma-related ED visit in the Edmonton area in 2017/2018. Characteristics of the ED visit included time from initial contact to analgesic administration, type of analgesics dispensed during and upon being discharged home directly from the ED (≤ 7 days after), and patient characteristics.

RESULTS

A total of 50,950 ED visits by 40,505 adults with trauma were included. Analgesics were administered in 24.2% of visits, of which non-opioids were dispensed in 77.0% and opioids were dispensed in 49.0%. Time to analgesic initiation occurred more than 2 h after first contact. Upon discharge, 11.5% received a non-opioid and 15.2% received an opioid analgesic, among whom 18.5% received a daily dose ≥ 50 morphine milligram equivalents (MME) and 30.2% received > 7 days of supply. Three hundred and seventeen adults newly met criteria for chronic opioid use after the ED visit, among whom 43.5% received an opioid dispensation upon discharge; of these individuals, 26.8% had a daily dose ≥ 50 MME and 65.9% received > 7 days of supply.

CONCLUSIONS

Findings can be used to inform optimization of analgesic pharmacotherapy practices for the treatment of acute pain, which may include reducing the time to initiation of analgesics in the ED, as well as close consideration of recommendations for acute pain management upon discharge to provide ideal patient-centered, evidence-informed care.

Associations between hearing loss and clinical outcomes: population-based cohort study

Background

Hearing loss (HL) is a leading cause of disability worldwide, but its clinical consequences and population burden have been incompletely studied.

Methods

We did a retrospective population-based cohort study of 4,724,646 adults residing in Alberta between April 1, 2004 and March 31, 2019, of whom 152,766 (3.2%) had HL identified using administrative health data. We used administrative data to identify comorbidity and clinical outcomes, including death, myocardial infarction, stroke/transient ischemic attack, depression, dementia, placement in long-term care (LTC), hospitalization, emergency visits, pressure ulcers, adverse drug events and falls. We used Weibull survival models (binary outcomes) and negative binomial models (rate outcomes) to compare the likelihood of outcomes in those with vs without HL. We calculated population-attributable fractions to estimate the number of binary outcomes associated with HL.

Findings

The age-sex-standardized prevalence of all 31 comorbidities at baseline was higher among participants with HL than those without. Over median follow-up of 14.4 y and after adjustment for potential confounders at baseline, participants with HL had higher rates of days in hospital (rate ratio 1.65, 95% CI 1.39, 1.97), falls (RR 1.72, 95% CI 1.59, 1.86), adverse drug events (RR 1.40, 95% CI 1.35, 1.45), and emergency visits (RR 1.21, 95% CI 1.14, 1.28) compared to those without, and higher adjusted hazards of death, myocardial infarction, stroke/transient ischemic attack, depression, heart failure, dementia, pressure ulcers and LTC placement. The estimated number of people with HL who required new LTC placement annually in Canada was 15,631, of which 1023 were attributable to HL. Corresponding estimates for new dementia among people with HL were 14,959 and 4350, and for stroke/TIA the estimates were 11,582 and 2242.

Interpretation

HL is common, is often accompanied by substantial comorbidity, and is associated with significant increases in risk for a broad range of adverse clinical outcomes, some of which are potentially preventable. This high population health burden suggests that increased and coordinated investment is needed to improve the care of people with HL.

Funding

Canadian Institutes of Health Research; David Freeze chair in health services research.

Population-Based Analysis of Nonsteroidal Anti-inflammatory Drug Prescription in Subjects With Chronic Kidney Disease

Background

Pain is a prevalent symptom experienced by patients with chronic kidney disease (CKD) and appropriate management of pain is an important element of comprehensive care. Nonsteroidal anti-inflammatory drugs (NSAID) are known to be nephrotoxic in persons with CKD.

Objective

This study examined the pattern of NSAID prescribing practices in a population based-cohort of patients with CKD.

Design

Retrospective cohort study using linked population-based health care data.

Setting

Entire province of Alberta, Canada.

Participants

All adults in Alberta with eGFR defined CKD G3 or greater between 2009 and 2017 were included.

Measurements

CKD was defined using at least 2 outpatient serum creatinine (SCr) greater than 90 days apart; the date of second SCr measurement was used as index date. We determined the incidence of hyperkalemia using the peak serum potassium. Prescription drug information was obtained from the Pharmaceutical Information Network (PIN) database.

Methods

All patients were followed from the index date until March 31, 2019, with a minimum follow-up of 2 years. Prescription drug information and the follow-up laboratory testing of serum creatinine and serum potassium were obtained. Patients with kidney failure defined as eGFR < 15 mL/min per 1.73 m², receiving chronic dialysis, or prior kidney transplant at baseline were excluded.

Results

A total of 170 574 adults (mean age 76.3; 44% male) with CKD were identified and followed for a median of 7 years; 27% were dispensed at least 1 NSAID prescription. While there was a trend toward fewer prescriptions in patients with more advanced CKD (P < .001), 16% of those with CKD G4 were prescribed an NSAID. Primary care providers provided 79% of the prescriptions. Among NSAID users, 21% had a follow-up serum creatinine (SCr) within 30 days of the index prescription.

Limitations

Data collected were from clinical and administrative databases not created for research purposes. The study cohort is limited to subjects who sought medical care and had a serum creatinine measurement obtained. Measurement of NSAID use is limited to those who were dispensed a prescription, over-the-counter NSAIDs use is not captured.

Conclusions

Despite guidelines advocating cautious use of NSAIDs in patients with CKD, this study indicates that there is a discrepancy from best practice recommendations. Effective strategies to better support and educate prescribers, as well as patients, may help reduce inappropriate prescribing and adverse events.

Long-Term Outcomes for Living Kidney Donors With Early Guideline-Concordant Follow-up Care: A Retrospective Cohort Study

Background

Current guidelines recommend that living kidney donors receive lifelong annual follow-up care to monitor kidney health. In the United States, the reporting of complete clinical and laboratory data for kidney donors has been mandated for the first 2 years post-donation; however, the long-term impact of early guideline-concordant care remains unclear.

Objective

The primary objective of this study was to compare long-term post-donation follow-up care and clinical outcomes of living kidney donors with and without early guideline-concordant follow-up care.

Design

Retrospective, population-based cohort study.

Setting

Linked health care databases were used to identify kidney donors in Alberta, Canada.

Patients

Four hundred sixty living kidney donors who underwent nephrectomy between 2002 and 2013.

Measurements

The primary outcome was continued annual follow-up at 5 and 10 years (adjusted odds ratio with 95% confidence interval, _LCLaOR_UCL). Secondary outcomes included mean change in estimated glomerular filtration rate (eGFR) over time and rates of all-cause hospitalization.

Methods

We compared long-term follow-up and clinical outcomes for donors with and without early guideline-concordant care, defined as annual physician visit and serum creatinine and albuminuria measurement for the first 2 years post-donation.

Results

Of the 460 donors included in this study, 187 (41%) had clinical and laboratory evidence of guideline-concordant follow-up care throughout the first 2 years post-donation. The odds of receiving annual follow-up for donors without early guideline-concordant care were 76% lower at 5 years (aOR _0.180.24_0.32) and 68% lower at 10 years (aOR _0.230.32_0.46) compared with donors with early care. The odds of continuing follow-up remained stable over time for both groups. Early guideline-concordant follow-up care did not appear to substantially influence eGFR or hospitalization rates over the longer term.

