Andrea Arfè

Are generic and brand-name statins clinically equivalent? Evidence from a real data-base

BACKGROUND Use of generic drugs can help contain drug spending. However, there is concern among patients and physicians that generic drugs may be clinically inferior to brand-name ones. This study aimed to compare patients treated with generic and brand-name statins in terms of therapeutic interruption and cardiovascular (CV) outcomes. METHODS 13,799 beneficiaries of the health care system of Lombardy, Italy, aged 40 years or older who were newly treated with generic or brand-name simvastatin during 2008, were followed until 2011 for the occurrence of two outcomes: 1) therapeutic discontinuation and 2) hospitalization for CV events. Hazard ratios (HR) associated with use of generic or brand-name at starting therapy (intention-to-treat analysis) and during follow-up (as-treated analysis) were estimated by fitting proportional hazard Cox models. A Monte-Carlo sensitivity analysis was performed to account for unmeasured confounders. RESULTS Patients who started on generic did not experience a different risk of discontinuation (HR: 0.98; 95% CI 0.94 to 1.02) nor of CV outcomes (HR: 0.98; 95% CI 0.79 to 1.22) from those starting on brand-name. Patients who spent >75% of time of follow-up with statin available on generics did not experience a different risk of discontinuation (HR: 0.94; 95% CI 0.87 to 1.01), nor of CV outcomes (HR: 1.06; 95% CI 0.83 to 1.34), compared with those who mainly or only used brand-name statin. CONCLUSIONS Our findings do not support the notion that in the real world clinical practice brand-name statins are superior to generics for keeping therapy and preventing CV outcomes.

Relationships of different types of event to cardiovascular death in trials of antihypertensive treatment: An aid to definition of total cardiovascular disease risk in hypertension

Background and objective: Guidelines for management of cardiovascular diseases stratify absolute cardiovascular risk into categories with a high-risk threshold defined at a 20% cardiovascular events risk in 10 years, but it is unclear whether only major events or the Framingham-extended definition should be considered. The 2013 ESH-ESC hypertension guidelines, instead, define cardiovascular risk as a risk of cardiovascular death in 10 years, as in the SCORE model, setting the threshold for high risk at the 5% level. It would be therefore convenient to know the quantitative relationship between the risks of the different outcomes adopted by the different guidelines, especially because some outcome definitions include serious nonfatal cardiovascular events relevant in cardiovascular prevention. We have therefore analysed these relationships in trials of antihypertensive therapy as an aid to defining total cardiovascular risk in hypertensive patients. Design and methods: Sixty-one trials were identified, and 51 retained for analysis of the relationship of cardiovascular death to the incidence of all-cause death, major cardiovascular events and inclusive (Framingham) cardiovascular events. The relationship between cardiovascular death rates and each type of event rates was explored by fitting flexible regression models. Results: The included trials provided 15 164 cardiovascular deaths and 1 674 427 patient-years. The relation of each event rate to cardiovascular death rate was best explained by a model considering the logarithm of each event rate as a dependent variable and the logarithm of cardiovascular death rate as a predictor. Mean patients’ age and treatment were also predictors, but to a minor extent. The increase of the incidence rates of all types of events was less steep the higher the CV death rate: the rate ratios of all-cause death to cardiovascular death were 2.2, 1.9 and 1.8 at low-moderate (cardiovascular death <5% in 10 years), high (cardiovascular death 5% to <10%) and very high risk (cardiovascular death ≥10%), respectively; the rate ratios of major cardiovascular events to cardiovascular death were 3.9, 2.7, 2.3 and the rate ratios of extended cardiovascular events to cardiovascular death were 8.4, 5.6 and 4.6, respectively. Ratios only slightly changed when 12 trials of secondary prevention were excluded. Conclusion: Ratios of various event rates to cardiovascular death rate vary with cardiovascular disease severity, cardiovascular mortality representing an increasing proportion of total cardiovascular risk when the former is higher. From the models, a total risk can be estimated in groups of hypertensive patients whose cardiovascular death risk is calculated by the SCORE model.

A validation study of a new classification algorithm to identify rheumatoid arthritis using administrative health databases: case-control and cohort diagnostic accuracy studies. Results from the RECord linkage On Rheumatic Diseases study of the Italian Society for Rheumatology.

