Interview with Diane L. Sabo Ph. D., Director of Audiology, Children's Hospital of Pittsburgh
Share:
AO/Beck: Hi Dr. Sabo. It's a pleasure to speak with you tonight. Thanks for giving us this time.
Sabo: Hi Doug, thanks for inviting me.
AO/Beck: Diane, you recently published an article in the New England Journal of Medicine (NEJM), dated 4-19-2001, and titled 'Effect of Early or Delayed Insertion of Tympanostomy Tubes for Persistent Otitis Media on Developmental Outcomes at the Age of Three Years.' The authors of the study were Jack Paradise, Heidi Feldman, Thomas Campbell, Christine Dollaghan, Kathleen Colborn, Beverly Bernard, Howard Rockette, Janine Janosky, Dayna Pitcairn, Marcia Kurs-Lasky, Clyde Smith, and of course yourself. Can you summarize the premise of the article for me please?
Sabo: Sure. We were reporting on our study that examines the question.... 'In children who develop persistent middle-ear effusion during the first 3 years of life, are tympanostomy tubes effective in improving later developmental outcomes?' Specifically we were concerned with issues involving speech, language, cognition, and psychosocial development. The results also bear on the question whether persistent middle-ear effusion actually impairs later development. To derive an answer, we had to examine a number of outcome measures. So we designed a study that included a randomized trial to see if we could establish a causal relationship between tympanostomy tube insertion and improved developmental outcome, and by inference, a causal relationship between middle-ear effusion and developmental outcome . Without a randomized trial, we may have established an association between the two phenomena, but our goal was to look for a causal relationship, so we had to use a randomized design.
AO/Beck: I want to just be certain I understand the breadth of the study, if I may. My understanding is that you were not investigating whether or not tubes were beneficial with regards to otologic issues, or even audiologic issues, but in fact, the study was limited to speech and language issues. Is that correct?
Sabo: That's partially correct. In fact, our outcome measures were cognitive, speech and language, and psychosocial measures.
AO/Beck: When did the study start?
Sabo: This study originated in 1991. If you look back in the literature you can find descriptions of the study design beginning in 1992. These data in the NEJM article are from children at the age of 3 years.
AO/Beck: How many kids were involved in the study?
Sabo: In total, we studied 6350 children. Of those, 429 kids with persistent middle ear effusion were randomly assigned to the early insertion group , meaning tubes placed ASAP, or the late insertion group, meaning the tubes were not placed until potentially 6 to 9 months later if the children's effusion persisted.
AO/Beck: So data collection has been going on for years and the kids are now ages 6 to 10 years or so?
Sabo: Yes, again, the data published at this time are about children when they reached three years of age..
AO/Beck: So if you were to 'boil it down to it's essence,' what were the differences between the two groups over the time the children were studied, with respect to the cognitive, speech and language and psychosocial measures?
Sabo: Basically, there were no differences between the two groups, on the measures studied.
AO/Beck: That is remarkable. Of course, I would assume the kids who received the tubes later, would have scored worse on these measures, as they have had longer periods of time with conductive hearing loss. Did you also compare kids who received tubes, either early or late, to kids who never received tubes, assuming that all of whom had persistent otitis?
Sabo: No, we didn't, because most of the randomized children who never received tubes didn't receive them because their effusion cleared. Our design called for tubes to be inserted eventually--after 6 or 9 months--in the late-treatment group only if effusion persisted.
AO/Beck: Diane, how do you imagine this information will be used, and what will the impact of this study be?
Sabo: Great questions. There are a few things that need to be mentioned. First of all, we have cautioned the readers that the study may not be applicable to children who have recurrent acute otitis media, or other more serious complications of otitis. The results of this study apply only to the garden variety, long term otitis media. This is an important point because people tend to try to generalize the results to the whole otitis population, and that would not be appropriate.
AO/Beck: What about the kids that all of us have seen who've had otitis for months, and they have significant delays in speech production. Then it seems like as soon as they get their tubes, they start speaking a mile a minute?
Sabo: Well, that's certainly an issue. I cannot explain all of the variations in outcomes based on the study. There are certainly kids who did better and kids who did worse, but on the whole, the two groups appeared to be about the same. One of the findings of this study was that kids who are socioeconomically advantaged, tended to do better than other children. Socioeconomic status does appear to be an important variable in most studies relating to these issues, and indeed, it was a factor in our study.
