J A Johnson

Publications (32)124.23 Total impact

• Article: Insulin use and cancer risk in patients with type 2 diabetes: A systematic review and meta-analysis of observational studies.

  I N Colmers, S L Bowker, L A Tjosvold, J A Johnson
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  ABSTRACT: AIMS: To determine whether data from observational studies supports the hypothesis of an increased risk of overall and site-specific cancer among individuals with diabetes using exogenous insulin therapies. METHODS: We conducted a comprehensive search of nine key biomedical databases for all years up to December 2011, restricted to the English language. Data from cohort and nested case-control studies were included in random effects meta-analyses of site-specific and overall cancer incidence comparing ever use and new use of: (1) insulin to no insulin and; (2) insulin glargine to other insulins. RESULTS: The search yielded 3052 unique citations, of which 19 were selected for inclusion, representing data for 1,332,120 people and 41,947 cancers. Pancreatic cancer risk was increased among new users of insulin (RR: 3.18, 95%CI: 3.27-3.71, I(2)=32%). New use of insulin glargine was associated with an increased risk of pancreatic cancer (RR: 1.63, 95%CI: 1.05-2.51, I(2)=0%) and prostate cancers (RR: 2.68, 95%CI: 1.50-4.79, I(2)=0%) but a decreased risk of colorectal cancer (RR: 0.78, 95%CI: 0.64-0.94, I(2)=15%). CONCLUSION: New use of insulin or insulin glargine was associated with an increased risk of pancreatic cancer, possibly due to reverse causality. New use of insulin glargine was associated with a decreased risk of colorectal cancer but an increased risk of prostate cancer. Our results should be interpreted with caution due to limitations of included studies.
  Diabetes & Metabolism 11/2012; · 2.41 Impact Factor
• Article: Thiazolidinedione use and cancer incidence in type 2 diabetes: A systematic review and meta-analysis.

  I N Colmers, S L Bowker, J A Johnson
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  ABSTRACT: AIMS: Evidence suggests thiazolidinediones (TZDs) may modify the relationship between type 2 diabetes and cancer incidence. We aimed to summarize data from randomized controlled trials (RCTs) and observational studies to examine risk of overall and site-specific cancers with TZD use in individuals with type 2 diabetes. METHODS: We searched 12 key biomedical databases and seven grey literature sources up to June 2011, without language restrictions. We performed separate meta-analyses according to cancer site and study design, comparing ever-use to never-use of TZDs, and pioglitazone alone. RESULTS: The search yielded 1338 unique citations; we included four RCT, seven cohort and nine nested case-control studies, contributing data from 2.5 million people. Estimates from observational studies suggested any TZD use was associated with a decreased risk of colorectal (pooled RR: 0.93, 95%CI 0.87-1.00, P=0.04, I(2)=30%), lung (pooled RR: 0.91, 95%CI 0.84-0.98, P=0.02, heterogeneity (I(2))=35%) and breast (pooled RR: 0.89, 95%CI 0.81-0.98, P=0.02, I(2)=44%) cancer. Risk of overall cancer with TZD use was not significantly modified in RCTs (pooled RR: 0.92, 95%CI 0.79-1.07, P=0.26, I(2)=0%) or observational studies (pooled OR: 0.95, 95%CI 0.78-1.16, P=0.63, I(2)=70%). Pioglitazone use was, however, associated with a decreased risk of overall cancer (colorectal, lung, breast, prostate and renal sub-sites combined) in observational studies (pooled RR: 0.95, 95%CI 0.91-0.99, P=0.009, I(2)=0%). CONCLUSIONS: Our findings suggest that use of TZDs is associated with a modest but significantly decreased risk of lung, colorectal and breast cancers. Results were limited by the paucity of studies designed to answer our research question. Further evaluation of TZD use, cancer risk factors and potential confounders is required.
  Diabetes & Metabolism 10/2012; · 2.41 Impact Factor
• Article: Time-varying incidence of cancer after the onset of type 2 diabetes: evidence of potential detection bias.

