Incidence and outcomes of critical illness in indigenous peoples: a systematic review and meta-analysis.

BACKGROUND: Indigenous Peoples experience health inequities and racism across the continuum of health services. We performed a systematic review and meta-analysis of the incidence and outcomes of critical illness among Indigenous Peoples. METHODS: We searched Ovid MEDLINE/PubMed, Ovid EMBASE, Google Scholar, and Cochrane Central Register of Controlled Trials (inception to October 2022). Observational studies, case series of > 100 patients, clinical trial arms, and grey literature reports of Indigenous adults were eligible. We assessed risk of bias using the Newcastle-Ottawa Scale and appraised research quality from an Indigenous perspective using the Aboriginal and Torres Strait Islander Quality Assessment Tool. ICU mortality, ICU length of stay, and invasive mechanical ventilation (IMV) were compared using risk ratios and mean difference (MD) for dichotomous and continuous outcomes, respectively. ICU admission was synthesized descriptively. RESULTS: Fifteen studies (Australia and/or New Zealand [n = 12] and Canada [n = 3]) were included. Risk of bias was low in 10 studies and moderate in 5, and included studies had minimal incorporation of Indigenous perspectives or consultation. There was no difference in ICU mortality between Indigenous and non-Indigenous (RR 1.14, 95%CI 0.98 to 1.34, I2 = 87%). We observed a shorter ICU length of stay among Indigenous (MD - 0.25; 95%CI, - 0.49 to - 0.00; I2 = 95%) and a higher use for IMV among non-Indigenous (RR 1.10; 95%CI, 1.06 to 1.15; I2 = 81%). CONCLUSION: Research on Indigenous Peoples experience with critical care is poorly characterized and has rarely included Indigenous perspectives. ICU mortality between Indigenous and non-Indigenous populations was similar, while there was a shorter ICU length of stay and less mechanical ventilation use among Indigenous patients. Systematic Review Registration PROSPERO CRD42021254661; Registered: 12 June, 2021.

A population-based assessment of avoidable hospitalizations and resource use of non-vaccinated patients with COVID-19.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has precipitated a prolonged public health crisis. Numerous public health protections were widely implemented. The availability of effective and safe vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presented an opportunity to resolve this crisis; however, vaccine uptake was slow and inconsistent. This study evaluated the potential for preventable hospitalizations and avoidable resource use among eligible non-vaccinated persons hospitalized for COVID-19 had these persons been vaccinated. METHODS: This was a retrospective, population-based cohort study. The population-at-risk were persons aged ≥ 12 years in Alberta (mid-year 2021 population ~ 4.4 million). The primary exposure was vaccination status. The primary outcome was hospitalization with confirmed SARS-CoV-2, and secondary outcomes included avoidable hospitalizations, avoidable hospital bed-days, and the potential cost avoidance related to COVID-19. The study inception period was 27 September 2021 to 25 January 2022. Data on COVID-19 hospitalizations, vaccination status, health services, and costs were obtained from the Government of Alberta and from the Discharge Abstract Database. RESULTS: Hospitalizations occurred in 3835, 1907, and 481 persons who were non-vaccinated, fully vaccinated, and boosted (risk of hospitalization/100,000 population: 886, 92, and 43), respectively. For non-vaccinated persons compared with fully vaccinated and boosted persons, the risk ratios (95%CI) of hospitalization were 9.7 (7.9-11.8) and 20.6 (17.9-23.6), respectively. For non-vaccinated persons, estimates of avoidable hospitalizations and bed-days used were 3439 and 36,331 if fully vaccinated and 3764 and 40,185 if boosted. Estimates of cost avoidance for non-vaccinated persons were $101.46 million if fully vaccinated and $110.24 million if boosted. CONCLUSION: Eligible non-vaccinated persons with COVID-19 had tenfold and 21-fold higher risks of hospitalization relative to whether they had been fully vaccinated or boosted, resulting in considerable avoidable hospital bed-days and costs.

