Safety of Concomitant Metformin and Proton Pump Inhibitor Use: A Population Retrospective Cohort Study

PURPOSE

The purpose of this study was to investigate the effect of concomitant use on important clinical outcomes.

METHODS

In this retrospective cohort study, a cohort of new metformin users was identified between 2004 and 2010 and followed up until termination of insurance coverage, December 31, 2010, or the outcomes were reached. The primary outcome was a composite of time to all-cause mortality or hospitalization; our secondary outcome was time to cardiovascular hospitalization. Exposures to metformin, a proton pump inhibitor (PPI), and/or a histamine2 receptor antagonist (H2RA) were compared with a Cox proportional hazards model after adjustment.

FINDINGS

Relative to metformin-only users, metformin and PPI users were at increased risk of the primary outcome (adjusted hazard ratio [HR] = 1.55; 95% CI, 1.46-1.64); metformin and H2RA users also had an elevated risk (adjusted HR = 1.29; 95% CI, 0.97-1.70). Similar patterns were seen with cardiovascular-specific hospitalization. Compared with no drug use, metformin users had an increased risk of the primary outcome, but risk was substantially elevated when patients were taking PPIs or H2RAs, alone or in combination with metformin.

IMPLICATIONS

Concomitant use of metformin and a PPI or metformin and an H2RA were associated with an increased risk of death or hospitalization. This finding suggests that the harm observed may not be due to a specific drug interaction but uncontrolled confounding secondary to an increased risk in those patients using a PPI or H2RA.

Recurrent pneumonia: a review with focus on clinical epidemiology and modifiable risk factors in elderly patients

Community-acquired pneumonia (CAP) is one of the most common reasons for physician visits and hospitalizations in North America. Rates of CAP increase with age and CAP is associated with significant morbidity and mortality, especially in the elderly. Though there is much written about the epidemiology and risk factors of incident (first episode) pneumonia, much less is known about recurrent pneumonia. Rates of recurrent pneumonia within 3-5-years of an episode of CAP are 9-12% with a median time to recurrence of 123-317 days and mortality ranging from 4 to 10%. Age ≥65-years-old and impaired functional status are the only patient characteristics that are independently associated with increased risk of recurrence. In terms of modifiable risk factors, only the use of proton-pump inhibitors and systemic and inhaled corticosteroids have consistently been associated with increased risk of recurrent pneumonia, while angiotensin-converting enzyme (ACE) inhibitors may exert a protective effect. Many chronic medical conditions typically associated with increased incident pneumonia-such as chronic obstructive pulmonary disease (COPD), neurological disease (resulting in dysphagia or silent aspiration), and heart failure-were not associated with increased risk of recurrent pneumonia. However, those who are immune-suppressed (e.g., immunoglobulin deficiencies) may be at increased risk of recurrent pneumonia. In summary, among those who survive an episode of pneumonia, recurrence is not uncommon, particularly in the elderly. Following recovery from an episode of pneumonia, patients should be evaluated for risk factors that would predispose to a second episode including seeking evidence of immunosuppression in younger patients and medication optimization, particularly in the elderly.

(1)H-NMR urinary metabolomic profiling for diagnosis of gastric cancer

Background:

Metabolomics has shown promise in gastric cancer (GC) detection. This research sought to identify whether GC has a unique urinary metabolomic profile compared with benign gastric disease (BN) and healthy (HE) patients.

Methods:

Urine from 43 GC, 40 BN, and 40 matched HE patients was analysed using ¹H nuclear magnetic resonance (¹H-NMR) spectroscopy, generating 77 reproducible metabolites (QC-RSD <25%). Univariate and multivariate (MVA) statistics were employed. A parsimonious biomarker profile of GC vs HE was investigated using LASSO regularised logistic regression (LASSO-LR). Model performance was assessed using Receiver Operating Characteristic (ROC) curves.

Results:

GC displayed a clear discriminatory biomarker profile; the BN profile overlapped with GC and HE. LASSO-LR identified three discriminatory metabolites: 2-hydroxyisobutyrate, 3-indoxylsulfate, and alanine, which produced a discriminatory model with an area under the ROC of 0.95.

Conclusions:

GC patients have a distinct urinary metabolite profile. This study shows clinical potential for metabolic profiling for early GC diagnosis.

