Audiology isn't lacking for best practice guidelines. The American Academy of Audiology and the American Speech-Language Hearing Association offer detailed recommendations for preferred practice patterns. The College of Audiologists & Speech-Language Pathologists of Ontario offers similar guidelines. Even state-level audiology associations are producing their own recommendations on best practices.
So why don't more audiologists integrate best practice guidelines into patient care? Must experts do a better job of communicating their benefits? Do practitioners need to be convinced that sometimes frustrating guidelines are worth the effort? Are implementing them just too time-consuming? Unfortunately, the only thing that experts know for sure is that they must search for answers.
The use of probe-microphone real-ear measurement (REM) to verify hearing aid performance for adults and children is a prime example of noncompliance with best practice guidelines. A number of surveys, including the 2010 MarkeTrak VIII survey from the Better Hearing Institute, found that approximately 60 percent of people receiving hearing aids don't undergo probe-microphone REM testing. (See FastLinks.) That's in line with findings from The Hearing Journal's own 2010 dispenser survey that found less than 40 percent of audiologists said they “always or nearly always” used REM to verify their fittings. (See FastLinks.)
Hearing healthcare practitioners also commonly neglect to use recorded stimuli when testing ability in word recognition. A large percentage of audiologists use their own voice in speech recognition testing, said George Lindley, PhD, an audiologist at East Penn Hearing Center in Emmaus, PA, and an adjunct professor at Osborne College of Audiology in Elkins Park, PA. “Using recorded media with a standardized voice allows you to minimize variation associated with live voice testing,” he said. “Results obtained at one facility, or from year to year, can be more reliably compared.”
Adherence to best practice guidelines among pediatric audiologists might be expected, given the lifelong implications for speech and language development involved with correcting hearing in children. Best practices, however, are often honored more in the breach than in the observance.
A high degree of variability is found even when practitioners employ best practices, said Ryan McCreery, PhD, an associate director of audiology at Boys Town National Research Hospital in Omaha, NE. “We've just completed a research study that looked at how well hearing aids are fit to the prescriptive approach for children,” he said. “While we expected some variation because children are growing and their hearing can change, even service providers who were saying that they were following best practices had some very different outcomes from what you'd expect.”
Providers who said, for example, that they were following the desired sensation level (DSL) method showed wide-ranging differences. Dr. McCreery said this most likely indicated that pediatric audiologists aren't using the method consistently.
Practitioners who deviate widely from accepted guidelines may be sacrificing their patients' satisfaction. Sheila Moodie, PhD, a research audiologist at the National Centre for Audiology in London, Ontario, said patients rate hearing professionals highly when they received the most benefit from their hearing aids. The MarkeTrak VIII study “found that those who practice according to evidence-based best practice guidelines have patients who are satisfied and benefiting from the amplification provided to them,” she said.
LACK OF EVIDENCE?
Hearing healthcare professionals may not be adhering to best practice guidelines, despite promising outcomes in MarkeTrak VIII, because of limited time. Dr. Lindley said many audiologists are overwhelmed, and pediatric audiologists especially aren't looking for more customers. “But you can make the case that if you take time to do this measure up front, it can save you time down the road with fewer and shorter visits, getting the patient to a happy place more quickly,” he said.
Experts assumed the growing number of students obtaining doctorates in audiology, which gives them more academic and clinic hours prior to graduation, would increase the use of best practice guidelines. But survey data from the past decade has shown no considerable shift in that direction. Dr. Lindley said his students often ask him why best practices are not used by their mentors in clerkships and externships. He simply answers, “You often adopt the practices of those around you.”
The fault does not lie entirely with clinicians, said Pamela Mason, ASHA's director of audiology professional practices. “The downfall in communication sciences and disorders is that there isn't a lot of evidence-based scientific research to support many of the things we do,” she admitted. “Many of our guidance documents are based on clinical expertise rather than randomized controlled trials. Sometimes such studies can be hard to conduct. For example, it might be unethical to deny a service to a control patient.”
This is particularly true for newborns. Ninety-five percent of newborns in the United States have their hearing screened prior to discharge, and Ms. Mason said a using control cohort would mean denying newborns this screening.
She was quick to stress, however, that the shortage of evidence doesn't mean a lack of effectiveness. “There are some treatments and practices that are clearly beneficial but don't have evidence. Best practice guidelines are often written by experts and provide the best available information. Evidence-based practice is based on three elements: scientific evidence, expert clinical opinion, and the patient's values and point of view,” Ms. Mason said.
Still, many clinicians may be more inclined to follow guidelines when they are based on a strong body of research. More data specific to hearing aid features and processing are available, such as whether directional microphones or digital noise reduction is helpful. “But the companies that make and sell the equipment used to fit hearing aids are much smaller with smaller markets, and they don't necessarily have the funding to sponsor research like hearing aid manufacturers,” Dr. Lindley said.
Even the evidence for a well-known and basic best practice like REM is not based on overwhelming scientific data. “It's not like there are studies out there comparing 100 patients fitted using REM and 100 patients fitted without it, showing the difference in their outcomes,” Dr. Lindley said. “We do know there are studies showing that the manufacturer's initial default settings are often inadequate in many fittings, with the patient getting amplification that's less than ideal. A lot of those patients could be provided with and tolerate greater speech audibility.”