RéSUMé: OBJECTIF: La pandémie de maladie à coronavirus 2019 (COVID-19) a précipité une crise de santé publique prolongée. De nombreuses mesures de protection de la santé publique ont été appliquées à grande échelle. La disponibilité de vaccins sûrs et efficaces contre le coronavirus du syndrome respiratoire aigu sévère 2 (SRAS-CoV-2) a présenté une occasion de résoudre la crise, mais l'acceptation de la vaccination a été lente et inégale. Dans cette étude, nous évaluons le potentiel d'hospitalisations évitables et d'utilisation évitable des ressources pour les personnes non vaccinées admissibles hospitalisées pour la COVID-19, si ces personnes avaient été vaccinées. MéTHODES: Il s'agissait d'une étude de cohorte populationnelle rétrospective. La population à risque était les personnes de ≥ 12 ans en Alberta (~ 4,4 millions au milieu de l'année 2021). Le principal risque était le statut vaccinal. Le principal résultat clinique était l'hospitalisation avec SRAS-CoV-2 confirmé, et les résultats cliniques secondaires étaient les hospitalisations évitables, les jours-lits à l'hôpital évitables et l'évitement potentiel des coûts liés à la COVID-19. La période initiale de l'étude s'est étendue du 27 septembre 2021 au 25 janvier 2022. Les données sur les hospitalisations pour la COVID-19, le statut vaccinal, les coûts et les services de santé provenaient du gouvernement de l'Alberta et de la Base de données sur les congés des patients. RéSULTATS: En tout, 3 835 personnes non vaccinées, 1 907 personnes ayant reçu tous leurs vaccins et 481 personnes ayant reçu des doses de rappel ont été hospitalisées (risque d'hospitalisation p. 100 000 personnes : 886, 92 et 43, respectivement). Pour les personnes non vaccinées, comparativement aux personnes ayant reçu tous leurs vaccins et/ou les doses de rappel, les risques relatifs d'hospitalisation (IC de 95%) étaient de 9,7 (7,9­11,8) et de 20,6 (17,9­23,6), respectivement. Selon nos estimations, les personnes non vaccinées auraient évité 3 439 hospitalisations et 36 331 jours-lits si elles avaient reçu tous leurs vaccins, et 3 764 hospitalisations et 40 185 jours-lits si elles avaient en plus reçu les doses de rappel. Nous avons aussi estimé que les personnes non vaccinées auraient évité des coûts de 101,46 millions de dollars si elles avaient reçu tous leurs vaccins et de 110,24 millions de dollars si elles avaient en plus reçu les doses de rappel. CONCLUSION: Les personnes non vaccinées admissibles ayant contracté la COVID-19 ont présenté un risque d'hospitalisation 10 fois plus élevé que si elles avaient reçu tous leurs vaccins et 21 fois plus élevé que si elles avaient en plus reçu les doses de rappel, ce qui représente des jours-lits à l'hôpital et des coûts évitables considérables.

Incidence and outcomes of critical illness in Indigenous Peoples: a systematic review protocol.

BACKGROUND: Indigenous Peoples experience health inequities across the continuum of health services. Improvements for Indigenous patients and their families during vulnerable experiences with the healthcare system may have a significant impact on the patient experience and outcomes. Improved understanding of the occurrence of critical illness in Indigenous Peoples and their use of critical care services, as a strategic priority, may aid in the development of initiatives for improving health equity. A global focus was selected to learn from Indigenous populations' experiences with critical care, as the understanding of critical illness among Indigenous Peoples in Canada is not well understood. This protocol outlines a systematic review focused on describing the incidence of critical illness and utilization of critical care services among Indigenous Peoples. METHODS: Ovid MEDLINE/PubMed, Ovid EMBASE, Google Scholar, and Cochrane Central Register of Controlled Trials will be searched. Relevant Canadian sites for gray literature (National Collaborating Centre for Indigenous Health, First Nations Health Authority, Canadian Institutes of Health Research Institute of Indigenous Peoples' Health, National Association of Friendship Centres, the Alberta First Nations Information Governance Centre, Métis Nation of Alberta) will also be searched. We will include studies of adults (≥18 years) either without critical illness (i.e., general population) or with critical illness (i.e., admitted to an intensive care unit (ICU)). The exposure of interest will be Indigenous identity. Primary outcome measures are ICU admission and ICU mortality. Because heterogeneity in populations, comparisons, and outcome measures is anticipated, it is likely that the findings will be summarized using a narrative synthesis. A meta-analysis will be performed if there is sufficient evidence on one or more outcomes of interest. DISCUSSION: This systematic review will provide a better understanding of the epidemiology, risk factors, and outcomes of critical illness and utilization of critical care services among Indigenous Peoples. The knowledge generated will be applied to a broader program of work designed to create ethical space to co-design, implement, and evaluate a culturally competent, safe, and innovative model for critical care services for Indigenous People. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021254661.