The Comparative Effectiveness of Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers in Patients With Diabetes

The evidence examining the effect of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) on mortality in high-risk patients is conflicting. To further examine this controversy, the authors compared outcomes between ACE inhibitors and ARBs in a large clinical diabetes registry. A retrospective cohort of 87,472 incident users followed for 105,702 patient-years was analyzed. Average age was 53.1±10.1 years, 54.2% were men, and 14.4% had cardiovascular disease. All-cause hospitalization or all-cause mortality, the composite primary endpoint, occurred in 10,943 (12.5%) patients. Compared with ACE inhibitors, the adjusted hazard for ARBs was 0.90 (95% confidence interval, 0.87-0.94) for all-cause hospitalization or mortality; 0.95 (0.65-1.40) for mortality; 0.90 (0.87-0.94) for all-cause hospitalization; and 0.81 (0.74-0.89) for cardiovascular admission. ARB use was associated with a reduced, not increased, risk of hospitalization/mortality relative to ACE inhibition. This was driven by lower hospitalization, with a null mortality result.

Quality indicators in continuous renal replacement therapy (CRRT) care in critically ill patients: protocol for a systematic review

BACKGROUND

Renal replacement therapy is increasingly utilized in the intensive care unit (ICU), of which continuous renal replacement therapy (CRRT) is most common. Despite CRRT being a relatively resource-intensive and expensive technology, there remains wide practice variation in its application. This systematic review will appraise the evidence for quality indicators (QIs) of CRRT care in critically ill patients.

METHODS

Ovid MEDLINE, Ovid EMBASE, CINAHL, and the Cochrane Library including the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials (CENTRAL), and databases from the National Information Center of Health Services Research and Health Care Technology will be searched for original studies involving QIs in CRRT. Gray literature sources will be searched for technical reports, practice guidelines, and conference proceedings. Websites of relevant organizations will be identified, and industry leaders in the development and marketing of CRRT technology and non-profit organizations that represent key opinion leads in the use of CRRT will be contacted. We will search the Agency of Healthcare Research and Quality National Quality Measures Clearinghouse for CRRT-related QIs. Studies will be included if they contain quality measures, occur in critically ill patients, and are associated with CRRT. Analysis will be primarily descriptive. Each QI will be evaluated for importance, scientific acceptability, usability, and feasibility using the four criteria proposed by the United States Strategic Framework Board for a National Quality Measurement and Reporting System. Finally, QIs will be appraised for their potential operational characteristics, for their potential to be integrated into electronic medical records, and on their affordability, if applicable.

DISCUSSION

This systematic review will comprehensively identify and synthesize QIs in CRRT. The results of this study will fuel the development of an inventory of essential QIs to support the appropriate, safe, and efficient delivery of CRRT in critically ill patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015015530.

Characteristics and health behaviors of diabetic patients receiving influenza vaccination

OBJECTIVE

Epidemiological research has posited a 'healthy user' bias in patients receiving influenza vaccination; thus we sought to evaluate potential healthy-user attributes and their associations with influenza vaccination.

RESEARCH DESIGN & METHODS

Between 2011 and 2013, adults with type 2 diabetes were enrolled in a prospective cohort in Alberta, Canada. Information collected included sociodemographics, diabetes-related data (e.g., duration, complications), health behaviors (e.g., smoking status), functional health status, and satisfaction with healthcare. Data were collected by a mailed, self-administered survey. Multivariable logistic regression analyses were used to identify potential healthy-user attributes independently associated with influenza vaccination.

RESULTS

From a cohort of 2040 patients, 1287 (63%) reported receiving the influenza vaccine in the previous year. Average age of the cohort was 64 years (standard deviation 11) and 55% were male. In multivariable analysis, attributes independently associated with influenza vaccination included receiving preventive medications: aspirin (64% vs 44%; adjusted odds ratio, aOR 1.65, 95% CI 1.34-2.04); blood pressure medications (76% vs 56%; aOR 1.36, 95% CI 1.07-1.71); and cholesterol-lowering medications (74% vs 53%; aOR 1.50, 95% CI 1.19-1.89), as well as having a healthcare professional check feet for lesions (47% vs 31%; aOR 1.39, 95% CI 1.12-1.74). Additional covariates independently associated with influenza vaccination included: age over 65 years, respiratory disease, the number of additional comorbidities, and higher ratings of healthcare experience.