  J A Johnson, S L Bowker, K Richardson, C A Marra
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  ABSTRACT: Despite the vast body of epidemiological literature on the risk of cancer in people with diabetes, few studies have examined the pattern of cancer risk during different time windows following diabetes onset. The objective of the study was to examine the risks of site-specific cancer in people with incident type 2 diabetes during different time windows following diabetes onset. This was a population-based retrospective cohort study. The study period was 1 April 1994 to 31 March 2006; censoring occurred at 31 March 2006, at death or on departure from British Columbia, Canada. Using linked health databases, we identified incident cohorts with and without diabetes, who were matched by age, sex and index year. Following a minimum 2-year cancer washout period, first site-specific cancers were identified prospectively in both cohorts. Within 3 months following diabetes onset, participants with diabetes had significantly increased risks of colorectal, lung, liver, cervical, endometrial, ovarian, pancreatic and prostate cancers. After the initial 3-month period, the risks for colorectal (HR 1.15, 95% CI 1.05, 1.25), liver (HR 2.53, 95% CI 1.93, 3.31) and endometrial (HR 1.58, 95% CI 1.28, 1.94) cancers remained significantly elevated compared with those without diabetes. The diabetes cohort remained at increased risk of pancreatic cancer in later years, but followed a different pattern: HR 3.71 at 3 months-1 year, 2.94 at 1-2 years, 1.78 at 2-3 years and 1.65 at 3-10 years (p value for all <0.01). After an initial period of elevated risk, men with type 2 diabetes subsequently had a decreased risk of prostate cancer (HR 0.82, 95% CI 0.76, 0.88). People with type 2 diabetes are at increased risk of select cancers; this risk is particularly elevated at the time of diabetes onset, which is likely to be due to increased ascertainment.
  Diabetologia 09/2011; 54(9):2263-71. · 6.81 Impact Factor
• Article: Meta-analysis of trial data may support a causal role of hyperglycaemia in cancer. Reply to Yang XL, Ma RCW, Chan JCN [letter].

  J A Johnson, S L Bowker
  Diabetologia 03/2011; 54(3):711-2. · 6.81 Impact Factor
• Source

  Available from: mcgill.ca

  Article: Insulin, glucose and the increased risk of cancer in patients with type 2 diabetes.

  J A Johnson, M Pollak
  Diabetologia 10/2010; 53(10):2086-8. · 6.81 Impact Factor
• Source

  Available from: Samantha L Bowker

  Article: Intensive glycaemic control and cancer risk in type 2 diabetes: a meta-analysis of major trials.

  J A Johnson, S L Bowker
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  ABSTRACT: The purpose of this study was to explore the relationship between hyperglycaemia in type 2 diabetes and risk of cancer incidence or cancer mortality. We were interested to determine if data from major randomised controlled trials would support a hypothesis that improving glycaemic control may reduce the risk of cancer outcomes. We included major randomised controlled trials conducted with an overall aim of intensified glycaemic control in type 2 diabetes. We abstracted data from published papers and supplemental material and conducted separate meta-analyses of cancer mortality and cancer incidence. Four trials reported cancer mortality for the intensive (222 events in 53,892 person-years) and standard control (155 events in 38,743 person-years) arms (UK Prospective Diabetes Study [UKPDS] 33, UKPDS 34, Action to Control Cardiovascular Risk in Diabetes [ACCORD] and Veterans Affairs Diabetes Trial [VADT]); the summary risk ratio for cancer mortality was 1.00 (95% CI 0.81-1.24; I² = 0%). Excluding the UKPDS metformin trial resulted in a pooled risk estimate of 1.03 (95% CI 0.83-1.29; I² = 0%). Three trials reported cancer incidence for the study arms (Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation [ADVANCE], PROspective pioglitAzone Clinical Trial In macroVascular Events [PROactive], Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of Glycaemia in Diabetes [RECORD]) with 357 events in 47,974 person-years with improved glycaemic control and 380 events in 45,009 person-years in the control arms; the pooled risk ratio for cancer incidence was 0.91 (95% CI 0.79-1.05; I² = 0%). Data from large randomised controlled trials of intensified glycaemic control suggest that cancer risk is not reduced by improving glycaemic control in type 2 diabetes. These data therefore do not support the hypothesis that hyperglycaemia is causally linked to increased cancer risk.
  Diabetologia 10/2010; 54(1):25-31. · 6.81 Impact Factor
• Article: Glucose-lowering therapies and cancer risk: the trials and tribulations of trials and observations.

