Study question: The precise delineation of the research phase is a recurrent subject of debate: When is the evidence base firm enough to decide that a new technology or treatment no longer needs to be regarded as 'experimental'?
Summary answer: We propose a framework that distinguishes between three instead of two types of treatment and describes a continuum from experimental over innovative to established treatment, offering a tool meant to facilitate decision-making about the introduction of new technologies in the clinic.
What is known already: Traditionally, guidelines from medical societies on the notion of 'experimental treatment' depart from a dichotomy between experimental and established treatment. However, in the field of reproductive medicine, there are several problems with a dichotomous framework. First, it does not offer an adequate account of the reality in the clinic. Secondly, this view may bring about several negative effects for the patient, such as techniques being considered established too early, holding risks unknown to patients. A further drawback of the dichotomy is that if a technique is no longer considered experimental, centres offering the technique may no longer consider it useful gathering and critically examining (follow-up) data.
Study design, size, duration: The framework and scoring tool were developed over several phases during which the authors operated as a consensus group of experts.
Participants/materials, setting, methods: The scoring tool reflects the continuous progression of a new procedure from experimental through innovative to established. For this evolution, four criteria were considered relevant. The first (efficacy) is a categorical criterion (pass/fail). The other three criteria (safety, procedural reliability and transparency and effectiveness) are ordinal in nature. Thresholds have been introduced for all four criteria to avoid that a technology scoring high on procedure and effectiveness but extremely low on safety could move to the next level because of a sufficiently high overall score.
Main results and the role of chance: Only treatments that are rated above the thresholds for all four criteria could be considered at least innovative treatments. When they score 4 or higher on the last three criteria, they are considered established treatments.
Limitations, reasons for caution: Knowledge about the procedures or techniques under discussion is essential in order to use the tool.
Wider implications of the findings: The tool is designed to be used on a macro-level (e.g. by professional societies) although it could also be valuable in the local setting. Both the framework and the tool can bring more clarity on the notion of 'experimental treatment', especially with regard to how to decide when a specific technology or treatment falls in this category and when it can move into one of the other categories.
Study funding/competing interest(s): none.
Trial registration number: none.
Keywords: follow-up studies; investigational therapies; patient safety; reproductive medicine; research ethics committees.