What is malingering?
Malingering is the intentional production of false or exaggerated psychological or physical symptoms motivated by external incentives. In short, "faking it"
While external incentives may vary, they usually fall into one of two categories:
- Avoiding something
Prison inmates might malinger to elicit sympathy and leniency from the security guards.
In occupational health, a patient may pretend to hear better than they do in reality to avoid losing their job.
- Trying to gain something
Particularly prevalent in occupational health, patients may "fake" hearing loss to claim compensation or access a disability grant.
- Non-organic hearing loss (NOHL)
- Functional hearing loss
- Exaggerated hearing loss
What to ask yourself when you suspect NOHL
Listed below are possible "red flags" and are by no means a diagnosis.
- Is there a discord between responses to the clinician’s questions.
- Is the patients audiogram atypical, and are there any changes of threshold responses at the same frequencies in repeated examinations?
- Does a patient who presents with profound functional hearing loss still respond to questions asked with a lower voice, especially when they cannot read your lips?
- Are air conduction thresholds worse than acoustic reflex thresholds?
- In speech audiometry, does the patient repeat only a part of the word presented? For example, half word responses to spondees.
- Has the patient expressed an obvious interest in obtaining some sort of financial benefit?
- Is there inconsistency between PTA and SRT?
- Are bone conduction results worse than air conduction results?
How to Diagnose Non-organic Hearing Loss
Functional hearing loss must always be diagnosed by thorough clinical examination and testing and there are several tests available for that purpose.
These tests are generally classified into two groups;
- Special subjective audiometry tests
- Objective audiometry tests.
Special tests for detecting NOHL are the Stenger test and the Lombard test while, objective testing would include Auditory-Evoked Potentials (AEP) and Otoacoustic Emissions (OAE).
Special Subjective Audiometry Tests
This well known test is used to determine malingering in the case of unilateral hearing loss. The principle behind this test is based on Stenger’s discovery that if two sounds of the same frequency and slightly different intensity are played at the same time in both the patient’s ears, the patient will believe that they hear the tone in the ear where the sound is louder.
A 10 dB sound is presented above the threshold in the good ear and a sound of 10 dB below the admitted threshold in the suspect ear (or poor ear).
A malingerer will claim that they cannot hear the tone presented as they are not aware that a sound was actually presented in both the good and the bad ear.
The Lombard test
Here a patient is asked to read some text out loud while wearing earphones. While the patient is reading the text, a sound is emitted in the earphones.
Unaware of their natural response, the suspect patient will increase the intensity of their voice because of the loud sound played in the earphones.
A patient with real(profound) hearing loss would not hear the noise and therefor not change the intensity of their voice.
While subjective tests are simple in theory, they are not easy to execute and are best handled by a skilled audiologist.
They are seldom used in occupational health where inconsistent test results should be directly referred to an audiologist. Objective tests are able to detect real thresholds which makes them more reliable and are often preferred in these cases.
Objective Audiometry Tests
Otoacoustic Emissions (OAE)
The principle of OAE is that the normal ear generates sounds that can be recorded. The presence of these sounds indicates whether the cochlear has normal or near normal functionality.
OAEs, especially transient-evoked otoacoustic emissions (TEOAEs), have been shown to be of value in cases of nonorganic hearing loss. However, these tests do not work as well for patients with actual hearing levels greater than 40 dB HL who wish the clinician to believe that their hearing is worse than that.
Auditory-Evoked Potentials (AEP)
AEP measurement has long been considered an important test in the diagnosis of non-organic hearing loss. Results obtained from this technique and from voluntary pure-tone testing generally agree within 10 dB.
Auditory evoked potentials and auditory brain-stem response (ABR) have proven to be more reliable than the auditory middle latency responses or the auditory late responses in detecting non-organic hearing loss.
Objective measures do not require the cooperation of the patient and are therefore a highly recommended way of catching out a would be malingerer.
The problem is that this specialised equipment for objective testing does not come cheap. While objective testing is clearly the preferred methodology, many practices simply can't afford it.
Objective, subjective and affordable
While malingering is not an everyday occurance, it does happen and deserves vigilance. This is especially true in the field of occupational health audiometry or industrial audiometry, where patients could stand to benefit from false claims, or pose a risk to themselves and others by remaining untreated.
There is another method of determining a malingerer.
Patient Response Monitoring.
This is where the use of a response button in audiometry has a massive advantage over raising your hand.
Patient response monitoring is something the KUDUwave does very well.
By monitoring and tracking patient response times and accuracy down to the millisecond we are able to distinguish between false and true responses as well as provide analyses the patient’s response times.
With this data attached to every report and available on the live audiogram screen, a clinician is able to make informed decisions based on a true representation of the patient's test results and provide the ability to detect a malingerer on the spot.
Some advice when dealing with malingering.
If a thorough investigation indicates that a patient is malingering, you may decide to confront the patient. In this case, avoid direct accusations. A thoughtful approach that asks patients to clarify inconsistencies is more likely to be safer and more productive for the examiner.
As specialists in this field, most of us have experienced a patient “faking it” and if you haven't, it is probably only a matter of time until you do.
Why not share your experience and advice in the comments below?