Improving Function in Older Adults With Hospital-Associated Deconditioning: Lessons Learned Comparing a Randomized Controlled Trial to Real World Practice

Abstract

Objective

The optimal approach for improving physical function following acute hospitalization is unknown. A recent clinical trial of home health physical therapy compared a high-intensity, progressive, multi-component (PMC) intervention to enhanced usual care (EUC). While both groups improved in physical function, no between-group differences were observed. However, the EUC group received care that differed from real world practice due to standardized treatments and a higher frequency of visits. This study compared a non-randomized true usual care (TUC) group to the EUC and PMC groups.

Methods

Participants in the parent trial were randomly assigned to the EUC group (n = 100) and PMC group (n = 100) following hospital discharge. A subset of eligible patients (n = 55) were concurrently enrolled in the TUC group. Both the PMC and EUC groups received strength, activities of daily living, and gait training that differed in intensity but were matched in frequency and duration. TUC group care was determined by the home health agency. The primary outcome at 60-days was the Short Physical Performance Battery (SPPB).

Results

In comparison to the TUC group, the EUC and PMC groups had significantly greater improvements in SPPB score (EUC: +1.04 points [CI = 0.18–1.90]; PMC: +1.12 points [CI = 0.23–2.00]).

Conclusion

While participants in the EUC and PMC groups experienced greater functional recovery compared to those in the TUC group, it cannot be determined whether these differences are due to the interventions received or confounding factors associated with the addition of a third, non-randomized, study group during the trial period.

Impact

This study illustrates the importance of design and interpretation of control groups for clinical trials. Further, the differences between the TUC group and the enhanced intervention groups warrant future research exploring whether increasing visits and standardizing care improve function in older adults receiving home health physical therapy after hospital associated deconditioning.

Lay summary

Participants in the intervention groups received standardized and more therapy than usual care, and experienced greater functional improvements. However, these differences may be due to factors associated with the addition of a non-randomized group during an ongoing clinical trial.

Control Group, Enhanced Usual Care, Function, Geriatrics, High Intensity Exercise, Home Health, True Usual Care

INTRODUCTION

Many older adults experience significant functional decline after hospitalization, which increases their risk for rehospitalization, disability, and mortality.^1–3 Over 3 million older adults are referred to home health physical therapy after hospitalization to mitigate the risks of acute functional decline within the United States.^4,5 Because optimal treatment for these patients is currently unknown, intervention studies within the home health setting could improve patient care for older adults.

Recently, our research team examined whether a high-intensity, progressive, multi-component (PMC) home health physical therapist intervention resulted in greater physical function improvements compared to an enhanced usual care (EUC) intervention.⁶ In this parent trial, participants received home health interventions by trained physical therapists from partner agencies. Both groups experienced clinically meaningful improvements, but there were no differences observed between groups. However, the authors could not conclude if the PMC intervention was superior to actual usual care practices because the EUC group did not reflect true real world home health care. Usual care refers to patient care in which the health care provider is responsible for determining care and is independent of a research team.⁷  EUC refers to usual care that is “systematically improved by the research protocol to overcome ethical or methodological problems that would accompany ordinary usual care.”⁷ As a usual care group is further enhanced it becomes less representative of true usual care (TUC).^7–9

In the parent trial, the EUC comparison group was termed enhanced due to the delivery of standardized care that matched the PMC group in frequency, duration, and exercise domain. For instance, the EUC group was prescribed 12 home health visits over 60 days which is substantially more than patients typically receive in real world home health care (approximately three visits per 30 day period).¹⁰ Using the EUC comparison group allowed the researchers to discern whether specific PMC intervention components (eg, exercise intensity) impacted patient outcomes. However, it did not provide evidence as to whether the PMC intervention was superior to real world home health care. Due to the differences in the EUC group and real-world care, including standardization of care and number of home health physical therapist visits, the study team added a third, non-randomized, group termed TUC in August 2018. The study team felt the addition of the TUC group would provide a helpful comparison with the anticipation of the Patient Driven Groupings Model (PDGM), which was expected to further reduce the number of physical therapist visits in real world home health care.

