Development of an EORTC questionnaire measuring instrumental activities of daily living (IADL) in patients with brain tumours: phase I–III

Purpose: Being able to function independently in society is an important aspect of quality of life. This ability goes beyond self-care, requires higher order cognitive functioning, and is typically measured with instrumental activities of daily living (IADL) questionnaires. Cognitive deficits are frequently observed in brain tumour patients, however, IADL is almost never assessed because no valid and reliable IADL measure is available for this patient group. Therefore, this measure is currently being developed. Methods: This international multicentre study followed European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group module development guidelines. Three out of four phases are completed: phases (I) generation of items, (II) construction of the item list, and (III) pre-testing. This paper reports the item selection procedures and preliminary psychometric properties of the questionnaire. Brain tumour patients (gliomas and brain metastases), their informal caregivers, and health care professionals (HCPs) were included. Results: Phase I (n = 44 patient-proxy dyads and 26 HCPs) generated 59 relevant and important activities. In phase II, the activities were converted into items. In phase III (n = 85 dyads), the 59 items were pre-tested. Item selection procedures resulted in 32 items. Exploratory factor analysis revealed a preliminary dimensional structure consisting of five scales with acceptable to excellent internal consistency (α = 0.73–0.94) and two single items. For three scales, patients with cognitive impairments had significantly more IADL problems than patients without impairments. Conclusion: A phase IV validation study is needed to confirm the psychometric properties of the EORTC IADL-BN32 questionnaire in a larger international sample

Do neurocognitive impairments explain the differences between brain tumor patients and their proxies when assessing the patient's IADL?

Background: Neurocognitive impairments are common among brain tumor patients, and may impact patients' awareness of performance in instrumental activities in daily life (IADL). We examined differences between patient-and proxy-reported assessments of the patient's IADL, and whether the level of (dis)agreement is associated with neurocognitive impairments. Methods: Brain tumor patients and their proxies completed the phase 3 version of the EORTC IADL-BN32 questionnaire measuring IADL, and patients completed six neurocognitive measures. Patient-proxy difference scores in IADL were compared between patients who were defined as neurocognitively impaired (≥2 neurocognitive measures ≥2.0 standard deviations below healthy controls) and non-neurocognitively impaired. With multinomial logistic regression analyses we examined if neurocognitive variables were independently associated with patient-proxy disagreement in IADL ratings. Results: Patients (n = 81) did not systematically (P <. 01) rate IADL outcomes different than their proxies. Proxies did report more problems on 19/32 individual items and all five scales. This effect was more apparent in dyads with a neurocognitively impaired patient (n = 37), compared to dyads with non-neurocognitively impaired patients (n = 44). Multinomial logistic regression analyses showed that several neurocognitive variables (e.g., cognitive flexibility and verbal fluency) were independently associated with disagreement between patients and proxies on different scales. Conclusion: Neurocognitive deficits seem to play a role in the discrepancies between brain tumor patients and their proxies assessment of patient's level of IADL. Although replication of our results is needed, our findings suggests that caution is warranted in interpreting self-reported IADL by patients with neurocognitive impairment, and that such self-reports should be supplemented with proxy ratings