Orthostatic Hypotension and Falls in Hospitalized Older Adults

Abstract

The aim of this retrospective study was to determine the prevalence of orthostatic hypotension (OH) among a convenience sample of older adults on two Acute Care of the Elderly (ACE) units of the ChristianaCare^™ in Delaware. Another aim was to determine if subjects with documented OH experienced falls. Retrospective de-identified data was obtained from electronic medical records for the years 2015 to 2018. Among all patients who had valid first orthostatic vital sign (OVS) readings (n=7745), 39.2% had orthostatic hypotension on the first reading. Among the patients, 42.8% were found to be hypotensive during OVS. Thirty-one (0.9%) of those with OH fell at some point during their stay. The odds ratio for falls in the presence of OH was 1.34 with a 95% confidence interval (0.82, 2.21), but a chi-square test failed to find significance (p=0.2494). The results could not determine if OVS should be mandatory in fall prevention protocols.

Introduction

Orthostatic hypotension (OH) may cause falls in hospitalized older adults (Feldstein et al., 2012; McDonald, Pearce, Kerr & Newton, 2016; Shaw & Claydon, 2016). This study determined OH prevalence and falls among older adults on two Acute Care of the Elderly (ACE) units at ChristianaCare^™ in Delaware, a level one trauma center with over 1200 beds within two hospital campuses. The ACE units improve clinical outcomes in older patients by preventing complications and preserving the patients’ functional ability. This includes preventing or minimizing the following during hospitalization: falls, skin breakdown, restraint use, delirium, cognitive decline, immobility, constipation and indwelling catheter use. The interdisciplinary ACE team meets regularly to conduct rounds and works to integrate care planning and improve continuity of care and communication with patients and families.

The Problem

Orthostatic hypotension (OH) has been considered a risk factor for falls in older adults (McDonald, Pearce, Kerr & Newton, 2016; Shaw & Claydon, 2016). Bouldin (2013) analyzed 2006 to 2008 data from the National Database of Nursing Quality Indicators (NDNQI) to determine prevalence and trends of falls occurring in adult medical-surgical patient care units. A total of 315,817 falls occurred during the 27 months, of which 26.1% resulted in an injury. However, a debate on the role of OH in patient falls persists (Finucane & Kenny, 2017; Frith, 2017; Hartog et al., 2017; Lipsitz, 2017). A systematic review by Jansen and colleagues (2016) found that there was an inconsistent relationship between orthostatic hypotension and falls.

OH is a sustained drop of at least 20 mm Hg for systolic blood pressure (SBP) or at least 10 mm Hg for diastolic blood pressure (DBP) when changing position from lying flat to sitting, sitting to standing, or lying flat to standing (Freeman et al., 2011). Upon standing, gravity redistributes approximately 500 to 800 milliliters of an individual’s lower extremity and splanchnic blood volume. This decreased venous return to the heart reduces stroke volume and cardiac output and stimulates high pressure aortic and carotid sinus baroreceptors and low-pressure receptors in the lungs and heart. The body typically compensates by increasing sympathetic outflow to the heart and vessels and decreasing cardiac vagal activity, thereby increasing cardiac contractility, vascular tone and heart rate. Renin-angiotensin system stimulation contributes to vasoconstriction. In individuals with OH, there is excessive reduction in cardiac output and/or defective vasoconstrictor mechanisms (Feldstein & Weder 2012; Freeman et al., 2011). Normal physiological diminished baroreceptor sensitivity with advancing age contributes to increased prevalence (Freeman et al., 2018). Insufficient blood volume and/or dehydration also contribute to this lack of compensation. Subsequent cerebral hypoperfusion may cause OH symptoms but some individuals are asymptomatic despite a drastic drop in systolic BP (Freeman et al., 2018).