A Population-level Analysis of the Differing Effects of Rheumatoid Arthritis and Spondyloarthritis on Peripartum Outcomes.

OBJECTIVE: The effects of rheumatoid arthritis (RA) and spondyloarthritis (SpA) on maternal and neonatal outcomes at a population level have not previously been well compared. METHODS: A contemporary pregnancy cohort of 312,081 women and corresponding birth events was assembled for the province of Alberta from the random selection of 1 live birth event per woman. We identified 3 groups: (1) no inflammatory arthritis (no IA, n = 308,989), (2) RA (n = 631), and (3) SpA (n = 2461). We compared maternal and neonatal outcomes, comorbid conditions, and medication use among the 3 groups. Multivariable logistic regression models evaluated the independent association between RA and SpA, relative to no IA, and the outcomes of small for gestation age (SGA) and hypertensive disorders during pregnancy. RESULTS: Pregnant women with RA were significantly more likely to have preterm delivery (13.5%), cesarean delivery (33.9%), hypertensive disorders in pregnancy (10.5%), and SGA babies (15.6%), compared to pregnant women with either SpA or no IA. Nonsteroidal antiinflammatory drugs and corticosteroid use were significantly higher in pregnant women with RA compared to the other groups. Women with RA were significantly more likely to have an SGA baby (OR 1.51, 95% CI 1.21-1.88; p < 0.01), and hypertensive disorder in pregnancy (OR 1.51, 95% CI 1.16-1.97; p < 0.01), compared to women with no IA, while no difference was found between women with SpA and those with no IA. CONCLUSION: Women with RA have a higher risk of worse maternal and neonatal outcomes, whereas the risk of these events is similar between women with and without SpA.

Association between maternal diabetes, being large for gestational age and breast-feeding on being overweight or obese in childhood.

AIMS/HYPOTHESIS: This study aimed to examine the association of maternal diabetes, being large for gestational age (LGA) and breast-feeding with being overweight or obese in pre-school-aged children. METHODS: Data on height and weight at the time of their pre-school (age 4-6 years) immunisation visit between January 2009 and August 2017, as well as breast-feeding status in the first 5 months of life, for 81,226 children born between January 2005 and August 2013 were linked with maternal hospitalisation and outpatient records and birth registry data. Children were grouped into six categories based on maternal diabetes status during pregnancy (no diabetes, gestational diabetes or pre-existing diabetes) and birthweight (appropriate for gestational age [AGA] or LGA). WHO criteria were used to identify children who were overweight or obese. RESULTS: There were 69,506 children in the no diabetes/AGA group (control), 5926 in the no diabetes/LGA group, 4563 in the gestational diabetes/AGA group, 573 in the gestational diabetes/LGA group, 480 in the pre-existing diabetes/AGA group and 178 in the pre-existing diabetes/LGA group. The rate of being overweight/obese at pre-school age ranged from 20.5% in the control group to 42.9% in the gestational diabetes/LGA group. The adjusted attributable risk per cent for LGA alone (39.4%) was significantly higher than that for maternal gestational diabetes (16.0%) or pre-existing diabetes alone (15.1%); the risk for the combinations of gestational diabetes/LGA and pre-existing diabetes/LGA were 50.1% and 39.1%, respectively. Further stratification of the pre-existing diabetes groups found the prevalence of being overweight/obese was 21.2% in the type 1/AGA group, 31.4% in the type 1/LGA group (similar to those in the no diabetes groups), 26.7% in the type 2/AGA group and 42.5% in the type 2/LGA group. Breast-feeding was associated with a lower likelihood of being overweight/obese in childhood in all groups except gestational diabetes/LGA and pre-existing diabetes/LGA (both type 1 and type 2). CONCLUSION/INTERPRETATION: LGA is a stronger marker for risk of being overweight/obese in early childhood, compared with maternal diabetes during pregnancy. Rates of being overweight/obese in childhood were highest in LGA children born to mothers with gestational diabetes or pre-existing type 2 diabetes. Breast-feeding was associated with a lower risk of being overweight/obese in childhood in the majority of children; however, this association was not maintained in LGA children of mothers with diabetes.

