How to develop a condition‐specific PROM

Abstract

Developing new patient-reported outcome measures (PROMs) for application in clinical studies can be necessary if an adequate PROM does not exist. For adequate measurement, it is essential that the PROM has face validity (ie, is perceived to be relevant by clinicians and researchers) and has high content validity (ie, content relevance and content coverage for the targeted patient group). The steps needed to create PROMs that possess face and content validity for a specific condition are described in this paper. Face validity is achieved by item identification and generation through literature review. Content validity is confirmed through repetitive cognitive interviews of patients from the targeted patient group in order to generate a consensus-based pilot-version of the new PROM. This qualitative process ensures that items are appropriately worded, understandable, and minimizes doubts about how items should be answered. A practical example of this process is presented, which shows the development of the Knee Numeric-Entity Evaluation Score (KNEES-ACL), a condition-specific PROM for patients with deficiency of the anterior cruciate ligament (ACL).

Responsiveness, minimal important difference, minimal relevant difference, and optimal number of patients for a study

“…Similarly, the correlation in the Symptoms domain in the example above (the results section) was 0.41, which is below the recommended 0.50 16 . This example emphasizes the need for proper qualitative work and high content validity—not only for the PROM used, but also for the GROC anchor item (see 31 ).…”

“…If no MID exists for the PROM and the specific patient group in a planned study, then MID can be calculated by applying one or two anchor items together with the PROM at each time point. Such a GROC anchor item should of course be developed with the same carefulness as when developing a new PROM 31 . This will give an impression of whether changes in the specific study are truly clinically relevant.…”

“…The responsiveness of various PROMs used in studies is in most cases not known and can therefore not be used as an argument for the choice of PROM. As high responsiveness is most importantly the result of the content and construct validity of the PROM, 34 a minimum requirement should be that PROMs are developed through feedback from the same patient group targeted in the planned study (ie, the PROM has high content validity for the actual study population) and are adequately validated with respect to its measurement properties (ie, has construct validity for the actual study population) 31,35 …”

Potential problems in the use of patient reported outcome measures (PROMs) and reporting of PROM data in sports science

“…Because two domains were developed through single interviews with few patients, this does not guarantee that they have coverage for these types of patients. 8 Likewise, if construct validity for the PROM has not been confirmed (i. e., are the items actually functioning?) for patients similar to the patients in a study, then the PROM cannot be assumed to be valid.…”

A catalogue of PROMs in sports science: Quality assessment of PROM development and validation

“…For each quality indicator, a positive score was added to the overall assessments for development and validation. The quality indicator rating system was based on the generally accepted criteria for achieving high face and content validity 14,17 The lowest score of one asterisk * would be given to a PROM based on a list of items developed without involvement of experts and patients and with no items from existing PROMs or an item bank. A PROM with items developed by a group of experts on the basis of a bank of items from existing PROMs of relevance would score two asterisks **, as the items would have face validity and be based on items that had been validated in existing PROMs. If the items had been discussed once in a group of patients with the health condition in focus, the score would be increased by one asterisk *. If items were discussed in focus groups until ‘data saturation’ (ie no further item themes emerged), the score would be increased by one asterisk * and If a provisional PROM had also been developed and tested through debriefing with the addition of debriefing interviews with individual patients with the health condition in focus, it would be increased by one asterisk *. …”