CONCLUSION

Vaccinated diabetic patients exhibit many postulated attributes of 'healthy users', which has implications for the interpretation of epidemiological studies of influenza vaccine effectiveness, as well as targeting future vaccination campaigns.

Cardiovascular safety of sulphonylureas: over 40 years of continuous controversy without an answer

More than 40 years after publication of the University Group Diabetes Program trial, the cardiovascular safety of sulphonylureas is still contentious. Although several hypotheses linking sulphonylureas to adverse cardiovascular effects exist, none provide conclusive evidence. Adding to the controversy, current clinical trials and observational studies provide inconsistent, and sometimes conflicting, evidence for the cardiovascular effects of sulphonylureas. Overall, observational evidence suggests that an increased risk of adverse cardiovascular outcomes is associated with sulphonylureas; however, these data may be subject to residual confounding and bias. Although evidence from randomized controlled trials has suggested a neutral effect, the majority of these studies were not specifically designed to assess the effect of sulphonylureas on adverse cardiovascular event risk. Current ongoing large clinical trials may provide some clarity on the cardiovascular safety of sulphonylureas, but the results are not expected for several years. With the continued uncertainties concerning the cardiovascular safety of all antidiabetic drugs, a clear answer with regard to sulphonylureas is warranted. The objectives of the present article were to provide an overview of the controversy surrounding sulphonylurea-related cardiovascular effects, to discuss the limitations of the current literature, and to provide recommendations for future studies aiming to elucidate the true relationship between sulphonylureas and adverse cardiovascular effects in people with type 2 diabetes.

Limited impact of drug exposure misclassification from non-benefit thiazolidinedione drug use on mortality and hospitalizations from Saskatchewan, Canada: a cohort study

PURPOSE

Our purpose was to measure the effect of non-benefit drug use on observed associations between exposure and outcome, thereby documenting an empirical example of the potential magnitude of biases introduced when exposure status is misclassified from a restrictive drug coverage policy.

METHODS

New users of antidiabetic agents were identified with a 1-year washout period between January 1, 1995, and December 31, 2005, in Saskatchewan, Canada, and were followed until December 31, 2008. Within this population-based cohort, persons were classified as users of benefit or non-benefit thiazolidinediones (TZDs) according to their first prescription record between January 1, 2006, and December 31, 2006 (non-benefit prescription records were not captured before 2006). An intention-to-treat approach was used to categorize TZD exposure over time. We evaluated the potential bias introduced by drug exposure misclassification by evaluating bootstrapped differences in hazard ratio (HR) estimates of all-cause hospitalization or death between users and nonusers of TZDs obtained from analyses that contained complete drug use (non-benefit and benefit drug use) versus benefit drug use only (non-benefit drug use was misclassified as unexposed). All analyses were replicated within the same cohort of new users of antidiabetic agents for clopidogrel and β-blocker (bisoprolol or carvedilol) users versus nonusers because these agents were also subject to exposure misclassification from non-benefit drug use during the period of the study.

FINDINGS

Among 27,333 new users of antidiabetic agents, we identified 5759 TZD users (28% non-benefit) and 21,574 nonusers of TZDs. The crude HR for hospitalization or death among TZD users versus nonusers was higher in a database that contained benefit-only prescriptions than in a database that contained all prescriptions (HR = 1.11 [95% CI, 1.05-1.18] vs HR = 0.99 [95% CI, 0.94-1.04]). However, the differences in HRs after adjustment for demographic characteristics, health care utilization, comorbidities, and medications suggested minimal bias was introduced when TZD exposure was misclassified in the benefit-only database (adjusted HR [aHR] = 1.04 [95% CI. 0.98-1.10] vs aHR = 0.99 [95% CI, 0.94-1.04]; bootstrapped aHR difference = +0.05 [95% CI, 0.02-0.08]). Minimal differences in aHRs were also observed within analyses of clopidogrel (1551 users [24% non-benefit]; bootstrapped aHR difference = +0.01 [95% CI, -0.04 to 0.06]) and β-blocker users (351 users [42% non-benefit]; bootstrapped aHR difference = +0.06 [95% CI, -0.09 to 0.20]) versus nonusers.