Regarding why some kids seem to 'perk-up' right after obtaining tubes, we don't know for sure. It may be that there are short-term surges in language development immediately after tubes without affecting the longer-term results. We didn't attempt to measure that. For cost and logistical considerations, we didn't really address detailed hearing data over time in the study, and as you know, that may well be the missing link that clarifies these issues. We have some hearing data on most of the kids, but we don't have large numbers of repeated measures across the majority of the kids. The purpose of the study was to look at the cognitive, speech and language and related issues in relation to persistent otitis media, not in relation to hearing per se., The study did not focus on pre versus post-tube audiometric data.
AO/Beck: So the bottom line is to not generalize the results from the speech and language results to the hearing results?
Sabo: That depends on how broadly you generalize. Our children seemed quite representative of children generally with persistent middle-ear effusion. We performed a total of 1717 audiometric examinations on the 402 children in their first 3 years of life, and hearing was abnormal in approximately one half of instances when they had unilateral effusion and three-quarters of instances when they had bilateral effusion. So certainly, after random assignment, the late-treatment group, which from that time forward had much more effusion than the early-treatment group, must also have had more hearing loss. However, we only studied what we studied. We can have hunches about the detailed pre- versus post-tube hearing results, and those would be interesting results to know about, but again, that was not what we looked at, and we can't make statements related to data we didn't collect. We really don't have a good handle on the pre versus post issues as they relate to hearing loss, and that's the next big area for us, or for others to look at. We can say that our results, especially when combined with results in other children in our study who had less effusion, strongly suggest no impact at age 3 years of mild to moderate hearing losses within the durations of effusion we studied, but we can't say anything yet about results at older ages and we certainly cannot speculate about the impact of longer periods of effusion or more severe losses. Kids may present with a 30 dB conductive loss one day, and then 15 dB at the next visit, and then 40 dB on a different day, but we didn't have frequent measures in our study--nor are they very often available in the real world. We do know there are trends across the groups..
AO/Beck: Thanks Diane. This really was an interesting paper and I thank you for your time to review it and explain it a little.
Sabo: My pleasure Doug. Thanks again for the invitation. I'll keep you posted if we come out with a study based on audiometric issues.
AO/Beck: That would be fantastic. Thanks Diane.
Sabo: Hi Doug, thanks for inviting me.
AO/Beck: Diane, you recently published an article in the New England Journal of Medicine (NEJM), dated 4-19-2001, and titled 'Effect of Early or Delayed Insertion of Tympanostomy Tubes for Persistent Otitis Media on Developmental Outcomes at the Age of Three Years.' The authors of the study were Jack Paradise, Heidi Feldman, Thomas Campbell, Christine Dollaghan, Kathleen Colborn, Beverly Bernard, Howard Rockette, Janine Janosky, Dayna Pitcairn, Marcia Kurs-Lasky, Clyde Smith, and of course yourself. Can you summarize the premise of the article for me please?
Sabo: Sure. We were reporting on our study that examines the question.... 'In children who develop persistent middle-ear effusion during the first 3 years of life, are tympanostomy tubes effective in improving later developmental outcomes?' Specifically we were concerned with issues involving speech, language, cognition, and psychosocial development. The results also bear on the question whether persistent middle-ear effusion actually impairs later development. To derive an answer, we had to examine a number of outcome measures. So we designed a study that included a randomized trial to see if we could establish a causal relationship between tympanostomy tube insertion and improved developmental outcome, and by inference, a causal relationship between middle-ear effusion and developmental outcome . Without a randomized trial, we may have established an association between the two phenomena, but our goal was to look for a causal relationship, so we had to use a randomized design.
AO/Beck: I want to just be certain I understand the breadth of the study, if I may. My understanding is that you were not investigating whether or not tubes were beneficial with regards to otologic issues, or even audiologic issues, but in fact, the study was limited to speech and language issues. Is that correct?
Sabo: That's partially correct. In fact, our outcome measures were cognitive, speech and language, and psychosocial measures.
AO/Beck: When did the study start?
Sabo: This study originated in 1991. If you look back in the literature you can find descriptions of the study design beginning in 1992. These data in the NEJM article are from children at the age of 3 years.
AO/Beck: How many kids were involved in the study?
Sabo: In total, we studied 6350 children. Of those, 429 kids with persistent middle ear effusion were randomly assigned to the early insertion group , meaning tubes placed ASAP, or the late insertion group, meaning the tubes were not placed until potentially 6 to 9 months later if the children's effusion persisted.
AO/Beck: So data collection has been going on for years and the kids are now ages 6 to 10 years or so?
Sabo: Yes, again, the data published at this time are about children when they reached three years of age..
AO/Beck: So if you were to 'boil it down to it's essence,' what were the differences between the two groups over the time the children were studied, with respect to the cognitive, speech and language and psychosocial measures?
