Development of Patient-Reported Outcome Measures (PROMs)
We already explained the benefits, importance and relevance of so-called patient-reported outcomes (PROs) in a previous article. In that article, we particularly highlighted the benefits of PROs for precision medicine, for randomized controlled trials (RCTs) and for the market authorization of drugs.
Today, by contrast, we want to look at the topic from a different angle and answer the question of who actually creates the questionnaires that capture patients' subjective views. How are PROMs tested for validity, i.e., how accurately the measurement result matches the construct being measured, and for reliability, i.e., error-free measurement, so that the measurements also match the overall population? Are there actually international standards for PROMs?
To answer these questions, we start at the beginning, with the developers of PROMs. Below, we first introduce the two key players in the field.
What is the ICHOM initiative?
In their 2006 book “Redefining Health Care,” authors Michael E. Porter and Elizabeth O. Teisberg introduced the concept of value-based health care. This means that health care should be organized in such a way that it creates “value” for patients. Value is defined as health outcomes divided by the costs incurred to achieve them.[1] The value calculation also includes, for example, outcomes reported by patients themselves. Ultimately, health care should thus be focused on value and on the composition of the outcome categories.[2] Until then, health care had only considered the outcome categories of mortality, i.e., the number of deaths from a particular disease per 1,000 people per year, and morbidity, the number of people in a population who fall ill each year.[2] Convinced that PROs in particular offer major additional benefits for health care, Porter and Teisberg founded ICHOM together with Boston Consulting Group in 2012 to collect these PROs.
ICHOM, which stands for International Consortium for Health Outcomes Measurement and is based in Boston, USA, works with patients, doctors and other industry experts to develop the tools needed to measure patient-reported outcomes. These are standardized questionnaires, known as Standard Sets, which patients complete themselves depending on the target group and disease.[3,4] These Standard Sets are then used to measure subjective treatment outcomes relating to patients' perceived quality of life. The results are then comparable within the same target group or among patients with the same disease.
What does ICHOM do?
ICHOM's task is therefore, first, to operationalize these questionnaires, i.e., to transform specific constructs, such as physical and mental well-being, into individual questions, known as items, and second, to standardize them, i.e., to make them comparable. ICHOM's tasks also include defining normative values for the individual constructs so that they can be used as reference values.[4] The nonprofit organization works with researchers from various disciplines, patients, doctors, healthcare professionals and other experts in order to use the latest medical findings to develop the sets. This keeps the Standard Sets up to date and ensures their consistently high quality.[5]
Conclusion
In summary, ICHOM's central task is to ensure the international comparability of patients' self-assessments within the individual disease and target groups along the entire treatment pathway. ICHOM currently offers 30 evaluated and standardized sets free of charge, covering the most important medical conditions.[4]
What is the PROMIS initiative?
When the director of the US National Institutes of Health (NIH) commissioned a roadmap for medical research in the 21st century over the course of many meetings in 2002, the idea of tapping into patient-reported outcomes of chronic diseases was developed as a new avenue for medical research.[6] Two years later, this led to the creation of the PROMIS group to turn exactly this idea into reality. PROMIS stands for Patient-Reported Outcomes Measurement Information System. Just like ICHOM, this international research initiative develops internationally standardized measurement systems for assessing patient-reported outcomes.[7] The difference is that the PROMIS questionnaires can be applied to all patients, with or without a disease or ongoing treatment. This means that these outcomes of the evaluation of physical, mental and social health are comparable across all people. Unlike ICHOM's sets, the PROMIS questionnaires deliver comparable results regardless of whether a person has a disease, and which one.[1]
National structure of the PROMIS initiative
The international PROMIS initiative is organized into national units. In Germany, for example, there is PROMIS Germany, based at Charité Berlin. These national units translate the individual questionnaires so that they remain internationally comparable. PROMIS Germany is also responsible for validating the sets. This means that PROMIS Germany ensures that the questionnaires actually measure the construct they are intended to measure.
Benefits and importance of the work of PROMIS and ICHOM
In general, there is strong scientific interest in the PROMIS items. In the first half of 2021 alone, almost 100 studies were published that either used PROMIS items to evaluate treatment outcomes or tested the PROMIS system for validity and confirmed its usefulness. Developing such instruments is important because, in the past, a wide variety of measurement methods were developed in the different medical fields, including ICHOM's sets, which measure the same characteristic but, due to their disease-specific focus, do not necessarily deliver comparable results. For example, physical functioning might be assessed differently in the question set for one condition than in the set for another condition. This leads to redundancy in data collection and to limited comparability between patients with different conditions. In addition, the quality of the various questionnaires often varied greatly. It is therefore now recommended to use generic (non-disease-specific) items, such as those from PROMIS, rather than disease-specific items, such as those from ICHOM. To support clinical diagnostics in addition to gold-standard studies (RCTs), standardized, generic measurement systems developed by research initiatives such as PROMIS are therefore needed.
Conclusion
The patient-reported outcomes collected by the two initiatives are making increasingly individualized and precise treatment management, prognoses and screenings possible. These measured outcomes have already become increasingly relevant in medical research and treatment evaluation in recent years. For example, in benefit assessment, the outcome “quality of life” has been firmly established as a subjective outcome in treatment evaluations for several years now.[4] We at XO Life therefore also regard PROs as a valuable tool to help medicine continue to develop in an even more precise, patient-centered and value-based way in the future.
Sources:
[1] Terwee C.B., Zuidgeest M., Vonkeman H.E, Cella D., Haverman L., Noorda L.D. (n.d.). Common patient-reported outcomes across ICHOM Standard Sets – the potential contribution of PROMIS. https://osf.io/fbw2j/download
[2] Harvard Business School. (n.d.) International Consortium for Health Outcome Measurement. https://www.isc.hbs.edu/about-michael-porter/affiliated-organizations-institutions/Pages/ichom.aspx
[3] IQWiG. (2020) Konzepte zur Generierung versorgungsnaher Daten und deren Auswertung zum Zwecke der Nutzenbewertung von Arzneimitteln nach § 35a SGB V. https://www.iqwig.de/download/a19-43_versorgungsnahe-daten-zum-zwecke-der-nutzenbewertung_rapid-report_v1-1.pdf?rev=184598
[4] Deutsches Ärzteblatt. (2020). Rehabilitation: Messbarer Patientennutzen als Ziel. https://www.aerzteblatt.de/archiv/212785/Rehabilitation-Messbarer-Patientennutzen-als-Ziel
[5] ICHOM. (n.d.). About Us. https://www.ichom.org/mission/#founders
[6] Cella D. et al. (2007). The Patient-Reported Outcomes Measurement Information System (PROMIS). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829758/
[7] PROMIS. (n.d.). Hintergrund. https://promis-germany.de/ueber-promis-2/hintergrund/
[8] PROMIS. (n.d.). Publications by Year. https://www.healthmeasures.net/explore-measurement-systems/promis/measure-development-research/publications-promis