Measurement of orthostatic vital signs (OVS) is often included in fall prevention initiatives (AHRQ, 2013). According to the NDNQI (2020), “A patient fall is a sudden, unintentional descent, with or without injury to the patient, that results in the patient coming to rest on the floor, on or against some other surface (e.g., a counter), on another person, or on an object (e.g., a trash can). When a patient rolls off a low bed onto a mat or is found on a surface where you would not expect to find a patient, this is considered a fall. If a patient who is attempting to stand or sit falls back onto a bed, chair, or commode, this is only counted as a fall if the patient is injured.” Fall prevention strategies include proactive toileting every two hours; continuous direct observation with patient while toileting; gait belt use with ambulation & transfer; engaged bed and/or chair exit alarm, and ongoing communication/education to patient/family regarding risk for fall & injury (Healthcare System, 2019).

ChristianaCare^™ requires OVS on admission on both ACE units; this is a unit-based protocol. The time needed for bedside staff to perform this assessment and the risk of measurement inaccuracy as a result of variations in time of day, device, and position influence the value of this assessment (Aydin, Soysal, & Isik, 2017; Cooke, Carew, O’Connor, Costelloe, Sheehy & Lyons, 2009; Dind, Short, Ekhlm, & Holdgate, 2011; McDonald et al., 2016; Soysal, Aydin, Okudu, & Isik, 2016). Additionally, inadequate staff knowledge (Irvin & White, 2004; O’Riordan, Vasilakis, Hussain et al., 2017; Vloet et al., 2012), the need for more than one set of measurements and the fact that OH is often not reproducible challenge the usefulness of bedside OVS.

The Purpose

The primary aim of this study was to determine the prevalence of OH among those hospitalized older adults for whom OVS were measured. A second aim was to determine if those older adults with documented OH experienced falls. The study results were used to determine if OVS should be mandatory in fall prevention protocols. An exploratory aim examined the role of comorbidities with OH/falls.

Design, Setting and Participants

This retrospective prevalence/cohort study included a convenience sample of adults (65 years of age and older) on two patient care units designated as ACE units of ChristianaCare^™ in Delaware for whom orthostatic vital signs were measured. ChristianaCare^™ is one of the country’s largest health care providers, serving more than 600,000 patients yearly, placing it as the 17th leading hospital in the nation and 10th on the East Coast in terms of admissions. It includes two hospitals with 1,200 patient beds, two Acute Care of the Elderly (ACE) units, a home health care service, preventive medicine, rehabilitation services, a network of primary care physicians and an extensive range of outpatient services including the System Center for Memory Care & Geriatric Consultation. In October 2020, ChristianaCare^™ received its third consecutive Magnet designation which includes Acute Care (both Hospitals), Ambulatory Services and ChristianaCare^™ Home Health.

The 39 bed ACE unit 1 was located at Christiana Hospital and the 30 bed ACE unit 2 was located at Wilmington Hospital, both part of the ChristianaCare^™ health system. Data between July 2015 and June 2018 were included for ACE Unit 1. A total of 6275 patients were admitted to ACE Unit 1 over the 3-year period. Data for ACE Unit 2 were included only between July 2017 and June 2018 since this unit was relocated in March 2017. A total of 1766 patients were admitted to ACE Unit 2 during the one year time frame..Demographic and clinical data were obtained from the electronic medical record using the medical record number (MRN).

Measurements

Orthostatic Vital Signs Measurement in Study Setting

Primarily unlicensed assistant personnel measure OVS upon patients’ admissions to the ACE units using the Welch Allyn oscillometric blood pressure monitor and OVS procedure in Lippincott Procedures©. They then document in the electronic medical record (EMR). If OH was present, the ACE Unit 1 policy dictated that OVS were measured and documented on three consecutive days. On ACE Unit 2, subsequent OVS were obtained if ordered by the healthcare provider. Subject age, sex, race, ethnicity and hospital unit were collected. Although some studies operationalize OVS by including time of measurement, time between position changes and OVS measurements were not available in this institution’s EMR. An OVS measurement session measurements (with position changes) are listed as a single time.

Clinical Information

Number of falls during hospitalization and if there were repeat falls were obtained from an event management system. The researchers selected twelve co-morbidities from the Elixhauser Comorbidity list that were more likely to impair mobility and functional status, and that could cause falls or orthostatic hypotension either due to illness/disease or due to medications that might be prescribed for that population. The Elixhauser Comorbidity list is a method of categorizing comorbidities based on the International Classification of Diseases 10. (Moore, White, Washington, Coenen & Elixhauser, 2017). Categories chosen for this study included arthritis (ARTH), congestive heart failure (CHF), diabetes without (DM (and with complications (DMCX), hypertension without (HTN) and with complications (HTNCX), other neurological disorders (NEURO), paralysis (PARA), peripheral vascular disease (PERIVSC), psychoses (PSYCH), renal failure (RENLFAIL) and heart valve disorder (VALVE).