Therefore, the purpose of this study was to compare a non-randomized TUC group, representing real world home health physical therapist care, to the standardized EUC and PMC groups from the parent randomized clinical trial. We compared the functional recovery of participants in the TUC group separately against the EUC and PMC groups over a 60-day episode of home health physical therapist care following discharge from a hospital or skilled nursing facility. We hypothesized that the participants within the EUC and PMC groups would experience greater improvements in physical function outcomes than those in the TUC group.

METHODS

Study Design

The data for this analysis are from a randomized controlled clinical trial in older adults who were referred to home health following a recent hospitalization. The trial was registered at clinicaltrials.gov on September 19, 2016 (https://clinicaltrials.gov/ct2/show/NCT02905370) and the study protocol was published.¹¹ The current study compares the recovery of a TUC group to the EUC and PMC intervention cohorts from the parent randomized controlled trial. All components of this study were approved by the University of Colorado Institutional Review Board (COMIRB 15–2125).

Participants

All participants were patients referred to home health physical therapy in the Denver, Colorado metropolitan area after acute hospitalization (eg, recent stay at hospital, skilled nursing facility). Patients were eligible to participate if they were ≥65 years old and had at least three comorbid conditions. Participants were excluded if they were unable to walk 10 ft without human assistance, with or without an assistive device, at time of discharge from a hospital, skilled nursing facility, or acute rehabilitation unit with a gait speed between 0.3 m/s and 1.0 m/s. Additional exclusion criteria included the presence of any factors that would prevent full participation in high-intensity resistance training or ability to complete the primary outcome measure. Predetermined factors included acute lower extremity fracture with weight-bearing restriction, recent joint replacement surgery, lower extremity amputation, active cancer treatment wherein high-intensity exercise is contraindicated, pulmonary embolus within 6 weeks of home health admission, stroke within 1 year of home health admission, progressive neurogenerative disease, hospice care referral, and use of illegal substances. Additionally, patients were initially excluded if they scored <20 on the St. Louis University Mental Status (SLUMS) exam. The study team removed this exclusion criteria in August of 2018 for all three study groups secondary to the high prevalence of impaired cognition in the home health population. Following the removal of exclusion by SLUMS cutoff, cognitive exclusion was based on capacity to safely participate in high-intensity exercise, as determined by a structured evaluation by study team members in consultation with the treating teams. Prior to consent, trained research assistants conducted chart reviews and consulted with physicians, rehabilitation practitioners, and case managers to ensure candidate participants were appropriate to participate in the study.

Recruitment and Randomization

Participants were recruited from hospitals and entered the clinical trial after providing written consent directly following acute hospitalization or the resultant institutional post-acute care episode (ie, skilled nursing facility or inpatient rehabilitation hospital stay). In the parent trial, after performing the trial baseline assessment, eligible participants were randomized to the PMC or EUC group using a computer-generated algorithm. Individuals who met the trial’s eligibility criteria but could not participate in the parent trial due to logistical barriers were recruited to the TUC group and enrolled following confirmation of eligibility during the baseline assessment. Specific logistical barriers that prevented assignment into the EUC or PMC groups include residence outside of treatment coverage area of the parent trial, a participant preference for a non-partnered home health agency, pre-existing orders with a non-partnered home health agency, and participant insurance not covering a partnered home health agency. Randomized participants were blinded to group assignment, but because of the nature of the clinical trial, physical therapists were not blinded to the group assignment after trial randomization. Physical therapists were trained by members of the study team to deliver either PMC or EUC interventions and were blinded to the alternative. Two study staff physical therapists were trained to provide both interventions for gap coverage to allow for continuity of care. Further, home health physical therapists treating TUC participants did not receive any trial information (Figure 1).

Figure 1

CONSORT Flow Diagram. EUC = enhanced usual care; PMC = progressive, high-intensity, multi-component intervention; TUC = true usual care.

