Relationships between orthostatic hypotension, frailty, falling and mortality in elderly care home residents

Abstract

Background: Orthostatic hypotension (OH; profound falls in blood pressure when upright) is a common deficit that increases in incidence with age, and may be associated with falling risk. Deficit accumulation results in frailty, regarded as enhanced vulnerability to adverse outcomes. We aimed to evaluate the relationships between OH, frailty, falling and mortality in elderly care home residents.

Methods: From the Minimum Data Set (MDS) document, a frailty index (FI-MDS) was generated from a list of 58 deficits, ranging from 0 (no deficits) to 1.0 (58 deficits). OH was evaluated from beat-to-beat blood pressure and heart rate (finger plethysmography) collected during a 15-min supine-seated orthostatic stress test. Retrospective and prospective falling rates (falls/year) were extracted from facility falls incident reports. All-cause 3-year mortality was determined. Data are reported as mean ± standard error.

Results: Data were obtained from 116 older adults (aged 84.2 ± 0.9 years; 44% males) living in two long term care facilities. The mean FI-MDS was 0.36 ± 0.01; FI-MDS was correlated with age (r = 0.277; p = 0.003). Those who were frail (FI ≥ 0.27) had larger Initial (- 17.8 ± 4.2 vs - 6.1 ± 3.3 mmHg, p = 0.03) and Consensus (- 22.7 ± 4.3 vs - 11.5 ± 3.3 mmHg, p = 0.04) orthostatic reductions in systolic arterial pressure. Frail individuals had higher prospective and retrospective falling rates and higher 3-year mortality. Receiver operating characteristic curves evaluated the ability of FI-MDS alone to predict prospective falls (sensitivity 72%, specificity 36%), Consensus OH (sensitivity 68%, specificity 60%) and 3-year mortality (sensitivity 77%, specificity 49%). Kaplan Meier survival analyses showed significantly higher 3-year mortality in those who were frail compared to the non-frail (p = 0.005).

Conclusions: Frailty can be captured using a frailty index based on MDS data in elderly individuals living in long term care, and is related to susceptibility to orthostatic hypotension, falling risk and 3-year mortality. Use of the MDS to generate a frailty index may represent a simple and convenient risk assessment tool for older adults living in long term care. Older adults who are both frail and have impaired orthostatic blood pressure control have a particularly high risk of falling and should receive tailored management to mitigate this risk.

Keywords: Falling; Frailty; Older adults; Orthostatic hypotension.

Fig. 1

Distribution of FI-MDS for the cohort as a whole (n = 116). The density distribution of the FI-MDS was bimodal, with two subgroups of non-frail and frail individuals. The crossing point distinguishing the two sub groups was approximately FI-MDS = 0.27. The horizontal box plots represent the mean FI-MDS in males and females

Fig. 2

Retrospective and prospective falling rates in individuals who were frail and non-frail (n = 116). Those who were frail had higher retrospective and prospective falling rates (falls/year) than those who were non-frail

Fig. 3

Severity of orthostatic hypotension in frail and non-frail individuals (n = 55). Those who were frail had larger Initial (a), and Consensus (b) declines in SAP than those who were non-frail. The delayed decline in SAP (c) was not different between groups. Solid horizontal lines indicate the median and dotted horizontal lines represent the mean. Abbreviations: SAP systolic arterial pressure, NS not significant

Fig. 4

Proportion of frail and non-frail individuals within each subdomain of deficits reported in the FI-MDS (n = 116). Individuals were considered to be frail when their frailty index (FI-MDS) was ≥0.27. For a full description of the deficits considered within each subdomain see Additional File 2. Abbreviations: ADL, activities of daily living

Fig. 5

Frequency of Consensus orthostatic hypotension (OH) among each cognitive symptom reported in the FI-MDS (n = 55). Individuals were considered to have Consensus OH when there was decrease in SAP ≥20 mmHg or in DAP ≥10 mmHg within the first 3 min of being upright. Abbreviations: OH orthostatic hypotension

Fig. 6

Relationships between frailty and 3-year mortality. (a) Kaplan-Meier survival analyses showing the impact of frailty (FI-MDS) on mortality (n = 116). The outcome of mortality was considered met in participants who had died after 36 months (n = 69) or who had been discharged to a higher level of care (n = 6). Individuals who were frail (FI-MDS ≥0.27) had a significantly higher 3-year mortality (P < 0.005) than those who were non-frail. (b) Receiver Operating Characteristic (ROC) curve for the prediction of 3-year mortality (n = 116) from the FI-MDS. The area under the curve (AUC) was 0.651 (p = 0.007) with 77% sensitivity and 49% specificity to predict 3-year mortality based on a FI-MDS ≥ 0.27