Procedure

Institutional Review Boards of ChristianaCare^™ and the University of Delaware approved this study. A hospital senior system analyst obtained retrospective data from the subjects’ EMRs. The analyst merged de-identified data found in the EMR with the Fall Event Reports from Risk Management into an Excel spreadsheet. The researchers cleaned the data, eliminating erroneous BP data values.

Statistical Analysis

Descriptive summaries were generated for demographic variables and comorbidities over all patients and by ACE unit. The prevalence of orthostatic hypotension (OH) and falls were estimated and reported over all patients and by ACE unit. The OVS method implemented (supine/sit, sit/stand, supine/stand) was also summarized to assess the most common position associated with OH. The researchers did not differentiate between right or left arm measurements. The association between falls and OH was examined within a contingency table framework using chi-square significance. Additional exploration with contingency table analysis sought to explore associations that might partially explain the prevalence of falls as they relate to single predictors among demographics, hypotension, and comorbidities. Multiple predictors were explored using logistic regression and classification tree models with forward stepwise inclusion of the most promising predictors. All analyses were carried out using JMP^®, Version 15.1.0 SAS Institute, Inc., Cary, NC, 1989–2020.

Findings

Baseline Characteristics

Subjects were mostly white (77.9%), mostly women (61.6%), and mostly Non-Hispanic Latino (NHL) (96.7%) with age overall reported as 80.2 (+/− 8.1) years. Similar demographics were seen across units. See Table 1. Hypertension was the most prevalent comorbidity over all patients (89.9%), followed by hypertension with complications (45.8%), other neurological disorders (45.0%), and diabetes without complications (42.2%). Comorbidity prevalence was also similar across the two patient units.

Table 1.

Demographic Summary for All (n=7969), ACE Unit 1 (n=6217), and ACE Unit 2 (n=1752)

Age	Mean (years)	Sd (year)
All	80.2	8.1
ACE Unit 1	79.9	8.0
ACE Unit 2	81.2	8.5
Sex	Male(%)	Female(%)
All	38.4	61.6
ACE Unit 1	39.2	60.8
ACE Unit 2	36.0	64.0
Race	White (%)	Black (%)	Other (%)
All	77.9	19.5	2.6
ACE Unit 1	81.9	15.5	2.6
ACE Unit 2	63.6	33.8	2.6
Ethnicity	Non-Hispanic/Latino (%)	Hispanic/Latino (%)	Other (%)
All	96.7	2.3	1.0
ACE Unit 1	96.4	2.5	1.0
ACE Unit 2	97.6	1.8	0.6

Orthostatic Hypotension Prevalence

Among all patients who had valid first orthostatic vital sign readings (n=7745), 39.2% (n=3039) had orthostatic hypotension on the first reading. For second readings (n=1530), 45.5% (n=696) were positive. Similar results were seen for ACE Unit 1. Of those patients on ACE Unit 1 who had valid first orthostatic vital sign readings (n=6035), 41.8% (n=2520) of patients had orthostatic hypotension on their first reading. Of those who had a second reading (n=1331), 46% (n=612) were positive for OH. Slightly lower values were recorded for ACE Unit 2. Of those subjects on ACE Unit 2 who had valid first orthostatic vital sign readings (n=1710), 30.4% (n=519) of subjects had orthostatic hypotension on their first reading. Of those who had a second reading (n=199), 42.2% (n=84) were positive for OH.

