Comorbidities in dementia during the last years of life: a register study of patterns and time differences in Finland

Abstract

Background: Comorbidities have major implications for the care of people with dementia.

Aim: To investigate the patterns of comorbidities in dementia in the last five years of life and how these patterns differed between three cohorts.

Methods: The study included people who died at age 70 and above in 2001 (n = 13,717), 2007 (n = 34,750) and 2013 (n = 38,087) in Finland. ICD-10 morbidity data for a five-year period prior to death were extracted from national registers. Principal component analysis was employed to identify patterns for several morbidities. The associations of principal component scores with dementia were analysed using binary logistic regression. Linear regression was used to examine changes in the number of morbidities in patterns over time.

Results: The morbidity patterns identified in the last years of life were (1) cardiometabolic disorders, (2) neurological, (3) cerebrovascular diseases and (4) musculoskeletal, thyroid and psychiatric disorders. Among the patterns, neurological and musculoskeletal, thyroid and psychiatric disorders were associated with dementia. The number of diagnoses in the cerebrovascular pattern increased and those in the musculoskeletal, thyroid and psychiatric pattern decreased over time.

Discussion: Comorbidity patterns identified in this nationwide register study are largely in line with previous evidence. Time difference in these patterns provide crucial information for service planning.

Conclusions: Comorbidities in dementia in the last years of life occur in patterns and change over time. More systematic monitoring and updated clinical guidelines are needed for the care of comorbidities with dementia.

Keywords: Comorbidity; Dementia; Last years of life; Morbidity patterns; Principal component analysis.