Interventions

In the parent trial, participants received 8 home health physical therapist visits (two visits/week) during the first 30 days of the intervention period followed by four weekly visits over the last 30 days of the 60-day intervention period (12 total visits). Physical therapist visits consisted of three primary components: strengthening exercises, ADL training, and gait training. Participants in EUC group performed four exercises without external load for one set of 10 repetitions and increased up to seven exercises per patient tolerance over the 8 weeks. ADL and gait training focused on safety. Participants within the EUC group also received a home exercise program containing two exercises from their physical therapist visits with the goal of completing 10 repetitions daily. Participants in the PMC group received the same components (ie, strengthening, ADL training, gait training) as the EUC group, but the intensity of these exercises differed between groups. For instance, participants in PMC group performed three exercises at an intensity of an eight-repetition maximum for three sets of eight repetitions. ADL and gait training were progressively made more difficult through environmental and task modification. Greater details on the EUC and PMC group interventions are discussed in our prior protocol and primary trial manuscripts.^6,11 Physical therapists delivering the EUC and PMC interventions were trained by members of the research team to ensure delivery of standardized care.

Participants in the TUC group received home health services as determined by their agency, physician orders, and treating clinician. Specific details of the interventions delivered were not available to the study team. However, agencies were contacted after all home health services were complete to request records for number of visits by discipline and episode of care length.

Outcome Assessors

Outcome assessors (clinically trained physical therapist or physical therapist assistant) were blinded to group assignment for the parent trial. The outcome assessors for the TUC group were identical to those assessing parent trial outcomes and were unaware of the specifics of the home health care provided for any group. However, for the TUC group, outcome assessors were not blinded due to the differing frequency of outcome assessments compared to the parent trial. All outcome testing was performed within participants’ homes. Assessments were standardized and reliability testing was performed every 6 months between outcome assessors to ensure consistency and reduce the potential for bias. Outcome assessors were identical to those assessing parent trial outcomes and were unaware of the specifics of home health care provided for any group.

Outcomes

The primary study outcome of the parent trial was the Short Physical Performance Battery (SPPB), a commonly used measure of global lower extremity function. The SPPB consists of walking speed, chair stands, and balance and is a strong predictor of disability, institutionalization, and mortality in older adults.^12,13 The SPPB was collected at baseline (within 72 h of hospital discharge) and 60 days following baseline collection.

Additional (secondary) outcomes were collected at baseline and 60-days post hospital discharge. Secondary outcomes collected include usual 4-m walking speed (SPPB subcomponent),¹⁴ fast 4-m walking speed (4 MW fast),¹⁵ modified Physical Performance Test (mPPT),¹⁶ grip strength,¹⁷ the Fatigue Severity Scale (FSS),¹⁸ and the Falls Efficacy Scale-International (FES-I).¹⁹

Baseline participant characteristics collected include age, sex, race, ethnicity, education level, marital status, height, weight, discharge location, and functional comorbidity index (FCI).²⁰ The FCI counts the presence/absence of comorbidities (out of a possible total of 18) that relate to physical function. The total number of physical therapist visits were examined for all groups. Additionally, the episode of care length, determined by the difference in days from the start of care to discharge, was calculated for participants in the TUC group.

Sample Size

The parent trial recruited a total of 200 participants, who were randomized to the PMC (n = 100) and the EUC group (n = 100). The sample size of the PMC and EUC groups were based on a power calculation described in the primary manuscript.⁶ Participants for the TUC group were concurrently recruited, but not randomized, during the parent clinical trial and reflected 55 participants based on the same parent trial qualifying inclusion criteria. The TUC sample size was based on the number of patients available to enroll during the study period and not via a predetermined power calculation.

Statistical Analyses

Analyses were performed using SAS v9.4 (SAS Institute; Cary, NC, USA) and assumed a two-tailed hypothesis test and significance level of 0.05. Participant demographics, number of visits, and baseline physical function were assessed and compared between groups descriptively. The primary analysis compared the differences between the TUC and EUC groups, and TUC and PMC groups in the amount of change in SPPB scores 60 days following home health admission. Differences in physical function change over the same period between the groups were accomplished via two separate linear regression models with a response variable of SPPB 60-day change and explanatory variables of group (EUC vs TUC; PMC vs TUC), inpatient facility discharge prior to home health admission (SNF vs hospital), age, and baseline SPPB score. In this model, the coefficient for the treatment group was our statistical measure for the difference between groups while controlling for discharge location, age, and baseline SPPB scores. This analysis was repeated for secondary variables (4 MW fast, mPPT, grip strength, FSS, and FES-I).