IMPLICATIONS

Although patient characteristics and outcomes differed between users of non-benefit and benefit drugs, misclassification of drug exposure did not meaningfully bias estimates of all-cause mortality and hospitalization after covariate adjustment in our study.

A primary care based healthy-eating and active living education session for weight reduction in the pre-diabetic population

AIMS

Many studies have demonstrated the effectiveness of primary prevention strategies in type 2 diabetes, however, questions remain around the feasibility of high resource, intensive interventions within a healthcare setting. We report the results of a dietitian-led pre-diabetes education session targeting healthy eating and active living as strategies for weight reduction.

METHODS

Participants were asked to complete a baseline questionnaire prior to completing the pre-diabetes education session and were sent follow-up questionnaires at 3 and 6 months. Differences between participants at baseline, 3 and 6 months were determined using χ(2), t-tests and ANOVA.

RESULTS

Of the 211 participants asked to fill out baseline questionnaires, 45 participants completed questionnaires at baseline, 3 months and 6 months. Although we observed general trends towards improvements in diet, physical activity and weight related behaviours among the 45 completers, no significant changes were observed among participants between questionnaire periods.

CONCLUSION

A "one-off", theory-guided group education session may be insufficient to support lifestyle modifications in the context of weight management in a pre-diabetic population. Further evaluation of the efficacy and feasibility of the PCN as a setting for lifestyle intervention is required.

Cardiovascular medication utilization and adherence among heart failure patients in rural and urban areas: a retrospective cohort study

BACKGROUND

Rural residence is a negative prognostic factor for heart failure (HF). The objective was to explore rural and urban differences in the utilization, adherence, and persistence with medications, and mortality among incident HF patients.

METHODS

Using administrative databases from Alberta (Canada), subjects > 65 years old with a first hospitalization for HF between 1999 and 2008 who survived ≥ 90 days after discharge were identified. Pharmacy claims for renin-angiotensin system (RAS) agents, β-blockers (BBs), digoxin, or spironolactone were identified. The association between rural and urban residence and medication utilization, adherence (optimal adherence defined as ≥ 80% adherence over 1 year), persistence, and 1-year mortality was assessed.

RESULTS

The cohort included 10,430 patients, with a mean age of 80.2 (SD, 7.7) years, 47% were male, and 25% were rural residents. Rural residents were less likely to receive RAS agents (74% vs 79%, adjusted odds ratio [aOR], 0.78; 95% confidence interval [CI], 0.69-0.89) or BBs (44% vs 54%; aOR, 0.83; 95% CI, 0.73-0.93) than urban residents, but had similar use of other medications. Although < 69% of patients who received RAS agents and 53% who received BBs had optimal adherence, few differences in adherence or persistence were detected among patients in rural vs urban areas. The 1-year mortality rate was significantly lower for patients who demonstrated optimal adherence to RAS agents or BBs (aOR, 0.78; 95% CI, 0.65-0.94) with no significant differences in the first 6 months between patients residing in rural vs urban areas.

CONCLUSIONS

Rural residents with HF were less likely to receive RAS agents or BBs, but few differences in adherence were noted compared with their urban counterparts. Suboptimal adherence with evidence-based HF therapy was associated with increased risk of mortality.

The impact of multimorbidity on short-term events in patients with community-acquired pneumonia: prospective cohort study