  J A Johnson, Y Yasui
  Diabetologia 09/2010; 53(9):1823-6. · 6.81 Impact Factor
• Article: Cost-effectiveness of a multifaceted intervention to improve quality of osteoporosis care after wrist fracture.

  S R Majumdar, D A Lier, B H Rowe, A S Russell, F A McAlister, W P Maksymowych, D A Hanley, D W Morrish, J A Johnson
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  ABSTRACT: In a randomized trial, a multifaceted intervention tripled rates of osteoporosis treatment in older patients with wrist fracture. An economic analysis of the trial now demonstrates that the intervention tested "dominates" usual care: over a lifetime horizon, it reduces fracture, increases quality-adjusted life years, and saves the healthcare system money. In a randomized trial (N = 272), we reported a multifaceted quality improvement intervention directed at older patients and their physicians could triple rates of osteoporosis treatment within 6 months of a wrist fracture when compared with usual care (22% vs 7%). Alongside the trial, we conducted an economic evaluation. Using 1-year outcome data from our trial and micro-costing time-motion studies, we constructed a Markov decision-analytic model to determine cost-effectiveness of the intervention compared with usual care over the patients' remaining lifetime. We took the perspective of third-party healthcare payers. In the base case, costs and benefits were discounted at 3% and expressed in 2006 Canadian dollars. One-way deterministic and probabilistic sensitivity analyses were conducted. Median age of patients was 60 years, 77% were women, and 72% had low bone mineral density (BMD). The intervention cost $12 per patient. Compared with usual care, the intervention strategy was dominant: for every 100 patients receiving the intervention, three fractures (one hip fracture) would be prevented, 1.1 quality-adjusted life year gained, and $26,800 saved by the healthcare system over their remaining lifetime. The intervention dominated usual care across numerous one-way sensitivity analyses: with respect to cost, the most influential parameter was drug price; in terms of effectiveness, the most influential parameter was rate of BMD testing. The intervention was cost saving in 80% of probabilistic model simulations. For outpatients with wrist fractures, our multifaceted osteoporosis intervention was cost-effective. Healthcare systems implementing similar interventions should expect to save money, reduce fractures, and gain quality-adjusted life expectancy.
  Osteoporosis International 09/2010; 22(6):1799-808. · 4.58 Impact Factor
• Article: Glucose-lowering agents and cancer mortality rates in type 2 diabetes: assessing effects of time-varying exposure.

  S L Bowker, Y Yasui, P Veugelers, J A Johnson
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  ABSTRACT: We explored the relationship between glucose-lowering agents and cancer mortality rates in type 2 diabetes patients, hypothesising a decreased risk of cancer mortality with metformin use and a dose-risk gradient for insulin therapy. This was a population-based cohort study using administrative data from Saskatchewan Health, Canada. We identified new users of metformin or sulfonylureas from 1 January 1991 to 31 December 1996, with follow-up until death, departure from the province or 31 December 1999. Cox regression analyses were used to estimate the HR of death from cancer, accounting for time-varying exposure to metformin, sulfonylurea, and exogenous insulin therapy. We identified 10,309 new users of metformin or sulfonylurea. The average follow-up was 5.4 (1.9) years, during which 407 (4.0%) cancer deaths occurred. Adjusting for age, sex and chronic disease score, the adjusted HR for metformin use was 0.80 (95% CI 0.65-0.98) compared with sulfonylurea monotherapy users. Adjusted HRs for subsequent insulin use were 2.22 (0.99-5.00), 3.33 (2.26-4.89) and 6.40 (4.69-8.73) for <3, 3 to 11 and > or = 12 insulin dispensations/year, respectively, compared with patients not on insulin. We observed a similar risk gradient among the sub-cohort of new insulin users. Our results support previous reports of a decreased risk of cancer outcomes associated with metformin use relative to sulfonylurea monotherapy. We also provide new evidence of a gradient of cumulative insulin dispensations and cancer mortality rates.
  Diabetologia 08/2010; 53(8):1631-7. · 6.81 Impact Factor
• Article: Nurse case-manager vs multifaceted intervention to improve quality of osteoporosis care after wrist fracture: randomized controlled pilot study.