Role of the Funding Source

The funding sources had no role in data collection or analysis.

RESULTS

Between the dates of October 1, 2016 and December 4, 2021, we enrolled and randomized 200 older adults to the EUC and PMC groups (100 participants per group). An additional 55 older adults were recruited to the TUC group between the dates January 25, 2019 and February 26, 2022. At baseline, the groups appear similar with the exception that a higher proportion of participants in the TUC group were discharged home directly from the hospital (EUC = 74%, PMC = 73%, TUC = 93%) and participants in the TUC group were slightly younger (EUC = 77.6, PMC = 78.7, TUC = 76.1) (Tables 1 and 2).

Table 1

Demographics^a

Characteristic	TUC (N = 55)	EUC (N = 100)	PMC (N = 100)
	Mean (SD) or N (%)	Mean (SD) or N (%)	Mean (SD) or N (%)
Age, y	76.1 (8.0)	77.6 (7.6)	78.7 (7.9)
Sex
Male	22 (40%)	42 (42%)	42 (42%)
Female	33 (60%)	58 (58%)	58 (58%)
Race
White	40 (73%)	81 (81%)	73 (73%)
Black	8 (15%)	9 (9%)	16 (16%)
Native American	2 (4%)	4 (4%)	2 (2%)
Asian	0 (0%)	3 (3%)	1 (1%)
Multiracial/Other	5 (9%)	3 (3%)	8 (8%)
Hispanic
Yes	9 (16%)	9 (9%)	11 (11%)
No	46 (84%)	91 (91%)	89 (89%)
Education
≤12 y, no diploma	7 (13%)	8 (8%)	8 (8%)
High school diploma	10 (19%)	22 (22%)	20 (21%)
Some college	15 (28%)	27 (27%)	32 (33%)
Associate/bachelor’s	16 (30%)	25 (25%)	14 (14%)
Master’s/doctoral	6 (11%)	17 (17%)	23 (24%)
Marital status
Single	7 (13%)	15 (15%)	9 (9%)
Married/cohabitating	24 (44%)	42 (42%)	34 (34%)
Divorced/separated	7 (13%)	12 (12%)	19 (19%)
Widowed	17 (31%)	31 (31%)	38 (38%)
Height (cm)	165.9 (10.6)	166.2 (11.2)	165.8 (10.2)
Weight (kg)	77.3 (20.0)	79.1 (25.2)	76.4 (19.8)
FCIb	5.11 (2.6)	4.87 (2.3)	5.02 (2.2)
Care descriptor
Discharge from
Hospital	51 (93%)	74 (74%)	73 (73%)
Skilled nursing facility	4 (7%)	22 (22%)	26 (26%)
Acute rehab	0 (0%)	4 (4%)	1 (1%)

^a

EUC = enhanced usual care; FCI = functional comorbidity index; PMC = progressive, high-intensity, multicomponent intervention; TUC = true usual care.

^b

FCI scores range from 0 to 18, with higher scores representing a greater number of comorbidities.

Table 2

Baseline Outcomes^a

Outcome	TUC		EUC		PMC
	N	Mean (SD)	N	Mean (SD)	N	Mean (SD)
Short Physical Performance Battery scoreb	55	4.91 (2.4)	98	5.39 (2.2)	98	5.05 (2.2)
Gait speed (m/s)	55	0.46 (0.18)	98	0.47 (0.16)	99	0.45 (0.17)
Gait speed fast (m/s)	55	0.64 (0.25)	94	0.71 (0.23)	98	0.64 (0.23)
Modified Physical Performance Test scorec	52	12.9 (6.1)	94	13.0 (5.8)	95	12.4 (6.1)
Grip strength (kg)	53	19.0 (7.5)	91	21.0 (7.5)	92	19.7 (7.5)
Fatigue Severity Scale scored (sum)	54	44.4 (14.6)	96	43.1 (12.4)	100	42.2 (13.9)
Fatigue Severity Scale scored (mean)	54	4.89 (1.8)	96	4.72 (1.5)	100	4.62 (1.7)
Falls Efficacy Scale-International scoree	53	36.9 (13.2)	93	36.3 (12.6)	97	36.9 (11.9)

^a

EUC = enhanced usual care; PMC = progressive, high-intensity, multipcomponent intervention; TUC = true usual care.