The impact of multimorbidity on patients with community-acquired pneumonia has not been well characterised. Thus, our aim was to explore the relationship between multimorbidity and adverse events within 90 days of discharge. Data were prospectively collected for a population-based cohort of all adults discharged from any of the seven emergency departments (ED) or six hospitals in Edmonton (Alberta, Canada) with community-acquired pneumonia. Multivariable Cox regression models were used to examine the independent association between multimorbidity (defined as two or more chronic conditions) and subsequent 90-day mortality, hospitalisation, or ED visits after treatment of pneumonia. The cohort included 5565 patients, mean age was 57 years (SD 20), 54% were male, and 59% were treated as outpatients; 1602 (29%) patients had multimorbidity. Within 90 days, 255 (5%) patients died, 1205 (22%) were hospitalised, 1280 (23%) died or were hospitalised, and 2049 (37%) were admitted to the ED. The presence of multimorbidity was independently associated with an increased risk of death or hospitalisation within 90 days (37% vs. 17% for those without multimorbidity, adjusted hazard ratio: 1.43, 95% confidence interval: 1.26 to 1.62) as well as ED visits (45% vs. 34%, adjusted hazard ratio: 1.40, 95% confidence interval: 1.26 to 1.56). Multimorbidity was present in one-third of all patients with pneumonia in our study, and it was independently associated with death, hospitalisation, or return to ED within 90 days of discharge. Our findings suggest that multimorbidity is strongly related to prognosis and should be considered when making site-of-care decisions in the ED or deciding upon readiness for discharge.

Sitagliptin use in patients with diabetes and heart failure: a population-based retrospective cohort study

OBJECTIVES

The study objective was to evaluate the effects of sitagliptin in patients with type 2 diabetes (T2D) and heart failure (HF).

BACKGROUND

There is uncertainty in the literature about whether dipeptidyl peptidase (DPP)-4 inhibitors cause harm in patients with HF and T2D.

METHODS

We analyzed data from a national commercially insured U.S. claims database. Patients with incident HF were identified from individuals with T2D initially treated with metformin or sulfonylurea and followed over time. Subjects subsequently using sitagliptin were compared with those not using sitagliptin in the 90 days before our primary outcome of all-cause hospital admission or death using a nested case-control analysis after adjustment for demographics and clinical and laboratory data. HF-specific hospital admission or death also was assessed.

RESULTS

A total of 7,620 patients with diabetes and incident HF met our inclusion criteria. Mean (SD) age was 54 years (9), and 58% (3,180) were male. Overall, 887 patients (12%) were exposed to sitagliptin therapy (521 patient years of exposure) after incident HF. Our primary composite endpoint occurred in 4,137 patients (54%). After adjustment, sitagliptin users were not at an increased risk for the primary endpoint (7.1% vs. 9.2%, adjusted odds ratio [aOR]: 0.84, 95% confidence interval [CI]: 0.69 to 1.03) or each component (hospital admission 7.5% vs. 9.2%, aOR: 0.93, 95% CI: 0.76 to 1.14; death 6.9% vs. 9.3%, aOR: 1.16, 95% CI: 0.68 to 1.97). However, sitagliptin use was associated with an increased risk of HF hospitalizations (12.5% vs. 9.0%, aOR: 1.84, 95% CI: 1.16 to 2.92).

CONCLUSIONS

Sitagliptin use was not associated with an increased risk of all-cause hospitalizations or death, but was associated with an increased risk of HF-related hospitalizations among patients with T2D with pre-existing HF.

Utility of telephone survey methods in population-based health studies of older adults: an example from the Alberta Older Adult Health Behavior (ALERT) study

BACKGROUND

Random digit dialing is often used in public health research initiatives to accrue and establish a study sample; however few studies have fully described the utility of this approach. The primary objective of this paper was to describe the implementation and utility of using random digit dialing and Computer Assisted Telephone Interviewing (CATI) for sampling, recruitment and data collection in a large population-based study of older adults [Alberta Older Adult Health Behavior (ALERT) study].

METHODS

Using random digit dialing, older adults (> = 55 years) completed health behavior and outcome and demographic measures via CATI. After completing the CATI, participants were invited to receive a step pedometer and waist circumference tape measure via mail to gather objectively derived ambulatory activity and waist circumference assessments.

RESULTS

Overall, 36,000 telephone numbers were called of which 7,013 were deemed eligible for the study. Of those, 4,913 (70.1%) refused to participate in the study and 804 (11.4%) participants were not included due to a variety of call dispositions (e.g., difficult to reach, full quota for region). A total of 1,296 participants completed telephone interviews (18.5% of those eligible and 3.6% of all individuals approached). Overall, 22.8% of households did not have an age 55+ resident and 13.6% of individuals refused to participate, Average age was 66.5 years, and 43% were male. A total of 1,081 participants (83.4%) also submitted self-measured ambulatory activity (i.e., via step pedometer) and anthropometric data (i.e., waist circumference). With the exception of income (18.7%), the rate of missing data for demographics, health behaviors, and health measures was minimal (<1%).

