Ludovic Casanova

Characteristics of patients and physicians correlated with regular influenza vaccination in patients treated for type 2 diabetes: a follow-up study from 2008 to 2011 in southeastern France

We studied a cohort of 110 823 patients treated with oral hypoglycaemic agents for type 2 diabetes in southeastern France from 1 January 2008 to 31 December 2011, to identify influenza vaccination coverage trends and the patient and physician correlates of influenza vaccine (IFV) uptake. We used French national health insurance fund (NHIF) databases to identify these patients and collect data on their IFV reimbursement claims (IFVC) and patient and physician characteristics. We used multilevel multivariate polytomous logistic regressions to test the correlates of IFVC. Between 2008 and 2011 the annual IFVC rate varied from 33.7% to 32.3% in the 18-64 age group and from 69.5% to 61.1% in the 65 + age group, among whom we saw a clear trend towards reduced vaccination after 2008. In the younger group, the probability of regular vaccination each year from 2008 to 2011 increased with diabetes severity and duration, comorbidities, and the number of general practitioner and nurse visits; it was higher among patients seeing endocrinologists and lower among low-income patients than in other patients. In the older group, there was no association with either diabetes severity or physician specialty. These results suggest different patterns of correlates of influenza vaccination according to age. Endocrinologists might help to improve IFV uptake in the younger group of patients with type 2 diabetes. Communication strategies regarding influenza vaccination should be adapted to age, and collaboration between healthcare professionals should be reinforced to achieve vaccination objectives for these patients.

Bias in the measure of the effectiveness of seasonal influenza vaccination among diabetics.

BACKGROUND The influenza virus is an important cause of morbidity and mortality for diabetics. The seasonal influenza vaccines immunologic effectiveness is proven within the type 1 and type 2 diabetic populations, but the level of evidence is low. This article presents a systematic review for the bias in the measure of the effectiveness of seasonal influenza vaccination among diabetics. METHODS Using systematic review methods, we searched three electronic databases for published literature (MEDLINE, EMBASE and the Cochrane Library) and two grey literature (SIGLE and NHS EED) databases, to identify studies published between 1997 and 2013, examining the effect of seasonal influenza vaccination, among diabetics, on any measure for influenza morbidity or mortality. RESULTS 725 records were identified from the three databases and screening, short-listing was undertaken independently by two reviewers. After de-duplication, all records were screened by title and then abstract, and 34 short-listed records were reviewed in full, with 7 studies included: 4 cohort studies and 3 case-control studies, conducted in 7 countries. The most common outcome of interest in studies (n=4) was all-cause mortality among elderly diabetics (>65 years), with individual studies reporting reductions in risk of between 33% [95%CI: 4%-54%] and 68% [95%CI: 58%-75%]. We found only two studies for working-age adult diabetics: one reporting that vaccination prevented hospitalizations due to pneumonia or influenza (vaccine effectiveness [VE] 43%, [95%CI: 28%-54%]) and all-cause hospitalizations (VE: 28% [95%CI: 24%-32%]); and, another reporting no significant decrease in all-cause mortality for working-age adult diabetics. We have identified three major biases: the use of indirect health outcomes, a risk of selection bias (health-seeking bias), and no adjustment for participant pneumococcal vaccination status. The most recent included article finds that morbimortality is still lower during off-season influenza in both vaccinated and non-vaccinated diabetics, indicating important residual confounding. CONCLUSION To date, the strength of evidence supporting the routine use of seasonal influenza vaccination is low for diabetics older than 65, and very low for working-age diabetics.