^b

Short Physical Performance Battery scores range from 0 to 12. Higher scores are indicative of better performance.

^c

Modified Physical Performance Test task scores range from 0 (unable to complete) to 4 (performed quickly and easily) with a maximum test score of 28.

^d

Fatigue Severity Scale scores range from 9 (no impact) to 64 (profound impact of fatigue on activities of daily living).

^e

Falls Efficacy Scale-International scores range from 16 (not at all concerned) to 64 (very concerned about falling).

The mean episode of care length in the TUC group was 47.0 days (SD = 34.1). Participants in the TUC group attended an average of 7.8 physical therapist visits (SD = 6.9) over their entire episode of care. In comparison, participants within the EUC and PMC group attended 10.2 (SD = 3.3) and 10.1 (SD = 3.6) physical therapist visits over a 60-day period.

In the model comparing EUC and TUC groups, the EUC group improved their SPPB score by 1.44 points with a 95% CI ranging from 0.90 to 1.99, while the TUC group improved by 0.40 points with a 95% CI ranging from −0.39 to 1.19 (Table 3). In the model comparing PMC and TUC groups, the PMC group improved their SPPB score by 1.69 points with a 95% CI ranging from 1.10 to 2.27, while the TUC group improved by 0.57 points with a 95% CI ranging from −0.26 to 1.40 (Table 4). Both the EUC and PMC groups also experienced improvements over the TUC group in 60-day changes for gait speed and fast gait speed, with the EUC group additionally experiencing improvements over the TUC group in the mPPT (Tables 3 and 4). There were no differences noted in the other secondary measures of grip strength, FSS, or FES-I.

Table 3

60-Day Model Estimates Comparing EUC and TUC^a

Model Response Variable	EUC		TUC		Estimated Difference in Change (95% CI)	P
	N	Least Squares Mean Change (95% CI)	N	Least Squares Mean Change (95% CI)
Short Physical Performance Battery scoreb	83	1.44 (0.90–1.99)	48	0.40 (−0.39 to 1.19)	1.04 (0.18–1.90)	.02c
Gait speed (m/s)	83	0.15 (0.11–0.19)	47	0.07 (0.02–0.13)	0.08 (0.02–0.14)	.01c
Gait speed fast (m/s)	79	0.18 (0.13–0.23)	47	0.08 (0.006–0.16)	0.10 (0.02–0.18)	.01c
Modified Physical Performance Test scored	75	3.72 (2.39–5.06)	43	1.15 (−0.76 to 3.07)	2.57 (0.51–4.63)	.01c
Grip strength (kg)	76	1.36 (0.35–2.37)	42	1.40 (−0.06 to 2.87)	−0.04 (−1.64 to 1.55)	.96
Fatigue Severity Scale scoree (sum)	83	−5.34 (−8.13 to −2.55)	50	−1.87 (−5.79 to 2.05)	−3.47 (−7.73 to 0.78)	.11
Fatigue Severity Scale scoree (mean)	83	−0.65 (−0.98 to −0.32)	50	−0.22 (−0.69 to 0.25)	−0.43 (−0.94 to 0.08)	.10
Falls Efficacy Scale-International scoref	79	−5.34 (−7.75 to −2.94)	49	−4.42 (−7.76 to −1.09)	−0.92 (−4.57 to 2.73)	.62

^a

EUC = enhanced usual care; TUC = true usual care.

^b

Short Physical Performance Battery scores range from 0 to 12. Higher scores are indicative of better performance.

^c

Significance of P < .05.