Limitations

We were unable to confirm whether the lack of physician visits or laboratory data in certain donors was due to physician or patient decisions.

Conclusions

Although policies directed toward improving early donor follow-up may encourage continued follow-up, additional strategies may be necessary to mitigate long-term donor risks.

Economic impact of self-administered subcutaneous versus clinic-administered intravenous immunoglobulin G therapy in Alberta, Canada: a population-based cohort study

BACKGROUND

Self-administered subcutaneous immunoglobulin G (SCIg) reduces nursing time and eliminates the need for treatment at ambulatory care clinics, as compared with clinic-based intravenously administered IgG (IVIg), and are therapeutically equivalent. Estimating the economic impact of self-administered SCIg versus clinic-administered IVIg therapy may guide treatment recommendations.

METHODS

A retrospective population-based cohort study using administrative data from Alberta was performed; those treated with IgG between April 1, 2012 and March 31, 2019 were included. Costs for medical laboratory staff and nursing time, as well as ambulatory care visits were considered. Univariate generalized linear model regression with gamma distribution and log link was used to compare cost ($CDN 2020) between SCIg and IVIg administration. Stratified analysis by age (≥ 18-years; < 18-years) was performed.

RESULTS

Among 7,890 (6,148 adults; 1,742 children) individuals who received IgG, the average administration cost per patient-year of self-administered SCIg was $5,386 (95% confidence interval [CI] $5,039, $5,734) lower than clinic-administered IVIg; per patient-year cost of self-administered SCIg was $817 (95% CI $723, $912) versus $6,204 (95% CI $6,100, $6,308) for clinic-administered IVIg. The per patient-year cost of self-administered SCIg was $5,931 (95% CI $5,543, $6,319) lower among adults and $3,177 (95% CI $2,473, $3,882) lower among children compared with clinic-administered IVIg. An estimated $31.0 million (95% CI $29.0, $33.0) in cost savings to the health system would be realised if 80% of individuals switched from clinic-administered IVIg to self-administered SCIg.

CONCLUSIONS

Self-administered SCIg is substantially less costly from a health care payer perspective in Canada. Within this type of health system, switching to self-administered SCIg has the potential to reduce overall health care costs, lessen nursing burden, and may increase clinic-based capacity for others.

Effect of Clinical Decision Support With Audit and Feedback on Prevention of Acute Kidney Injury in Patients Undergoing Coronary Angiography: A Randomized Clinical Trial

IMPORTANCE

Contrast-associated acute kidney injury (AKI) is a common complication of coronary angiography and percutaneous coronary intervention (PCI) that has been associated with high costs and adverse long-term outcomes.

OBJECTIVE

To determine whether a multifaceted intervention is effective for the prevention of AKI after coronary angiography or PCI.

DESIGN, SETTING, AND PARTICIPANTS

A stepped-wedge, cluster randomized clinical trial was conducted in Alberta, Canada, that included all invasive cardiologists at 3 cardiac catheterization laboratories who were randomized to various start dates for the intervention between January 2018 and September 2019. Eligible patients were aged 18 years or older who underwent nonemergency coronary angiography, PCI, or both; who were not undergoing dialysis; and who had a predicted AKI risk of greater than 5%. Thirty-four physicians performed 7820 procedures among 7106 patients who met the inclusion criteria. Participant follow-up ended in November 2020.

INTERVENTIONS

During the intervention period, cardiologists received educational outreach, computerized clinical decision support on contrast volume and hemodynamic-guided intravenous fluid targets, and audit and feedback. During the control (preintervention) period, cardiologists provided usual care and did not receive the intervention.

MAIN OUTCOMES AND MEASURES

The primary outcome was AKI. There were 12 secondary outcomes, including contrast volume, intravenous fluid administration, and major adverse cardiovascular and kidney events. The analyses were conducted using time-adjusted models.

RESULTS

Of the 34 participating cardiologists who were divided into 8 clusters by practice group and center, the intervention group included 31 who performed 4327 procedures among 4032 patients (mean age, 70.3 [SD, 10.7] years; 1384 were women [32.0%]) and the control group included 34 who performed 3493 procedures among 3251 patients (mean age, 70.2 [SD, 10.8] years; 1151 were women [33.0%]). The incidence of AKI was 7.2% (310 events after 4327 procedures) during the intervention period and 8.6% (299 events after 3493 procedures) during the control period (between-group difference, -2.3% [95% CI, -0.6% to -4.1%]; odds ratio [OR], 0.72 [95% CI, 0.56 to 0.93]; P = .01). Of 12 prespecified secondary outcomes, 8 showed no significant difference. The proportion of procedures in which excessive contrast volumes were used was reduced to 38.1% during the intervention period from 51.7% during the control period (between-group difference, -12.0% [95% CI, -14.4% to -9.4%]; OR, 0.77 [95% CI, 0.65 to 0.90]; P = .002). The proportion of procedures in eligible patients in whom insufficient intravenous fluid was given was reduced to 60.8% during the intervention period from 75.1% during the control period (between-group difference, -15.8% [95% CI, -19.7% to -12.0%]; OR, 0.68 [95% CI, 0.53 to 0.87]; P = .002). There were no significant between-group differences in major adverse cardiovascular events or major adverse kidney events.

CONCLUSIONS AND RELEVANCE

Among cardiologists randomized to an intervention including clinical decision support with audit and feedback, patients undergoing coronary procedures during the intervention period were less likely to develop AKI compared with those treated during the control period, with a time-adjusted absolute risk reduction of 2.3%. Whether this intervention would show efficacy outside this study setting requires further investigation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03453996.

Age, multimorbidity and dementia with health care costs in older people in Alberta: a population-based retrospective cohort study

BACKGROUND

The growing burden associated with population aging, dementia and multimorbidity poses potential challenges for the sustainability of health systems worldwide. We sought to examine how the intersection among age, dementia and greater multimorbidity is associated with health care costs.

METHODS

We did a retrospective population-based cohort study in Alberta, Canada, with adults aged 65 years and older between April 2003 and March 2017. We identified 31 morbidities using algorithms (30 algorithms were validated), which were applied to administrative health data, and assessed costs associated with hospital admission, provider billing, ambulatory care, medications and long-term care (LTC). Actual costs were used for provider billing and medications; estimated costs for inpatient and ambulatory patients were based on the Canadian Institute for Health Information's resource intensive weights and Alberta's cost of a standard hospital stay. Costs for LTC were based on an estimated average daily cost.

RESULTS

There were 827 947 people in the cohort. Dementia was associated with higher mean annual total costs and individual mean component costs for almost all age categories and number of comorbidities categories (differences in total costs ranged from $27 598 to $54 171). Similarly, increasing number of morbidities was associated with higher mean total costs and component costs (differences in total costs ranged from $4597 to $10 655 per morbidity). Increasing age was associated with higher total costs for people with and without dementia, driven by increasing LTC costs (differences in LTC costs ranged from $115 to $9304 per age category). However, there were no consistent trends between age and non-LTC costs among people with dementia. When costs attributable to LTC were excluded, older age tended to be associated with lower costs among people with dementia (differences in non-LTC costs ranged from -$857 to -$7365 per age category).