Position Change & OH

The first orthostatic vital sign readings (n=6035) for ACE Unit 1 were also summarized in terms of Hg change and the specific source of the OH determination according to definition. Prior to that report, it is important to clarify how the data were processed. In practice, when OVS were measured, they were recorded as supine, sitting, or standing for left/right upper extremity. A valid reading consisted of at least two different positions on at least one side for both systolic and diastolic. Many times, data were collected in all three positions and sometimes all three positions on both sides. Thus, the determination of OH in this study could be validly based on up to six reading comparisons. In processing, the maximum change across valid reading comparisons available was used to determine OH in terms of diastolic, systolic, or both. OH determination was then separated according to a drop in diastolic alone, systolic alone, or both. The total number of OH (n=2520) identified in ACE Unit 1 for the first reading can then be further broken down by diastolic (n=702), systolic (n=965), or both (n=853). Summary statistics regarding maximum mm Hg drop are reported in Table 2. The maximum mm Hg drop was seen in systolic BP with mean 31 (range 23–36 mm Hg).

Table 2.

Maximum mm Hg Drop for OH ACE Unit 1 First Reading by Parameter

Source of OH	N	Median	IQR	Mean	Sd
Diastolic BP	702	14	(11, 17)	15.4	5.9
Systolic BP	965	28	(23, 36)	31.0	10.6
Diastolic & Systolic BP	853	16	(12, 22)	18.7	19.3
		34	(26, 47)	38.2	15.3

OH orthostatic hypotension; BP blood pressure

Also of interest were the specific position comparisons that led to the determination of OH. Table 3 lists all possible comparisons that resulted in OH (n=5061), based on the OH definition (drop of 20 mm Hg systolic, 10 mm Hg diastolic) and the specific positions chosen for the readings. The table shows the combined six possible comparisons where the position resulted in a BP drop based on the OH definition for diastolic or systolic alone or both. The most common position change resulting in OH was from supine to standing for systolic and diastolic BP, respectively.

Table 3.

Position Change Resulting in OH

		# Subjects with Presence of OH in BP Parameter
BP Parameter, Position Change	All Subjects	Diastolic (n=)	Systolic (n=)	Both (n=)
Diastolic BP, Supine to Sitting	633	300	0	333
Diastolic BP, Supine to Standing	930	319	0	611
Diastolic BP, Sitting to Standing	670	287	0	383
Systolic BP, Supine to Sitting	652	0	324	328
Systolic BP, Supine to Standing	1452	0	724	728
Systolic BP, Sitting to Standing	724	0	330	394
Total	5061	906	1378	2777

BP Blood Pressure

Overall Prevalence of Falls

Of all patients (n=7969) for whom falls were recorded, 99.22% (n=7907) had no falls over the three years of data for ACE Unit 1 and the one year of data for ACE Unit 2. Fifty-eight subjects (0.73%) had one fall and four subjects (0.05%) had two falls. For ACE Unit 1, of subjects (n=6217) with falls recorded, 99.31% (n=6174) had no falls over 3 years. Forty-one subjects (0.66%) had one fall and two subjects (0.02%) had two falls. Therefore, 45 patient falls were recorded during those 3 years. For ACE Unit 2, of subjects (n=1752), 98.92% (n=1733) had no falls over one year. Seventeen subjects (0.97%) had one fall and two subjects (0.11%) had two falls. Therefore, 21 patient falls were recorded during that year.

Orthostatic Hypotension and Falls

Among patients who fell (n=62) 61.6% (n=38) were female and 38.4% (n=24) were male, which exactly matched the representation of male/female over the two units. The age distribution of those who fell also matched well with the age distribution overall, appearing symmetric with 81.2 years (+/− 8.9), median 82, and range (65, 99). Among the patients (n=7969), 42.8% (n=3410) were found to be hypotensive during OVS measurement; 0.9% (n=31) of these fell at some point during the stay. The odds ratio for falls in the presence of an OH reading relative to falls without an OH reading was 1.34 with a 95% confidence interval (0.82, 2.21); a chi-square test failed to find significance (p=0.2494).

Influence of Comorbidities

The odds ratio was similarly determined for falls in the presence of each comorbidity. Only two, HX_HTN, and HX_NEURO, were statistically significant. Comorbidities of arthritis, congestive heart failure, diabetes without and with complications, hypertension with complications, paralysis, peripheral vascular disease, psychoses, renal failure and heart valve disorder did not influence fall prevalence. The odds of a fall in the presence of other neurological disorders is 1.95 times as large as the odds of a fall with no neurological disorders and the odds of a fall in the presence of hypertension without complications is 0.38 times as large as the odds of a fall without hypertension. See Table 4.

