How dirty does your high-pile carpet get? These are beautiful but high-maintenance carpets, so you might need a specially-made vacuum cleaner.
Most vacuums will either get stuck in the long fibers or have insufficient suction power that can’t reach deep enough to get the dirt and debris out.
In the article below, you’ll discover all their features and specifications, before moving on to some of the most important buying factors you should consider.
And if you’re in a hurry, here’s a list of our favorites:
- Our #1 Pick: Soniclean Soft Carpet Upright Vacuum Cleaner
- Versatile Option: Eureka PowerSpeed Bagless Upright Vacuum Cleaner, Lite
- Best Choice for Households with Pets: BISSELL Cleanview Swivel Rewind Pet Upright Bagless Vacuum Cleaner
- Whole-Machine HEPA Filtration: Dyson Ball Animal Upright Vacuum
- Powerful Suction: Hoover WindTunnel 3 Max Performance UH72625
Top-Notch Vacuums for High Pile Carpet Reviewed
Soniclean Soft Carpet Upright Vacuum Cleaner
(Our #1 Pick)
This heavy-duty Soniclean is among the best vacuum cleaners for large areas. It’s a big upright vacuum cleaner with powerful suction and an adjustable vent system that helps with maneuverability. This one is unlikely to get stuck or require lots of elbow grease to push around on a plush carpet.
It features a soft nylon brush roll with effective yet gentle bristles. The bristles will lift-away up even the most persistent dirt and dust without damaging the soft carpet.
Its large front wheels help you push it across your high and low-pile carpet. On top of that, it has a relatively lightweight design, weighing only around 10 pounds.
Soniclean emits 200 sonic vibrations per second, which helps loosen the embedded dirt and dust that’s been building up in your carpet. Plus, the powerful suction delivered by its Paramagnetic motor picks all the contaminants immediately.

Specifications
- Filtration: Hospital-grade HEPA
- Cord Length: 35 min
- Weight: 10.5 lbs
Pros
- Lightweight design
- Strong suction
- Adjustable vent system
Cons
- Loud operation
Eureka PowerSpeed Bagless Upright Vacuum Cleaner, Lite
(Versatile Option)
Eureka PowerSpeed is among the best uprights from the brand. It’s a powerful vacuum cleaner with a dynamic motor and a powerful brush roll that can lift away even the heaviest and most stubborn debris, dirt, and dust. It has a 12.6” cleaning path that helps you clean more on an initial pass.
It weighs 10 pounds, so it’s quite easy to maneuver with, although it looks a bit bulky. Plus, it has five height adjustment settings that help you adapt the vacuum to the particular surface you’re deep-cleaning.
It’s a bagless cleaner, featuring a 4.1L dust cup that’s easy to empty. On top of that, PowerSpeed comes with a 7” crevice tool, upholstery nozzle, a dust brush, and a stretch hose that extends its reach. It’s a corded vacuum cleaner with a 25′ long power cord.
Pros
- Suitable for different types of floors
- Quick-release handle
- Lightweight design
Cons
- Not the best for tight spaces
BISSELL Cleanview Swivel Rewind Pet Upright Bagless Vacuum Cleaner
(Best Choice for Households with Pets)
Bissell Cleanview is a bagless upright vacuum cleaner with a triple-action brush roll. It’s among the best vacuum cleaners for pet owners since it features the brand’s scatter-free technology for maximized pet hair pickup even on high-pile carpets.
It’s a corded vacuum cleaner, featuring a 27′ cord with automatic rewinding for easier storage. It comes with specialized pet tools, including Pet Turbo Eraser and Pet Hair Corner Tool.
This is among the best vacuum cleaners to use for edge-to-edge cleaning since it can get close to corners and edges. Plus, its specialized tools help to extract more dirt on an initial pass.
The vacuum cleaner features swivel steering that helps with maneuverability even though it weighs 16 pounds. It’s easy to push across different surfaces and to clean under furniture.
Pros
- Easy to empty
- Wide cleaner head
- Great for pet hair
Cons
- Relatively small dust cup (1L)
Dyson Ball Animal Upright Vacuum
(Whole-Machine HEPA Filtration System)
Dyson Ball Animal is probably one of the most popular upright vacuums on the market. It features the brand’s Ball technology that’s only featured in another few uprights by Dyson. It was originally designed to help with maneuverability because this vacuum cleaner weighs nearly 18 pounds.