Sabo: Basically, there were no differences between the two groups, on the measures studied.
AO/Beck: That is remarkable. Of course, I would assume the kids who received the tubes later, would have scored worse on these measures, as they have had longer periods of time with conductive hearing loss. Did you also compare kids who received tubes, either early or late, to kids who never received tubes, assuming that all of whom had persistent otitis?
Sabo: No, we didn't, because most of the randomized children who never received tubes didn't receive them because their effusion cleared. Our design called for tubes to be inserted eventually--after 6 or 9 months--in the late-treatment group only if effusion persisted.
AO/Beck: Diane, how do you imagine this information will be used, and what will the impact of this study be?
Sabo: Great questions. There are a few things that need to be mentioned. First of all, we have cautioned the readers that the study may not be applicable to children who have recurrent acute otitis media, or other more serious complications of otitis. The results of this study apply only to the garden variety, long term otitis media. This is an important point because people tend to try to generalize the results to the whole otitis population, and that would not be appropriate.
AO/Beck: What about the kids that all of us have seen who've had otitis for months, and they have significant delays in speech production. Then it seems like as soon as they get their tubes, they start speaking a mile a minute?
Sabo: Well, that's certainly an issue. I cannot explain all of the variations in outcomes based on the study. There are certainly kids who did better and kids who did worse, but on the whole, the two groups appeared to be about the same. One of the findings of this study was that kids who are socioeconomically advantaged, tended to do better than other children. Socioeconomic status does appear to be an important variable in most studies relating to these issues, and indeed, it was a factor in our study.
Regarding why some kids seem to 'perk-up' right after obtaining tubes, we don't know for sure. It may be that there are short-term surges in language development immediately after tubes without affecting the longer-term results. We didn't attempt to measure that. For cost and logistical considerations, we didn't really address detailed hearing data over time in the study, and as you know, that may well be the missing link that clarifies these issues. We have some hearing data on most of the kids, but we don't have large numbers of repeated measures across the majority of the kids. The purpose of the study was to look at the cognitive, speech and language and related issues in relation to persistent otitis media, not in relation to hearing per se., The study did not focus on pre versus post-tube audiometric data.
AO/Beck: So the bottom line is to not generalize the results from the speech and language results to the hearing results?
Sabo: That depends on how broadly you generalize. Our children seemed quite representative of children generally with persistent middle-ear effusion. We performed a total of 1717 audiometric examinations on the 402 children in their first 3 years of life, and hearing was abnormal in approximately one half of instances when they had unilateral effusion and three-quarters of instances when they had bilateral effusion. So certainly, after random assignment, the late-treatment group, which from that time forward had much more effusion than the early-treatment group, must also have had more hearing loss. However, we only studied what we studied. We can have hunches about the detailed pre- versus post-tube hearing results, and those would be interesting results to know about, but again, that was not what we looked at, and we can't make statements related to data we didn't collect. We really don't have a good handle on the pre versus post issues as they relate to hearing loss, and that's the next big area for us, or for others to look at. We can say that our results, especially when combined with results in other children in our study who had less effusion, strongly suggest no impact at age 3 years of mild to moderate hearing losses within the durations of effusion we studied, but we can't say anything yet about results at older ages and we certainly cannot speculate about the impact of longer periods of effusion or more severe losses. Kids may present with a 30 dB conductive loss one day, and then 15 dB at the next visit, and then 40 dB on a different day, but we didn't have frequent measures in our study--nor are they very often available in the real world. We do know there are trends across the groups..
AO/Beck: Thanks Diane. This really was an interesting paper and I thank you for your time to review it and explain it a little.
Sabo: My pleasure Doug. Thanks again for the invitation. I'll keep you posted if we come out with a study based on audiometric issues.
AO/Beck: That would be fantastic. Thanks Diane.
Diane L. Sabo, PhD
Associate Professor Communication Science and Disorders, University of Pittsburgh
Diane L. Sabo, Ph.D. is the Director of Audiology and Communication Disorders at Children’s Hospital of Pittsburgh. She is an Associate Professor in the Department of Communication Science and Disorders in the School of Health and Rehabilitation Sciences, University of Pittsburgh. She has over 25 years of clinical work with infants and children, particularly in the area of electrophysiologic evaluation of the auditory system. Her primary research interests are in the area of her clinical expertise in the physiologic evaluation of infants and children using evoked potentials and otoacoustic emissions with special emphasis on the screening of newborns for hearing loss. A secondary area of interest is the maturation of the auditory system and impact of disease process on the auditory system.