Ethnic and sex differences in ambulance activation among hospitalized patients with acute coronary syndromes: Insights from the Alberta contemporary acute coronary syndrome patients invasive treatment strategies (COAPT) study.

BACKGROUND: With acute coronary syndromes (ACS), activation of emergency medical services (EMS) ensures early treatment. However, EMS activation remains under-utilized. We examined whether ground EMS use varied by sex or ethnicity among a population-based cohort of ACS patients. METHODS: We used linked administrative health datasets to identify patients who were hospitalized with an ACS (April 1, 2002-March 31, 2016). Validated naming algorithms were used to categorize patients according to ethnicity (Caucasian, South Asian, Chinese). RESULTS: Of the 60,717 patients with an ACS (male: 41,175; female: 19,542), 42.3% presented to hospital via ground ambulance. Compared to males, females were more likely to activate EMS (38.9% vs. 49.3%, p < 0.001). Compared to the Caucasians (n = 58,666), EMS activation was significantly higher among Chinese (n = 793) (42.1% vs. 49.8%; p = 0.0007) and slightly higher in South Asians (n = 1258) (42.1% vs. 44.7%; p = 0.45). The relatively higher EMS use among females was maintained across the ethnic groups. In multivariable adjusted analyses, females were more likely to use EMS compared to males (OR: 1.31; 95% CI: 1.26-1.36). Compared to the Caucasians, a weaker trend towards South Asian and Chinese EMS activation was observed (OR: 1.08; 95% CI 0.96-1.21; OR: 1.10; 95% CI 0.95-1.28, respectively). In the male cohort only, South Asians and Chinese tended to activate EMS more often than the Caucasians (Males: South Asian OR: 1.14; 95% CI 1.00-1.31, Chinese OR: 1.15; 95% CI 0.96-1.38; Females: South Asian OR: 0.93; 95% CI 0.75-1.15, Chinese OR: 1.01; 95% CI 0.77-1.30). CONCLUSION: EMS use was sub-optimal and differed based on sex and ethnicity. Our results reinforce the need for targeted public health efforts to enhance ambulance activation.

Time-Varying Risk for Breast Cancer Following Initiation of Glucose-Lowering Therapy in Women with Type 2 Diabetes: Exploring Detection Bias.

OBJECTIVES: To explore detection bias in the association between glucose-lowering therapies and breast cancer in a cohort of women with type 2 diabetes. METHODS: This was a retrospective, population-based cohort study. We identified new users of metformin, sulfonylureas, thiazolidinediones and insulin during the index period of January 1, 2003, to December 31, 2010. The main outcome was incident breast cancer, and patients were followed up from drug exposure index date until death, diagnosis of another type of cancer, termination of medical insurance or December 31, 2010. To explore detection bias, we split follow-up time into 2 discrete time periods of 0 to 3 months and 3 months to 6 years after drug index date. We performed time-varying Cox regression analyses, including duration of cumulative drug exposure and ever/never drug exposure for each glucose-lowering therapy into our model. The reference was no use of the same drug-exposure category. RESULTS: There were 22,169 women with type 2 diabetes, with a mean (SD) age of 53.0 (9.2) years and mean (SD) follow up of 2.2 (1.5) years. Hazard ratios for breast cancer in the first 3 months following initiation of metformin, sulfonylurea or thiazolidinedione were 0.66 (0.43 to 1.02), 0.74 (0.44 to 1.25) and 0.67 (0.38 to 1.18), respectively. In the later period of 3 months to 6 years following drug start, hazard ratios (95% CI) for breast cancer were 1.00 (0.98 to 1.02), 1.01 (0.98 to 1.03) and 0.98 (0.95 to 1.01) for metformin, sulfonylurea and thiazolidinedione cumulative exposure, respectively. CONCLUSIONS: Our findings suggest that no detection bias exists for glucose-lowering therapies and breast cancer in this population.

Pioglitazone and bladder cancer risk: a multipopulation pooled, cumulative exposure analysis.

