Gender differences in subjective memory impairment in a general population: the HUNT study, Norway

Background: There is increased focus on early diagnosis of dementia, and subjective awareness of memory impairment is often assumed to be an early symptom of dementia. Subjective memory impairment (SMI) is used to describe subjective awareness of memory problems in the elderly after identifiable diseases which include this symptom are excluded. The aim of the present cross-sectional study was to examine the occurrence of SMI in a general adult population and its association with education level, subjective health, anxiety, depression and satisfaction with life. Methods: Nine items about memory were included in the questionnaire for participants aged 30+ in the large population based HUNT Study(2006–08). Health data, such as global health, symptoms of anxiety and depression and satisfaction with life in addition to level of education was collected. Stratified analyses were used to study gender differences in SMI sum score. Cohen’s d was measured as an effect size. One-way ANOVA followed by a Tukey post-hoc test was used to test the association between SMI sum score and each category of gender, age, education, global health and satisfaction with life. Bivariate correlation between symptoms of anxiety and depression and SMI were tested and finally the association between SMI sum score and age, gender, education level, subjective health and symptoms of depression and anxiety was tested in a linear regression model. Results: Nearly half of the participants (n=37,405: 44.6% women, 46.2% men) reported minor memory problems. Severe problems were reported by 1.2% of women and 1.6% of men. Remembering names and dates were the most frequent problems, and they increased with age. In eight out of nine items, more men than women reported memory problems. Elevated SMI was associated with poor self-perceived global health, symptoms of anxiety and depression and low education in both men and women and in all age groups. Conclusion: Minor subjective memory problems were very common, and SMI was clearly associated with health measures and with level of education. The relatively strong association between SMI and symptoms of depression might be of clinical interest. The reason for men reporting more memory problems than women remains unexplained.