^d

Modified Physical Performance Test task scores range from 0 (unable to complete) to 4 (performed quickly and easily) with a maximum test score of 28.

^e

Fatigue Severity Scale scores range from 9 (no impact) to 64 (profound impact of fatigue on activities of daily living).

^f

Falls Efficacy Scale-International scores range from 16 (not at all concerned) to 64 (very concerned about falling).

Table 4

60-Day Model Estimates Comparing PMC and TUC^a

Model Response Variable	PMC		TUC		Estimated Difference in Change (95% CI)	P
	N	Least Squares Mean Change (95% CI)	N	Least Squares Mean Change (95% CI)
Short Physical Performance Battery scoreb	77	1.69 (1.10–2.27)	48	0.57 (−0.26 to 1.40)	1.12 (0.23–2.00)	.01c
Gait speed (m/s)	78	0.15 (0.11–0.19)	47	0.08 (0.03–0.14)	0.07 (0.006–0.13)	.03c
Gait speed fast (m/s)	76	0.23 (0.16–0.30)	47	0.10 (0.009–0.20)	0.12 (0.02–0.23)	.02c
Modified Physical Performance Test scored	72	4.24 (3.03–5.45)	43	2.58 (0.88–4.29)	1.66 (−0.16 to 3.48)	.07
Grip strength (kg)	73	1.05 (−0.009 to 2.12)	42	0.83 (−0.69 to 2.35)	0.22 (−1.43 to 1.87)	.79
Fatigue Severity Scale scoree (sum)	80	−4.53 (−7.62 to −1.44)	50	−1.29 (−5.55 to 2.97)	−3.24 (−7.91 to 1.44)	.17
Fatigue Severity Scale scoree (mean)	80	−0.61 (−0.98 to −0.23)	50	−0.15 (−0.66 to 0.36)	−0.45 (−1.01 to 0.11)	.11
Falls Efficacy Scale-International scoref	74	−2.94 (−5.54 to −0.34)	49	−3.38 (−6.94 to 0.19)	0.44 (−3.53 to 4.40)	.83

^a

PMC = progressive, high-intensity, multipcomponent intervention; TUC = true usual care.

^b

Short Physical Performance Battery scores range from 0 to 12. Higher scores are indicative of better performance.

^c

Significance of P < .05.

^d

Modified Physical Performance Test task scores range from 0 (unable to complete) to 4 (performed quickly and easily) with a maximum test score of 28.

^e

Fatigue Severity Scale scores range from 9 (no impact) to 64 (profound impact of fatigue on activities of daily living).

^f

Falls Efficacy Scale-International scores range from 16 (not at all concerned) to 64 (very concerned about falling).

DISCUSSION

A randomized clinical trial aimed to understand whether a high-intensity, PMC intervention resulted in superior physical function than EUC in older adults receiving home health care following hospital associated deconditioning. Due to recognition from the study team that the EUC group differed from real world home health care, particularly with the introduction of PDGM, an additional non-randomized group, TUC, was added during the clinical trial. Findings from the current study revealed that the EUC and PMC groups had significantly greater improvements in physical function and walking speed when compared to the TUC group. However, it cannot be determined whether the greater improvement of the EUC and PMC groups are due to components of the interventions delivered or confounding factors associated with the addition of a non-randomized group during the clinical trial.

A major difference in the interventions received includes the number of visits and length of care. Individuals in the EUC and PMC groups participated in 10.2 and 10.1 physical therapist sessions over 60 days, respectively. In contrast, participants in the TUC group participated in 7.8 physical therapist sessions over 47 days. Considering the established relationship between physical therapist visits attended and change in function,^21,22 the higher number of visits in the EUC and PMC group compared to the TUC group potentially contributed to differences in study outcomes. It is noteworthy that the number of sessions in the TUC group exceeded what has been reported in real world home health care (approximately three visits per 30-day period of care). This difference may be due to characteristics of our sample (eg, age, health status, diagnoses) resulting in receipt of more home care.²³ Another difference between groups that may have contributed to the greater improvements in function seen within the EUC and PMC groups is the standardization of care received.^24,25 Both the EUC and PMC groups standardized care in terms of treatment type, intensity, frequency, and duration. While we were unable to assess the treatment type or intensity in the TUC group, it is likely that treatments differed across participants given the variation that exists within home health care.²⁶