AIMS/HYPOTHESIS: The evidence on the association between pioglitazone use and bladder cancer is contradictory, with many studies subject to allocation bias. The aim of our study was to examine the effect of exposure to pioglitazone on bladder cancer risk internationally across several cohorts. The potential for allocation bias was minimised by focusing on the cumulative effect of pioglitazone as the primary endpoint using a time-dependent approach. METHODS: Prescription, cancer and mortality data from people with type 2 diabetes were obtained from six populations across the world (British Columbia, Finland, Manchester, Rotterdam, Scotland and the UK Clinical Practice Research Datalink). A discrete time failure analysis using Poisson regression was applied separately to data from each centre to model the effect of cumulative drug exposure on bladder cancer incidence, with time-dependent adjustment for ever use of pioglitazone. These were then pooled using fixed and random effects meta-regression. RESULTS: Data were collated on 1.01 million persons over 5.9 million person-years. There were 3,248 cases of incident bladder cancer, with 117 exposed cases and a median follow-up duration of 4.0 to 7.4 years. Overall, there was no evidence for any association between cumulative exposure to pioglitazone and bladder cancer in men (rate ratio [RR] per 100 days of cumulative exposure, 1.01; 95% CI 0.97, 1.06) or women (RR 1.04; 95% CI 0.97, 1.11) after adjustment for age, calendar year, diabetes duration, smoking and any ever use of pioglitazone. No association was observed between rosiglitazone and bladder cancer in men (RR 1.01; 95% CI 0.98, 1.03) or women (RR 1.00; 95% CI 0.94, 1.07). CONCLUSIONS/INTERPRETATION: The cumulative use of pioglitazone or rosiglitazone was not associated with the incidence of bladder cancer in this large, pooled multipopulation analysis.

Detection bias and overestimation of bladder cancer risk in type 2 diabetes: a matched cohort study.

OBJECTIVE: To investigate whether the risk of bladder cancer in individuals with newly diagnosed type 2 diabetes is influenced by the frequency of physician visits before diagnosis as a measure of detection bias. RESEARCH DESIGN AND METHODS: With the use of linked administrative databases from 1996 to 2006, we established a cohort of 185,100 adults from British Columbia, Canada, with incident type 2 diabetes matched one to one with nondiabetic individuals on age, sex, and index date. Incidence rates and adjusted hazard ratios (aHRs) for bladder cancer were calculated during annual time windows following the index date. Analyses were stratified by number of physician visits in the 2 years before diabetes diagnosis and adjusted for age, sex, year of cohort entry, and socioeconomic status. RESULTS: The study population was 54% men and had an average age of 60.7±13.5 years; 1,171 new bladder cancers were diagnosed over a median follow-up of 4 years. In the first year after diabetes diagnosis, bladder cancer incidence in the diabetic cohort was 85.3 (95% CI 72.0-100.4) per 100,000 person-years and 66.1 (54.5-79.4) in the control cohort (aHR 1.30 [1.02-1.67], P=0.03). This first-year increased bladder cancer risk was limited to those with the fewest physician visits 2 years before the index date (≤12 visits, aHR 2.14 [1.29-3.55], P=0.003). After the first year, type 2 diabetes was not associated with bladder cancer. CONCLUSIONS: The results suggest that early detection bias may account for an overestimation in previously reported increased risks of bladder cancer associated with type 2 diabetes.

Use of thiazolidinediones and the risk of bladder cancer among people with type 2 diabetes: a meta-analysis.

BACKGROUND: Patients with type 2 diabetes have a 40% increased risk of bladder cancer. Thiazolidinediones, especially pioglitazone, may increase the risk. We conducted a systematic review and meta-analysis to evaluate the risk of bladder cancer among adults with type 2 diabetes taking thiazolidinediones. METHODS: We searched key biomedical databases (including MEDLINE, Embase and Scopus) and sources of grey literature from inception through March 2012 for published and unpublished studies, without language restrictions. We included randomized controlled trials (RCTs), cohort studies and case-control studies that reported incident bladder cancer among people with type 2 diabetes who ever (v. never) were exposed to pioglitazone (main outcome), rosiglitazone or any thiazolidinedione. RESULTS: Of the 1787 studies identified, we selected 4 RCTs, 5 cohort studies and 1 case-control study. The total number of patients was 2,657,365, of whom 3643 had newly diagnosed bladder cancer, for an overall incidence of 53.1 per 100,000 person-years. The one RCT that reported on pioglitazone use found no significant association with bladder cancer (risk ratio [RR] 2.36, 95% confidence interval [CI] 0.91-6.13). The cohort studies of thiazolidinediones (pooled RR 1.15, 95% CI 1.04-1.26; I(2) = 0%) and of pioglitazone specifically (pooled RR 1.22, 95% CI 1.07-1.39; I(2) = 0%) showed significant associations with bladder cancer. No significant association with bladder cancer was observed in the two RCTs that evaluated rosiglitazone use (pooled RR 0.87, 95% CI 0.34-2.23; I(2) = 0%). INTERPRETATION: The limited evidence available supports the hypothesis that thiazolidinediones, particularly pioglitazone, are associated with an increased risk of bladder cancer among adults with type 2 diabetes.

