Medical Doctors and Dementia: A Longitudinal Study

Abstract

Objective: To examine the association between being a medical doctor (MD) and the risk of incident dementia.

Design: Cohort study.

Setting: Olmsted County, Minnesota.

Participants: A total of 3460 participants (including 104 MDs), aged 70 years or older, of the population-based Mayo Clinic Study of Aging.

Measurements: Participants were randomly selected from the community and had comprehensive cognitive evaluations at baseline and approximately every 15 months to assess for diagnosis of dementia. For participants who withdrew from the follow-up, dementia diagnosis was also assessed using information available in their medical record. The associations were examined using Cox proportional hazards models, adjusting for sex, education, and apolipoprotein E ε4, using age as the time scale.

Results: MDs were older (vs "general population"), and most were males (93.3%). MDs without dementia at baseline did not have a significantly different risk for incident dementia (hazard ratio = 1.12; 95% confidence interval = 0.69-1.82; P = .64) compared to the general population.

Conclusions: Although the study includes a small number of older, mainly male, MDs, it provides a preliminary insight on cognitive health later in life in MDs, while most previous studies examine the health of younger MDs. Larger longitudinal studies are needed to examine these associations and investigate if associations are modified by sex. J Am Geriatr Soc 68:1250-1255, 2020.

Keywords: cohort study; dementia; medical doctors.

Figure 1.

Study flowchart. There were 3460 Mayo Clinic Study of Aging (MCSA) participants (aged ≥70 years at baseline) without dementia, with available education and occupation information and at least one in-person MCSA evaluation or follow-up information available in their medical records. All participants who were evaluated at least in the baseline visit are eligible for medical record review (MRR) for incident dementia at 70 years of age and every 5 years thereafter, if they provided MRR authorization. A total of 228 participants were excluded (3 did not have education data; 147 had only the baseline visit and await their in-person follow-up evaluation; 13 died before they could come in for follow-up; 1 withdrew from the study and withdrew consent for MRR; 43 withdrew from the in-person MCSA evaluation and await MMR; and 21 withdrew from the in-person MCSA evaluation but we could not have MRR for unspecified reasons).

Figure 2.

Survival curves for outcome of incident dementia, adjusted for sex, education, and apolipoprotein E ε4 status, with age as the time scale. The y axis presents the proportion of participants without dementia. MD indicates medical doctor.