Over the past decades, there has been a paradigm shift from focussing solely on objective and clinician-assessed outcomes such as overall survival or progression-free survival to patient-reported outcomes such as quality of life. It is increasingly accepted that a clinicians’ focus should be on the patients’ ability to function in daily activities and their self-perceived quality of life. This is especially true for patients with chronic diseases such as neurofibromatosis type 2 (NF2), which is a rare autosomal-dominant hereditary disease. Patients with NF2 develop widespread tumours of the central and peripheral nervous systems such as vestibular schwannomas, meningiomas, spinal ependymomas or peripheral nerve schwannomas. In addition, polyneuropathy and cataract are commonly associated with NF2 . This in turn leads to a wide range of disabilities, including hearing loss, motor and sensory deficits.
In 2012, Hornigold et al. introduced the English-language disease-specific neurofibromatosis 2 impact on quality of life (NFTI-QOL) questionnaire and demonstrated its usefulness in a large multicentric NF2 patient cohort in the UK. The NFTI-QOL questionnaire showed strong correlation with the SF-36 and EuroQOL questionnaires, which are both well-established and non-disease-specific tools for the assessment of quality of life .
The advantage of a disease-specific questionnaire, however, is the targeted evaluation of disease aspects that are relevant to NF2 patients and the omission of generic or superfluous items. The more pointed (and shorter) the questionnaire the more likely patients are to complete it and the easier it is to interpret the results. This is especially true for multi-morbid patients with visual and manual disabilities as in NF2. The NFTI-QOL is shorter than generic QOL questionnaires such as the SF-36 and can be completed in approximately 3 min .
Further studies in UK, American and Canadian contexts yielded similar results to the original study and found correlations between quality of life and patient- and physician-reported disease severity [3,4,5]. However, there was no association between the size of the pathognomonic tumours of NF2, vestibular schwannomas, and patient-reported quality of life .
There is a large German-speaking group of NF2 patients, which has not yet been systematically assessed with respect to disease-specific quality of life. Based on the reported incidence of 1 in 25,000–40,000 [6, 7] and the current German population of 83.2 million , there are estimated to be over 2,000 German NF2 patients, with even more native German-speaking NF2 patients in Austria and Switzerland. From this large number of German-speaking patients much could be learned about improving disease-related health outcomes and quality of life in NF2, as well as the lived experience of those with NF2.
In addition, the impact of healthcare provision, encompassing the structures and funding of NF2 care at regional and national level, in relation to NF2 outcomes including quality of life, has not been addressed. A standardised quality of life instrument could facilitate international comparison of patient-reported outcomes and enhance the validity and reproducibility of comparisons across centres as well as longitudinal follow-up of individual patients.
The aim of this study was to design and implement a standardised German version of the English-language NFTI-QOL and to assess quality of life in a large German-speaking cohort of NF2 patients.