It has a self-adjusting cleaner head that allows the vacuum cleaner to transition from one floor surface to another. This makes it great for combined flooring since you can easily go from a high pile carpet to a bare floor.
It comes with a Tangle Free Turbine Tool, a combination tool, and a multi-angle tool for a more versatile performance. On top of that, Dyson Ball Animal has an instant-release wand to make cleaning hard-to-reach areas easy.
This is a heavy-duty bagless upright, featuring an extra-large dust cup that’s transparent and easy to empty.

Specifications
- Filtration: Whole-machine HEPA
- Weight: 17 lbs
- Cord Length: 35 ft
Pros
- HEPA filter
- Self-adjusting cleaner head
- Radial Root Cyclone Technology
Cons
- It struggles to stand on its own
Hoover WindTunnel 3 Max Performance UH72625
(Powerful Suction)
If you’re looking for a powerful and easy-to-use vacuum cleaner, you might want to consider this one. Hoover is among the best in the industry, and its WindTunnel 3 didn’t disappoint.
It’s a bagless upright with an extra-large dust cup that’s easy to empty. Another thing worth noting is the WindTunnel 3 technology featuring three channels of suction for more efficient airflow.
Combined with the extra-wide nozzle, the technology provides enough suction to lift-away even the most embedded dirt. Its 13 powerful cyclones enhance the suction, ensuring that it remains at a certain level at all times.
The vacuum cleaner features a HEPA filter that helps keep all the dirty contents within the canister. It’s especially suitable for allergy-prone people and pet owners. Plus, this one comes with a crevice and pivoting dust tool, and a Pet Turbo tool.
Pros
- 30′ power cord
- 15′ extension hose
- Seven height adjustment settings
Cons
- No swivel steering
Oreck Swivel Axis Upright Vacuum Cleaner
If you’re a fan of uprights but don’t like bagless vacuums, you might want to try the Oreck Swivel Axis. It’s a bagged upright that works with a large HEPA inner bag.
It has swivel steering, so it’s quite easy to work around furniture legs and other obstacles. Its ball joint and pivot connection allows easy steering regardless of the floor surface.
It’s important to note that this one has two brush roll speeds. This is especially critical if you have other floors combined with high pile carpets. High speed is usually the best for a high pile carpet while low speed is more suitable for area rugs, low-pile rugs, and hard floors.
It weighs some 10 pounds and has a 30′ long power cord, so you can easily cover larger areas at once.

Specifications
- Filtration: HEPA & AirClean filter
- Weight: 11 lbs
- Cord Length: 30 ft
Pros
- 13” wide cleaning path
- Headlights on the base
- HEPA + AirClean filtration
Cons
- The bag starts to smell when used for too long
BISSELL Cleanview Rewind Pet Deluxe Upright Vacuum Cleaner 24899
Bissell Cleanview is a pet vacuum cleaner for a high pile carpet. It’s a bagless cleaner with a 1L dirt cup that’s easy to empty and clean. It’s transparent so that you can see when it’s time to empty it.
Its triple-action brush roll loosens the embedded dust before its powerful suction picks it up. It’s suitable for different floor surfaces, although the brush roll might not be the best for hardwood.
Cleanview has a 27′ long power cord with automatic rewind, which helps you store the vacuum cleaner away neatly. On top of that, its on-board tools include the Pet TurboEraser tool, dust brush, pet hair corner tool, crevice nozzle, and an extension wand.
It’s among the best vacuum cleaners for edge-to-edge cleaning, which is especially great for pet owners since pet hair tends to build up in corners.
Pros
- Scatter-free for hard floors
- Multi-cyclonic suction
- Easy-to-clean filters
Cons
- Heavy (nearly 20 pounds)
Eureka NEU562A FloorRover Upright Vacuum Cleaner
FloorRover might look a bit bulky and unusual, but it’s actually quite easy to use and maneuver with. It’s somewhat heavy, weighing nearly 20 pounds, but swivel steering and its large wheels help with ease help a lot.
Among the best things about this vacuum cleaner is the Easy-Glide big wheel technology. It helps the cleaner to glide across different surfaces, including high pile carpets. Plus, it has a 30′ long power cord providing an extended reach.
