Variations in quantifying patient reported outcome measures to estimate treatment effect.

In the practice of healthcare, patient-reported outcomes (PROs) and PRO measures (PROMs) are used as an attempt to observe the changes in complex clinical situations. They guide us in making decisions based on the evidence regarding patient care by recording the change in outcomes for a particular treatment to a given condition and finally to understand whether a patient will benefit from a particular treatment and to quantify the treatment effect. For any PROM to be usable in health care, we need it to be reliable, encapsulating the points of interest with the potential to detect any real change. Using structured outcome measures routinely in clinical practice helps the physician to understand the functional limitation of a patient that would otherwise not be clear in an office interview, and this allows the physician and patient to have a meaningful conversation as well as a customized plan for each patient. Having mentioned the rationale and the benefits of PROMs, understanding the quantification process is crucial before embarking on management decisions. A better interpretation of change needs to identify the treatment effect based on clinical relevance for a given condition. There are a multiple set of measurement indices to serve this effect and most of them are used interchangeably without clear demarcation on their differences. This article details the various quantification metrics used to evaluate the treatment effect using PROMs, their limitations and the scope of usage and implementation in clinical practice.