Effectiveness of seasonal influenza vaccination in patients with diabetes: protocol for a nested case–control study

Introduction Seasonal influenza vaccination (SIV) is recommended for people with diabetes, but its effectiveness has not been demonstrated. All of the available studies are observational and marred with the healthy vaccine bias, that is, bias resulting from the generally better health behaviours practised by people who choose to be vaccinated against influenza, compared with those who do not. This protocol is intended to study the effectiveness of SIV in people with treated diabetes and simultaneously to control for bias. Methods and analyses This case-control study is nested in a historical cohort and is designed to study vaccine effectiveness (VE) assessed by morbidity, mortality and anti-infective drug use. The cohort will comprise a representative sample of health insurance beneficiaries in France and will cover 10 consecutive epidemic seasons. It will include all patients reimbursed three separate times for drugs to treat diabetes. The first study of VE will use reasons for hospitalisation as the primary end point, and the second with the use of neuraminidase inhibitors and of antibiotics as the end points. A case will be defined as any person in the cohort reaching any end point at a given date. The case patient will be matched with the largest possible number of controls (individuals not reaching the end point by this date) according to the propensity score method with an optimal calliper width. A conditional logistic model will be used to estimate ORs to take into account both the matching and the repetition of measurements. The model will be applied separately during and outside of epidemic periods to estimate the residual confounding. Ethics and dissemination The study has been approved by the French Commission on Individual Data Protection and Public Liberties (ref: AT/CPZ/SVT/JB/DP/CR05222O). The studys findings will be published in peer-reviewed journals and disseminated at international conferences and through social media.

Membership in a diabetes-care network and adherence to clinical practice guidelines for treating type 2 diabetes among general practitioners: A four-year follow-up

OBJECTIVES To assess whether private general practitioners (GPs) belonging to a diabetes-care network adhered more closely to clinical practice guidelines for diabetes care than GPs not in such a network, for all their patients with type 2 diabetes treated with medication (patients with diabetes), regardless of whether they received care through a network (that is, whether a halo effect occurred). RESEARCH DESIGN AND MEASURES The study, based on health insurance reimbursement databases in southeastern France, included 468 GPs in two networks and 468 non-network GPs in the same geographical area, matched one-to-one by propensity scores. We followed up their patients with diabetes (n=22,808) from 2008 through 2011, conducting multivariate time-to-event analyses (Cox models) that took the matching design into account to evaluate time from inclusion until performance of the given number of each of six recommended examinations/tests. RESULTS GPs belonging to a diabetes-care network adhered more closely to clinical practice guidelines but our result were slightly pronounced. Hazard ratios (HR) were significantly higher for patients of network GPs for the implementation of 3 HbA1C assays (HRa=1.13; [95%CI=1.10-1.16]), or 1 microalbuminuria assay (1.4 [1.35-1.45]); they were lower for LDL-cholesterol assays (1.04 [1.01-1.07]) and ophthalmological checkups (1.07 [1.04-1.10]), and not significant for creatinemia or cardiac monitoring. CONCLUSIONS Network GPs had better diabetes monitoring practices for all their patients with diabetes than the other GPs, especially for the most diabetes-specific tests. Further research is needed in other settings to confirm the existence of this halo effect.

Membership in a Diabetes Care Network Improves General Practitioners’ Practices for HbA1c and Microalbuminuria Monitoring: A Cohort Study Among Patients With Type 2 Diabetes

To prevent complications of diabetes, clinical practice guidelines recommend specific frequencies of several checkups. Following these guidelines can decrease all-cause mortality and cardiovascular morbidity (1). France, like other countries, has sought to improve diabetes management, specifically by establishing diabetes care networks (DCNs) that coordinate care, provide continuing medical education for health care professionals, and educate network patients. Nonetheless, less than 5% of all patients with type 2 diabetes participate in these networks. Our aim was to study whether general practitioners (GPs) belonging to a DCN adhered more closely to guidelines for diabetes monitoring than GPs not belonging to a DCN for all their patients with type 2 diabetes and not only those in a DCN. Analyses focused on orders for two diabetes-specific examinations: HbA1c and microalbuminuria testing. Using health insurance reimbursement databases in southeastern France, we included 468 GPs in two networks …