It operates with a multi-stage cyclonic system that maintains its suction at peak regardless of how full the cup is. Also, it comes with a 16” crevice tool, 2-in-1 upholstery tool, and a pet turbo brush that adds a bit to its versatility, allowing you to lift away whatever is hiding in the nooks and crannies of your home.
Pros
- Easy-to-empty dust bin
- Washable filters
- Suction release valve
Cons
- It tends to tip over
Maytag M1200 Upright Vacuum Cleaner
This Maytag is a bit heavy, weighing some 21 pounds. However, it has six height adjustment settings that make it easy to adjust it according to the surface you’re cleaning. Lift the cleaner head up when deep-cleaning high pile carpet to push the vacuum cleaner without as much effort.
M1200 uses the brand’s Dual-Intake system of two motors. This provides stronger suction usually needed for a high pile carpet, especially if you have pets.
The vacuum cleaner is equipped with a lifetime belt and a full-bag indicator. This way, you know when it’s time to replace the self-sealing HEPA filter bag.
Also, it has LED lights, a 35′ long power cable, and a set of on-board accessories. It comes with an extension hose and a telescopic wand, providing some 17′ cleaning radius suitable for hard-to-reach areas.

Specifications
- Filtration: Self-sealing HEPA filter bag
- Weight: 21.6 lbs
- Cord Length: 35 ft
Pros
- Odor-absorbing charcoal filters
- Lifetime belt
- 35′ long cable
Cons
- Heavy
Miele Dynamic U1 Powerline Upright Bagged Vacuum Cleaner
Miele Dynamic U1 Powerline looks like one of those old-school uprights. It comes with a large filter bag with a capacity of 6 liters, which means you won’t have to replace it as frequently.
The vacuum uses two motors – one that provides suction and the other that powers the brush roll. This allows you to turn the brush off to stop it from rolling when cleaning hard floors.
Another great thing about this upright is its adjustable suction. It has a 4-setting Rotary Dial that allows you to set up its suction power according to the surface you’re deep-cleaning.
The vacuum cleaner features a HEPA Air Clean filter along with an AirClean Sealed System filter. It also features Swivel Neck technology that helps with maneuverability. It comes with a 39.5′ power cable and a 12′ hose for some extended reach.

Specifications
- Filtration: HEPA AirClean & AirClean Sealed System filter
- Weight: 28.3 lbs
- Cord Length: 39.5 ft
Pros
- Crevice tool and a dust brush included
- LED headlights
- All-rubber wheels
Cons
- Very heavy
Kenmore Elite 81714 Pet Friendly
This bagged canister vacuum cleaner is designed to clean all kinds of surfaces. It’s one of the best vacuum cleaners for hard floors and high pile carpets in households with pets.
It comes with a Pet Powermate motorized attachment that lifts even the most stubborn dander and pet hair away from the long carpet fibers. Plus, the ultra-plush nozzle is also included, although it’s more suitable for hardwood floors.
The vacuum cleaner features manual height adjustment settings, making it easy to transition from plush carpet to bare floor with ease. It operates using the 2-motor system that provides sufficient suction power to extract even the most embedded dust, dirt, and hair from different carpet types.
It comes with an adjustable wand that extends up to 10′, adding some reach to its 26′ long power cable. Also, this one has a HEPA filter, so it’s suitable for allergy-prone people.

Specifications
- Filtration: Enhanced HEPA filter system
- Weight: 29.6 lbs
- Cord Length: 26 ft
Pros
- Crevice tool and dust brush included
- Automatic cord rewind
- Variable power
Cons
- Weighs 22 pounds
Sebo 90640AM Airbelt D4 Premium Canister Vacuum
This is another canister vacuum cleaner designed for cleaning high pile carpets as well as area rugs, low-pile rugs, and bare floors. It features a commercial-grade powerhead with enhanced steering, so it’s quite easy to maneuver around furniture.
One of the best things about it is its patented AirBelt bumper. It serves to protect the vacuum as well as your furniture in case you ever bump it into them while deep-cleaning high-pile carpets and other floor types.
It comes with a 40′ long power cable, an extension hose, and a telescoping wand that provide a total of 50′ cleaning radius. This should be enough to cover larger areas so that you don’t have to re-plug it as frequently.
The canister vacuum cleaner comes with a large 1.5-gallon filter bag that’s easy to replace when full. It features a full-bag indicator as well, which helps with overall maintenance.
