How to calculate and what it means


Chronic Obstructive Pulmonary Disease (COPD) refers to a group of progressive lung conditions that affect the functioning of the lungs, causing breathing difficulties. The COPD Assessment Test (CAT) is a questionnaire that measures how much COPD affects a person’s life. A CAT score can help guide treatment plans.

COPD is an umbrella term for irreversible lung conditions that cause breathing difficulties and can be life-threatening. Many cases of COPD are due to smoking or exposure to other chemicals that affect the lungs. Although there is currently no cure for COPD, treatments can help people manage symptoms.

Doctors can use different methods to understand how COPD is affecting a person and ensure that they receive appropriate treatment. One tool they can use is the CAT, which aims to assess the health status of people with COPD to help minimize disease burden and manage symptoms.

In this article, we discuss what CAT is, how to calculate the score, and how to interpret the results.

The CAT is a questionnaire that people who have been diagnosed with COPD complete to assess their health status. Healthcare professionals use the results to understand the impact of COPD on an individual’s daily life and track its progress over time. The CAT is a valuable communication tool between the person with COPD and their healthcare team.

The questionnaire consists of eight simple statements, which people answer using a numerical scale. For each statement, the person with COPD chooses the number between 0 and 5 that reflects their answer. A zero indicates no effect on quality of life, while a 5 suggests a very significant effect.

A person can complete the test online or on paper. A healthcare professional will review and discuss the results with the person and may suggest changes to their treatment plan.

CAT does not replace treatment. It’s a tool people can use to help improve COPD management and ensure they get the most out of treatment.

Different versions of the questionnaire are available online, including translations into different languages. The CAT Governing Council regulates the use of CAT and provides the original version. However, people can also use other online versions to calculate their score.

Because COPD causes breathing difficulties, the CAT questionnaire focuses on how the lungs work and how the symptoms affect a person’s overall health.

The eight sections cover:

  • cough frequency
  • amount of phlegm in the chest
  • tightness in the chest
  • shortness of breath when climbing a hill or stairs
  • how limited the person’s activity is
  • how confident they leave their homes
  • sleep
  • energy levels

Each section of the test provides statements at each end of the spectrum. People with COPD rate their health in each domain from 0 to 5. For example, they would select zero for “my chest is not tight at all” and 5 for “my chest is very tight.” If someone’s chest seems tight only occasionally, they can choose the most relevant value between the two.

Combining these scores will give a total between zero and 40. A higher score denotes a more severe impact of COPD on a person’s life.

The total score gives medical professionals an idea of ​​the severity of COPD symptoms and how the disease affects the individual’s daily life. A doctor may have the person take CAT every 2 to 3 months so they can monitor the progression of COPD symptoms and the effectiveness of treatment. This monitoring can help guide future treatment plans.

The scores can provide healthcare professionals with an assessment of clinical impact. Clinical impact is the effect that COPD symptoms have on an individual’s health and daily life. A doctor may use the following ranges to classify severity:

  • 0–9 (low): The guidelines suggest that a healthy person who does not smoke should score 5 or less. A person with a low score may not experience many severe COPD symptoms. They may cough frequently and be short of breath during activity, but they can generally function well most days.
  • 11–20 (medium): An average score indicates that COPD significantly affects a person’s life. Some days may be good, but the person will often feel short of breath and need to move slowly. They cough up phlegm almost every day and often have chest tightness when they wake up.
  • 21–30 (high): A person with a high score may feel like COPD is preventing them from functioning well every day. They will likely be tired from coughing, have chest problems that can disrupt their sleep, and be constantly short of breath.
  • 31–40 (very high): A very high score indicates high COPD severity. People with these scores are unlikely to have a day when they feel healthy, because their COPD symptoms may prevent them from leaving their homes or caring for themselves effectively.

CAT results can help healthcare professionals understand how COPD is affecting a person’s life and make recommendations for their treatment plan. The treatment plan will vary depending on the person’s current health, lifestyle, and medications.

A doctor may review the following management considerations, based on a person’s CAT score:

Rating from 0 to 10 (low)

Considerations may include:

  • review current medications
  • advise a person to quit smoking
  • recommend reducing exposure to any factors that aggravate COPD symptoms
  • recommend that a person receive flu and COVID-19 vaccines
  • prescribe long-acting muscarinic antagonists (LAMAs) or rescue inhalers

Score 11–20 (average)

Considerations may include:

  • all those in orientation for people with low scores
  • prescribe inhaled corticosteroids (ICS) and long-acting beta-2 agonists (LABAs)
  • refer a person for pulmonary rehabilitation and possible lung transplant evaluation

Score 21–40 (high and very high)

Considerations may include:

  • all those in orientation for people with average scores
  • prescribe a triple therapy combining CSI, LABA and LAMA
  • prescribe supplemental oxygen

Research on the CAT suggests that it is a reliable and consistent method that can help measure how the condition affects a person’s health and daily life.

Global healthcare company GlaxoSmithKline developed the CAT in 2009 as a short and simple method for assessing the impact of COPD. Although other tools, such as the St George’s Respiratory Questionnaire (SGRQ), Clinical COPD Questionnaire (CCQ), and Chronic Respiratory Disease Questionnaire (CRQ) are available, they are more complex and time-consuming to use.

The CAT can produce results that correlate with these other more complex questionnaires. CAT does not replace the use of these other tools, but it can provide a quick and reliable way to generate similar results.

A 2014 systematic review supports the reliability and validity of the CAT. A study 2021 also notes that the CAT score can help capture the overall impact of COPD. Additionally, a 2020 study concludes that the CAT can be a useful and practical tool in primary care settings to assess the severity of COPD.

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines classify the CAT as a comprehensive assessment of COPD symptoms and a useful tool for measuring a person’s health status.

The COPD Assessment Test is a tool that healthcare professionals can use to help assess the health of someone with COPD. This is a quick and simple numerical scale questionnaire comprising eight items. The total score out of 40 gives doctors a reliable indication of how severe the impact of COPD is on a person’s life.

The test can be a useful communication tool between a person with COPD and their doctor. A person can take the test at their own pace, and a doctor will review the results to make sure the person is getting the most out of their treatment plan.


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