  S R Majumdar, J A Johnson, D Bellerose, F A McAlister, A S Russell, D A Hanley, S Garg, D A Lier, W P Maksymowych, D W Morrish, B H Rowe
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  ABSTRACT: Few outpatients with fractures are treated for osteoporosis in the years following fracture. In a randomized pilot study, we found a nurse case-manager could double rates of osteoporosis testing and treatment compared with a proven efficacious quality improvement strategy directed at patients and physicians (57% vs 28% rates of appropriate care). Few patients with fractures are treated for osteoporosis. An intervention directed at wrist fracture patients (education) and physicians (guidelines, reminders) tripled osteoporosis treatment rates compared to controls (22% vs 7% within 6 months of fracture). More effective strategies are needed. We undertook a pilot study that compared a nurse case-manager to the multifaceted intervention using a randomized trial design. The case-manager counseled patients, arranged bone mineral density (BMD) tests, and prescribed treatments. We included controls from our first trial who remained untreated for osteoporosis 1-year post-fracture. Primary outcome was bisphosphonate treatment and secondary outcomes were BMD testing, appropriate care (BMD test-treatment if bone mass low), and costs. Forty six patients untreated 1-year after wrist fracture were randomized to case-manager (n = 21) or multifaceted intervention (n = 25). Median age was 60 years and 68% were female. Six months post-randomization, 9 (43%) case-managed patients were treated with bisphosphonates compared with 3 (12%) multifaceted intervention patients (relative risk [RR] 3.6, 95% confidence intervals [CI] 1.1-11.5, p = 0.019). Case-managed patients were more likely than multifaceted intervention patients to undergo BMD tests (81% vs 52%, RR 1.6, 95%CI 1.1-2.4, p = 0.042) and receive appropriate care (57% vs 28%, RR 2.0, 95%CI 1.0-4.2, p = 0.048). Case-management cost was $44 (CDN) per patient vs $12 for the multifaceted intervention. A nurse case-manager substantially increased rates of appropriate testing and treatment for osteoporosis in patients at high-risk of future fracture when compared with a multifaceted quality improvement intervention aimed at patients and physicians. Even with case-management, nearly half of patients did not receive appropriate care. clinicaltrials.gov identifier: NCT00152321.
  Osteoporosis International 04/2010; 22(1):223-30. · 4.58 Impact Factor
• Article: Insulin use and increased risk of mortality in type 2 diabetes: a cohort study.

