Comparative effectiveness of branded vs. generic versions of antihypertensive, lipid-lowering and hypoglycemic substances: a population-wide cohort study.

Generic medications offer substantial potential cost savings to health systems compared to their branded counterparts. In Europe and the US, they are only approved if they are bioequivalent to the respective originator product. Nevertheless, the lack of clinical outcomes is sometimes used as the reason for hesitancy in prescribing generics. We performed an observational retrospective study on 17 branded vs. generic pharmaceutical substances for the treatment of hypertension/heart failure, hyperlipidemia, and diabetes mellitus in a dataset of 9,413,620 insured persons, representing nearly the full population of Austria, from 2007 to 2012. We compared generic vs. branded medications using hazard ratios for all-cause death and major adverse cardiac and cardiovascular events (MACCE) as outcomes of interest. Using patient demographics, health characteristics from hospitalization records, and pharmacy records as covariates, we controlled for confounding in Cox models through inverse probability of treatment weighting (IPTW) using high-dimensional propensity scores. We observed that the unadjusted hazard ratios strongly favor generic drugs for all three pooled treatment indications (hypertension/heart failure, hyperlipidemia, diabetes mellitus), but were attenuated towards unity with increasingly larger covariate sets used for confounding control. We found that after IPTW adjustment the generic formulation was associated with significantly fewer deaths in 10 of 17 investigated drugs, and with fewer MACCE in 11 of 17 investigated drugs. This result favoring generic drugs was also present in a number of sub-analyses based on gender, prior disease status, and treatment discontinuation. E-value sensitivity analyses suggested that only strong unmeasured confounding could fully explain away the observed results. In conclusion, generic medications were at least similar, and in some cases superior, to their branded counterparts regarding mortality and major cardiovascular events.

Prevalence and determinants of unintended double medication of antihypertensive, lipid-lowering, and hypoglycemic drugs in Austria: a nationwide cohort study.

PURPOSE: Double medication is defined as the unintended overlapping prescription of two identical substances with the same route of administration by two different prescribers to the same patient. Consequences of double medication are reduced patient safety and excess healthcare costs. Based on nationwide prescription data from 2011 covering 97% of Austria's population, we estimated double medication prevalences for treatment of hypertension, hyperlipidemia, and diabetes mellitus. METHODS: We investigated prescriptions of 88 antihypertensive, 16 lipid-lowering and 29 hypoglycemic substances in 7,971,323 persons in 2011. Prevalence of double medication was calculated patientwise (prevalence by patients) and timewise (prevalence by patient-years). Risk factors for double medication were identified by logistic regression. RESULTS: For antihypertensive, lipid-lowering, and hypoglycemic subtances, overall 15.0% (men: 15.1%, women: 15.0%), 13.1% (13.7%, 12.5%), and 13.0% (13.0%, 13.4%) of patients were doubly medicated, respectively. Corresponding prevalences by patient-years were 1.6%, 2.0%, and 1.2%. Logistic regression confirmed lower age and copayment waiver as independent risk factors of double medication. Furthermore, double medication occurred more often with prescriptions from hospitals or internal medicine specialists compared with general practitioners, as well as in August compared with earlier or later in the calendar year. CONCLUSION: While appropriate care or comanagement of patients by internal medicine specialists and general practitioners may explain some of the double prescriptions, our data indicate that unintended double medication is frequent. In Austria, lack of financial incentives of patients to avoid filling duplicate prescriptions explains a considerable fraction of double medication occurrences.

Prediction of prevalence of chronic kidney disease in diabetic patients in countries of the European Union up to 2025.

BACKGROUND: Diabetes and chronic kidney disease (CKD) are a growing burden for health-care systems. The prevalence of diabetes has increased constantly during the last decade, although a slight flattening of end-stage renal disease as a result of diabetes has been observed recently in some European countries. In this study, we project the prevalence of CKD in patients with diabetes in European countries up to the year 2025. METHODS: We analysed the population with diabetes and development of nephropathy in 12 European countries, which we computed from models published previously and on data from the annual reports of the European Renal Association (1998-2011). The prevalence of CKD stage 5 in patients with diabetes up to the year 2025 was projected by the Lee-Carter algorithm. Those for stage 3 and 4 were then estimated by applying the same ratios of CKD prevalences as estimated in the Austrian population with diabetic nephropathy. RESULTS: The estimated prevalence of CKD in patients with diabetes is expected to increase in all 12 countries up to the year 2025. For CKD stage 3, we estimate for Austria in 2025 a prevalence of 215 000 per million diabetic population (p.m.p.) (95% confidence interval 169 000, 275 000), for CKD4 18 600 p.m.p. (14 500, 23 700) and for CKD5 6900 p.m.p. (5400, 8900). The median prevalence in the considered countries is 132 900 p.m.p. (IQR: 118 500, 195 800), 11 500 (10 200, 16 900) and 4300 (3800, 6300) for CKD stages 3, 4 and 5, respectively. Altogether, these data predict in the years 2012-25 an annual increase of 3.2% in the prevalence of diabetic CKD stage 5. CONCLUSIONS: Due to the increase in prevalence of diabetes and CKD5, the costs of renal therapy are expected to rise. We believe that these data may help health-care policy makers to make informed decisions.