Risk of breast cancer after onset of type 2 diabetes: evidence of detection bias in postmenopausal women.

OBJECTIVE: To examine the risk of breast cancer in pre- and postmenopausal women with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: This was a population-based retrospective cohort study. Cox regression, stratified by pre- (<55 years) and postmenopausal (≥55 years) status, was used to estimate hazard ratios (HRs) for breast cancer, during earlier (0-3 months) and later (3 months to 10 years) time windows after diabetes index date. RESULTS: Compared with women without T2D, HRs for breast cancer were 0.95 (95% CI 0.48-1.86; P = 0.88) and 1.31 (0.92-1.86; P = 0.14) in pre- and postmenopausal women with T2D, respectively, in the early time window, and 0.92 (0.75-1.13; P = 0.45) and 1.00 (0.90-1.11; P = 0.93) in pre- and postmenopausal women with T2D, respectively, in the later time window. CONCLUSIONS: We observed a trend toward an increased risk of breast cancer in postmenopausal women with T2D, but only in the time period immediately after diabetes index date.

A cross-sectional study of health-related quality of life deficits in individuals with comorbid diabetes and cancer.

BACKGROUND: Numerous studies have identified a reduced health related quality of life (HRQL) in patients that have either diabetes or cancer. We assessed the HRQL burden in patients with these comorbid conditions, postulating that they would have even greater HRQL deficits. METHODS: Data from the Public Use File of the Canadian Community Health Survey (PUF CCHS) Cycle 1.1 (September 2000-November 2001) were used for this analysis. The total sample size of the CCHS PUF is 130,880 individuals. We used the Health Utilities Index Mark 3 (HUI3) to assess HRQL in patients with: 1) comorbid diabetes and cancer, 2) diabetes alone, 3) cancer alone, and 4) no diabetes or cancer. Analysis of covariance was used to compare the mean overall HUI3 score, controlling for age, sex, marital status, body mass index (BMI), physical activity level, smoking status, education level, depression status, and other chronic conditions. RESULTS: We identified 113,587 individuals (87%) with complete data for the analysis. The comorbid diabetes and cancer group were older and a larger proportion reported being obese, inactive, having less than a secondary education and more chronic conditions when compared to the other three cohorts (p < 0.0001). However, the diabetes and cancer cohort was less likely to be depressed (p < 0.0001). Overall HUI3 scores were significantly lower for the diabetes and cancer group (unadjusted mean (SD): 0.67 (0.30)), compared to diabetes (0.78 (0.27)), cancer (0.78 (0.25)), and the reference group (0.89 (0.18)) (p < 0.0001). After adjusting for covariates, the comorbid diabetes and cancer group continued to have significantly lower overall HUI3 scores than the reference group (unstandardized mean difference: -0.11, 95% CI: -0.13 to -.0.09) (p < 0.0001). CONCLUSION: Individuals with diabetes and cancer had a clinically important and significantly lower HRQL than those with either condition alone. A better understanding of the relationship between diabetes and cancer, and their associated comorbidities, complications, and HRQL deficits may have important implications for prevention and management strategies.

Increased cancer-related mortality for patients with type 2 diabetes who use sulfonylureas or insulin.