Table 4.

Relationship Between Comorbidities and Falls

Comorbidity	Cases Present (7938 Subjects)	Falls (62 Total)	OR	95% CI	Chi-sq. p-value
HX_ARTH	809	7	1.12	(0.51, 2.47)	0.7740
HX_CHF	2981	21	0.85	(0.50, 1.44)	0.5478
HX_DM	3352	21	0.70	(0.41, 1.18)	0.1811
HX_DMCX	2009	13	0.78	(0.42, 1.44)	0.4300
HX_HTN	7138	48	0.38	(0.21, 0.69)	0.0010*
HX_HTNCX	3633	28	0.98	(0.59, 1.61)	0.9234
HX_NEURO	3572	38	1.95	(1.16, 3.25)	0.0096*
HX_PARA	722	7	1.27	(0.58, 2.81)	0.5463
HX_PERIVSC	2612	25	1.38	(0.83, 2.30)	0.2121
HX_PSYCH	805	7	1.13	(0.51, 2.49)	0.7635
HX_RENLFAIL	2759	19	0.83	(0.48, 1.42)	0.4949
HX_VALVE	2680	14	0.57	(0.31, 1.04)	0.0616

^*p < .05

arthritis (ARTH), congestive heart failure (CHF), diabetes without (DM (and with complications (DMCX), hypertension without (HTN) and with complications (HTNCX), other neurological disorders (NEURO), paralysis (PARA), peripheral vascular disease (PERIVSC), psychoses (PSYCH), renal failure (RENLFAIL), heart valve disorder (VALVE)

Modeling

Two approaches were implemented in modeling a dichotomous falls response using OH, demographic, and comorbidity predictors. Stepwise logistic regression, reaffirmed the effect of hypertension without complications (p=0.0007) and other neurological disorders (p=0.0062), but within a model that had only a modest area under the Receiver Operating Curve (ROC) curve (AUC=0.63) and that failed to ever predict a patient as having a fall. No other predictors among OH, demographics, and comorbidities entered into the model. A nonparametric approach (classification trees) using the same falls response with the same candidate predictors also identified hypertension without complications and other neurological disorders as the first predictors to be entered into the model, but the model performance was equally poor as the logistic model attempted.

Discussion

Prevalence of Orthostatic Hypotension

In this study’s sample, 30–39% of subjects experienced orthostatic hypotension. Several studies reported an increased prevalence of OH with age (Coutaz, Inglesias, & Morisod, 2012; Jodaitis, 2015; Passant, 1997; Shibao 2007; Weiss, 2002). Systolic BP was the most common parameter that declined enough to deem the individual had an episode of orthostatic hypotension (Jodaitis, 2015). This finding differs from Weiss (2002) who reported that diastolic BP was the statistically significant parameter.

OH and Falls in Hospitalized Older Adult

A major challenge to analyzing study results is the limited number and heterogeneity of studies investigating the relationship of OH and falls in hospitalized older adults. A systematic review of 39 cross-sectional and 24 longitudinal studies (n=51,800) of the relationship between OH and falls by Mol and colleagues (2019) focused on sample populations with a mean or median age >/=65 years from a variety of inpatient, outpatient and nursing home settings. Thirty-eight percent of these 63 studies reported a positive association of OH and falls. A meta-analysis of 50 of these studies included over 49,000 individuals. Orthostatic hypotension, measured by active stand tests and either continuous or intermittent BP measurement, was positively associated with falls with an odds ratio of 1.73 and 95% confidence interval of 1.50–1.99. Study population, study design quality, orthostatic hypotension definition and method of BP measurement did not influence this finding. However, this finding was strongest in those studies using continuous BP measurements. This association is not supported by this current study. However, the low incidence of falls in our subjects with orthostatic hypotension may reflect the standard of care at The Healthcare System, a thrice designated Magnet hospital. There were few subjects who fell twice. A systemwide Fall Prevention Team, with representation from every service line and nursing unit, has implemented standardized interventions and guidelines. Risk trends and opportunities to improve are highlighted weekly on each unit. Successful strategies are shared. The Fall Prevention Care Management Guideline includes the fall risk assessment tool, general recommended interventions for all patients, specific interventions based on the patient’s fall risk, referrals to consider, and post fall evaluation & treatment. Fall prevention standards include:

