Abstract
BACKGROUND: Next to health-related quality of life, information on daily life functioning in brain tumour patients is essential. Instrumental Activities of Daily Living (I-ADL) are complex daily activities, such as food preparation and shopping. I-ADL may be negatively influenced by a cognitive decline, characteristic of brain tumor patients. OBJECTIVE: In the first phase of this project, we generated a provisional list of items measuring I-ADL that are relevant for primary brain tumour patients. METHODS: Questions from the Amsterdam IADL Questionnaire(®), a 70-item questionnaire developed and validated to measure I-ADL in patients with dementia, were evaluated for relevance to brain tumour patients. In addition, new activities were generated. In the first step, 6 professional experts in neuro-oncology and 10 primary brain tumour patient-proxy dyads were asked to evaluate items in the Amsterdam IADL Questionnaire(®). Experts had to indicate if these activities (1) could be considered as I-ADL, (2) were affected in brain tumour patients and (3) were clearly formulated. Patients and their proxies only needed to answer the latter two questions. In the second step, the same 6 experts, and in addition 6 other patient-proxy dyads were asked to generate new activities. To do so, in-depth interviews were conducted. Decision rules were determined to aid in deciding which items to retain (step 1) or to add (step 2). Activities that were indicated as IADL, affected and clearly formulated were retained. Activities that were considered as IADL and affected, but not clearly formulated, were rephrased. New activities that were frequently generated were added to the existing list of items. RESULTS: In step 1, experts indicated that 37% of the activities described in the Amsterdam IADL questionnaire(®) fulfilled all three criteria: conform the definition of IADL, clearly formulated and affected in brain tumour patients. Twenty-three per cent of the activities were affected and conform the provided definition, but not clearly formulated. According to patients and their proxies, 19% and 17% of the activities were clearly formulated and affected in brain tumour patients, respectively. Moreover, 1-3% of the activities were indicated to be affected, but not clearly formulated. Several new activities (concerning social interaction and work) were generated in step 2. With the decision rules as guide, it was decided in consensus that a total of 30 questions of the Amsterdam IADL questionnaire(®) could also be used to measure I-ADL in primary brain tumour patients. In addition, 16 new questions covering other relevant activities for brain tumour patients were added. CONCLUSION: This first phase resulted in a provisional questionnaire of 46 items intending to measure I-ADL in primary brain tumour patients. The next step is to validate this provisional questionnaire in a larger sample of patients.