OBJECTIVE: Numerous studies have identified an increased risk of cancer in type 2 diabetes. We explored the association between antidiabetic therapies and cancer-related mortality in patients with type 2 diabetes, postulating that agents that increase insulin levels might promote cancer. RESEARCH DESIGN AND METHODS: This was a population-based cohort study using administrative databases from Saskatchewan Health. Cancer-related mortality was compared among inception cohorts of metformin users and sulfonylurea monotherapy users. Multivariate Cox regression was used to estimate the hazard ratio (HR) of cancer-related mortality, after adjusting for age, sex, insulin use, and chronic disease score. All statistical tests were two-sided. RESULTS: We identified 10,309 new users of metformin or sulfonylureas with an average follow-up of 5.4 +/- 1.9 years (means +/- SD). The mean age for the cohort was 63.4 +/- 13.3 years, and 55% were men. Cancer mortality over follow-up was 4.9% (162 of 3,340) for sulfonylurea monotherapy users, 3.5% (245 of 6,969) for metformin users, and 5.8% (84 of 1,443) for subjects who used insulin. After multivariate adjustment, the sulfonylurea cohort had greater cancer-related mortality compared with the metformin cohort (adjusted HR 1.3 [95% CI 1.1-1.6]; P = 0.012). Insulin use was associated with an adjusted HR of cancer-related mortality of 1.9 (95% CI 1.5-2.4; P < 0.0001). CONCLUSIONS: Patients with type 2 diabetes exposed to sulfonylureas and exogenous insulin had a significantly increased risk of cancer-related mortality compared with patients exposed to metformin. It is uncertain whether this increased risk is related to a deleterious effect of sulfonylurea and insulin or a protective effect of metformin or due to some unmeasured effect related to both choice of therapy and cancer risk.

Lack of insurance coverage for testing supplies is associated with poorer glycemic control in patients with type 2 diabetes.

BACKGROUND: Public insurance for testing supplies for self-monitoring of blood glucose is highly variable across Canada. We sought to determine if insured patients were more likely than uninsured patients to use self-monitoring and whether they had better glycemic control. METHODS: We used baseline survey and laboratory data from patients enrolled in a randomized controlled trial examining the effect of paying for testing supplies on glycemic control. We recruited patients through community pharmacies in Alberta and Saskatchewan from Nov. 2001 to June 2003. To avoid concerns regarding differences in provincial coverage of self-monitoring and medications, we report the analysis of Alberta patients only. RESULTS: Among our sample of 405 patients, 41% had private or public insurance coverage for self-monitoring testing supplies. Patients with insurance had significantly lower hemoglobin A(1c) concentrations than those without insurance coverage (7.1% v. 7.4%, p = 0.03). Patients with insurance were younger, had a higher income, were less likely to have a high school education and were less likely to be married or living with a partner. In multivariate analyses that controlled for these and other potential confounders, lack of insurance coverage for self-monitoring testing supplies was still significantly associated with higher hemoglobin A(1c) concentrations (adjusted difference 0.5%, p = 0.006). INTERPRETATION: Patients without insurance for self-monitoring test strips had poorer glycemic control.

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) in a Northern Alberta population.

OBJECTIVE: To describe the demographics and estimate the prevalence of hepatitis C virus (HCV) in a cohort of Human Immunodeficiency Virus (HIV) positive patients in Northern Alberta. METHODS: A cross-sectional (prevalence) study was performed on a cohort of HIV-positive patients. HCV testing was not widely available until December 1989, and the more sensitive, second generation immunoassay was not available until 1992. To reduce the effect of testing bias, we restricted consideration of HCV status to patients first seen January 1, 1992 onward. RESULTS: Forty-four percent of patients in the whole cohort were tested for HCV (564/1,276) and 62% (505/809) of patients entered since January 1, 1992 were tested for HCV. During the period January 1, 1992-December 31, 1999, the prevalence of HCV in our cohort of northern Alberta HIV-positive patients was at least 37.9% (307/809) and was 60.8% (307/505) among those who were tested for HCV in 1992 or later. The mean age of the co-infected group was 33.6 years, 66.1% were male, 91.2% were injection drug users (IDUs), 56.8% were Caucasian, and 40.0% were Aboriginal. A statistically significant difference was found between the HCV-negative cohort, the HCV co-infected cohort, and the HCV-untested cohort for the following variables: risk behaviour, gender, ethnic status, death, occurrence of an AIDS-defining illness (p < 00.0001), and mean baseline CD4 cell count (p = 0.002). CONCLUSION: A high proportion of the HIV-infected IDUs was co-infected with HCV. Compared to the HCV-negative group, the co-infected group appears to have had less advanced HIV disease. This is likely a reflection of more recent HIV infection in the HCV co-infected group.