5-Year health-related quality of life outcome in patients with idiopathic normal pressure hydrocephalus.

Background: Health-related quality of life (HRQoL) is severely impaired in persons with idiopathic normal pressure hydrocephalus (iNPH). The HRQoL improves in a number of patients after the placement of a cerebrospinal fluid (CSF) shunt, but long-term follow-up of HRQoL is rare.

Methods: Extended follow-up (60 months) of a prospective cohort study involving 189 patients with iNPH who underwent shunt surgery. Preoperative variables were used to predict favorable HRQoL outcome (improvement or non-deterioration) measured by the 15D instrument 5 years after shunting.

Results: Out of the 189 initially enrolled study participants, 88 had completed 5-year HRQoL follow-up (46%), 64 had died (34%), and 37 (20%) failed to complete the HRQoL follow-up but were alive at the end of the study. After initial post-operative HRQoL improvement, HRQoL deteriorated so that 37/88 participants (42%) had a favorable HRQoL outcome 5 years after shunting. Multivariate binary logistic regression analysis indicated that younger age (adjusted OR 0.86, 95% CI 0.77-0.95; p < 0.005), lower body mass index (adjusted OR 0.87, 95% CI 0.77-0.98; p < 0.05) and better Mini-Mental State Examination performance (adjusted OR 1.16, 95% CI 1.01-1.32; p < 0.05) before surgery predicted favorable 5-year outcome.

Conclusions: This extended follow-up showed that the self-evaluated HRQoL outcome is associated with iNPH patients' pre-operative cognitive status, overweight and age. The post-operative deterioration may reflect the natural progression of iNPH, but also derive from aging and comorbidities. It indicates a need for long-term follow-up.