Standardizing patient-reported outcome measurement in pediatrics Validation & implementation of PROMIS

This thesis focusses on the harmonization and standardization of patient-reported outcome measures (PROMs) in pediatrics in the Netherlands. PROMs are questionnaires completed by patients to measure domains of health; e.g. physical, mental and social functioning. PROMs are increasingly used in research as relevant outcomes in clinical trials and in clinical practice to monitor individual patients over time. The selection of an appropriate PROM is a complex issue due to PROMs varying in administration modes, length, psychometric properties or reference data. Most existing PROMs are disease-specific, which means they are not applicable to all patients and incomparable across populations. This has resulted in an impractical and unmanageable number of PROMs. Item banks assessing generic domains of health (-related quality of life) are a solution to harmonize and standardize these PROMs. An item bank is a large collection of items that asses the same domain of health, developed using item response theory modelling (IRT). With IRT we can reduce patient burden by administering item banks as computerized adaptive test (CAT). The Patient-Reported Outcomes Measurement Information System (PROMIS®) has developed generic item banks for assessing domains of health that were deemed relevant for most patients.
To facilitate the implementation of PROMIS, in this thesis we showed that:
1) The Dutch pediatric PROMIS item banks and scales show sufficient psychometric properties for use in research and clinical practice;
2) The PROMIS pediatric instruments outperform traditional (legacy) instruments;
3) Computerized adaptive testing (CAT) is the most efficient way to administer PROMIS and can be optimized to reduce patient burden;
4) Dutch reference values with cut-offs can be used in line graph with traffic light colors to enhance the visualization of PROMIS data;
Further interdisciplinary collaboration is required with governmental institutions, academics and health care to successfully continue the journey towards standardizing outcomes in pediatrics.