Some audiologists do not feel the need to use probe-microphone REM when fitting patients because the outcome is satisfactory without it. And new patients don't know what to expect. “They put a hearing aid on, and they can hear better, and they're happy about that,” Dr. Lindley said. “But if you don't conduct probe-microphone or test-box measurements to assess the audibility being provided, it's hard to say whether they could perform even better if you would have provided them with more audibility. It's the information you aren't getting.”
Receiving that kind of information when fitting children for hearing aids is even more challenging and critically important, said Dr. McCreery. “Adults can tell you what's going on and how their hearing is changing because they can explain things better. Children don't have the same ability to describe what they're hearing, and there's a lot more at stake in terms of their speech and language development,” he said.
That is all the more reason to use best practice tools such as the DSL method, but Dr. McCreery said practitioners have be taught how to use best practices step by step. “We have to be much more specific about what we're asking of practitioners,” he said. “Not just ‘do DSL,’ but [show them] what the audibility of a hearing aid fitting should be. It's not enough to trust that what a manufacturer says is DSL is DSL as it was conceived.”
Dr. Lindley admitted that even he doesn't always follow best practice guidelines to the letter. Best practice guidelines require measuring loudness discomfort levels up from and using that information to program hearing aids, he said, though the vast majority of audiologists do not do that “I don't routinely do this. There's very little evidence in the literature indicating whether getting this measure up front leads to a better outcome,” he said. “I've found that loudness discomfort levels measured are heavily influenced by the instructions that are given to the patient, and some patients aren't very reliable. I'd rather assess comfort using real-world sounds on the day of the fitting.”
COMPREHENSION AND IMPLEMENTATION
One way to improve compliance with best practice guidelines may be to fine-tune their specificity. The Knowledge and Implementation in Pediatric Audiology working group, for one, has assessed compliance among pediatric audiologists with REM during assessment and verification. “We saw that most pediatric audiologists who made the measurement, and not all did, did so mostly at verification but not always at assessment,” said Dr. Moodie, a member of the working group. “It's considered best practices to do both, but some guidelines are more broad, and simply say that it might be a good idea to measure at assessment, rather than giving a strict recommendation.”
Other factors are also likely at play in noncompliance, and Dr. Moodie said the profession must it understand the phenomenon better before trying to remedy it. “What internal conditions for the individual hearing healthcare practitioner [and in his] social and physical work environment need to be in place to achieve best practice behavior? I'm not sure we have a handle on that,” he said.
Strategies to change behavior can be developed once the barriers are better understood. “From the literature in hearing healthcare and in the business world, we know that this will be complex and require multifaceted intervention,” Dr. Moodie said. “You can't just go out and give people lectures. Multiple strategies for change are more likely to achieve real change in practice behavior. But what we don't know at this point, despite all kinds of systematic reviews, is the best combination that will work.”
One thing that is known is the importance of practitioner involvement. “The more that end users participate in the development of guidelines, the more likely those guidelines will be successfully translated into actual best practice behavior,” said Dr. Moodie. “That's likely one reason that individual states are taking AAA's and ASHA's guidelines and modifying them somewhat for their own use. If you look at the field of knowledge translation, they advocate that adaptations are best achieved by getting this information while creating knowledge. You find out barriers and overcome them during the development process, rather than issuing guidelines and having people read them only to say, ‘We can't do that!’”
Acknowledging the field's variability is another important issue that must be addressed. Practitioners have been frustrated when they follow best practices but do not obtain the result they wanted. “In the past we've just said, ‘This is what you need to do,’” Dr. McCreery said. “Practitioners are … saying, ‘I follow best practices and I'm still not getting what I would expect in a fitting outcome,’ or ‘I fit to DSL, but I still get feedback.’ We can acknowledge that there are situations in which people have to use their best professional judgment to deviate from guidelines, and that's very different from not using them at all.”
Ultimately, however, it may take some compensation to gain compliance with best practices in audiology. “I get the sense from talking to people in the field that there are varying amounts of commitment because there's some degree of skepticism that what we're telling them are actually best practices,” Dr. McCreery said. “There has been discussion about tying outcomes and best practices to reimbursement. We can tell people what to do until we're blue in the face, but until there's an incentive, I think we're not going to see big changes.”
No clear answers suggest how to improve best practice compliance in audiology, but experts agree that further research is needed to provide higher quality evidence to support the guidelines that now exist and to develop a better understanding of what is being implemented in practice.
- More information on AAA's best practice guidelines is available at http://bit.ly/AAAGuidelines.
- Access ASHA's best practice guidelines at http://bit.ly/ASHAGuidelines.
- Read more about the best practice guidelines from Ontario's College of Audiologists & Speech-Language Pathologists at http://bit.ly/CaslpoGuidelines.
- The MarkeTrak VIII study is available at http://bit.ly/MarketTrakVIII.
- Read The Hearing Journal's 2010 dispenser survey at http://bit.ly/HJ2010Survey.
- Click and Connect! Access the links in The Hearing Journal by reading this issue on thehearingjournal.com.
- Comments about this article? Write to HJ at HJ@wolterskluwer.com.
- Follow us on Twitter at twitter.com/hearingjournal.
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