  J-M Gamble, S H Simpson, D T Eurich, S R Majumdar, J A Johnson
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  ABSTRACT: To compare population-based rates of all-cause and cardiovascular (CV) mortality in newly treated patients with type 2 diabetes according to levels of insulin exposure. Using the administrative databases of Saskatchewan Health, 12272 new users of oral antidiabetic therapy were identified between 1991 and 1996 and grouped according to cumulative insulin exposure based on total insulin dispensations per year: no exposure (reference group); low exposure (0 to <3); moderate exposure (3 to <12) and high exposure (> or =12). Time-varying multivariable Cox proportional hazards models were used to examine the relationship between insulin exposure and all-cause, CV-related and non-vascular mortality after adjustment for demographics, medications and comorbidities. Average age was 65 (s.d. 13.9) years, 45% were female, and mean follow-up was 5.1 (s.d. 2.2) years. In total, 1443 (12%) subjects started insulin, and 2681 (22%) deaths occurred. The highest mortality rates were in the high exposure group; 95 deaths/1000 person-years compared with 40 deaths/1000 person-years in the no exposure group [unadjusted hazard ratio (HR): 2.32; 95% confidence interval (CI): 1.96-2.73]. After adjustment, we observed a graded risk of mortality associated with increasing exposure to insulin: low exposure [adjusted HR (aHR): 1.75; 95% CI: 1.24-2.47], moderate exposure (aHR: 2.18; 1.82-2.60) and high exposure (aHR: 2.79; 2.36-3.30); p = 0.005 for trend. Analyses restricted to CV-related (p = 0.042 for trend) and non-vascular (p = 0.004 for trend) mortality showed virtually identical results. We observed a significant and graded association between mortality risk and insulin exposure level in an inception cohort of patients with type 2 diabetes that persisted despite multivariable adjustment.
  Diabetes Obesity and Metabolism 09/2009; 12(1):47-53. · 3.38 Impact Factor
• Article: Persistence, reproducibility, and cost-effectiveness of an intervention to improve the quality of osteoporosis care after a fracture of the wrist: results of a controlled trial.

  S R Majumdar, J A Johnson, D A Lier, A S Russell, D A Hanley, S Blitz, I P Steiner, W P Maksymowych, D W Morrish, B R Holroyd, B H Rowe
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  ABSTRACT: Older patients with fragility fractures are not commonly tested or treated for osteoporosis. Compared to usual care, a previously reported intervention led to 30% absolute increases in osteoporosis treatment within 6 months of wrist fracture. Our objective was to examine longer-term outcomes, reproducibility, and cost-effectiveness of this intervention. We conducted an extended analysis of a non-randomized controlled trial with blinded ascertainment of outcomes that compared a multifaceted intervention to usual care controls. Patients >50 years with a wrist fracture treated in two Emergency Departments in the province of Alberta, Canada were included; those already treated for osteoporosis were excluded. Overall, 102 patients participated in this study (55 intervention and 47 controls; median age: 66 years; 78% were women). The interventions consisted of faxed physician reminders that contained osteoporosis treatment guidelines endorsed by opinion leaders and patient counseling. Controls received usual care; at 6-months post-fracture, when the original trial was completed, all controls were crossed-over to intervention. The main outcomes were rates of osteoporosis testing and treatment within 6 months (original study) and 1 year (delayed intervention) of fracture, and 1-year persistence with treatments started. From the perspective of the healthcare payer, the cost-effectiveness (using a Markov decision-analytic model) of the intervention was compared with usual care over a lifetime horizon. Overall, 40% of the intervention patients (vs. 10% of the controls) started treatment within 6 months post-fracture, and 82% (95%CI: 67-96%) had persisted with it at 1-year post-fracture. Delaying the intervention to controls for 6 months still led to equivalent rates of bone mineral density (BMD) testing (64 vs. 60% in the original study; p = 0.72) and osteoporosis treatment (43 vs. 40%; p = 0.77) as previously reported. Compared with usual care, the intervention strategy was dominant - per patient, it led to a $13 Canadian (U.S. $9) cost savings and a gain of 0.012 quality-adjusted life years. Base-case results were most sensitive to assumptions about treatment cost; for example, a 50% increase in the price of osteoporosis medication led to an incremental cost-effectiveness ratio of $24,250 Canadian (U.S. $17,218) per quality-adjusted life year gained. A pragmatic intervention directed at patients and physicians led to substantial improvements in osteoporosis treatment, even when delivered 6-months post-fracture. From the healthcare payer's perspective, the intervention appears to have led to both cost-savings and gains in life expectancy.
  Osteoporosis International 04/2007; 18(3):261-70. · 4.58 Impact Factor
• Article: The effect of specialist care within the first year on subsequent outcomes in 24,232 adults with new-onset diabetes mellitus: population-based cohort study.