INTERPRETATION

Multimorbidity, older age and dementia were all associated with increased use of LTC and thus health care costs, but some costs among people with dementia decreased at older ages. These findings illustrate the complexity of projecting the economic consequences of the aging population, which must account for the interplay between multimorbidity and dementia.

Mortality and Resource Use Among Individuals With Chronic Kidney Disease or Cancer in Alberta, Canada, 2004-2015

IMPORTANCE

Although the public is aware that cancer is associated with excess mortality and adverse outcomes, the clinical consequences of chronic kidney disease (CKD) are not well understood.

OBJECTIVE

To compare the clinical consequences of incident severe CKD and the first diagnosis with a malignant tumor, focusing on the 10 leading causes of cancer in men and women residing in Canada.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study enrolled individuals aged 19 years and older with severe CKD or certain types of cancer between 2004 and 2015 in Alberta, Canada. Data were analyzed in November 2021.

EXPOSURES

Individuals were categorized as having severe CKD (based on estimated glomerular filtration rate <30 mL/min/1.73 m2 or nephrotic albuminuria without dialysis or kidney transplantation) or nonmetastatic or metastatic cancer (defined by a diagnosis of lung, breast, colorectal, prostate, bladder, thyroid, kidney or renal pelvis, uterus, pancreas, or oral cancer).

MAIN OUTCOMES AND MEASURES

All-cause mortality, number of hospitalizations, total number of hospital days, and placement into long-term care were calculated after diagnosis.

RESULTS

Of 200 494 individuals in the cohort (104 559 women [52.2%]; median [IQR] age, 66.8 [55.9-77.7] years), 51 159 (25.5%) had incident severe CKD, 115 504 (57.6%) had nonmetastatic cancer, and 33 831 (16.9%) had metastatic cancer. Kaplan-Meier 1-year survival was 83.3% (95% CI, 83.0%-83.6%) for patients with CKD, 91.2% (95% CI, 91.0%-91.4%) for patients with nonmetastatic cancer, and 52.8% (95% CI, 52.2%-53.3%) for patients with metastatic cancer. Kaplan-Meier 5-year survival was 54.6% (95% CI, 54.2%-55.1%) for patients with CKD, 76.6% (95% CI, 76.3%-76.8%) for patients with nonmetastatic cancer, and 33.9% (95% CI, 33.3%-34.4%) for patients with metastatic cancer. Compared with nonmetastatic cancer, the age-, sex-, and comorbidity-adjusted relative rate of death was similar for CKD (adjusted relative rate, 1.00; 95% CI, 0.97-1.03; P = .92) during the first year of follow-up and was higher for CKD at years 1 to 5 (adjusted relative rate 1.23; 95% CI, 1.19-1.26). During the first year of follow-up, for patients with CKD, adjusted rates of placement in long-term care (adjusted relative rate, 0.88; 95% CI, 0.82-0.94) and hospitalization (adjusted relative rate, 0.65; 95% CI, 0.64-0.66) were lower than rates for patients with nonmetastatic cancer; however, those rates were higher for the CKD group than for the nonmetastatic cancer group during years 1 to 5 (long-term care placement, adjusted relative rate, 1.36; 95% CI, 1.29-1.43; hospitalization, adjusted relative rate, 1.55; 95% CI, 1.52-1.58). As expected, adjusted rates of long-term care placement and hospitalization were higher for patients with metastatic cancer than for the other 2 groups.

CONCLUSIONS AND RELEVANCE

In this study, mortality, hospitalization, and likelihood of placement into long-term care were similar for CKD and nonmetastatic cancer. These data highlight the importance of CKD as a public health problem.

The real-world cost-effectiveness of bariatric surgery for the treatment of severe obesity: a cost-utility analysis

BACKGROUND

Severe obesity is associated with adverse health outcomes and increased risk of death. This study evaluates the real-world cost-utility of therapy for severe obesity, from the publicly funded health care system and societal perspectives.

METHODS

We conducted a cost-utility analysis using primary data from a prospective observational cohort of adults living with severe obesity (BMI ≥ 35 kg/m² and a major medical comorbidity or BMI ≥ 40 kg/m²) who were enrolled in a regional obesity program over 2 years. We extrapolated 10-year and lifetime Markov models, validated and supplemented with literature sources, to compare medical, surgical and standard care therapies. We performed deterministic and probabilistic sensitivity analyses.

RESULTS

The cohort included 500 adults living with severe obesity, 150 of whom received laparoscopic surgical therapy. From a publicly funded health system perspective, at 2 years, surgical therapy had an incremental cost-effectiveness ratio (ICER) of $54 456 per quality-adjusted life-year (QALY) compared with standard care therapy. Over a lifetime, it had an ICER of $14 056 per QALY. From the societal perspective, at 2 years, surgical therapy had an ICER of $340 per QALY; over a lifetime, it was the dominant option. The results were robust to sensitivity analysis.

INTERPRETATION

From a public health care perspective, surgery for severe obesity is cost effective, and when approached from a societal perspective, it becomes cost saving. Real-world data support using surgical therapy for severe obesity, and our results contribute to the health economic and clinical literature with regard to a robust analysis from a societal perspective.

Secular Changes in Mortality and Hospitalization over Time in People with Kidney Failure or Severe CKD as Compared with Other Noncommunicable Diseases

Background

Few new treatments have been developed for kidney failure or CKD in recent years, leading to perceptions of slower improvement in outcomes associated with CKD or kidney failure than for other major noncommunicable diseases.

Methods

Our retrospective cohort study included 548,609 people with an incident noncommunicable disease, including cardiovascular diseases, diabetes, various cancers, and severe CKD or kidney failure treated with renal replacement (KF-RRT), treated in Alberta, Canada, 2004–2015. For each disease, we assessed presence or absence of 8 comorbidities; we also compared secular trends in relative (compared to a referent year of 2004) and absolute risks of mortality and mean annual days in the hospital associated with each disease after 1 year and 5 years.

Results

Comorbidities increased significantly in number over time for all noncommunicable diseases except diabetes, and increased most rapidly for CKD and KF-RRT. Significant but relatively small reductions over time in the risk ratio of mortality at 1 year occurred for nearly all noncommunicable diseases. Secular trends in the absolute risk of mortality were similar; CKD and KF-RRT had a relatively favorable ranking at 1 year. Breast cancer, KF-RRT, diabetes, and colorectal cancer displayed the largest relative reductions in number of hospital days at 1 year. Significant absolute reductions in the number of hospital days were observed for both KF-RRT and CKD; the former had the highest absolute reduction among all noncommunicable diseases. Results were similar at 5 years.

Conclusions

We observed secular reductions in mortality and annual hospital days at 1 year and 5 years among incident patients with KF-RRT and severe CKD, as well as several other common noncommunicable diseases.

A Cost Analysis and Cost-Utility Analysis of a Community Pharmacist-Led Intervention on Reducing Cardiovascular Risk: The Alberta Vascular Risk Reduction Community Pharmacy Project (RxEACH)

BACKGROUND

A randomized trial (the Alberta Vascular Risk Reduction Community Pharmacy Project) showed that a community pharmacist-led intervention was efficacious for reducing cardiovascular (CV) risk. However, the cost of this strategy is unknown.

