Information concerning baseline characteristics, including the presence of hypertension, diabetes mellitus, heart disease and history of stroke (Table 1), the date and type of primary surgery and reoperations, preoperative and 3-month postoperative clinical evaluations, along with long-term evaluations from postal follow-ups, was extracted from the SHQR on the 1st of September 2014.Table 1Baseline characteristics for 979 patients diagnosed and operated on for iNPH during 2004–2011, included in the Swedish Hydrocephalus Quality Registry, SHQR DemographyiNPH patients, n = 979Age (years), median (IQR)74 (68–78)Sex, female, n (%)413 (42)Preoperative modified Rankin Scale (mRS), median (IQR)2 (2–3)Vascular comorbidity n (%)Hypertension438 (49)Diabetes mellitus189 (21)History of stroke119 (14)Heart disease231 (26)Number of vascular comorbidities n (%)0401 (41)1279 (28)2175 (18)365 (6.6)48 (0.8)Not available51 (5.2) INPH idiopathic normal pressure hydrocephalus, IQR interquartile range, mRS modified Rankin Scale