Functional Incremental Stepping in Place Test (F-IST) Validation (F-IST)

A Cardiorespiratory Fitness Test for Acute Illness: Validity, Reliability, and Clinical Utility of Functional Incremental Stepping-in-Place Test

The purpose of this multi-site prospective study is to assess validity of a new step test called Functional-Incremental Stepping-in-place- Test (F-IST) compared to gold-standard cardiopulmonary exercise testing (CPET) and to physical function and health perception, respectively. The investigators will also assess test-retest reliability of the F-IST. The investigators hypothesize that the F-IST will have high validity and test-retest reliability to be used in field testing environments such as the ICU.

Study Overview

• Status: Recruiting
• Conditions: Intensive Care Medicine; Acute Care Medical

Detailed Description

Acutely hospitalized patients are at risk for hospital-acquired functional decline (HAD). This decline increases the likelihood of developing physical disability after discharge, particularly in those with older age, multimorbidity, pre-existing functional impairment and life support exposures (i.e. mechanical ventilation). Identifying patients at increased risk provides important prognostic data to inform planning strategies for both in-hospital and post-acute intervention.

Common physiological consequences associated with HAD are diminished skeletal muscle function and cardiorespiratory fitness (CRF). Historically, the six-minute walk test (6MWT) has been utilized as a chief outcome measure in the acute hospitalization and post-discharge phases to examine functional exercise capacity, estimate maximal capacity, and prescribe exercise intervention. The 6MWT is a submaximal field test that allows patients to self-select their walking pace and may be influenced by several factors including motivation. The internally-selected pace coupled with the lack of incremental increases in intensity can underrepresent CRF. In addition, the test requires a 30-meter straight course, which can be challenging to find in the hospital environment. Thus, to address the limitations of submaximal field tests, our team developed the Functional-Incremental Stepping-in-place Test (F-IST).

Designed to objectively examine CRF across the variety of patients encountered in clinical practice, the F-IST is an incremental, externally-paced, symptom-limited stepping-in-place test. While maintaining the graded components of gold standard cardiopulmonary exercise testing (CPET), it has high clinical utility since it requires minimal equipment (UE support allowed), minimal space (performed at bedside), and short administration time (< 10 min). Also, the incremental increase in intensity is individualized to perceived exertion and heart rate responses during test stages, which ultimately enables precise exercise prescription. Preliminary data on F-IST from the ongoing randomized controlled trial (NCT05218083) demonstrate potential for strong construct validity when compared to 6MWT (n = 9, spearman rho = 0.65, p = 0.05). However, before implementation in clinical practice, a new test requires the study of its measurement properties to assure that its selection is evidence-based.

Findings from this study will demonstrate that F-IST is a robust valid and reliable assessment of CRF that can be implemented on the frontline of acute care physical therapy. The F-IST addresses important limitations of field tests with an enhanced rigor by maintaining principles of gold-standard CPET. The F-IST will enable clinicians and researchers to provide precision exercise prescription to optimize patient function.

• Study Type: Observational
• Enrollment (Estimated): 60

Contacts and Locations

• Study Contact: Name: Research Associate Senior; Phone Number: 859-323-5438; Email: delong2@uky.edu
• Study Contact Backup: Name: Primary Investigator; Phone Number: 859-218-0596; Email: kpmaye2@uky.edu

Study Locations

• United States
  • Florida
    • Boca Raton, Florida, United States, 33431
      • Recruiting
      • Florida Atlantic University
      • Contact: Principal Investigator; Phone Number: (561) 297-2938; Email: aartese@fau.edu
      • Principal Investigator: Ashley Artese, PhD
  • North Carolina
    • Durham, North Carolina, United States, 27708
      • Recruiting
      • Duke University
      • Contact: Principal Investigator; Phone Number: 919-681-3595; Email: amy.pastva@duke.edu
      • Principal Investigator: Amy Pastva, PT, MA, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

This project may include adults aged 18 and older without regard to sex, race, or ethnicity. Exclusions will include pregnancy and vulnerable groups such as children, prisoners, adults with impaired consent capacity or are non-English speaking. All participation must be on a voluntary basis.