  F A McAlister, S R Majumdar, D T Eurich, J A Johnson
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  ABSTRACT: Although specialty care has been shown to improve short-term outcomes in patients hospitalised with acute medical conditions, its effect on patients with chronic conditions treated in the ambulatory care setting is less clear. To examine whether specialty care (ie, consultative care provided by an endocrinologist or a general internist in concert with a patient's primary care doctor) within the first year of diagnosis is associated with improved outcomes after the first year for adults with diabetes mellitus treated as outpatients. Population-based cohort study using linked administrative data. The province of Saskatchewan, Canada. Sample: 24 232 adults newly diagnosed with diabetes mellitus between 1991 and 2001. Method: The primary outcome was all-cause mortality. Analyses used multivariate Cox proportional hazards models with time-dependent covariates, propensity scores and case mix variables (demographic, disease severity and comorbidities). In addition, restriction analyses examined the effect of specialist care in low-risk subgroups. The median age of patients was 61 years, and over a mean follow-up of 4.9 years 2932 (12%) died. Patients receiving specialty care were younger, had a greater burden of comorbidities, and visited doctors more often before and after their diabetes diagnosis (all p< or =0.001). Compared with patients seen by primary care doctors alone, patients seen by specialists and primary care doctors were more likely to receive recommended treatments (all p< or =0.001), but were more likely to die (13.1% v 11.7%, adjusted hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.08 to 1.27). This association persisted even in patients without comorbidities or target organ damage (adjusted HR 1.16, 95% CI 1.01 to 1.34). Specialty care was associated with better disease-specific process measures but not improved survival in adults with diabetes cared for in ambulatory care settings.
  Quality and Safety in Health Care 03/2007; 16(1):6-11. · 1.68 Impact Factor
• Article: Do radiographic indices of distal radius fracture reduction predict outcomes in older adults receiving conservative treatment?

  J L Jaremko, R G W Lambert, B H Rowe, J A Johnson, S R Majumdar
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  ABSTRACT: To investigate whether radiographic deformities suggesting inadequate reduction would be associated with adverse clinical outcomes. Consecutive patients over 50 years of age (n=74) with non-operatively managed distal radius fractures were enrolled in a prospective cohort study. They had radiographs at cast removal ( approximately 6 weeks) and completed DASH (Disabilities of the Arm, Shoulder and Hand), SF-12 (health-related quality of life), and satisfaction surveys 6-months post-fracture. A reference-standard musculoskeletal radiologist, blinded to outcomes status, measured palmar (dorsal) tilt, radial angle, radial height, ulnar height, and intra-articular step and gap. Radiographic indices were correlated to each other and to the various patient-reported outcomes in univariate and multivariate regression analyses. DASH score was the primary study outcome. Of the cohort studied (n=74, mean age 68.5 years, primarily white women), 71% had at least one "unacceptable" radiographic deformity by traditional criteria. Acceptable reduction varied from 60-99% depending on which single index was reported, and 44% of patients had more than two indices reported as unacceptable. Despite these radiographic findings, 6-months post-reduction, self-reported disability was low (DASH=24+/-17), health-related quality of life was near normal, and 72% were satisfied with their care. No radiographic index of wrist deformity (alone or in combination) was significantly correlated to any of the patient-reported outcomes. Self-reported outcomes in older adults with conservatively managed wrist fractures were not related to the "acceptability" of radiographic fracture reduction. The proportion of acceptable reductions varied by 40% depending on which index was reported. Consequently, detailed reporting of these indices in older adults with distal radius fracture may be inefficient or perhaps even unnecessary.
  Clinical Radiology 02/2007; 62(1):65-72. · 1.95 Impact Factor
• Source

  Available from: Samantha L Bowker

  Article: Self-monitoring in Type 2 diabetes: a randomized trial of reimbursement policy.

