Health-related quality of life in patients with idiopathic normal pressure hydrocephalus.

BACKGROUND AND PURPOSE: Factors affecting health-related quality of life (HRQoL) were explored in patients with idiopathic normal pressure hydrocephalus (iNPH).

METHODS

Using the 15D instrument HRQoL was evaluated in 132 patients diagnosed with iNPH by clinical and neuroradiological examinations. The severity of iNPH symptoms was measured with the iNPH grading scale (iNPHGS), depressive symptoms with the Beck Depression Inventory (BDI-21) and cognitive impairment with the Mini-Mental State Examination.

RESULTS

The mean (SD) 15D score (on a 0-1 scale) of patients with iNPH was significantly lower than that of an age- and gender-matched sample of the general population [0.718 (0.103) vs. 0.870 (0.106); P < 0.001]. The mean 15D score was lower in iNPH patients with moderate or severe depressive symptoms than in patients without depressive symptoms (P = 0.003). According to stepwise multiple linear regression analysis, a higher total iNPHGS score (b = -0.62, P < 0.001) and a higher BDI-21 total score (β = -0.201, P = 0.025) predicted a lower 15D score; in combination, these explained 51% of the variance in the 15D score (R(2)  = 0.506, P < 0.001).

CONCLUSIONS

Idiopathic normal pressure hydrocephalus impairs patients' HRQoL on multiple dimensions, similarly to other chronic diseases. Potentially treatable depressive symptoms contribute greatly to the HRQoL impairment of iNPH patients, but only if they are moderate or severe. The 15D portrayed HRQoL dimensions affected by iNPH in a similar way to broader assessment batteries and thus is a potentially useful tool for treatment evaluation and cost-utility analysis.