OBJECTIVES

We examined the short- and long-term cost of a pharmacist-led intervention to reduce CV risk compared to usual care.

METHODS

We conducted a trial-based cost analysis from the perspective of a publicly funded healthcare system. Over 3 and 12 months of follow-up, we examined specific intervention costs (pharmacy claims), related intervention costs (laboratory tests and medications), and ongoing healthcare costs (physician claims, emergency department visits, and hospital admissions). We also used the validated CV Disease Policy Model-Canada to estimate the long-term effects.

RESULTS

A total of 684 participants (mean age 62, 57% male) were included. Overall, there were no significant differences in healthcare costs at 3 or 12 months between the usual care and intervention groups (P = .127). The CV disease-related healthcare cost of managing a patient over a lifetime was estimated to be Can$45 530 (95% uncertainty interval [UI], 45 460-45 580) and Can$40 750 (95% UI, 37 780-43 620) in usual care and intervention groups, respectively, an incremental cost savings of Can$4770 per patient (95% UI, 1900-7760). The intervention dominated usual care (better outcomes and lower costs) across 3-year, 5-year, 10-year, and lifetime horizons.

CONCLUSION

This economic analysis suggests that a clinical pathway-driven pharmacist-led intervention (previously shown to reduce CV risk) was associated with similar measured healthcare costs over 1 year, and lower extrapolated healthcare costs over a patient lifetime. This strategy could be broadly implemented to realize its benefits.

Canadian-Australasian Randomised trial of screening kidney transplant candidates for coronary artery disease-A trial protocol for the CARSK study

Transplantation is the preferred treatment for patients with kidney failure, but the need exceeds the supply of transplantable kidneys, and patients routinely wait >5 years on dialysis for a transplant. Coronary artery disease (CAD) is common in kidney failure and can exclude patients from transplantation or result in death before or after transplantation. Screening asymptomatic patients for CAD using noninvasive tests prior to wait-listing and at regular intervals (ie, annually) after wait-listing until transplantation is the established standard of care and is justified by the need to avoid adverse patient outcomes and loss of organs. Patients with abnormal screening tests undergo coronary angiography, and those with critical stenoses are revascularized. Screening is potentially harmful because patients may be excluded or delayed from transplantation, and complications after revascularization are more frequent in this population. CARSK will test the hypothesis that eliminating screening tests for occult CAD after wait-listing is not inferior to regular screening for the prevention of major adverse cardiac events defined as the composite of cardiovascular death, nonfatal myocardial infarction, urgent revascularization, and hospitalization for unstable angina. Secondary outcomes include the transplant rate, safety measures, and the cost-effectiveness of screening. Enrolment of 3,306 patients over 3 years is required, with patients followed for up to 5 years during wait-listing and for 1 year after transplantation. By validating or refuting the use of screening tests during wait-listing, CARSK will ensure judicious use of health resources and optimal patient outcomes.

Characteristics of Adults With Type 2 Diabetes Mellitus by Category of Chronic Kidney Disease and Presence of Cardiovascular Disease in Alberta Canada: A Cross-Sectional Study

Background:

Type 2 diabetes mellitus (T2DM) is associated with an excess risk of cardiovascular disease (CVD) and chronic kidney disease (CKD). Although CVD, CKD, and use of antihyperglycemic treatments are all key drivers of the costs and consequences experienced by people with diabetes, no recent Canadian data describe these characteristics among adults with diabetes.

Objective:

To describe prevalence of CVD, CKD, and use of antihyperglycemic treatments among adults with diabetes.

Design:

Retrospective population-based, cross-sectional study.

Setting:

Alberta, Canada.

Patients:

All adults with T2DM as of March 31, 2017.

Measurements:

We described the demographic and clinical characteristics by CKD stage and CVD status and type. CKD stage was categorized according to international guidelines and based on estimated glomerular filtration rate (eGFR) and severity of albuminuria.

Methods:

Clinical and demographic characteristics were defined using provincial administrative data; medication use was based on data from the provincial drug plan. Additional analyses examined subgroups based on demographic characteristics, clinical characteristics, and medication use.

Results:

There were 260 903 participants, all of whom had T2DM. Median age was 64 years; 53.6% were male; and 10.9% lived in rural communities. Median duration of diabetes was 7.7 years. Half of the participants had A1C <7%. Overall, 33.0% had CKD; among these most had eGFR <60 mL/min/1.73 m²; 11.1%, 5.6%, and 2.9% had CKD stages 3a, 3b, and 4/5, respectively. The overall prevalence of CVD (prior myocardial infarction, stroke/transient ischemic attack, or peripheral artery disease) was 22.5%; prevalence increased in parallel with the presence of CKD: 14.4%, 28.8%, 35.7%, 44.3%, and 50.9% for stages 1, 2, 3a, 3b, and 4/5, respectively. Prescriptions for antihyperglycemic medications were more common in people with CKD as compared with those without. However, the use of all antihyperglycemic medications except insulin and meglitinide was progressively lower in the presence of more severe CKD.

Limitations:

The study is based on administrative data; therefore, the findings could be influenced by measurement error (eg, accuracy of diagnostic and procedural codes and prescription drug codes used).

Conclusions:

These findings will be useful to policy makers seeking to understand the burden of diabetes-related kidney disease as well as the potential budget implications and potential clinical benefits of expanded use of antihyperglycemic use in this population.

Joint associations of obesity and estimated GFR with clinical outcomes: a population-based cohort study

BACKGROUND

Despite the interrelationships between obesity, eGFR and albuminuria, few large studies examine how obesity modifies the association between these markers of kidney function and adverse clinical outcomes.

METHODS

We examined the joint associations between obesity, eGFR and albuminuria on four clinical outcomes (death, end-stage renal disease [ESRD], myocardial infarction [MI], and placement in a long-term care facility) using a population-based cohort with procedures from Alberta. Obesity was defined by body mass index ≥35 kg/m² as defined by a fee modifier applied to an eligible procedure.

RESULTS

We studied 1,293,362 participants, of whom 171,650 (13.3%) had documented obesity (BMI ≥ 35 kg/m² based on claims data) and 1,121,712 (86.7%) did not. The association between eGFR and death was J-shaped for participants with and without documented obesity. After full adjustment, obesity tended to be associated with slightly lower odds of mortality (OR range 0.71-1.02; p for interaction between obesity and eGFR 0.008). For participants with and without obesity, the adjusted odds of ESRD were lowest for participants with eGFR > 90 mL/min*1.73m² and increased with lower eGFR, with no evidence of an interaction with obesity (p = 0.37). Although albuminuria and obesity were both associated with higher odds of ESRD, the excess risk associated with obesity was substantially attenuated at higher levels of albuminuria (p for interaction 0.0006). The excess risk of MI associated with obesity was observed at eGFR > 60 mL/min*1.73m² but not at lower eGFR (p for interaction < 0.0001). Participants with obesity had a higher adjusted likelihood of placement in long-term care than those without, and the likelihood of such placement was higher at lower eGFR for those with and without obesity (p for interaction = 0.57).

CONCLUSIONS

We found significant interactions between obesity and eGFR and/or albuminuria on the likelihood of adverse outcomes including death and ESRD. Since obesity is common, risk prediction tools for people with CKD might be improved by adding information on BMI or other proxies for body size in addition to eGFR and albuminuria.

