Keywords: comparative effectiveness research • evidence-based medicine • health technology assessmentReal world evidence (RWE) is defined as a form of evidence generated to answer a question or test a hypothesis using real world data (RWD) and using appropriate design and statistical analyses [1]. Others define RWE as the intersection between the randomized controlled trials (RCTs) and effectiveness of treatment in usual clinical practice [2]. To those with public health expertise, RWE is not totally a new phenomenon. Population-based studies using RWD are often conducted to evaluate the effectiveness and value of health programs and policies. Thus, RWE is an old wine in a new bottle. RWD characterized as patient registries have been a long tradition in the Nordic countries due to publicly financed healthcare and a unique person identifier, which enables linkage of data from different registries [3]. However, the impact of RWD/ RWE on health technology assessment (HTA) decision-making process regarding new treatments is not well assessed and the explanatory factors are not well known.
Why RWE now?RWE has recently gained attention from patients, providers, payers, regulators and pharma industry. People are living longer in almost every part of the world with increasing demand for a healthy living. Technological advancement enables quick flow of data and information, thus increasing level of knowledge on health and on what works and what does not [4]. Patients have high expectations on health systems to offer safe and effective treatments.Parallel to this, global public health trends show increasing burden of noncommunicable diseases due to unhealthy lifestyle [5], implying a large proportion of people living a long unhealthy life about 30-40 years.Healthcare costs are rising at a much faster rate than gross domestic product (GDP), creating budget deficiencies [5]. This reinforces payers to ensure that they put money in treatments that are cost effective, add value to patients and improve population health.Thus, regulatory agencies begin to realize the benefit of RWE for regulatory decisionmaking for medicines and medical devices.Thus, in order for the industry to sell their products, they need RWE studies to address effectiveness, efficiency, value and safety of their products. Some companies have developed strategies to generate RWE, others are using ad hoc solutions, while the rest are waiting for the RWE wave to pass. Developing a new treatment is costly, yet a large proportion will never make it to the market. RWE is a potential cost-saver in various phases of the drug development lifecycle [6].RCTs are regarded as the gold standard for providing the scientific evidence of clinical Editorial Andersson & Kyhlstedt efficacy of treatments. However, evidence from the RCTs does not address real life conditions due to strict selection criteria with a limited study population, questionable external validity and generalizability [7]. RWE studies, on the other hand, demonstrate effectiveness in real world clinical pra...