Association between patient-reported outcomes and objective disease indices in people with NF2

ObjectiveThe association between patient-reported outcomes and currently used clinical trial endpoints, including total vestibular schwannoma (VS) volume and word recognition score (WRS) in neurofibromatosis type 2 (NF2), is not known.MethodsA prospective observational study enrolling adult patients with NF2 was conducted at a single specialty center. Measures included: NF2 impact on quality of life (NFTI-QOL), short form (SF)-36; total VS volume, WRS; provider- and patient-reported disease severity (ProvSev, PatSev) measured with an institutionally derived multi-item (e.g., symptom burden, age-of-onset, and fatality-risk) and single-item Likert (mild, moderate, severe) scale.ResultsFifty-one patients were enrolled between June 2014 and August 2017. Mean age was 42.1 ± 18.2 years and 37.3% patients were male. Mean WRS was 74.4 ± 37.3%; mean total VS volume was 4.2 ± 5.2 cc. Additional lesions were common including meningioma (79.2%) and spinal ependymoma (39.6%). Mean NFTI-QOL score was 7.6 ± 4.9 and correlated with responses on the SF-36. NFTI-QOL also correlated well with PatSev (r = 0.63, p < 0.001) and both multi- and single-item ProvSev (r = 0.62, p < 0.001; r = 0.52, p < 0.001, respectively). A weak correlation was observed between NFTI-QOL and WRS (r = -0.34, p = 0.0156). There was no correlation with VS volume (r = 0.23, p = 0.15).ConclusionsThe NFTI-QOL correlated well with multiple measures of disease severity but not commonly accepted endpoints for NF2 clinical trials including total VS volume in this US cohort of patients with NF2. This suggests that the NFTI-QOL captures components of the patient experience not sufficiently represented by objective measures of disease and underscores the important and complementary role of patient-focused measures in therapeutic outcome assessment in people with NF2.