Incidence and Prognosis of Acute Kidney Diseases and Disorders Using an Integrated Approach to Laboratory Measurements in a Universal Health Care System

Importance

Abnormal measurements of kidney function or structure may be identified that do not meet criteria for acute kidney injury (AKI) or chronic kidney disease (CKD) but nonetheless may require medical attention. The Kidney Disease: Improving Global Outcomes Clinical Practice Guideline for AKI proposed criteria for the definition of acute kidney diseases and disorders (AKD), which include AKI; however, the incidence and prognosis of AKD without AKI remain unknown.

Objective

To characterize the incidence and outcomes of AKD without AKI, with or without CKD.

Design, Setting, and Participants

Retrospective cohort study including all adult residents in a universal health care system in Alberta, Canada, without end-stage kidney disease (ESKD) and with at least 1 serum creatinine measurement between January 1 and December 31, 2008, in a community or hospital setting. Data analysis took place in 2018.

Main Outcomes and Measures

The Kidney Disease: Improving Global Outcomes guideline definitions for CKD, AKI, and AKD based on serum creatinine, estimated glomerular filtration rate, and albuminuria criteria were applied to estimate the proportion of patients with CKD, AKI, and AKD without AKI, and combinations of the conditions. Patients were followed up for up to 8 years (study end date, June 31, 2016) to characterize their risks of mortality, development of new CKD, progression of preexisting CKD, and ESKD.

Results

Among 1 109 099 Alberta residents included in the cohort, the mean (SD) age was 52.3 (17.6) years, and 43.0% were male. Findings showed that AKD without AKI was common (3.8 individuals without preexisting CKD and 0.6 with preexisting CKD per 100 population tested). In Cox proportional hazards and competing risks models over a median (interquartile range) of 6.0 (5.7-6.3) years of follow-up, AKD without AKI (compared with no kidney disease) was associated with higher risks of developing new CKD (37.4% vs 7.4%%; adjusted sub-hazard ratio [sHR], 3.17; 95% CI, 3.10-3.23), progression of preexisting CKD (49.5% vs 34.6%; adjusted sHR, 1.38; 95% CI, 1.33-1.44), ESKD (0.6% vs 0.1%; adjusted sHR, 8.56; 95% CI, 7.32-10.01), and death (25.8% vs 7.3%; adjusted hazard ratio, 1.42; 95% CI, 1.39-1.45).

Conclusions and Relevance

Criteria for AKD identified many patients who did not meet the criteria for CKD or AKI but had overall modestly increased risks of incident and progressive CKD, ESKD, and death. The clinical importance of AKD remains to be determined.

Statin use and the risk of acute kidney injury in older adults

Background

As more patients at lower cardiovascular (CV) risk are treated with statins, the balance between cardiovascular benefits and the risk of adverse events becomes increasingly important.

Methods

We did a population-based cohort study (May 1, 2002 to March 30, 2013) using province-wide laboratory and administrative data in Alberta. We studied new statin users aged 66 years of age and older who were not receiving renal replacement therapy at baseline. We assessed statin use at 30-day intervals to allow time-varying assessment of statin exposure in Cox proportional hazards models that examined the relation between statin use and hospitalization with acute kidney injury (AKI).

Results

Of the 128,140 new statin users, 47 and 46% were prescribed high- and medium-intensity regimens at the index date. During median follow-up of 4.6 years (interquartile range 2.2, 7.4), 9118 individuals were hospitalized for AKI. Compared to non-use, the use of high- and medium-intensity statin regimens was associated with significant increases in the adjusted risks of hospitalization with AKI: hazard ratios 1.16 [95% confidence interval (CI) 1.10, 1.23] and 1.07 (95% CI 1.01, 1.13), respectively. Risks of AKI were higher among women than men, and among users of angiotensin converting enzyme inhibitors/angiotensin receptor blockers than non-users, and among diuretic users (p for interaction 0.002, 0.01, and 0.04 respectively).

Conclusions

We found a graded, independent association between the intensity of statin use and the risk of hospitalization with AKI, although the absolute magnitude of the excess risk was small.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1280-7) contains supplementary material, which is available to authorized users.

Comparison of the Complexity of Patients Seen by Different Medical Subspecialists in a Universal Health Care System

IMPORTANCE

Clinical experience suggests that there are substantial differences in patient complexity across medical specialties, but empirical data are lacking.

OBJECTIVE

To compare the complexity of patients seen by different types of physician in a universal health care system.

DESIGN, SETTING, AND PARTICIPANTS

Population-based retrospective cohort study of 2 597 127 residents of the Canadian province of Alberta aged 18 years and older with at least 1 physician visit between April 1, 2014 and March 31, 2015. Data were analyzed in September 2018.

EXPOSURES

Type of physician seeing each patient (family physician, general internist, or 11 types of medical subspecialist) assessed as non-mutually exclusive categories.

MAIN OUTCOMES AND MEASURES

Nine markers of patient complexity (number of comorbidities, presence of mental illness, number of types of physicians involved in each patient's care, number of physicians involved in each patient's care, number of prescribed medications, number of emergency department visits, rate of death, rate of hospitalization, rate of placement in a long-term care facility).

RESULTS

Among the 2 597 127 participants, the median (interquartile range) age was 46 (32-59) years and 54.1% were female. Over 1 year of follow-up, 21 792 patients (0.8%) died, the median (range) number of days spent in the hospital was 0 (0-365), 8.1% of patients had at least 1 hospitalization, and the median (interquartile range) number of prescribed medications was 3 (1-7). When the complexity markers were considered individually, patients seen by nephrologists had the highest mean number of comorbidities (4.2; 95% CI, 4.2-4.3 vs [lowest] 1.1; 95% CI, 1.0-1.1), highest mean number of prescribed medications (14.2; 95% CI, 14.2-14.3 vs [lowest] 4.9; 95% CI, 4.9-4.9), highest rate of death (6.6%; 95% CI, 6.3%-6.9% vs [lowest] 0.1%; 95% CI, <0.1%-0.2%), and highest rate of placement in a long-term care facility (2.0%; 95% CI, 1.8%-2.2% vs [lowest] <0.1%; 95% CI, <0.1%-0.1%). Patients seen by infectious disease specialists had the highest complexity as assessed by the other 5 markers: rate of a mental health condition (29%; 95% CI, 28%-29% vs [lowest] 14%; 95% CI, 14%-14%), mean number of physician types (5.5; 95% CI, 5.5-5.6 vs [lowest] 2.1; 95% CI, 2.1-2.1), mean number of physicians (13.0; 95% CI, 12.9-13.1 vs [lowest] 3.8; 95% CI, 3.8-3.8), mean days in hospital (15.0; 95% CI, 14.9-15.0 vs [lowest] 0.4; 95% CI, 0.4-0.4), and mean emergency department visits (2.6; 95% CI, 2.6-2.6 vs [lowest] 0.5; 95% CI, 0.5-0.5). When types of physician were ranked according to patient complexity across all 9 markers, the order from most to least complex was nephrologist, infectious disease specialist, neurologist, respirologist, hematologist, rheumatologist, gastroenterologist, cardiologist, general internist, endocrinologist, allergist/immunologist, dermatologist, and family physician.