• Wear non-skid footwear when ambulating

• Use gait belts on high-risk patients or on those who need assistance

• Stay with and be within arm’s reach of high-risk patients in bathroom/bedside commode

• Chair and bed exit alarms on and functioning; perform battery checks with patient rounds

• Beds are “green”, brakes are on, bed in low position, 2 side rails up

In the current study, there was a statistically significant association of OH with the comorbidities of essential hypertension and neurological disorders (e.g., Parkinson’s Disease, Multiple Sclerosis, Demyelinating Diseases, Encephalopathy, Epilepsy). Over 250 diseases and conditions are included in the NEURO Elixhauser classification limiting the ability to further analyze this finding. Neurogenic orthostatic hypotension is a known complication of Parkinson’s Disease (LeWit, 2020) and a 2016 meta-analysis reported a 30% prevalence in this population (Velsebour, 2016). Some experts have found that OH in hypertension may be a consequence of the antihypertensive medications prescribed (Biaggioni, 2018) while recent randomized controlled trials (Juraschek, Simpson, Davis, Becah, Ishak, & Mukamal, 2019; Margolis et al., 2014; SPRINT, 2015) suggest no long term effect on OH incidence.

Strengths and Limitations

This study’s strengths include a large sample size and a sample population who are at high risk for falls. There are several limitations to this study. Retrospective chart review prohibited the ability to assess accuracy of the caregivers’ BP measurement procedures. Documentation of time between each measurement during OVS was not a part of the electronic health record. OVS reflected one point in time and did not reflect that possibility that OH occurred at other times during the subjects’ hospitalization. Inaccuracies were noted in some data point electronic health record entries based on the range of possibilities for vital sign parameters. If orthostatic hypotension was within a subject’s history, information on concurrent symptoms, fluid intake, medications, and other treatments was not collected. Although the intention was to document prescribed medications, the information obtained was only medications upon admission with no relationship to the actual time of OVS measurement. Thus, influence of medications was not explored. Additionally, a large sample size can magnify bias because statistical tests tend to be more sensitive (Kaplan, Chamber, & Glasgow, 2014). The sample lacked ethnic diversity. Results of this study are not generalizable and may reflect one health system’s population and practices.

Conclusions and Application to Nursing Practice

According to this study’s results, about 40% of the sample of hospitalized elderly patients experienced orthostatic hypotension, but less than one percent fell during the study period. Neither orthostatic hypotension nor demographic variable explained the falls. The comorbidities categorized as hypertension and neurological disorders may potentially relate to falls but further exploration is warranted. Modeling showed no synergistic effect of multiple predictors. From our results, we could not determine if OVS should be mandatory in falls protocols. Further study is needed, particularly prospective and longitudinal data collection. Incorporation of quality control training on BP measurement will promote measurement validity. Consistent measurement of fall risk and strict adherence to OVS procedures will strengthen future studies.

Consistency in OVS measurement techniques in daily hospital routine is challenging and, even if performed accurately, OVS may not detect OH. Study results prompted refinement of the electronic medical record at ChristianaCare^™ including but not limited to notification when an OVS order is placed and arranging the order of the blood pressure charting so that right lying, sitting and standing are grouped together and left lying, sitting and standing are grouped together for easier charting. Judicious implementation of fall risk precautions within ChristianaCare^™ contributed to these findings & should be continued.

Biographies:

Kathleen Schell, PhD, RN, is a tenured Associate Professor in the School of Nursing, University of Delaware, Newark, DE.

Denise Lyons, DNP, APRN, AGCNS-BC, FNGNA, is a Gerontological/Adult Clinical Nurse Specialist and the WISH/NICHE Program Coordinator at ChristianaCare^™, Newark, DE.

Barry Bodt, PhD, is a Senior Biostatistician in the College of Health Sciences, University of Delaware, Newark, DE.