Pros
- Parquet brush included
- Adjustable suction
- Large cleaning radius
Cons
- Weighs nearly 30 pounds
Miele Complete C3 Vacuum for Soft Carpet
Miele is a well-known name in the industry of canister vacuums with Miele Complete C3 being among the most popular models.
It’s a powerful canister vacuum with five height adjustment settings for deep-cleaning all carpet types and hard floors.
Miele Complete C3 comes with a Parquet Twister with soft bristles that won’t damage your hardwood floors. Plus, it has six suction power settings for when you’re deep-cleaning your high-pile carpet.
It features the brand’s AirClean System and a HEPA AirClean filter. The two lift away over 99.9% of fine dust, allergens, and pollen.
Miele Complete C3 comes with integrated accessories. It includes a dusting brush, a crevice attachment, and an upholstery tool.
One thing to keep in mind is that Miele Complete C3 weighs approximately 20 pounds. It also has automatic cord rewind for easier storage.
Pros
- Five height settings
- Automatic cord rewind
- HEPA filtration system
Cons
- It’s a bit bulky
Buying Guide
Finding an adequate vacuum for carpeted areas is relatively simple if you know what you’re looking for. If it’s your first time buying a vacuum for a high pile carpet, you should first consider a few important buying factors we discuss in the buyer’s guide below.
Filtration
Filtration is always important, but even more so if you’re struggling with allergic reactions and sensitive to dust. The HEPA filtration system is by far the best option for pet owners and everyone who suffers from allergies.
Still, other options exist as well, so you’ll probably come across AirClean and sealed-system filters. It’s up to you to choose the type of filtration system, but keep in mind the maintenance as well. In other words, some filters are washable and easy to clean, while others are replaceable.
A quality carpet vacuum cleaner can make all the difference when it comes to extracting allergens from all thin and plush carpets.
Your soft carpet attracts and holds a lot of fine dust, pet hair, dander, pollen, dust mites, and other allergens. By walking over it, you disturb the particles, sending them straight into your breathing space.
The issue is especially troubling for allergy-prone people and small children.
Luckily, one of the best vacuum cleaners for high-pile carpet types can help you. A high-pile carpet vacuum cleaner has a HEPA filtration system combined with strong suction to extract even the most embedded dust.
Cord / Cordless
Whether a vacuum cleaner has a cord or not has very little to do with how well it cleans high pile carpets. A cordless vacuum might be a bit easier to use when it comes to hard-to-reach surfaces. However, a corded one has an unlimited run time and also more powerful suction than a cordless vacuum.
Bagged / Bagless
Choosing between bagless and bagged is entirely up to you. Whether a vacuum cleaner has a bag or not doesn’t affect its performance on high pile carpets, so you can choose according to your preference.
Keep in mind that bagged models are better for allergy-prone people, while bagless ones are more eco-friendly.
Warranty
Warranty differs from brand to brand, so you’ll notice that the best vacuums come with longer-lasting deals than others. Look for a reliable warranty deal that covers damage caused by faulty materials and manufacturing.
Although some warranties last longer than others, no manufacturer covers damage caused by neglect, misuse, unauthorized repair, and normal wear and tear.
Accessories
As you probably noticed, the best vacuums come with a wide range of different accessories. In most cases, you’ll receive a crevice tool, dusting brush and an upholstery tool along with extension hoses and telescopic wands.
Also, you might want to look for some motorized tools as well.
Price Range
Some vacuum cleaners are more expensive than others, and that usually depends on more than just the brand name. Luckily, you can easily find the best vacuum for high pile carpet that matches your needs and budget. Among the best vacuums we reviewed there are quite affordable cleaners, yet efficient and easy to use.
Flooring in Your Home
While deep-cleaning a plush carpet is the trickiest, you want the vacuum cleaner to be able to clean other surfaces as well. For this, you should look for a versatile cleaner.
It should have adjustable suction as well as height adjustments so that you can easily go from thick carpet fibers to bare floors. Make sure that its wheels (if it has any) won’t tangle in the thick carpet fibers.
Weight & Height
Maneuvering a heavy vacuum is always difficult, especially when it comes to vacuuming around furniture legs and other obstacles. You should look for a vacuum with a lightweight design that’s easy to move across the surface, even with a full bag/cup.