CONCLUSIONS

Older adults are willing to participate in telephone-based health surveys when randomly contacted. Researchers can use this information to evaluate the feasibility and the logistics of planned studies using a similar population and study design.

Comparative Effectiveness of Olmesartan and Other Angiotensin Receptor Blockers in Diabetes Mellitus

Olmesartan has been linked with increased risk of cardiovascular mortality and sprue-like enteropathy. We compared outcomes between olmesartan and other angiotensin receptor blockers in a large clinical registry of patients with diabetes mellitus. A retrospective cohort analysis using nationwide US-integrated insurance and laboratory claims was performed in 45 185 incident diabetic angiotensin receptor blocker users, including 10 370 (23%) olmesartan users. Hazard ratios were computed using time-dependant Cox models adjusted for sociodemographic characteristics, comorbidities, laboratory data, drug use, healthcare utilization, and the propensity to receive olmesartan. Blood pressure data were unavailable. Subjects were followed up for 116 721 patient-years. The primary end point was all-cause hospitalization or all-cause mortality and occurred in 10 915 (24%) patients. Average age was 54.3±9.6 years, 52% were men, 17% had cardiovascular disease, and 10% chronic kidney disease. Compared with other angiotensin receptor blockers, the adjusted hazard for olmesartan was 0.99 (95% confidence interval, 0.94–1.05) for all-cause hospitalization and mortality; 0.90 (0.62–1.30) for all-cause mortality; 0.99 (0.94–1.05) for all-cause hospital admission; 0.88 (0.78–1.00) for cardiovascular disease–related admission, and 1.09 (0.98–1.20) for gastrointestinal disease–related hospitalization in the overall cohort. Olmesartan use was associated with an adjusted hazard for the primary outcome of 1.11 (0.99–1.24) in subjects with history of cardiovascular disease and 1.21 (1.04–1.41) in subjects with chronic kidney disease. In conclusion, there is no robust signal for harm with olmesartan use. Risk may be increased in kidney disease; thus, given the widespread availability of alternate agents, olmesartan should be used with caution in this subgroup pending further study.

Rates and risk factors for recurrent pneumonia in patients hospitalized with community-acquired pneumonia: population-based prospective cohort study with 5 years of follow-up

BACKGROUND

The rates and risk factors for developing recurrent pneumonia following hospitalization with community-acquired pneumonia (CAP) are poorly understood.

METHODS

We examined a population-based cohort of patients with CAP who survived hospital admission and who were free of pneumonia for at least 3 months. We collected clinical, functional, and medication-related information and pneumonia severity index (PSI). Using linked databases we followed patients for 5 years and captured any clinical episode of pneumonia 90 days or more post-discharge. We used Cox proportional hazards models (adjusted for age, sex, PSI, functional status, medications) to determine rates and independent correlates of recurrent pneumonia.

RESULTS

The final cohort included 2709 inpatients; 43% were 75 years or older, 34% were not fully independent, and 56% had severe pneumonia. Over 5 years of follow-up, 245 (9%; 95% confidence interval [CI], 8%-10%) patients developed recurrent pneumonia, and 156 (64%) of these episodes required hospitalization. Rate of recurrence was 3.0/100 person-years and median time to recurrence was 317 days (interquartile range, 177-569); 32 (13%) patients had 2 or more recurrences. In multivariable analyses only age >75 years (adjusted P = .047) and less than fully independent functional status (12% recurrence rate with impaired functional status vs 7% for fully independent; adjusted hazard ratio, 1.7; 95% CI, 1.3-2.2; P < .001) were significantly associated with recurrent pneumonia.

CONCLUSIONS

One of 11 patients who survived CAP hospitalization had recurrent pneumonia over 5 years and those with impaired functional status were at particularly high risk. Recurrent pneumonia is common and more attention to preventive strategies at discharge and closer follow-up over the long-term seem warranted.

Working-age adults with diabetes experience greater susceptibility to seasonal influenza: a population-based cohort study

AIMS/HYPOTHESIS

The aim of this work was to compare the incidence of illness attributable to influenza in working-age adults (age <65 years) with and without diabetes.

