Progression of Alzheimer’s Disease: A Longitudinal Study in Norwegian Memory Clinics

Article type: Research Article

Authors: Eldholm, Rannveig Sakshaug^{a; *} | Barca, Maria Lage^{b; c} | Persson, Karin^{b; c} | Knapskog, Anne-Brita^c | Kersten, Hege^{b; d; e} | Engedal, Knut^{b; c} | Selbæk, Geir^{b; f; g} | Brækhus, Anne^{b; c; h} | Skovlund, Evaⁱ | Saltvedt, Ingvild^{a; j}

Affiliations: [a] Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway | [b] Norwegian National Advisory Unit on Ageing and Health, Vestfold Hospital Trust, Tønsberg, Norway | [c] Department of Geriatric Medicine, Memory Clinic, Oslo University Hospital, Ullevaal, Oslo, Norway | [d] Department of Pharmaceutical Bioscience, School of Pharmacy, University of Oslo, Norway | [e] Department of Research and Development, Telemark Hospital Trust, Norway | [f] Centre for Old Age Psychiatric Research, Innlandet Hospital Trust, Ottestad, Norway | [g] Institute of Health and Society, University of Oslo, Oslo, Norway | [h] Department of Neurology, Oslo University Hospital, Ullevaal, Oslo, Norway | [i] Department of Public Health and Nursing, Norwegian University of Science and Technology (NTNU), Trondheim, Norway | [j] Department of Geriatrics, St Olav Hospital, University Hospital of Trondheim, Trondheim, Norway

Correspondence: [*] Correspondence to: Rannveig S. Eldholm, Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway. Tel.: +47 40456303; E-mail: rannveig.s.eldholm@ntnu.no.

Abstract: Background:The course of Alzheimer’s disease (AD) varies considerably between individuals. There is limited evidence on factors important for disease progression. Objective:The primary aim was to study the progression of AD, as measured by the Clinical Dementia Rating Scale Sum of Boxes (CDR-SB). Secondary aims were to investigate whether baseline characteristics are important for differences in progression, and to examine the correlation between progression assessed using three different instruments: CDR-SB (0–18), the cognitive test Mini-Mental State Examination (MMSE, 0–30), and the functional measure Instrumental Activities of Daily Living (IADL, 0-1). Methods:The Progression of AD and Resource use (PADR) study is a longitudinal observational study in three Norwegian memory clinics. Results:In total, 282 AD patients (mean age 73.3 years, 54% female) were followed for mean 24 (16–37) months. The mean annual increase in CDR-SB was 1.6 (SD 1.8), the mean decrease in MMSE score 1.9 (SD 2.6), and the mean decrease in IADL score 0.13 (SD 0.14). Of the 282 patients, 132 (46.8%) progressed slowly, with less than 1 point yearly increase in CDR-SB. Cognitive test results at baseline predicted progression rate, and together with age, ApoE, history of hypertension, and drug use could explain 17% of the variance in progression rate. The strongest correlation of change was found between CDR-SB and IADL scores, the weakest between MMSE and IADL scores. Conclusion:Progression rate varied considerably among AD patients; about half of the patients progressed slowly. Cognitive test results at baseline were predictors of progression rate.

Keywords: Alzheimer’s disease, cognitive decline, dementia, mild cognitive impairment, prognosis, progression

DOI: 10.3233/JAD-170436

Journal: Journal of Alzheimer's Disease, vol. 61, no. 3, pp. 1221-1232, 2018