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Instrument Descriptions


  • The EXAcerbations of Chronic pulmonary disease Tool (EXACT) is a 14-item patient-reported outcome (PRO) daily diary used to quantify and measure exacerbations of chronic obstructive pulmonary disease (COPD).
    • This instrument provides a single, standardized approach for assessing the symptomatic manifestations of COPD exacerbations, with a development and validation history consistent with guidelines proposed by the FDA, EMA, and well-known measurement principles.
  • Exacerbations are events characterized by an acute, sustained worsening in the patient’s COPD beyond normal day-to-day variability, including an increase in respiratory symptoms such as dyspnea, cough, and sputum production that may require a change in treatment.
    • The EXACT is designed to standardize the assessment of the patient’s condition in order to capture this dynamic process.
  • EXACT scores complement and extend information provided by traditional health care resource utilization (HCRU) data by:
    • Standardizing the magnitude of symptomatic change around HCRU events (those seen in the clinic, emergency room or hospital);
    • Quantifying frequency, severity, and duration of reported and unreported, symptom-defined events.
  • The EXACT may be used in longitudinal, natural history studies, or clinical trials, including:
    • Maintenance/prevention trials testing the efficacy of therapies to modify or prevent COPD exacerbations;
    • Acute treatment trials evaluating therapies to treat exacerbations of COPD.
  • The EXACT was developed under the EXACT-PRO Initiative, a multi-year, multi-sponsor project involving experts in pulmonary medicine, instrument development, and drug development regulatory issues, dedicated to the development of a single, standardized instrument for evaluating the effects of treatment on acute exacerbations of COPD. See the summary of development methods here.
  • The EXACT has been translated into 50 languages, for use in 49 countries. See the full list of translations here.
  • To facilitate standardized use, an EXACT User Manual describing the instrument’s development, intended use, administration procedures, and scoring is provided to all licensed users.


  • The Evaluating Respiratory Symptoms (E-RS) in COPD (E-RS: COPD) scale is a derivative instrument used to measure the effect of treatment on the severity of respiratory symptoms in stable COPD.
    • The E-RS was designed to address the need for a standardized respiratory symptom diary with a development history consistent with good research practices and FDA PRO requirements. See the FDA PRO guidance here.
    • Formerly known as the EXACT-Respiratory Symptoms Scale (E-RS), it was renamed the E-RS: Evaluating Respiratory Symptoms measure. When referring specifically to its use in COPD, the proposed context of use for qualification, the full name is now “Evaluating Respiratory Symptoms in COPD (E-RS™: COPD).”
  • The E-RS utilizes the 11 respiratory symptom items contained in the 14-item EXACT.
    • The RS-Total score represents respiratory symptom severity, overall.
    • Three subscales can be used to assess breathlessness (RS-Breathlessness), cough and sputum (RS-Cough and Sputum), and chest-related symptoms (RS-Chest Symptoms).
  • Subject and investigator burden is minimized by providing two validated uses for 1 diary:
    • Assessment of COPD exacerbations via EXACT Total Score;
    • Quantification of respiratory symptoms in stable COPD using RS-Total and subscale scores.
  • Because the E-RS is administered as part of the EXACT, translations of the EXACT apply. See full list of translations here.
  • To facilitate standardized use, an E-RS User Manual describing the instrument’s development, intended use, administration procedures, and scoring, is provided to all licensed users.
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