Feasibility, criterion validity and retest reliability of exercise testing using the Astrand-rhyming test protocol with an adaptive ergometer in stroke patients

Abstract

Purpose: (i) to establish feasibility of the Astrand-Rhyming submaximal protocol using the adaptive ergometer in healthy participants, (ii) to test feasibility of this protocol in stroke patients, (iii) to identify clinical characteristics of stroke patients which limit testing, (iv) to establish criterion validity of V·O_{2 steady state} ergometry data against the gold standard open-circuit spirometry measure and, lastly, (v) to test–retest reliability of the data generated by the test protocol. Methods: A descriptive, cross sectional study design was implemented. Ten healthy participants (5 men, mean age 32 ± 6.6 y) and 20 chronic stroke patients (14 men, mean age 61.0 ± 11.6 y; mean months since stroke, 65.6 ± 34.4 y) took part in this study. Independent t-tests, Mann Whitney U tests and chi-square test identified characteristics of those who failed to successfully complete the protocol. Interclass correlation coefficients (ICCs) tested criterion validity and test–retest reliability. Results: No adverse events occurred. All healthy participants (100%) complied with the test protocol and estimation of V·O_2max. 90% of stroke patients completed the test, with V·O_2max estimated in 35% (7 / 20) stroke patients. Age and beta-blocker medication demonstrated statistical significance as barriers to the test protocol at p = 0.04 and p = 0.03, respectively. Criterion validity established by comparison with breath-by-breath gas analysis was excellent (ICC 0.93). Retest reliability of V·O_2max, steady-state V·O₂ and oxygen pulse had ICCs of 0.94, 0.96 and 0.97, respectively. Conclusions: The Astrand-Rhyming test protocol and MOTOmed Viva2 adaptive ergometer were feasible in healthy participants. The protocol was not feasible for V·O_2max estimation for the majority of stroke patients based on heart rate response. The adapted steady state VO2 measures used however were feasible and had strong relationship to actual VO2 consumption. Criterion validity and retest reliability of test data were excellent.

Implications for Rehabilitation

• Maximal fitness test protocols exclude disabled populations including many stroke patients.

• The Astrand Rhyming submaximal test protocol using an adaptive ergometer was a feasible tool for estimating VO_{2 max} in healthy subjects.

• The Astrand Rhyming submaximal test protocol based on heart rate response to exercise was not feasible for estimating VO_{2 max} in the majority of stroke patients despite the use of adaptive equipment.

Keywords::

• Cerebrovascular disorders
• Astrand-Rhyming protocol
• stroke
• exercise

Declaration of Interest: The authors certify that no party having a direct interest in the results of the research supporting this article has or will confer a benefit on them or on any organization with which they are associated AND they certify that all financial and material support for this research and work are clearly identified.

The authors state that they have no conflict of interest.

The study was supported by a Health Research Board Ireland Fellowship Award HSR/2007/06 and by University College Dublin Seed Funding SF109.