CONCLUSION AND RELEVANCE

Substantial differences were found in 9 different markers of patient complexity across different types of physician, including medical subspecialists, general internists, and family physicians. These findings have implications for medical education and health policy.

Concentrations of Trace Elements and Clinical Outcomes in Hemodialysis Patients: A Prospective Cohort Study

BACKGROUND AND OBJECTIVES

Deficiency of essential trace elements and excess of potentially toxic trace elements are common in patients on hemodialysis. Whether these abnormalities are associated with poor outcomes is unknown but worth investigating, because they are potentially treatable.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We did a prospective longitudinal study of 1278 patients on incident hemodialysis, assessing blood concentrations of 25 trace elements at baseline. We used adjusted logistic regression to evaluate the association between trace element status and four outcomes (death, cardiovascular events, systemic infection, and hospitalization). A priori hypotheses concerned (1) deficiency of zinc, selenium, and manganese and (2) excess of lead, arsenic, and mercury. Concentrations of the other 19 elements were tested in hypothesis-generating analyses.

RESULTS

Over 2 years of follow-up, 260 (20%) patients died, 285 (24%) experienced a cardiovascular event, 117 (10%) were hospitalized for systemic infection, and 928 (77%) were hospitalized for any cause. Lower concentrations of zinc or manganese and higher concentrations of lead, arsenic, or mercury were not independently associated with higher risk of clinical outcomes. Lower concentrations of selenium were strongly and independently associated with death (odds ratio, 0.86 per decile; 99.2% confidence interval, 0.80 to 0.93) and all-cause hospitalization (odds ratio, 0.92 per decile; 99.2% confidence interval, 0.86 to 0.98). In exploratory analyses, higher copper concentrations were significantly associated with higher risk of death (odds ratio, 1.07 per decile; 99.2% confidence interval, 1.00 to 1.15), and cadmium levels in the highest decile were associated with higher risk of death (odds ratio, 1.89; 99.2% confidence interval, 1.06 to 3.38).

CONCLUSIONS

Lower levels of zinc or manganese and higher concentrations of lead, arsenic, or mercury were not associated with higher risk of clinical outcomes, but lower concentrations of selenium were strongly and independently associated with the risks of death and hospitalization.

Concentrations of Trace Elements in Hemodialysis Patients: A Prospective Cohort Study

BACKGROUND

Low concentrations and excessive concentrations of trace elements have been commonly reported in hemodialysis patients, but available studies have several important limitations.

STUDY DESIGN

Random sample of patients drawn from a prospective cohort.

SETTING & PARTICIPANTS

198 incident hemodialysis patients treated in 3 Canadian centers.

MEASUREMENTS

We used mass spectrometry to measure plasma concentrations of the 25 elements at baseline, 6 months, 1 year, and 2 years following enrollment in the cohort. We focused on low concentrations of zinc, selenium, and manganese and excessive concentrations of lead, arsenic, and mercury; low and excessive concentrations of the other 19 trace elements were treated as exploratory analyses. Low and excessive concentrations were based on the 5th and 95th percentile plasma concentrations from healthy reference populations.

RESULTS

At all 4 occasions, low zinc, selenium, and manganese concentrations were uncommon in study participants (≤5.1%, ≤1.8%, and ≤0.9% for zinc, selenium, and manganese, respectively) and a substantial proportion of participants had concentrations that exceeded the 95th percentile (≥65.2%, ≥74.2%, and ≥19.7%, respectively). Almost all participants had plasma lead concentrations above the 95th percentile at all time points. The proportion of participants with plasma arsenic concentrations exceeding the 95th percentile was relatively constant over time (9.1%-9.8%); the proportion with plasma mercury concentrations that exceeded the 95th percentile varied between 15.2% and 29.3%. Low arsenic, platinum, tungsten, and beryllium concentrations were common (>50%), as were excessive cobalt, manganese, zinc, vanadium, cadmium, selenium, barium, antimony, nickel, molybdenum, lead, and chromium concentrations.

CONCLUSIONS

There was no evidence that low zinc, selenium, or manganese concentrations exist in most contemporary Canadian hemodialysis patients. Some patients have excessive plasma arsenic and mercury concentrations, and excessive lead concentrations were common. These findings require further investigation.

Multimorbidity, dementia and health care in older people:a population-based cohort study

BACKGROUND

Little is known about how multimorbidity, dementia and increasing age combine to influence health outcomes or utilization. Our objective was to examine the joint associations between age, dementia and burden of morbidity with mortality and other clinical outcomes.

METHODS

We did a retrospective population-based cohort study of all adults aged 65 years and older residing in Alberta, Canada, between 2002 and 2013. We used validated algorithms applied to administrative and laboratory data from the provincial health ministry to assess the presence/absence of dementia and 29 other morbidities, and their associations with mortality (our primary outcome), other clinical outcomes (emergency department visits, all-cause hospital admissions) and a proxy for loss of independent living (discharge to long-term care). Cox and Poisson models were adjusted for year-varying covariates. A 3-way interaction was modelled for dementia, the number of comorbidities, and age.

RESULTS

There were 610 457 adults aged 65 years and older living in Alberta over the study period. Over median follow-up of 6.8 years, 153 125 (25.1%) participants died and 5569 (0.9%) were discharged to long-term care. The prevalence of people with at least 3 morbidities was 33.7% in 2003 and 50.2% in 2012. The prevalence of dementia rose from 6.2% in fiscal year 2003 to 8.3% in fiscal year 2012, representing a net increase of approximately 13 700 people. The likelihood of all 4 outcomes increased with age and with greater burden of morbidity; the presence of dementia further increased these risks. For example, the risk of mortality increased by 1.54 to 6.38 in the presence of dementia, depending on age and morbidity burden. The risk associated with dementia was attenuated by increasing comorbidity.

INTERPRETATION

Older age, multimorbidity and dementia are all strongly correlated with adverse health outcomes as well as a proxy for loss of independent living. The increasing prevalences of dementia and multimorbidity over time suggest the need for coordinated national strategies aimed at mitigating the health challenges associated with the aging of the population.

Quality Assurance Audit of Technique Failure and 90-Day Mortality after Program Discharge in a Canadian Home Hemodialysis Program

BACKGROUND AND OBJECTIVES

Little is known about patients exiting home hemodialysis. We sought to characterize the reasons, clinical characteristics, and pre-exit health care team interactions of patients on home hemodialysis who died or underwent modality conversion (negative disposition) compared with prevalent patients and those who were transplanted (positive disposition).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted an audit of all consecutive patients incident to home hemodialysis from January of 2010 to December of 2014 as part of ongoing quality assurance. Records were reviewed for the 6 months before exit, and vital statistics were assessed up to 90 days postexit.

RESULTS

Ninety-four patients completed training; 25 (27%) received a transplant, 11 (12%) died, and 23 (25%) were transferred to in-center hemodialysis. Compared with the positive disposition group, patients in the negative disposition group had a longer mean dialysis vintage (3.15 [SD=4.98] versus 1.06 [SD=1.16] years; P=0.003) and were performing conventional versus a more intensive hemodialysis prescription (23 of 34 versus 23 of 60; P<0.01). In the 6 months before exit, the negative disposition group had significantly more in-center respite dialysis sessions, had more and longer hospitalizations, and required more on-call care team support in terms of phone calls and drop-in visits (each P<0.05). The most common reason for modality conversion was medical instability in 15 of 23 (65%) followed by caregiver or care partner burnout in three of 23 (13%) each. The 90-day mortality among patients undergoing modality conversion was 26%.