METHODS

We performed a cohort study using administrative data from Manitoba, Canada, between 2000 and 2008. All working-age adults with diabetes were identified and matched with up to two non-diabetic controls. We analysed the rates of influenza-like illness physician visits and hospitalisations, pneumonia and influenza hospitalisations, and all-cause hospitalisations. Multivariable regressions were used to estimate the influenza-attributable rate of each outcome.

RESULTS

We included 745,777 person-years of follow-up among 166,715 subjects. The median age was 50-51 years and 48-49% were women; adults with diabetes had more comorbidities and were more likely to be vaccinated for influenza than those without diabetes. Compared with similar adults without diabetes, those with diabetes had a 6% greater (RR 1.06, 95% CI 1.02, 1.10; absolute risk difference 6 per 1,000 adults per year) increase in all-cause hospitalisations associated with influenza, representing a total of 54 additional hospitalisations. There were no differences in the influenza-attributable rates of influenza-like illness (p = 0.06) or pneumonia and influenza (p = 0.11).

CONCLUSIONS/INTERPRETATION

Guidelines calling for influenza vaccinations in diabetic, in addition to elderly, adults implicitly single out working-age adults with diabetes. The evidence supporting such guidelines has hitherto been scant. We found that working-age adults with diabetes appear more susceptible to serious influenza-attributable illness. These findings represent the strongest available evidence for targeting diabetes as an indication for influenza vaccination, irrespective of age.

Medication transitions and polypharmacy in older adults following acute care

Background/objective

Medication changes at transitions of care and polypharmacy are growing concerns that adversely impact optimal drug use. We aimed to describe transitions and patterns of medication use before and 1 year after older patients were hospitalized for community-acquired pneumonia, the second-most common reason for admission in North America.

Materials and methods

This was an analysis of a population-based clinical registry of patients treated in any of the six hospitals or seven emergency departments in Edmonton, Alberta, Canada, comprising 2,105 patients 65 years and older with community-acquired pneumonia who had survived at least 1 year. The prevalence of polypharmacy (five or more unique prescription drugs), as well as new use and persistence of common drug classes were assessed.

Results

The mean age was 78 years (standard deviation 8 years), 50% were female, 62% were hospitalized, and 58% had severe pneumonia. Among the 2,105 patients, 949 (45%) were using five or more medications prior to hospitalization, increasing to 1,559 (74%) within 90 days postdischarge and remaining over 70% at 1 year. Overall, 1,690 (80%) patients newly started and 1,553 (74%) patients stopped at least one medication in the first 90 days of follow-up. The prevalence of the most common drug classes (ie, cardiovascular, alimentary/metabolism) remained stable, with the exception of anti-infective agents, whereby 25% of patients were dispensed an anti-infective agent 3 months to 1 year after hospitalization.

Conclusion

Most older patients with pneumonia are subject to polypharmacy, and almost every patient had a medication started or stopped during 1-year follow-up, with 25% using antibiotics again. The period following an episode of pneumonia represents an opportunity potentially to optimize pharmacotherapy.

Risk of acute coronary events associated with glyburide compared with gliclazide use in patients with type 2 diabetes: a nested case-control study

AIM

Sulfonylureas might increase the risk of adverse cardiovascular events; however, emerging evidence suggests there may be important differences amongst these drugs. Some, like glyburide, inhibit KATP channels in the heart and pancreas, while others, like gliclazide, are more likely to selectively inhibit KATP channels in the pancreas. We hypothesized that the risk of acute coronary syndrome (ACS) events would be higher in patients using glyburide compared with gliclazide.

METHODS

This nested case-control study used administrative health data from Alberta, Canada. New users of glyburide or gliclazide aged ≥66 years between 1998 and 2010 were included. Cases were individuals with an ACS-related hospitalization or death. Up to four controls were matched based on birth year, sex, cohort-entry year and follow-up time. Multivariable conditional logistic regression was used to estimate adjusted odds ratios (OR), controlling for baseline drug use and co-morbidities.

