Determining the Minimal Clinically Important Difference (MCID) for the TOPICS-SF and PROMIS-10 in Older Patients That Suffered an Ischemic Stroke or Transient Ischemic Attack (TIA), Using an Anchor-based Approach

Patient-related outcome measures (PROMs) play a crucial role in assessing patient outcomes in healthcare. Two of these PROMs are the TOPICS-Short Form (TOPICS-SF) and PROMIS Global Health-10 (PROMIS-10). The TOPICS-SF, a shortened version of the TOPICS MDS, is a 20-item survey used in geriatric medicine to collect data on daily functioning. The PROMIS-10, a 10-question survey, is a global measure of the mental and physical health of stroke survivors.

The Minimal Clinically Important Difference (MCID) for PROMs is used to determine the clinical significance of differences in patients' scores. The MCID is defined as "the smallest difference in score in the domain of interest which patients perceive as beneficial and which would mandate, in the absence of troublesome side effects and excessive cost, a change in the patient's management".

MCID values vary across different populations. Despite the significance of MCID in interpreting PROM results, neither TOPICS-SF nor PROMIS-10 have established MCID values for the population of older adults that suffered a stroke.

One option to determine the MCID for these PROMs is a distribution-based method: this method compares the change in scores on the PROMS to statistical measures of spread of the data like the standard deviation. However, this approach may not always provide clinically relevant differences. A method that provides a more clinically meaningful MCID estimate is the anchor-based method.

With the anchor-based method, a specific question or "anchor" is chosen that is related to the concept being measured by the PROM. This anchor question typically asks participants about their perceived change in health or well-being over a specified period. For example, it might be a question like, "Has your physical health improved since ....?" The response options often include choices like "yes/no" or a range of improvement levels. The PROMs and the anchor questions are administered to the same group of participants, both before and after a specific time period. Based on the responses to the anchor question, participants are categorized into different groups like "improved" and "not improved". The MCID is then calculated using the predictive modeling approach. This technique uses statistical modeling techniques to analyze the relationship between changes in PROM scores and the categories established by the anchor question. The MCID value obtained through this process represents the minimum change in PROM scores that is considered clinically significant from the participant's perspective.