Free Asthma Screening Test

Abstract

The Free Running Asthma Screening Test (FRAST) is a straightforward, outdoor performance test designed to screen for airway hyperresponsiveness related to physical activity. The procedure involves measuring the patient’s peak expiratory flow (PEF) both prior to and repeatedly following a period of free running.

A significant decline in PEF—defined as a reduction exceeding 15% from the baseline value—is utilized as a clinical indicator suggesting the presence of exercise-induced asthma (EIA) or exercise-induced bronchoconstriction (EIB). The test is noted for its ease of administration and its relevance to real-world physical activity.

Keywords

FRAST, Peak flow, Exercise-induced asthma, Asthma screening, Performance assessment, Children, Respiratory function, Bronchoconstriction

Authors

Jones RS, Buston MH, Wharton MJ

Purpose

The primary purpose of the FRAST is to provide a rapid, non-laboratory-based screening tool for identifying individuals, particularly children, who may be suffering from exercise-induced bronchoconstriction (EIB) or exercise-induced asthma (EIA). It offers a practical alternative to standardized laboratory exercise challenges by utilizing a free-running format that mimics typical physical activity.

The test is specifically designed to assess immediate changes in respiratory function following strenuous physical activity. By quantifying the percentage drop in peak flow measurements, the FRAST helps healthcare providers determine the need for further diagnostic testing or the initiation of appropriate prophylactic treatment.

Construct

The FRAST measures the physiological construct of Airway Responsiveness to Exercise. This construct refers to the degree to which the airways narrow (bronchoconstriction) in response to physical exertion. In individuals with asthma, exercise, particularly in cold or dry air, can trigger this narrowing, resulting in measurable declines in airflow capacity.

The core mechanism assessed is the dynamic relationship between mobility/physical activity and immediate respiratory function, focusing specifically on the resulting changes in peak expiratory flow rate, which reflects the caliber of the large airways. This makes the FRAST a specialized performance test within the domain of respiratory physiology.

Validity

While detailed psychometric validation data for the original 1962 version of the FRAST is often sought in contemporary literature, the test relies fundamentally on its criterion validity against established clinical standards for diagnosing EIA, such as standardized laboratory exercise tests or methacholine challenges. The threshold of a greater than 15% reduction in peak flow post-exercise serves as the diagnostic criterion.

The ecological validity of the FRAST is considered high, as the “free running” nature simulates real-world physical exertion more closely than controlled treadmill or cycling tests, making the resulting bronchoconstriction potentially more representative of daily life symptoms experienced by children.

Reliability

The reliability of the FRAST depends heavily on standardized administration and measurement accuracy. Inter-rater reliability is generally high, as the key measurement—peak expiratory flow (PEF)—is conducted using a standardized measuring device (peak flow meter), minimizing subjective interpretation.

Test-retest reliability for performance-based screening tools like the FRAST requires consistency in the exercise load, duration, and environmental conditions (temperature and humidity). Variations in these factors can significantly impact the airway response, potentially affecting the reliability of repeated positive or negative results over time.

Factor Analysis

The Free Running Asthma Screening Test is a physiological performance test that yields a single, calculated metric (percentage drop in PEF). As such, it does not involve multiple items designed to measure latent psychological constructs.

Therefore, Factor Analysis is not applicable to the FRAST methodology, as this statistical technique is typically reserved for multi-item questionnaires or scales used to explore underlying dimensional structures.

Instrument

• Test Type: Performance test / Physiological screening tool

• Format: Observational and objective measurement (using a peak flow meter) following an outdoor exercise challenge.

• Language Available: The procedure itself is non-verbal, but standardized instructions are required (typically English, given the authors).

• Population Group: Clinical and general populations requiring screening for airway hyperresponsiveness.

• Age Group: Primarily Children (pediatric population), though the methodology can be adapted for adolescents and adults.

• Population Details: Individuals engaged in physical activities, particularly those reporting symptoms suggestive of exercise-induced asthma.

• Test Methodology: The process involves three key steps: 1) Baseline peak flow measurement. 2) Unstructured, sustained physical exertion (free running) outdoors. 3) Repeated post-exercise measurements of peak flow at timed intervals. A positive result is indicated by a post-exercise reduction in PEF greater than 15% from the baseline value.

Keywords

EIA diagnosis, Respiratory screening, Pediatric asthma, Jones RS, Buston MH, Wharton MJ, Airway hyperresponsiveness, Outdoor exercise test

Authors

Author ORCID Identifier: Information not available in the source documentation.

Affiliation Email addresses: Information not available in the source documentation.

Correspondence Address: Correspondence should be directed to the institution associated with the original publication (1962).

Permissions & Fee and Test Year

The Free Running Asthma Screening Test was first documented in 1962 by Jones, Buston, and Wharton. Given the age and nature of this physiological screening protocol, the methodology is generally considered to be in the public domain for clinical and research application, though specific scoring forms or instruction manuals may be proprietary or require citation.

The original explanatory document (Toelichtingsformulier) for the instrument can be accessed here: https://scales.arabpsychology.com/wp-content/uploads/instrumenten/FRAST-meetinstr.pdf (PDF).

Reference’s

• Jones RS, Buston MH, Wharton MJ. (1962). A simple exercise test for the diagnosis of asthma in children. Archives of Disease in Childhood, 37(193), 209-213.

• Documentation regarding the FRAST methodology is available. The original PDF can be downloaded here: https://scales.arabpsychology.com/wp-content/uploads/instrumenten/FRAST-meetinstr.pdf

Items of the Free Running Asthma Screening Test

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

The Free Running Asthma Screening Test is a performance-based physiological challenge rather than a traditional item-based questionnaire. Therefore, there are no discrete verbal or written items associated with the scale. The components of the test involve a structured procedure and objective measurements:

1. Measurement of baseline Peak Expiratory Flow (PEF).

2. Execution of the Free Running Exercise Challenge (typically 6–8 minutes of strenuous outdoor activity).

3. Post-exercise serial measurement of PEF at specified intervals (e.g., 1, 3, 5, 10, and 15 minutes post-exercise).

4. Calculation of the maximum percentage drop in PEF relative to baseline.