RESULTS

Our cohort included 7441 gliclazide and 13 884 glyburide users; 51.4% men, mean (s.d.) age 75.5 (6.6) years and mean (s.d.) duration of follow-up 5.5 (4.0) years. A total of 4239 patients had an ACS-related hospitalization or death and were matched to 16 723 controls. Compared with gliclazide use, glyburide use was associated with a higher risk (adjusted OR 1.14; 95% CI 1.06-1.23) of ACS-related hospitalization or death over 5.5 years (number needed to harm: 50).

CONCLUSION

In this observational study, glyburide use was associated with a 14% higher risk of ACS events compared with gliclazide use. Although the difference is small and probably to have implications at the population level rather than the individual patient or clinician, any causal inferences regarding sulfonylurea use and adverse cardiovascular risk should be tested in a large-scale randomized controlled trial.

Review of models used in economic analyses of new oral treatments for type 2 diabetes mellitus

BACKGROUND

Economic models are considered to be important, as they help evaluate the long-term impact of diabetes treatment. To date, it appears that no article has reviewed and critically appraised the cost-effectiveness models developed to evaluate new oral treatments [glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors] for type 2 diabetes mellitus (T2DM).

OBJECTIVES

This study aimed to provide insight into the utilization of cost-effectiveness modelling methods. The focus of our study was aimed at the applicability of these models, particularly around the major assumptions related to the clinical parameters (glycated haemoglobin [A1c], systolic blood pressure [SBP], lipids and weight) used in the models, and subsequent clinical outcomes.

METHODS

MEDLINE and EMBASE were searched from 1 January 2004 to 14 February 2013 in order to identify published cost-effectiveness evaluations for the treatment of T2DM by new oral treatments (GLP-1 receptor agonists and DPP-4 inhibitors). Once identified, the articles were reviewed and grouped together according to the type of model. The following data were captured for each study: comparators; country; evaluation and key cost drivers; time horizon; perspective; discounting rates; currency/year; cost-effectiveness threshold, sensitivity analysis; and cost-effectiveness analysis curves.

RESULTS

A total of 15 studies were identified in our review. Nearly all of the models utilized a health care payer perspective and provided a lifetime horizon. The CORE Diabetes Model, UK Prospective Diabetes Study (UKPDS) Outcomes Model, Cardiff Diabetes Model, Centers for Disease Control and Prevention (CDC) Diabetes Cost-Effectiveness Group Model and Diabetes Mellitus Model were cited. With the exception of two studies, all of the studies made significant assumptions surrounding the impact of GLP-1 receptor agonists or DPP-4 inhibitors on clinical parameters and subsequent short- and long-term outcomes. Moreover, often the differences in the clinical parameters were relatively small (e.g. 1 or 2 mmHg in blood pressure) and would not be considered by many as clinically important. Yet, the impact of these small clinical changes often resulted in large lifetime changes in health outcomes in the models. In particular, many studies assumed that changes in weight associated with the therapies would equate to improved outcomes, despite limited evidence for this assumption. Although the new oral treatments were regarded as cost effective in most studies based upon the studies reviewed, the validity of these projections, particularly for the longer time frames, is questionable. Indeed, although most of these studies have been conducted in the last 5 years, recent trial evidence has already questioned the validity of most of these studies.

CONCLUSION

It is clear that a number of changes are required in the evaluation of diabetes therapies. First and foremost, the basic models need to be updated to include contemporary important clinical trial data assessing hard clinical outcomes in patients with diabetes. Second, there should be less emphasis on 40-year or lifetime costs and consequences of the therapies and a greater focus on short-term (5-year) and intermediate-term (10-year) outcomes. Practice is continually evolving, and the probability that these models would provide any valid predictions beyond 10 years is remote. Third, all modellers should immediately remove the basic assumption that small clinically inconsequential changes in A1c, SBP, lipids and weight result in major clinical improvements in patients. Future models should aim to include all relevant treatment outcomes, whether these relate to effects on underlying diabetes and its complications or to short- or long-term side effects of treatment. We need to explore why cost-saving interventions could benefit further from adding patient characteristics, which may be able to better predict the use of lower-cost alternatives. Moreover, the vast array of different clinical, cost and utility data used in the different models reviewed makes it apparent that a uniform methodology should be developed for diabetes economic models. In this manner, future models could be run using the same data, which would allow for more acceptable comparability between studies.