Chances and challenges of using routine data collections for renal health care research.

BACKGROUND: Collections of electronic medical records (EMRs) can provide a rich source of information for renal health care research. However, their use in statistical analyses requires many preparatory steps, including coding of freetext entries and clear definitions of time windows for harvesting prognostic factors and outcomes. We analyse a large collection of EMRs to identify prognostic factors of adequate health care in diabetic patients at risk for chronic kidney disease, and discuss benefits and risks of such re-use of routine data. METHODS: In a representative sample of 695 068 patient records collected in 58 Austrian general practitioners' offices, we could identify 31 374 patients with diabetes mellitus. As outcomes, we investigated whether a patient received a serum creatinine measurement, and the time elapsing between two consecutive serum creatinine measurements. Prognostic factors were defined by extracting previous diagnoses, laboratory measurements, drug prescriptions and demographic characteristics from the records. RESULTS: Serum creatinine was measured annually in 44.4% of diabetic patients with previous signs of reduced kidney function and in 20.5% of the patients without such signs. Within 1 year after the first measurement, a follow-up measurement was made in 79.4 and 68.4% of the patients, respectively. Previous diagnoses, laboratory measurements, drug prescriptions and demographic characteristics explained 41% of the observed variance of kidney function monitoring. With 24% explained variance, previous referrals to laboratories were identified as the most important prognostic factor group. CONCLUSIONS: The analysis of large routine data collections poses various challenges, among which the need for coding free text into variables and various sources of biases are most demanding. However, routine data collections represent the daily practice of health care and offer many chances for renal health services and outcomes research.

Potential savings in prescription drug costs for hypertension, hyperlipidemia, and diabetes mellitus by equivalent drug substitution in Austria: a nationwide cohort study.

BACKGROUND: Healthcare systems spend considerable proportions of their budgets on pharmaceutical treatment of hypertension, hyperlipidemia, and diabetes mellitus. From data on almost all residents of Austria, a country with mandatory health insurance and universal health coverage, we estimated potential cost savings by substituting prescribed medicines with the cheapest medicines that were of the same chemical substance and strength, and available during the same time. METHODS: Data from 8.3 million persons (98.5 % of the total Austrian insured population) from 2009-2012 were analyzed. Real prescription costs for antihypertensive, lipid-lowering, and hypoglycemic medicines achievable by same-substance, same-strength drug substitution were computed for each active ingredient, and per gender and 1-year age category of patients. RESULTS: In 2012, health insurance providers spent 231.3 million, 77.8 million, and 91.9 million for antihypertensive, lipid-lowering, and diabetes medications, of which 52.2 million (22.6 %), 15.9 million (20.5 %), and 4.1 million (4.5 %), respectively, could have been saved by same-substance drug substitution. Highest potential savings were calculated for amlodipine (8.0 million, 65.4 %), simvastatin (12.2 million, 59.3 %), and metformin (2.4 million, 54.6 %), respectively. Higher savings for men than for women resulted from differing prescribed cumulative dosages and proportions of patients with co-payment waiver. Potential cost savings in antihypertensive and lipid-lowering drugs increased from 2009-2012. CONCLUSION: Our study highlights the cost-savings potential from arguably the most acceptable of interventions, simply switching to the cheapest available same-substance, same-strength product. In 2012, this strategy could have reduced costs for antihypertensive, lipid-lowering, and hypoglycemic treatment by up to 18.0 %.

Fragmentation of diabetes treatment in Austria - an indicator for the need for shared electronic health record systems.

Shared electronic health record (EHR) systems aim to support continuity of care within the joint treatment of a patient by a community of cooperating care providers. By analyzing the fragmentation of care of Austrian diabetes patients, we aim to find evidence whether there is actually a need for shared EHR systems in this context. Our results show that almost three quarters of the observed diabetes patients visit two or more different care providers during their diabetes-related visits. Overall, our findings strongly support the demand for shared EHR systems for the treatment of diabetes patients.