Why is this paper important?
It is because there are no reliable means of patient-reported outcomes (PRO). These metrics are an essential part of monitoring the course of treatment as well as quantifying the impact of the same. For years, we have been relying on metrics like Mini-Mental State Examination. I have found that examination to be sorely limited because it is full of biases and highly dependent on the cognition/mood status of patients. There has to be a more robust metric.
Hence, the great blurb from this paper:
The first step would be to provide an overview of the guidelines of previous initiatives on the collection, analysis, interpretation, and reporting of PRO data
It is the step in the right direction because of it an acknowledgement of what we don’t know. I have attempted to involve formal psychometric testing, but it usually takes hours and have limited clinical utility. The existing tests have undergone validation in different “trials” (most of which are either single author led studies or institutional trials) leading to much confusion. Do we have a standard way of reporting them?
It leads us to the second step.
The second step would be to identify what PRO measures have been applied in brain tumour studies so far. As mentioned, several PRO measures are already used frequently (e.g., MD Anderson Symptom Inventory Brain Tumor Module, Functional Assessment of Cancer Treatment-Br, EORTC Quality of Life Questionnaire C30 and BN20, and the Barthel Index)
Content validity should also be culturally sensitive. What applies in one geography doesn’t translate in another part of the world (which adds to the complexity of the task).
Therefore, I feel that the third step is the most crucial question in patient-reported outcomes.
The third step would be to establish the content validity of the existing PRO measures identified in the second step. Are all essential aspects of functioning and health for patients with brain tumours covered by these instruments?
The next excerpt nails this in the right direction. It is not the patient defined outcomes alone but has to be validated by physician scoring system as well.
How is this going to shape up?
This framework refers to a patient’s functioning at three distinct levels. The most basic level is a patient’s impairment in body function, such as muscle weakness. Assessment of these impairments can be done with PRO measures, such as a symptom questionnaire, but also with clinician-reported outcome measures such as a neurological examination
Last but not the least is the psychometric properties-it has to prove its reliability as well! This, of course, applies to reproducibility across different domains.
The fourth step is to identify the psychometric properties of the detected PRO measures. How valid and reliable are these instruments for patients with brain tumours
To achieve this goal, the committee proposes to use COSMIN taxonomy and defines it as such:
The COSMIN taxonomy distinguishes three quality domains: reliability, validity, and responsiveness, each of which includes one or more measurement properties. Reliability refers to the degree in which the measurement is without measurement error, whereas validity refers to the degree in which an instrument truly measures the construct intended to measure. Responsiveness refers to the ability of an instrument to detect (clinically relevant) changes over time.
These criteria will help to shape up the course of treatment beyond the survival outcomes and focus on preservation of quality of life.
More on that later.