Description

Inclusion Criteria:

-Currently able to walk with or without a walking aid, such as a cane or walker or rollator

Exclusion Criteria:

Pregnancy

specifically related to cardiopulmonary testing

• A recent significant change in resting ECG
• Unstable angina
• Uncontrolled cardiac dysrhythmias causing symptoms or hemodynamic compromise
• Symptomatic severe aortic stenosis
• Uncontrolled symptomatic heart failure
• Acute pulmonary embolus or pulmonary infarction
• Acute myocarditis or pericarditis
• Suspected or known dissecting aneurysm
• Acute systemic infection accompanied by fever, body aches, or swollen lymph glands
• Left Main Coronary Stenosis
• Moderate stenotic valvular heart disease
• Electrolyte abnormalities
• Severe arterial hypertension (>200 systolic, >110 diastolic) at rest
• Tachydysrhythmia or bradydysrhythmia
• Hypertrophic cardiomyopathy and other forms of outflow tract obstruction
• Neuromuscular, musculoskeletal, or rheumatic disorders that are exacerbated by exercise
• High degree AV block
• Ventricular aneurysm
• Uncontrolled metabolic disease (diabetes, thyrotoxicosis, or myxedema)
• Chronic infectious disease (hepatitis, AIDS, mono)
• Mental or physical impairment leading to inability to exercise adequately

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort
Healthy; Community-dwelling older adults (≥60 years) with no recent hospitalization
ICU Survivor; Patients who survived ICU admission for ARF or sepsis in the last year
Chronic Pulmonary Disease; Community-dwelling adults with diagnosis of COPD, ILD, or PF

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Modified Bruce Treadmill VO2 Peak	Peak oxygen consumption during the modified Bruce cardiorespiratory test using a PARVO metabolic cart	Upon enrollment at baseline (day 0-7)
F-IST VO2 Peak	Peak oxygen consumption during the F-IST cardiorespiratory test using a PARVO metabolic cart	Upon enrollment at baseline (day 0-7)
F-IST VO2 Peak Reliability	Peak oxygen consumption during the F-IST cardiorespiratory test using a PARVO metabolic cart	Approximately 1-2 weeks following baseline (day 14-21)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
6MWT distance	Six minute walking test distance in meters	Approximately 1-2 weeks following baseline (day 14-21)
4m habitual gait speed	Habitual gait speed across a 4 meter distance	Approximately 1-2 weeks following baseline (day 14-21)
Sit to Stand Test (5x)	Time in seconds it takes to rise and sit from a chair 5 times	Approximately 1-2 weeks following baseline (day 14-21)
Sit to Stand Test (30 seconds)	The number of full repetitions completed to rise and sit from a chair over 30 seconds	Approximately 1-2 weeks following baseline (day 14-21)
EQ5D-5L Questionnaire	Health related quality of life scale patient reported outcome	Approximately 1-2 weeks following baseline (day 14-21)
Visual Analog Scale Questionnaire	Health related quality of life scale patient reported outcome	Approximately 1-2 weeks following baseline (day 14-21)
FACIT-fatigue Questionnaire	Patient reported outcome indicating fatigue	Approximately 1-2 weeks following baseline (day 14-21)
SF-36 Questionnaire	Patient reported outcome indicating eight different domains of health	Approximately 1-2 weeks following baseline (day 14-21)
St. George's Respiratory Questionnaire	Patient reported outcome measuring impact of overall health, daily life, and respiratory systems	Approximately 1-2 weeks following baseline (day 14-21)

Collaborators and Investigators

• Sponsor: Kirby Mayer
• Collaborators: Duke University; Florida Atlantic University

Study record dates

Study Major Dates

• Study Start (Actual): July 2, 2024
• Primary Completion (Estimated): July 2, 2026
• Study Completion (Estimated): July 2, 2026

Study Registration Dates

• First Submitted: February 14, 2025
• First Submitted That Met QC Criteria: February 24, 2025
• First Posted (Actual): February 28, 2025

Study Record Updates

• Last Update Posted (Actual): March 17, 2026
• Last Update Submitted That Met QC Criteria: March 16, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: validity; physical function; reliability; Cardio respiratory fitness; incremental step test; graded exercise testing
• Other Study ID Numbers: 86390; 1000400362 (Other Grant/Funding Number: Foundation for Physical Therapy)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The dissemination plan emphasizes transparency of the study, and as a study team, the investigators are committed to sharing de-identified data for external researchers.
• IPD Sharing Time Frame: IPD will be available at the time of manuscript acceptance and publishing. A published manuscript is planned for late 2026.
• IPD Sharing Access Criteria: Any external researcher will be able to access de-identified, non, PHI, individual participant data as part of the journal's supplementary information.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No