Letter regarding “Acceptability and feasibility of neurocognitive assessments with adults with primary brain cancer and brain metastasis: A systematic review”

With interest, we read the review by Carlson et al. who aimed to identify neurocognitive assessments in patients with brain tumors that are both pragmatic and acceptable for use in clinical settings.¹ While we encourage any efforts to reduce the burden of neuropsychological assessments, both for patients and test administrators, we have substantial critique on the way the authors determined acceptability. Generally speaking, a neuropsychological evaluation is performed to quantify, understand and potentially manage neurocognitive symptoms. In this review, the authors addressed the acceptability and feasibility of neurocognitive tests, but without taking the actual purpose and clinical value of neuropsychological assessment into account. In our opinion, this results in a unidimensional view of the usefulness of neurocognitive tests, and we want to stress that neuropsychological assessment should first and foremost serve a clinical purpose.

Considering the patient’s dismal prognosis where the potential neurotoxic effects of treatments need to be balanced against their survival benefits, neuropsychological assessment can serve at least three purposes²: (1) define the extent and nature of neurocognitive impairment and its impact on the individual, (2) determine the underlying causes of neurocognitive deficits and ways to ameliorate neurocognitive functioning, and (3) measure change in neurocognitive functioning, for example after tumor treatment. Furthermore, with regard to prognostication, cognitive deterioration may additionally serve as an early indicator of tumor progression³ and thus may aid in clinical decision-making. When evaluating neurocognitive tests, it is important to report on the purposes of neuropsychological assessment and consider the burden of tests compared to the benefits of achieving those purposes. The evaluation could for example focus on how well a neurocognitive test support patients in understanding their deficits, provide tools for patients to compensate for their impairment, or support physicians in clinical decision-making. This kind of evaluation is, in our opinion, the way forward to truly test the acceptability of neuropsychological testing in specific patient populations.

Furthermore, due to limited data on acceptability and feasibility, the authors only made recommendations about the Mini-Mental State Examination, the Montreal Cognitive Assessment (MoCA), and NIH Health Toolbox Cognitive Battery (NIHTB-CB). According to the authors, these tests are beneficial when health services seek short tests and do not have access to trained neuropsychologists. However, while comprehensive neurocognitive assessments may be associated with considerable use of personnel and financial resources, we fully concur with Meyers and Wefel who states that: “The use of a screening tool that lacks adequate sensitivity and that may provide misleading information is not a wise use of money and resources.”⁴ Therefore, recommending the use of these screening tools does not serve a clinical purpose, especially since the authors themselves also describe how screening tools like the Mini-Mental State Examination and MoCA might not be sensitive to the subtle neurocognitive changes brain tumor patients might experience.

Lastly, we would like to address some methodological shortcomings in this review. First, the Pragmatism according to the Psychometric And Pragmatic Evidence Rating Scale (PAPERS) that the authors used to assess pragmatism was not designed to evaluate neurocognitive screeners, individual tests, or test batteries.⁵ Second, the authors looked at the feasibility and acceptability measurements of single tests but did not compare the acceptability of different tests within a patient. There was only one study included that directly compared the use of different neurocognitive tests.⁶ Third, study-specific settings were not taken into account, for example when comparing completion rates of tests between in-hospital⁷ and outpatient clinic settings.⁸ Evidently, this is an unbalanced comparison since in-hospital completion rates of tests before and after tumor resection are likely to be different from completion rates in a longitudinal study addressing long-term neurocognitive outcomes in an outpatient setting. Determining the burden of a specific test by the percentage of lost follow-up data is questionable in this population because disease progression, death, and other factors could contribute to patient dropout.

In conclusion, we want to stress that evaluating the feasibility en acceptability of neuropsychological assessments is important and we appreciate that the authors explore these practical aspects. While it is relevant to investigate the burden of neurocognitive tests, this should always be seen in the light of the actual aim of evaluating neurocognitive functioning in the individual patient. Ultimately, the goal of neuropsychological assessment is to provide patients and clinicians with a meaningful and valid interpretation of a patient’s (change in) neurocognitive functioning. Because of this, the why, where, and when of neurocognitive testing should always be leading in selecting appropriate neurocognitive measurement tools.

Funding

The work of MG, JR, and VB is funded by the Stichting Anita Veldman Foundation CCA.2019.2-21.

Conflict of interests statement

The authors declare that they have no competing interests.