CONCLUSIONS

Over a 6-year period, approximately one third of patients exited the program due to death or modality conversion. Patients who die or transfer to another modality have significantly higher health care resource utilization (e.g., hospitalization, respite treatments, nursing time, etc.).

Association of Preference-Based Health-Related Quality of Life with Weight Loss in Obese Adults

BACKGROUND

The obesity epidemic is linked to substantial health care resource use, reduction in workforce and home productivity, and poor health-related quality of life (HRQOL). Changes in body mass index (BMI) are associated with improvements in HRQOL; the nature of this relationship, however, has not been reliably described.

OBJECTIVES

To determine the independent association between changes in BMI and change in utility-based HRQOL.

METHODS

Data were prospectively collected on 500 severely obese adult patients enrolled in a single-center obesity management clinic. Univariable and multivariable linear regressions were performed, adjusting for the effect of the intervention itself, obesity-related comorbidities, BMI at enrollment, age, and sex.

RESULTS

A 1-unit reduction in BMI was associated with a 0.0075 (95% confidence interval 0.0041-0.0109) increase in the EuroQol five-dimensional questionnaire score. This relationship was unaltered in various analyses, and is likely applicable to any health-care-induced changes in BMI.

CONCLUSIONS

The quantification of this association advances the understanding of the clinical benefits of interventions that affect BMI, and can inform more robust cost-utility analyses.

A Systematic Review of the Cost-Effectiveness of Long-Term Mechanical Circulatory Support

BACKGROUND

Mechanical circulatory support (MCS) is an option for the treatment of medically intractable end-stage heart failure. MCS therapy, however, is resource intensive.

OBJECTIVE

The purpose of this report was to systematically review the MCS cost-effectiveness literature as it pertains to the treatment of adult patients in end-stage heart failure.

METHODS

We conducted a systematic search and narrative review of available cost- effectiveness and cost-utility analyses of MCS in adult patients with end-stage heart failure.

RESULTS

Eleven studies analyzing the cost-effectiveness or cost-utility of MCS were identified. Seven studies focused on bridge to transplantation, three studies focused on destination therapy, and one study presented analyses of both strategies. Two articles evaluated the cost-effectiveness of the HeartMate II (Thoratec Corp., Pleasanton, CA). Incremental cost-effectiveness ratios between MCS and medical management ranged between $85,025 and $200,166 for bridge to transplantation and between $87,622 and $1,257,946 for destination therapy (2012 Canadian dollars per quality-adjusted life-year). Sensitivity analyses indicated that improvements in survival and quality of life and reductions in device and initial hospital-stay costs may improve the cost-effectiveness of MCS.

CONCLUSIONS

Current studies suggest that MCS is likely not cost-effective with reference to generally accepted or explicitly stated thresholds. Refined patient selection, complication rates, achieved quality of life, and device/surgical costs, however, could modify the cost-effectiveness of MCS.

Methods for identifying 30 chronic conditions: application to administrative data

BACKGROUND

Multimorbidity is common and associated with poor clinical outcomes and high health care costs. Administrative data are a promising tool for studying the epidemiology of multimorbidity. Our goal was to derive and apply a new scheme for using administrative data to identify the presence of chronic conditions and multimorbidity.

METHODS

We identified validated algorithms that use ICD-9 CM/ICD-10 data to ascertain the presence or absence of 40 morbidities. Algorithms with both positive predictive value and sensitivity ≥70% were graded as "high validity"; those with positive predictive value ≥70% and sensitivity <70% were graded as "moderate validity". To show proof of concept, we applied identified algorithms with high to moderate validity to inpatient and outpatient claims and utilization data from 574,409 people residing in Edmonton, Canada during the 2008/2009 fiscal year.

RESULTS

Of the 40 morbidities, we identified 30 that could be identified with high to moderate validity. Approximately one quarter of participants had identified multimorbidity (2 or more conditions), one quarter had a single identified morbidity and the remaining participants were not identified as having any of the 30 morbidities.

CONCLUSIONS

We identified a panel of 30 chronic conditions that can be identified from administrative data using validated algorithms, facilitating the study and surveillance of multimorbidity. We encourage other groups to use this scheme, to facilitate comparisons between settings and jurisdictions.

Trace element supplementation in hemodialysis patients: a randomized controlled trial

BACKGROUND

People with kidney failure are often deficient in zinc and selenium, but little is known about the optimal way to correct such deficiency.

METHODS

We did a double-blind randomized trial evaluating the effects of zinc (Zn), selenium (Se) and vitamin E added to the standard oral renal vitamin supplement (B and C vitamins) among hemodialysis patients in Alberta, Canada. We evaluated the effect of two daily doses of the new supplement (medium dose: 50 mg Zn, 75 mcg Se, 250 IU vitamin E; low dose: 25 mg Zn, 50 mcg Se, 250 IU vitamin E) compared to the standard supplement on blood concentrations of Se and Zn at 90 days (primary outcome) and 180 days (secondary outcome) as well as safety outcomes.

RESULTS

We enrolled 150 participants. The proportion of participants with low zinc status (blood level <815 ug/L) did not differ between the control group and the two intervention groups at 90 days (control 23.9% vs combined intervention groups 23.9%, P > 0.99) or 180 days (18.6% vs 28.2%, P = 0.24). The proportion with low selenium status (blood level <121 ug/L) was similar for controls and the combined intervention groups at 90 days (32.6 vs 19.6%, P = 0.09) and 180 days (34.9% vs 23.5%, P = 0.17). There were no significant differences in the risk of adverse events between the groups.

CONCLUSIONS

Supplementation with low or medium doses of zinc and selenium did not correct low zinc or selenium status in hemodialysis patients. Future studies should consider higher doses of zinc (≥75 mg/d) and selenium (≥100 mcg/d) with the standard supplement.

TRIAL REGISTRATION

Registered with ClinicalTrials.gov (NCT01473914).

Organ donation and transplantation in Canada: insights from the Canadian Organ Replacement Register

PURPOSE OF REVIEW

To provide an overview of the transplant component of the Canadian Organ Replacement Register (CORR).

FINDINGS

CORR is the national registry of organ failure in Canada. It has existed in some form since 1972 and currently houses data on patients with end-stage renal disease and solid organ transplants (kidney and/or non-kidney). The transplant component of CORR receives data on a voluntary basis from individual transplant centres and organ procurement organizations across the country. Coverage for transplant procedures is comprehensive and complete. Long-term outcomes are tracked based on follow-up reports from participating transplant centres. The longitudinal nature of CORR provides an opportunity to observe the trajectory of a patient's journey with organ failure over their life span. Research studies conducted using CORR data inform both practitioners and health policy makers alike.

IMPLICATIONS

The importance of registry data in monitoring and improving care for Canadian transplant candidates/recipients cannot be over-stated. This paper provides an overview of the transplant data in CORR including its history, data considerations, recent findings, new initiatives, and future directions.