The potential exists that unique aspects of the EUC and PMC interventions (eg, number of visits, standardization) contributed to greater changes in physical function. However, confounding factors associated with the addition of a third, non-randomized, group while the trial was ongoing may have introduced bias and must also be considered as potentially responsible for the differences in functional recovery observed with TUC. Most notably, there may be differences in participant characteristics, selection bias, due to the lack of randomization for the TUC group. While most measured characteristics were similar between groups (Tables 1 and 2), more participants in the TUC group were discharged from the hospital, with no participants in the TUC group being discharged from acute rehabilitation units, and participants in the TUC group were slightly younger. That said, the differences in recovery between the TUC group and EUC and PMC groups persisted while controlling for discharge location and age (Tables 3 and 4). There are also measures not captured in this study that could have influenced change in physical function. Examples include environmental characteristics, socioeconomic characteristics, and characteristics of inpatient stay. The addition of the TUC group while the clinical trial was ongoing, August 2018, also introduced potential bias associated with time. The different timing may have been especially influential within this trial as the later recruitment initiation date for the TUC group resulted in a higher percentage of participants in the TUC group being recruited after the start of the CoVID-19 pandemic (enrollment after March 2020; TUC = 87%, EUC = 39%, PMC = 40%). Another potential confounding factor is that outcome assessors were not blinded to TUC group assignment due to participants’ lower frequency of outcome assessments, which can introduce bias into outcome assessments. That said, the potential for bias was reduced as assessors were blinded to the specifics of the interventions received by all groups and were trained to assess outcomes in a standardized manner.

There are several lessons to be learned and considerations for future exercise trials from our addition of the TUC group to an ongoing clinical trial. As stated above, the addition of a non-randomized group whose recruitment began at a later timepoint may have introduced potential sources of bias (selection, time). These potential sources of bias may limit researchers’ ability to conclusively determine the cause of differences in group outcomes. Therefore, while this approach was taken due to the impending adoption of PDGM, which the authors anticipated would further differentiate the PMC and EUC groups from real world care, it is not ideal. An associated consideration is the importance of determining which type of comparison group is most appropriate and feasible for a study question. Two common comparison groups are (1) an active control group and (2) a usual care group. An active control group is typically used to understand why an intervention is effective. Within this trial, the EUC intervention, our active control group, was matched to the PMC intervention on the number and duration of visits as well as the standardization of care but differed in the intensity of the intervention delivered. If outcomes differed between these groups, then the difference would likely be due to intervention intensity. A usual care comparison group is often used if the research question includes understanding whether the proposed intervention is superior to what is currently used clinically, the intention of the added TUC group.

Prior research has discussed advantages and disadvantages of choosing an active control or usual care comparison group in pragmatic research.^7–9,27,28 The use of an active control group allows researchers to account for potential placebo effects and determine the specific treatment effect of their intervention of interest. Accounting for the placebo effect via use of an active control group can be important in exercise trials as participants’ perceptions of the exercise they are doing can impact their outcomes.²⁹ A disadvantage of using an active control is that this control group choice can increase the likelihood of a null study result, due to the greater treatment effect of the active control group relative to a usual care group. Null results can delay change in clinical practice³⁰ and are particularly disadvantageous when an intervention may be superior to real world practice but not to the active control.

In contrast, the primary advantage of using a usual care control group is the potential faster translation of evidence as researchers can determine if the proposed intervention is superior to real world care. A disadvantage of a usual care control group is that usual care varies depending on clinical site and geographic location. As such, study results may be less reliable if the usual care intervention does not broadly reflect what is being performed at the population level. An additional disadvantage is that the use of a usual care group does not allow for an understanding of why an intervention is effective.