Also, think about its height as well, especially if you’re tall because bending too much to push a heavy vacuum cleaner is tiring.
Suction Power
While suction power should be strong, too much of it could damage your carpet. Look for a vacuum cleaner that has adjustable suction, especially if you have combined floors throughout your house.
Being able to customize suction power gives you more control over how the vacuum cleaner performs on every floor type.
Venting & Brushes
Venting is a form of suction control usually used on older or more affordable vacuum cleaners. Soft, high pile carpets require a soft brush that can lift up the dirt without damaging the delicate fibers. Luckily, nearly every vacuum for high pile comes with a suitable brush roll.
Beater Bar / Brush Control
A beater brush is among the best tools to use on low to medium pile carpets. Still, it’s not meant for a high pile carpet as it can damage the fibers.
In case the vacuum cleaner of your choice has a beater brush, make sure that you can switch it off when going from a medium pile to a high pile carpet.
Wheel Design
Wheels are critical for easier maintenance, especially if the carpet vacuum cleaner of your choice is on the heavy side. However, wheels can also easily damage your carpet, so make sure that they’re gentle and made of rubber. Also, keep in mind that large wheels are better than small ones.
Upright / Canister
Choosing between an upright vacuum cleaner and a canister vacuum might seem overwhelming. However, both types of vacuums are equally as suitable for cleaning a plush carpet as long as you opt for a specialized model.
In most cases, uprights are more suitable for this type of carpet cleaning because they usually have height adjustment and suction control.
Still, a combination of different features can make both upright and canister vacuums suitable to clean a high pile carpet.
Read more: Our Upright vs. Canister Vacuum Face-Off
Carpet Placement
Have you ever thought about your carpet placement? Maybe your thick carpet is in the wrong place which is why it’s usually so dirty and difficult to clean.
Soft carpet and shag carpet types aren’t the best for high-traffic areas. If you have a shag carpet or another high-pile carpet, you might want to place it in your bedroom. If not, place it in another room that doesn’t have as much traffic.
As we said, plush carpets hold lots of dirt and dust, making it more difficult to vacuum each time. Placing them in your hallway or living room is usually a bad idea, especially if you have lots of furniture and hard-to-reach areas.
A high-pile carpet vacuum can only do so much, so make sure to place your carpet in a low-traffic area. It will require less maintenance and its fibers will stay looking plush for a longer time.
Pets
Cleaning after pets can be quite tricky, especially if you’re prone to allergies. Pet hair and dander in a shag carpet requires deep-cleaning that’s typically not suitable for this type of carpet.
For this reason, you might want to think about relocating your carpet. If that’s impossible, you should choose among the best vacuum cleaners for high-pile carpets. Consider getting one with a HEPA filtration system and at least one pet tool.
Maintenance of a high pile carpet can be challenging when trying to extract pet hair from its long fibers. This is what powerful suction and a HEPA filtration system can help you with.
Keep in mind that you’ll probably have to vacuum at least twice a week if you let your pet on a high-pile carpet. Look for a powerful vacuum with gentle tools and bristles that won’t damage its fibers.
High Pile Carpet Info & Maintenance
At this point, you probably understand why high pile carpets are as challenging to clean. Once all the dust is well-embedded in the long fibers, you have to work extra-hard to get it out. That’s exactly why regular maintenance is as critical.
Check below to discover how to maintain your high-pile carpet.
What Is Considered a High Pile Carpet?
High pile carpets are often referred to as plush because there’s minimal difference. A high pile carpet usually has long fibers that are 1/2-inch and up. Most popular high pile carpets have the length of fibers somewhere between 1/2 and 3/4 of an inch.
However, you can find even longer fibers, although those carpets are called shag carpet surfaces. These fibers aren’t only long, but they’re also very densely packed. As a result, the shag carpet is thick, soft, and pleasant to walk on. These specially woven fibers tend to attract grime, dust, and dirt that gets well-embedded within the shag carpet.
Difference Between Low and High Pile Carpet
The main difference between a low and high pile carpet is the length of the fibers. As we said, a high pile carpet has long fibers, while a low pile carpet has shorter fibers.
Low pile rugs are more suitable for allergy-prone people because they’re not as thick and dense. Dirt and allergens are easier to lift away from the shorter fibers with nearly every vacuum. On the other hand, a high pile carpet requires a more specifically made vacuum cleaner.