Weight loss required by the severely obese to achieve clinically important differences in health-related quality of life: two-year prospective cohort study

BACKGROUND

Guidelines and experts describe 5% to 10% reductions in body weight as 'clinically important'; however, it is not clear if 5% to 10% weight reductions correspond to clinically important improvements in health-related quality of life (HRQL). Our objective was to calculate the amount of weight loss required to attain established minimal clinically important differences (MCIDs) in HRQL, measured using three validated instruments.

METHODS

Data from the Alberta Population-based Prospective Evaluation of Quality of Life Outcomes and Economic Impact of Bariatric Surgery (APPLES) study, a population-based, prospective Canadian cohort including 150 wait-listed, 200 medically managed and 150 surgically treated patients were examined. Two-year changes in weight and HRQL measures (Short-Form (SF)-12 physical (PCS; MCID = 5) and mental (MCS; MCID = 5) component summary score, EQ-5D Index (MCID = 0.03) and Visual Analog Scale (VAS; MCID = 10), Impact of Weight on Quality of Life (IWQOL)-Lite total score (MCID = 12)) were calculated. Separate multivariable linear regression models were constructed within medically and surgically treated patients to determine if weight changes achieved HRQL MCIDs. Pooled analysis in all 500 patients was performed to estimate the weight reductions required to achieve the pre-defined MCID for each HRQL instrument.

RESULTS

Mean age was 43.7 (SD 9.6) years, 88% were women, 92% were white, and mean initial body mass index was 47.9 (SD 8.1) kg/m2. In surgically treated patients (two-year weight loss = 16%), HRQL MCIDs were reached for all instruments except the SF-12 MCS. In medically managed patients (two-year weight loss = 3%), MCIDs were attained in the EQ-index but not the other instruments. In all patients, percent weight reductions to achieve MCIDs were: 23% (95% confidence interval (CI): 17.5, 32.5) for PCS, 25% (17.5, 40.2) for MCS, 9% (6.2, 15.0) for EQ-Index, 23% (17.3, 36.1) for EQ-VAS, and 17% (14.1, 20.4) for IWQOL-Lite total score.

CONCLUSIONS

Weight reductions to achieve MCIDs for most HRQL instruments are markedly higher than the conventional threshold of 5% to 10%. Surgical, but not medical treatment, consistently led to clinically important improvements in HRQL over two years.

TRIAL REGISTRATION

Clinicaltrials.gov NCT00850356.

Predictors of health-related quality of life in 500 severely obese patients

OBJECTIVE

To characterize health-related quality of life (HRQL) impairment in severely obese subjects, using several validated instruments.

METHODS

A cross-sectional analysis of 500 severely obese subjects was completed. Short-Form (SF)-12 [Physical (PCS) and Mental (MCS) component summary scores], EuroQol (EQ)-5D [Index and Visual Analog Scale (VAS)], and Impact of Weight on Quality of Life (IWQOL)-Lite were administered. Multivariable linear regression models were performed to identify independent predictors of HRQL.

RESULTS

Increasing BMI was associated with lower PCS (-1.33 points per 5 kg/m(2) heavier; P < 0.001), EQ-index (-0.02; P < 0.001), EQ-VAS (-1.71; P = 0.003), and IWQOL-Lite (-3.72; P = 0.002), but not MCS (P = 0.69). The strongest predictors (all P < 0.005) for impairment in each instrument were: fibromyalgia for PCS (-5.84 points), depression for MCS (-7.49 points), stroke for EQ-index (-0.17 points), less than full-time employment for EQ-VAS (-7.06 points), and coronary disease for IWQOL-Lite (-10.86 points). Chronic pain, depression, and sleep apnea were associated with reduced HRQL using all instruments.

CONCLUSION

The clinical impact of BMI on physical and general HRQL was small, and mental health scores were not associated with BMI. Chronic pain, depression, and sleep apnea were consistently associated with lower HRQL.

Potentially preventable hospitalization as a complication of CKD: a cohort study

BACKGROUND

Ambulatory care-sensitive conditions have been described as those that (if appropriately managed in an outpatient setting) generally do not require subsequent hospitalization. Our goal was to identify clinical populations of people who are at the highest risk of ambulatory care-sensitive conditions related to chronic kidney disease (CKD).

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

2,003,054 adults (including 238,747 adults with CKD) residing in Alberta, Canada, with at least one serum creatinine measurement between 2002 and 2009.

PREDICTORS

Estimated glomerular filtration rate and albuminuria categories, CKD status, demographics, and clinical characteristics.

OUTCOMES

Hospitalization with heart failure, hyperkalemia, volume overload, or malignant hypertension.

MEASUREMENTS

We used the Alberta Kidney Disease Network database, which incorporates data from Alberta Health, the Northern and Southern Alberta Renal Programs, and clinical laboratories in Alberta.

RESULTS

During a median follow-up of 4.1 years, 43,863 participants were hospitalized for heart failure; 6,274 participants, for hyperkalemia; 2,035 participants, for volume overload; and 481 participants, for malignant hypertension. All 4 conditions were more common at lower estimated glomerular filtration rates and in the presence of albuminuria. In the subset of participants with CKD, heart failure, hyperkalemia, and volume overload were associated most strongly with older age, diabetes, chronic liver disease, and prior heart failure. Malignant hypertension was associated with prior hypertension, aboriginal status, and peripheral vascular disease. Remote-dwelling participants were more likely to experience heart failure and malignant hypertension than those living closer to providers.

LIMITATIONS

No data for medication use or potentially important process-based outcomes for study participants.

CONCLUSIONS

Our findings suggest that future studies seeking to determine how to prevent ambulatory care-sensitive conditions in people with CKD should target remote dwellers and those with comorbid conditions such as concomitant heart failure and liver disease.

Prioritization and willingness to pay for bariatric surgery: the patient perspective

BACKGROUND

Access to publicly funded bariatric surgery is limited, potential candidates face lengthy waits, and no universally accepted prioritization criteria exist. We examined patients' perspectives regarding prioritization for surgery.

METHODS

We surveyed consecutively recruited patients awaiting bariatric surgery about 9 hypothetical scenarios describing patients waiting for surgery. Respondents were asked to rank the priority of these hypothetical patients on the wait list relative to their own. Scenarios examined variations in age, clinical severity, functional impairment, social dependence and socioeconomic status. Willingness to pay for faster access was assessed using a 5-point ordinal scale and analyzed using multivariable logistic regression.

RESULTS

The 99 respondents had mean age of 44.7 ± 9.9 years, 76% were women, and the mean body mass index was 47.3 ± SD 7.6. The mean wait for surgery was 34.4 ± 9.4 months. Respondents assigned similar priority to hypothetical patients with characteristics identical to theirs (p = 0.22) and higher priority (greater urgency) to those exhibiting greater clinical severity (p < 0.001) and functional impairment (p = 0.003). Lower priority was assigned to patients at the extremes of age (p = 0.006), on social assistance (p < 0.001) and of high socioeconomic status (p < 0.001). Most (85%) respondents disagreed with payment to expedite access, although participants earning more than $80 000/year were less likely to disagree.

CONCLUSION

Most patients waiting for bariatric surgery consider greater clinical severity and functional impairments related to obesity to be important prioritization indicators and disagreed with paying for faster access. These findings may help inform future efforts to develop acceptable prioritization strategies for publicly funded bariatric surgery.