Depression and Functional Impairment: A Pernicious Pairing in Older Adults

Association between vitamin D insufficiency and depressive symptoms, and functional disability in community-dwelling Brazilian older adults: results from ELSI-Brazil study

Low serum 25(OH)D levels (< 30 nmol/L) have been associated with increased depressive symptom scores over time, and it is believed that functionality may play a mediating role in the relationship between 25(OH)D and depressive symptoms. To comprehend the association between these factors could have significant implications for public health policy. The aim of this study was to verify the association between simultaneous vitamin D insufficiency and depressive symptoms, and functional disability in community-dwelling older adults. This was a cross-sectional study with data from the Brazilian Longitudinal Study of Aging (ELSI-Brazil), collected between 2015 and 2016. The outcomes were functional disability assessed through basic activities of daily living (ADL) and instrumental activities of daily living (IADL). The exposures were vitamin D insufficiency (< 30 nmol/L) and depressive symptoms (≥ 4 points in 8-item version of the Center for Epidemiological Studies-Depression). Crude and adjusted Poisson regression was performed to estimate associations. A total of 1781 community-dwelling older adults included in this study, 14.6% had disability in ADL and 47.9% in IADL; 59.7% had vitamin D insufficient levels, and 33.2% depressive symptoms. The concomitant presence of vitamin D insufficient and depressive symptoms increased the prevalence of ADL by 2.20 (95% CI: 1.25; 3.86) and IADL by 1.54 (95% CI: 1.24; 1.91), respectively. Therefore, preventive strategies to keep older adults physically and socially active, with a good level of vitamin D, are essential to avoid depression and functional disability.

Depressive Symptoms and Total Healthcare Costs: Roles of Functional Limitations and Multimorbidity

OBJECTIVES

Depressive symptoms can be both a cause and a consequence of functional limitations and medical conditions. Our objectives were to determine the association of depressive symptoms with subsequent total healthcare costs in older women after accounting for functional limitations and multimorbidity.

DESIGN

Prospective cohort study (Study of Osteoporotic Fractures [SOF]).

SETTING

Four US sites.

PARTICIPANTS

A total of 2508 community-dwelling women (mean age = 79.4 years) participating in the SOF year 10 (Y10) examination linked with their Medicare claims data.

MEASUREMENTS

At Y10, depressive symptoms were measured using the 15-item Geriatric Depression Scale (GDS) and functional limitations were assessed by number (range = 0-5) of impairments in performing instrumental activities of daily living. Multimorbidity was ascertained by the Elixhauser method using claims data for the 12 months preceding the Y10 examination. Total direct healthcare costs, outpatient costs, acute hospital stays, and skilled nursing facility during the 12 months following the Y10 examination were ascertained from claims data.

RESULTS

Annualized mean (SD) total healthcare costs were $4654 ($9075) in those with little or no depressive symptoms (GDS score = 0-1), $7871 ($14 534) in those with mild depressive symptoms (GDS score = 2-5), and $9010 ($15 578) in those with moderate to severe depressive symptoms (GDS score = 6 or more). After adjustment for age, site, self-reported functional limitations, and multimorbidity, the magnitudes of these incremental costs were partially attenuated (cost ratio = 1.34 [95% confidence interval {CI} = 1.14-1.59] for those with mild depressive symptoms, and cost ratio = 1.29 [95% CI = 0.99-1.69] for those with moderate to severe depressive symptoms vs women with little or no depressive symptoms).

CONCLUSION

Depressive symptoms were associated with higher subsequent healthcare costs attributable, in part, to greater functional limitations and multimorbidity among those with symptoms. Importantly, even mild depressive symptoms were associated with higher healthcare costs. J Am Geriatr Soc 67:1596-1603, 2019.