Summary Objectives:  To review studies of patient compliance/persistence with cardiovascular or antidiabetic medication published since the year 2000; to compare the methods used to measure compliance/persistence across studies; to compare reported compliance/persistence rates across therapeutic classes and to assess whether compliance/persistence correlates with clinical outcomes. Methods:  English language papers published between January 2000 and November 2005 investigating patient compliance/persistence with cardiovascular or antidiabetic medication were identified through searches of the MEDLINE and EMBASE databases. Definitions and measurements of compliance/persistence were compared across therapeutic areas using contingency tables. Results:  Of the 139 studies analysed, 32% focused on hypertension, 27% on diabetes and 13% on dyslipidaemia. The remainder covered coronary heart disease and cardiovascular disease (CVD) in general. The most frequently reported measure of compliance was the 12‐month medication possession ratio (MPR). The overall mean MPR was 72%, and the MPR did not differ significantly between treatment classes (range: 67–76%). The average proportion of patients with an MPR of > 80% was 59% overall, 64% for antihypertensives, 58% for oral antidiabetics, 51% for lipid‐lowering agents and 69% in studies of multiple treatments, again with no significant difference between treatment classes. The average 12‐month persistence rate was 63% and was similar across therapeutic classes. Good compliance had a positive effect on outcome in 73% of the studies examining clinical outcomes. Conclusions:  Non‐compliance with cardiovascular and antidiabetic medication is a significant problem, with around 30% of days ‘on therapy’ not covered by medication and only 59% of patients taking medication for more than 80% of their days ‘on therapy’ in a year. Good compliance has a positive effect on clinical outcome, suggesting that the management of CVD may be improved by improving patient compliance.

Health economic models rely on data from trials to project the risk of events (e.g., death) over time beyond the span of the available data. Parametric survival analysis methods can be applied to identify an appropriate statistical model for the observed data, which can then be extrapolated to derive a complete time-to-event curve. This paper describes the properties of the most commonly used statistical distributions as a basis for these models and describes an objective process of identifying the most suitable parametric distribution in a given dataset. The approach can be applied with both individual-patient data as well as with survival probabilities derived from published Kaplan-Meier curves. Both are illustrated with analyses of overall survival from the Sorafenib Hepatocellular Carcinoma Assessment Randomised Protocol trial.

Objectives To review studies on the cost consequences of compliance and/or persistence in cardiovascular disease (CVD) and related conditions (hypertension, dyslipidaemia, diabetes and heart failure) published since 1995, and to evaluate the effects of noncompliance on healthcare expenditure and the cost-effectiveness of pharmaceutical interventions. Methods English language papers published between January 1995 and February 2007 that examined compliance/persistence with medication for CVD or related conditions, provided an economic evaluation of pharmacological interventions or cost analysis, and quantified the cost consequences of noncompliance, were identified through database searches. The cost consequences of noncompliance were compared across studies descriptively. Results Of the 23 studies identified, 10 focused on hypertension, seven on diabetes, one on dyslipidaemia, one on coronary heart disease, one on heart failure and three covered multiple diseases. In studies assessing drug costs only, increased compliance/persistence led to increased drug costs. However, increased compliance/persistence increased the effectiveness of treatment, leading to a decrease in medical events and non-drug costs. This offset the higher drug costs, leading to savings in overall treatment costs. In studies evaluating the effect of compliance/persistence on the cost-effectiveness of pharmacological interventions, increased compliance/persistence appeared to reduce cost-effectiveness ratios, but the extent of this effect was not quantified. Conclusions Noncompliance with cardiovascular and antidiabetic medication is a significant problem. Increased compliance/persistence leads to increased drug costs, but these are offset by reduced non-drug costs, leading to overall cost savings. The effect of noncompliance on the cost-effectiveness of pharmacological interventions is inconclusive and further research is needed to resolve the issue.

The economic evaluation indicates that sorafenib is cost-effective compared to best supportive care, with a cost-effectiveness ratio within the established threshold that US society is willing to pay (i.e. $US50,000-$US100,000) and significantly lower than alternative thresholds suggested in recent years ($US183,000-$US264,000/life-year gained, or $US300,000/quality-adjusted life-year) in oncology.

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