An alternative approach is designing a clinical trial with three-arms (intervention, active control, usual care). This approach can allow researchers to determine whether an intervention is superior to what is performed clinically and why. That said, a three-arm approach is resource intensive and may require advanced statistical methodologies to adjust for multiple comparisons across groups.^8,31 Further, depending on the target population it may be difficult for researchers to recruit the necessary sample size for a three-arm clinical trial. Therefore, careful consideration is needed when determining whether a three-arm clinical trial is feasible.

Along with the aforementioned potential confounding factors associated with the addition of the TUC group, additional limitations existed within this study. First, the home health agencies and responsible health care providers solely determined the physical therapist interventions and care in the TUC group. While this closely resembles real-world practices, specifics of the intervention focus and intensity in the TUC group are unknown. Thus, the intervention type and intensity for TUC are undefined. An additional limitation is the geographic specificity of our findings. All participants in the TUC group received care in the greater Denver area. As such, the study findings may be less applicable outside of this area as usual care can vary by location. Lastly, a limitation is that comparisons with the TUC group are likely underpowered considering the sample size of the TUC group is smaller than the groups included in the parent trial, which were determined by a power calculation based on pilot data.

In summary, older adults in home health care that received a high-intensity, PMC intervention or EUC intervention with an increased number of visits and standardized care experienced greater functional improvements relative to those receiving real-world home health physical therapist care. However, it cannot be determined whether this difference is due to the differing interventional components or confounding factors associated with adding a non-randomized group to an ongoing pragmatic clinical trial. As such there is a need for future research to explore whether increasing visit number and standardizing of care improves physical function in older adults receiving home health care following hospital associated deconditioning. Additionally, these results, and the lessons learned from this clinical trial, highlight the importance of clinical trial design in relation to the selection of control groups.

ACKNOWLEDGMENTS

The authors thank Berkley Home Health Care in Denver, Colorado and the Colorado Visiting Nurse Association for their support of this study. We also wish to thank Amy Nordon-Craft, PT, DSc, Julie Stutzbach, PT, DPT, PhD, and Maegan Olivos, PT, DPT for their contributions to this work.

CRediT – CONTRIBUTOR ROLES

Alexander J. Garbin (Formal analysis [supporting], Writing—original draft [equal], Writing—review & editing [lead]), Melissa K. Tran (Formal analysis [supporting], Writing—original draft [equal], Writing—review & editing [supporting]), Jeremy Graber (Formal analysis [supporting], Writing—original draft [supporting], Writing—review & editing [supporting]), Danielle Derlein (Data curation [lead], Project administration [lead], Validation [lead]), Deborah Currier (Investigation [supporting]), Rebecca Altic (Investigation [supporting], Writing—review & editing [supporting]), Robert Will (Investigation [supporting]), Ethan Cumbler (Investigation [supporting], Methodology [supporting]), Jeri E. Forster (Data curation [supporting], Formal analysis [lead], Writing—review & editing [supporting]), Kathleen K. Mangione (Conceptualization [supporting], Investigation [supporting], Methodology [supporting], Writing—review & editing [supporting]), and Jennifer E. Stevens-Lapsley (Conceptualization [lead], Funding acquisition [lead], Investigation [lead], Methodology [lead], Writing—review & editing [supporting]).

FUNDING

This trial was funded by the National Institute on Nursing Research and the Eunice Kennedy Shriver National Institute on Child Health and Human Development (grant no. R01NR016209). BOOST Nutritional Drinks were provided via a research grant from Nestlé HealthCare Nutrition, Inc. The funding sources had no role in data collection or analysis.

ETHICS APPROVAL

All components of this study were approved by the University of Colorado Institutional Review Board (COMIRB 15–2125).

CLINICAL TRIAL REGISTRATION

The trial was registered at clinicaltrials.gov on September 19, 2016 (https://clinicaltrials.gov/ct2/show/NCT02905370) and the study protocol was published.¹¹

DISCLOSURES AND PRESENTATIONS

The authors completed the ICMJE Form for Disclosure of Potential Conflicts of Interest and reported no conflicts of interest.

Aspects of this work have been presented at: the American Physical Therapy Association Combined Sections Meeting, February 15–17, 2024, Boston, Massachusetts, USA.

DATA AVAILABILITY

Data will be made available upon request.