My PFT Lab has recently been asked by several doctor’s offices and clinics to advise them on the purchase of an office spirometry system. I am not a fan of office spirometry because I think the test quality is often low. Office spirometry is usually performed by poorly trained office staff using poorly maintained equipment and under these conditions quality is going to suffer. Despite my misgivings the reality is that office spirometry is not going away and in fact its use is probably expanding.

There are several good reasons why this is happening. More testing of all kinds is being done at the point of care and there is an increased awareness of standards of care for COPD and Asthma. There is also revenue generation (the websites of several office spirometer manufacturers have downloadable documents showing return on investment and the proper codes to use (ICD9 and CPT) when billing).

I think that we ignore this trend at our own peril and that the proper response should be to reach out and offer assistance in selecting office spirometers and training office staff to perform spirometry instead. Although this will require extra effort with no immediately apparent payback I think this should be done not only because it is the right thing to do for the patient’s sake but also because it will pay dividends in the long run.

I actually do not think that office spirometry is a significant threat to pulmonary function labs. Yes, there may be a slight decrease in patients referred just for spirometry but most spirometry performed in my PFT Lab is performed for the pulmonary physician clinics and I suspect that to one degree or another this is true for most hospital-based PFT Labs. Office spirometry is actually more likely to generate additional referrals to pulmonary physicians and for more complete pulmonary function testing than not. When that happens if a doctor’s office or clinic has a choice about where to refer their patients then being part of the solution for them rather than part of the problem is going to make it more likely these patients end up with you than not.

One of the first concerns I have about physician offices and clinics selecting a spirometer without assistance is that the choice will often be made according to the up-front cost without thinking about long term costs and staff work flow.

My list of recommended office spirometer features includes:

• Accuracy
• Patient hygiene
• Reference equations
• Ability to configure reports
• Data storage

The last time I researched office spirometers was several years ago and when I started researching them again I was struck by the increase in features and the decrease in price. I have been unable to find any comparative reviews (other than those from the manufacturers themselves) so it is hard to determine what the current level of test quality and accuracy is like. Having said that, the same can also be said of the equipment from the major pulmonary function test equipment manufacturers. Most office spirometer manufacturers claim that their systems meet the ATS-ERS standards and in the absence of any evidence to the contrary I am willing to assume that this is more or less true. If an office spirometer does not make this claim then it should not be considered.

One thing I am adamant about for the sake of the patient’s health is that an office spirometer should either use a barrier filter or a disposable sensor. Spirometers that only use a plastic or cardboard mouthpiece or that are supposed to be cleaned between uses absolutely should not be considered. This increases the per-test costs (which offices and clinics often do not factor into their buying process) but patient hygiene is non-negotiable.

An office spirometer should be able to use the same reference equations as your own PFT Lab (and if you are not using NHANESIII or GLFI then why not?). I’ve noticed that several office spirometers either did not list which reference equations they used or had a very limited set of (out-) dated reference equations. The correct set of reference equations is of course important for the patient’s sake but you also don’t want to have to waste your time repeatedly explaining why the percent predicted values on your test results differ from those of the office spirometer when the results are the same.

I think I once counted all of the numerical values that can be obtained from a Forced Vital Capacity and came up with over two dozen of them. A report with all of these values looks very impressive but is mostly useless noise. There are at most a half-dozen test values that should be reported (and in my opinion that list is FVC, FEV1, FEV1/FVC ratio, Peak Flow, expiratory time, back-extrapolation). If an office spirometer report cannot be pared down to the essential values then that spirometer should not be considered.

If patient demographics (name, date of birth, height, etc) are not stored in some kind of a database then the office staff will have to re-enter it every time spirometry needs to be performed. If the patient’s test results are not stored (and if a trend page in the report is not available) then how will results from the current test be compared to previous tests? A test system that does not have a patient database should not be considered. I would also argue that if it is not able to trend results on a report it should not be included.

Other issues that have to do with staff work flow include:

• how results are physically reported
• portable versus stationary 

How are the test results are physically reported? LCD display? 4-inch wide thermal paper? 8-1/2 x 11 inch paper from a regular computer printer? This can have a significant bearing on staff work flow. If the results only appear on an LCD display then they will have to be manually written down or typed into the patient’s records (I would also suggest that there may also be an issue with insurer payments if the office is audited because a paper report of any kind is evidence the test was actually performed whereas results that only appear in notes may not be). A strip of thermal paper (or the equivalent) will likely have to be stapled onto a backing sheet if it is going to go into a patient’s chart and for this reason a report on 8-1/2 x 11 paper saves extra work.

There’s portable and then there’s portable. Some of the less-expensive but fully-featured office spirometry systems consist of just a flow sensor that is plugged into the USB port of an existing desktop or laptop computer. A laptop can be considered to be portable but the reality is that it needs to be placed on a work surface of some kind and the patient will need to be positioned nearby in order to use the spirometer attached to it. As an alternative a number of office spirometers consist of a portable, battery-powered sensor and a docking station. In these systems the sensor can be brought to wherever the patient is located and the tests performed there. When docked the results are automatically uploaded into the computer. Neither approach is necessarily better or worse than the other, but how they effect staff work flow does matter and needs to be considered.

One final technical consideration that I have is how are the results shared? The hospital I work for is the tertiary care facility for a network of hospitals, clinics and physician offices. If each clinic or office goes it alone and chooses office spirometry systems by themselves then most of these systems will not talk to each other or to the hospital information system. Patient results will then be spread across numerous systems and in the worst case patient results will either remain in paper format in a paper chart or the test results will be hand entered into the patient visit notes. At the moment I do not have a good answer to this question. Several solutions come to mind but which, if any, of them actually makes sense is unclear.

My PFT Lab has already developed a program for training office staff in spirometry and we already use it in a small number of local clinics. I’d like to say that we anticipated the trend in office spirometry but the fact is that we have a relationship with several physicians and clinics associated with, but not part of, the Pulmonary division and started this program a number of years ago at their request. Regardless of the reason this has left us in a position to support staff education programs in local offices and clinics with little additional effort (other than the actual training, of course). We also have the ability to support a regular (annual? biannual? quarterly?) program of visits to offices and clinics to perform calibration checks with a 3-liter syringe. I think this is important service to provide because it would reinforce the need for quality assurance and give us the opportunity to run a quick refresher course for the office staff.

My current recommendation to the lab’s medical director, manager and hospital administrator is to develop system-wide technical and procurement standards for office spirometers. In addition I also recommend that the Pulmonary Lab reach out to all offices and clinics associated with the hospital and offer staff training and quality assurance for their office spirometry.

A long term problem for hospitals, clinicians and patients is sharing patient test results. Eventually I think there is going to be a long term solution and it will probably be a standards-based web-enabled system but at the moment the closest we can come to this would be to approach the hospital’s Information Systems department and see if a more universal interface for patient test results can be developed.

So far there has been a positive response to these recommendations but it’s still too early in the process to see where this will go.

Office spirometry is not going away. Instead of considering it an ignorable problem think about doing what you can to improve it and treat it as the opportunity it really is.

PFT Blog by Richard Johnston is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.