  J A Johnson, S R Majumdar, S L Bowker, E L Toth, A Edwards
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  ABSTRACT: Self-monitoring of blood glucose is often considered a cornerstone of self-care for patients with diabetes. We assessed whether provision of free testing strips would improve glycaemic control in non-insulin-treated Type 2 diabetic patients. Adults with Type 2 diabetes, excluding those with private insurance or using insulin, were recruited through community pharmacies and randomized to receive free testing strips for 6 months or not; all patients received similar baseline education and a glucose meter. Primary outcome was change in HbA(1c) over 6 months. We randomized 262 patients (131 intervention and 131 control subjects). Mean age was 68.4 years (sd 10.9), 48% were male, mean duration of diabetes was 8.2 years (sd 7.2), 97% used oral glucose-lowering agents and mean baseline HbA(1c) was 7.4% (sd 1.2). After 6 months, we observed no difference in HbA(1c) between intervention and control patients, after adjusting for baseline HbA(1c)[adjusted difference 0.03, 95% confidence interval (CI) -0.16, 0.22; P = 0.78]. A per protocol analysis of study completers (152/262; 60%) yielded similar results. Intervention patients reported testing 0.64 days per week more often than control subjects (95% CI 0.18, 1.10; P = 0.007), although testing was not associated with better glycaemic control (Pearson r = -0.10, P = 0.12). Reducing financial barriers by providing free testing strips did not improve glycaemic control in patients with Type 2 diabetes not using insulin. Our results question the value of policies that reduce financial barriers to testing supplies in this population.
  Diabetic Medicine 12/2006; 23(11):1247-51. · 2.90 Impact Factor
• Article: Comment on: Evans JM, Ogston SA, Emslie-Smith A, Morris A (2006) risk of mortality and adverse cardiovascular outcomes in type 2 diabetes: a comparison of patients treated with sulfonylureas and metformin. Diabetologia 49:930-936.

  J A Johnson, S H Simpson, D T Eurich, S R Majumdar
  Diabetologia 12/2006; 49(11):2805-6. · 6.81 Impact Factor
• Source

  Available from: braiddm.ca

  Article: Reduced cardiovascular morbidity and mortality associated with metformin use in subjects with Type 2 diabetes.

  J A Johnson, S H Simpson, E L Toth, S R Majumdar
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  ABSTRACT: Metformin therapy reduces microvascular complications in Type 2 diabetes; questions remain, however, regarding its impact on macrovascular events. This study examined metformin use in relation to risk of cardiovascular-related hospitalization and mortality. We conducted a retrospective cohort analysis, using Saskatchewan Health administrative databases to identify new users of oral antidiabetic drugs. Subject groups were defined by medication use during 1991-1999: sulphonylurea monotherapy, metformin monotherapy, or combination therapy. Deaths and non-fatal hospitalizations recorded during the study period were identified as cardiovascular-related from ICD-9 codes. The main outcome was a composite of first non-fatal hospitalization or death. Standard multivariate techniques, including propensity scores, were used to adjust for potential confounding. Multivariate Cox proportional hazard models were used to examine the relationship between metformin use and the composite endpoint. Metformin monotherapy was associated with a lower risk of the composite endpoint (adjusted hazard ratio 0.81; 95% confidence interval 0.68, 0.97) compared with sulphonylurea monotherapy. Combination therapy with meformin and a sulphonylurea was associated with lower mortality, but had similar hospitalization rates, to sulphonylurea monotherapy. Metformin monotherapy was associated with a lower risk of cardiovascular-related morbidity and mortality, and combination metformin and sulphonylurea therapy was associated with a reduced risk of fatal cardiovascular events, when compared with sulphonylurea monotherapy.
  Diabetic Medicine 05/2005; 22(4):497-502. · 2.90 Impact Factor
• Article: Statin use in Type 2 diabetes mellitus is associated with a delay in starting insulin.