Objectives To develop and validate a new algorithm to identify patients with rheumatoid arthritis (RA) and estimate disease prevalence using administrative health databases (AHDs) of the Italian Lombardy region. Design Case–control and cohort diagnostic accuracy study. Methods In a randomly selected sample of 827 patients drawn from a tertiary rheumatology centre (training set), clinically validated diagnoses were linked to administrative data including diagnostic codes and drug prescriptions. An algorithm in steps of decreasing specificity was developed and its accuracy assessed calculating sensitivity/specificity, positive predictive value (PPV)/negative predictive value, with corresponding CIs. The algorithm was applied to two validating sets: 106 patients from a secondary rheumatology centre and 6087 participants from the primary care. Alternative algorithms were developed to increase PPV at population level. Crude and adjusted prevalence estimates taking into account algorithm misclassification rates were obtained for the Lombardy region. Results The algorithms included: RA certification by a rheumatologist, certification for other autoimmune diseases by specialists, RA code in the hospital discharge form, prescription of disease-modifying antirheumatic drugs and oral glucocorticoids. In the training set, a four-step algorithm identified clinically diagnosed RA cases with a sensitivity of 96.3 (95% CI 93.6 to 98.2) and a specificity of 90.3 (87.4 to 92.7). Both external validations showed highly consistent results. More specific algorithms achieved >80% PPV at the population level. The crude RA prevalence in Lombardy was 0.52%, and estimates adjusted for misclassification ranged from 0.31% (95% CI 0.14% to 0.42%) to 0.37% (0.25% to 0.47%). Conclusions AHDs are valuable tools for the identification of RA cases at the population level, and allow estimation of disease prevalence and to select retrospective cohorts.

Persistence with inhaled corticosteroids reduces the risk of exacerbation among adults with asthma: A real-world investigation

Real‐world evidence suggests that persistence with inhaled corticosteroids (ICS), the mainstay of asthma drug therapy, is generally poor. The effect of persistence with ICS on the risk of asthma exacerbation was addressed in a population‐based study.

Tutorial: strategies addressing detection bias were reviewed and implemented for investigating the statins-diabetes association.

OBJECTIVES Literature on specific analytic methods for addressing detection bias is fragmented. We illustrate some analytic strategies to account for detection bias. STUDY DESIGN AND SETTING Several tools addressing detection bias are described, namely (1) sensitivity analysis, (2) conditioning on outcome detectability, and (3) use of negative controls. These tools are applied in a population-based cohort study on the association between adherence to statins and start of antidiabetic therapy (as proxy of type 2 diabetes mellitus onset). RESULTS Compared with patients on very low adherence to statins, those with high adherence had hazard ratio (HR) for diabetes of 1.53 (95% confidence interval: 1.44, 1.64). The observed association was potentially affected by detection bias because long-term exposure to statins implies a more regular use of primary care services, triggering the search for diabetes. Nevertheless, from the considered tools, (1) we showed that the HR for diabetes risk decreased to 1.28 if diabetes detection was assumed to be 20% more likely in highly adherent patients; (2) an increased risk of diabetes was found among patients with no specialist visits during the first year of follow-up; (3) no association was found between adherence to bisphosphonates (negative exposure) and diabetes nor between adherence to statins and initiation of antihypertensive pharmacotherapy (negative outcome). CONCLUSION Implementation of analytic strategies for addressing detection bias is advisable whenever this is suspected. As illustrated, several methods could be considered. Their implementation suggested that detection bias had a limited impact in our application.

Respiratory drugs and macrolides prevent asthma exacerbations: A real-world investigation

OBJECTIVE We investigated the real-world effectiveness of several drugs (including short- and long-acting beta-agonists [SABAs and LABAs], inhaled corticosteroids [ICS], and antibiotics) in preventing severe asthma exacerbations by carrying-out a large observational study based on the healthcare utilization databases of the Italian Lombardy Region. METHODS We identified all patients aged 6-40 years who performed an Emergency Department visit for asthma during 2010-2012 as cases. To address bias due to unmeasured confounders, we implemented a case-crossover (CC) design. Addressing other specific sources of systematic errors (e.g. protopathic bias) was of particular concern in this study. RESULTS A total of 7300 cases were included in the study. The CC odds ratios (95% confidence intervals) for current vs. past use were 0.81 (0.71, 0.92) for SABAs, 0.83 (0.72, 0.96) for ICS, 0.78 (0.66, 0.91) for LABA/ICS fixed combinations, 0.79 (0.65, 0.97) for other respiratory drugs, and 0.79 (0.69, 0.92) for macrolides antibiotics. Sensitivity analyses showed that our results were robust with respect to several sources of bias. CONCLUSIONS Our study provides evidence from the real-world clinical practice on the effectiveness of several respiratory drugs and macrolides in reducing the risk of severe asthma exacerbations.