Although high pile carpets look more stylish, thin carpets are far easier to maintain, especially if you have pets.
Maintenance Tips
The key to keeping your carpet is clean is spot-cleaning. It’s a critical part of maintenance, so it’s important that you act fast regardless of the stain.
Get a clean towel to blot the stain dry. Press is down to absorb as much moisture as possible so that it doesn’t go as deep inside the carpet.
Make a cleaning solution of water and liquid soap and spray it on the spot. Wash it off with water and let it dry.
High Pile Carpet Vacuuming Guide
As we pointed out, keeping a high pile carpet clean is rather tricky, especially if you have toddlers or pets. Any excessive mess and stains are challenging to lift-away and remove, even more so if you don’t act immediately.
The first thing you should do is take the carpet outside, if possible. Shake out the dirt and let the carpet to sit in the sun for at least 2 hours. Use your best vacuum for high pile carpet to clean the dirt from the underside of the rug.
Vacuum the floor before you bring the carpet back in. Once you place it back, you can use a steam cleaner to give the carpet a more thorough cleaning.
You should apply a dry shampoo occasionally, following the instructions on the product packaging. From time to time, you should also consider having the carpet professionally cleaned.
FAQ
Q:
How to recognize high pile carpets?
A: You can recognize a high pile carpet even before you step on it as it always looks plush and soft. Its fibers are long and densely packed, so the surface is soft, pleasant to touch, and comfortable to walk/sit/lay on.
Q:
Are high pile carpets hard to vacuum?
A: They are a bit challenging to keep clean, but regular maintenance can make the whole process much easier. The key in simple maintenance is in using the right vacuum for a high pile that’s made specifically to tackle embedded dirt without damaging the fibers.
Q:
Is a high pile carpet suitable for asthma sufferers?
A: High pile carpets aren’t the best choice for asthma sufferers and allergy-prone people. It’s because its treads are so densely woven and long that they can keep plenty of dirt and allergens well-embedded inside.
If you do opt for a high pile carpet, make sure to have a sealed vacuum cleaner with a HEPA filter.
Q:
How to fluff high pile carpet?
A: The first thing you should do is vacuum the surface thoroughly regardless of whether you have a shag carpet or another type plush carpet.
Use a carpet rake to rejuvenate the fibers by combing them. However, be careful when using a rake because some thick carpets might be too sensitive for the tool. What you can do is start slowly to ensure that the rake isn’t pulling on its shag carpet fibers.
You can also try sprinkling some lukewarm water before going over the surface with a nylon brush to fluff the fibers.
Steam cleaning might also rejuvenate your carpet, but make sure the steam doesn’t damage it.
Q:
Can a robot vacuum clean high pile carpet?
A: Cleaning a high-pile carpet with a robot vacuum is usually a bad idea. These vacuum cleaners struggle to move across a thick carpet, often getting stuck in the long fibers.
Still, some features can help your robot move around, cleaning a high-pile carpet with ease.
The first thing you should look for is automatically adjustable suction. Look for large wheels, a HEPA filtration system, easy navigation sensors to get the job done.
Keep in mind that you’ll still need a full-size vacuum cleaner for thick carpets because robot vacuums usually can’t clean under furniture or get to hard-to-reach places, corners, and edges.
Conclusion
A high pile carpet can make any room look much better and more stylish. It’s the center and pride of the room, so it’s only logical that you look after it in the best possible way.
The only way to maintain is by using the best vacuum for high pile carpet. Luckily, the market is packed with plenty of suitable vacuums that have strong suction power to clean these thick carpets.
However, there are a few other things you’ll have to consider when looking for a vacuum for thick carpets. Consider your needs and preferences, as well as whether you have other floor types in your house as well. You should also look for a HEPA filter if you or someone in your family is prone to allergies.
Hopefully, you found the best vacuum for your plush carpet from our reviews. If not, we suggest you go back, keeping in mind all the buying factors we discussed.
Sources and Resources
- Indoor HEPA filters significantly reduce pollution indoors when outside air unhealthy, study finds
– https://www.sciencedaily.com/releases/2018/09/180925110030.htm - A Placebo-controlled Trial of a HEPA Air Cleaner in the Treatment of Cat Allergy– https://www.atsjournals.org/doi/full/10.1164/ajrccm.158.1.9712110