  A Yee, S R Majumdar, S H Simpson, F A McAlister, R T Tsuyuki, J A Johnson
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  ABSTRACT: It has been suggested that HMG Co-A reductase inhibitors ('statins') may reduce the risk of developing Type 2 diabetes mellitus. This study was designed to evaluate whether use of statins would also delay progression to insulin therapy. This was a retrospective cohort study using Saskatchewan Health databases to identify subjects newly started on oral antidiabetic agents from 1991 to 1996. < 30 years of age or with previous lipid-lowering drug use were excluded. Medications known to influence glycaemic control, co-morbidity, and demographic data were collected. Statin exposure was defined as at least 1 year of use. Primary outcome was starting insulin treatment. Multivariate Cox proportional hazards models were used to examine the association between statin use and starting insulin. The final cohort included 10,996 new users of oral antidiabetic agents, of which 484 (4.4%) used statins. Mean age was 64 years and 55% were male. Mean duration of follow-up was 5.1 years; 11.1% (n = 1221) eventually started insulin treatment. Statin users were no less likely than non-users to start insulin treatment eventually (11.6% vs. 11.1%, P = 0.74). After multivariate adjustment, however, statin use was associated with a 10-month delay before newly treated diabetic subjects needed to start insulin treatment (adjusted hazard ratio 0.74; 95% confidence interval 0.56, 0.97, P = 0.028). The use of statins is associated with a delay in starting insulin treatment in patients with Type 2 diabetes initially treated with oral antidiabetic agents. Whether this relationship exists for patients at high risk of developing diabetes should be examined in a randomized trial.
  Diabetic Medicine 09/2004; 21(9):962-7. · 2.90 Impact Factor
• Article: Practice-based research: lessons from community pharmacist participants.

  S H Simpson, J A Johnson, C Biggs, R S Biggs, A Kuntz, W Semchuk, J G Taylor, K B Farris, R T Tsuyuki
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  ABSTRACT: We designed this project to determine community pharmacists' opinions regarding the challenges and motivations of their recent participation in a pharmacy practice-based research study At the conclusion of a randomized, multicenter study, 87 community pharmacist-investigators were sent a questionnaire that explored four areas: motivating factors to participate, barriers to participation, communication tools used by study coordinators, and design issues for future studies. Fifty-eight (67%) completed questionnaires were returned. Key factors motivating participation in the study were desire to improve the profession and opportunity to learn. Time was the greatest barrier to participation. Pharmacy practice-based research has two distinct advantages. First, it translates clinical knowledge into direct application in the community. Second, it provides needed data to demonstrate the value of enhanced pharmacy practice. Thorough understanding of pharmacists' opinions is necessary to optimize the design of future studies.
  Pharmacotherapy 07/2001; 21(6):731-9. · 2.90 Impact Factor
• Article: Economic impact of community pharmacist intervention in cholesterol risk management: an evaluation of the study of cardiovascular risk intervention by pharmacists.

  S H Simpson, J A Johnson, R T Tsuyuki
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  ABSTRACT: The Study of Cardiovascular Risk Intervention by Pharmacists, a randomized, controlled trial in over 50 community pharmacies in Alberta and Saskatchewan, Canada, demonstrated that a pharmacist intervention program improved cholesterol risk management in patients at high risk for cardiovascular disease. In a substudy, costs and consequences were analyzed to describe the economic impact of the program. Two perspectives were taken: a government-funded health care system and a pharmacy manager. Costs were reported in 1999 Canadian dollars. Incremental costs to a government payor and community pharmacy manager were $6.40/patient and $21.76/patient, respectively, during the 4-month follow-up period. The community pharmacy manager had an initial investment of $683.50. The change in Framingham risk function for the intervention group from baseline also was reported. The 10-year risk of cardiovascular disease decreased from 17.3% to 16.4% (p<0.0001) during the 4 months. The intervention program in this study led to a significant reduction in cardiovascular risk in the intervention group during the 4-month follow-up period. The incremental cost to provide the program appeared minimal from both government and pharmacy manager perspectives. It is hoped that these results could support negotiations for reimbursement of clinical pharmacy services with payors.
  Pharmacotherapy 05/2001; 21(5):627-35. · 2.90 Impact Factor