Cost-effectiveness of enhancing adherence with oral bisphosphonates treatment in osteoporotic women: an empirical approach based on healthcare utilisation databases

Objective Adherence with bisphosphonates therapy is generally low. Enhancing adherence with bisphosphonates would be effective in achieving the full benefits of therapy albeit a growth in the expenditure for supporting incremented drug use is expected. The cost-effectiveness of enhancing adherence with oral bisphosphonates in a large population of osteoporotic women has been assessed in the current study. Design Retrospective cohort study. Setting Healthcare utilisation databases of Lombardy Region, Italy. Participants A cohort of 28 558 women aged 45 years or more, resident in the Italian Region of Lombardy, who were newly treated with oral bisphosphonates during 2003–2004, was followed for 6 years after index prescription. Outcome measures Fracture-free survival time, healthcare cost and incremental cost-effectiveness ratio (ICER) of enhancing adherence, that is, the additional cost that would be spent every year for gaining one fracture-free year as a consequence of enhancing adherence at a certain level. Results Enhanced adherence from 33% (baseline) to 80%, increased both fracture-free survivals from 970 to 973 years and healthcare costs from €118 000 to €265 000 every 1000 woman-years, with ICER value of €53 000 (95% CI €49 000 to €58 000). ICER values were lower for older women (€50 000; 95% CI €42 000 to €58 000) and for those suffering from at least a chronic comorbidity (€25000; 95% CI 95% CI €7000 to €47 000). Conclusions Enhancing adherence with oral bisphosphonates offers important benefits in reducing the risk of fracture, although at a substantial cost.

A probabilistic bias analysis for misclassified categorical exposures, with application to oral anti-hyperglycaemic drugs.

The effect of drug exposure misclassification generally receives little attention in pharmacoepidemiological research. In this paper, we illustrate a probabilistic bias analysis approach for misclassified categorical exposures and apply it in a database study of oral anti‐hyperglycaemic drugs (OADs).

Incidence, Predictors, and Clinical Implications of Discontinuing Therapy with Inhaled Long-Acting Bronchodilators among Patients with Chronic Obstructive Pulmonary Disease

abstract Incidence, predictors and effect of discontinuation of long-acting bronchodilators on the risk of death or hospital admission among adults with Chronic Obstructive Pulmonary Disease (COPD) were assessed in a large population-based prospective study carried out by linking Italian healthcare utilization databases. Specifically, the cohort of 17,490 beneficiaries of the National Health Service in the Italian Region of Lombardy, aged 40 years or older, who started long-acting bronchodilators therapy during 2005–2008 was followed from first dispensation until 2012. During this period, patients who experienced discontinuation of long-acting bronchodilators were identified. Hospitalizations for COPD and deaths for any cause (composite clinical outcome) were also identified during follow-up. A Cox proportional hazards model was fitted to identify predictors of discontinuation. The case-crossover design was used to assess the implications of treatment discontinuation on the clinical outcome risk. Cumulative incidences of discontinuation were, respectively, 67%, 80%, and 92% at 6 months, 1 year, and 5 years since initial treatment. Significant predictors of discontinuation were female gender, younger age, starting treatment with fixed-dose combination of inhaled bronchodilators and corticosteroids, using antibiotics, inhaled long-acting bronchodilators and corticosteroids and not using short-acting bronchodilators, other respiratory drugs and systemic corticosteroids during follow-up. Odds ratios (95% confidence intervals) for the clinical outcome associated with not discontinuing long-acting bronchodilators was 0.64 (0.50 to 0.82). In conclusion, in the real-life setting, discontinuation of inhaled long-acting bronchodilators in adults with COPD is high even after just 6 months, even though persistence to these drugs reduces the risk of severe outcomes.

Risk of ischemic stroke and the use of individual non-steroidal anti-inflammatory drugs: A multi-country European database study within the SOS Project

Background and purpose A multi-country European study using data from six healthcare databases from four countries was performed to evaluate in a large study population (>32 million) the risk of ischemic stroke (IS) associated with individual NSAIDs and to assess the impact of risk factors of IS and co-medication. Methods Case-control study nested in a cohort of new NSAID users. For each case, up to 100 sex- and age-matched controls were selected and confounder-adjusted odds ratios for current use of individual NSAIDs compared to past use calculated. Results 49,170 cases of IS were observed among 4,593,778 new NSAID users. Use of coxibs (odds ratio 1.08, 95%-confidence interval 1.02–1.15) and use of traditional NSAIDs (1.16, 1.12–1.19) were associated with an increased risk of IS. Among 32 individual NSAIDs evaluated, the highest significant risk of IS was observed for ketorolac (1.46, 1.19–1.78), but significantly increased risks (in decreasing order) were also found for diclofenac, indomethacin, rofecoxib, ibuprofen, nimesulide, diclofenac with misoprostol, and piroxicam. IS risk associated with NSAID use was generally higher in persons of younger age, males, and those with a prior history of IS. Conclusions Risk of IS differs between individual NSAIDs and appears to be higher in patients with a prior history of IS or transient ischemic attack (TIA), in younger or male patients. Co-medication with aspirin, other antiplatelets or anticoagulants might mitigate this risk. The small to moderate observed risk increase (by 13–46%) associated with NSAIDs use represents a public health concern due to widespread NSAID usage.