Risk factors in clinically diagnosed Alzheimer's disease: A retrospective hospital-based case control study in Warrington

Abstract

The objective of the study was to assess risk factors for Alzheimer's disease, previously reported in cases control studies from other countries. It was conducted in a psychiatric of unit for the elderly in Warrington, a town in the northwest of England. A retrospective hospital-based, case control method was used comparing 198 cases of Alzheimer's disease (ADRDANINCDS diagnostic criteria) to selected controls (164 other dementias and 176 non-dementing group) in respect of their family, medical and personal histories.The subjects included all patients referred to and seen by the author during a two-year study period. Fifty-eight of 198 Alzheimer's cases reported family history of dementia, compared with 35 of 340 controls (OR=3.27 95% CI 1.89–5.39), p <0.01. The Odds ratio for smoking was 0.68; significant only in men (0.45, p <0.05). The odds ratio for having a history of head injury was 1.52 (0.98–2.35), also significant only in male patients (OR=2.1, p <0.05). The study confirms a family history of dementia in first-degree relatives as a risk factor for Alzheimer's disease. No cases with either Down's syndrome or having family history of it were reported in the study sample. Previously reported head injury as a risk factor appears to apply to all dementias and was not confined to Alzheimer's disease. The inverse relationship with smoking was evident, but significant only in men.