Philosophy(PhD) / This thesis presents a randomised controlled trial of the Lidcombe Program of Early Stuttering Intervention. The Lidcombe Program was developed for the treatment of stuttering in preschool-age children. The effectiveness of the Lidcombe Program was compared to a control group in a parallel group randomised controlled trial with blinded outcome assessment. A number of supplementary studies were conducted in support of the trial; two literature reviews, two retrospective file audits and a statistical simulation study. A review of randomised studies of treatments for stuttering showed that there have been 27 such studies published in English language journals. Of these only one was devoted to a treatment for early stuttering and that was the Lidcombe Program. The randomised study showed that 3 months of this treatment was associated with a lower level of stuttering compared to a control group who received no treatment. However, with a sample size of 23, this study lacked power and the children did not receive a full course of treatment. Despite these limitations, this study provided evidence that a medium to large effect size could be anticipated in an adequately powered and properly conducted randomised controlled trial. The second review was of sample size and power in stuttering research studies that had been published in two speech pathology journals; the Journal of Speech, Language and Hearing Research (Vol 39, No. 1 to Vol 40, No, 4) and the Journal of Fluency Disorders (Vol 21, No. 1 to Vol 22, No, 3). Results suggested that the majority (73%) of the 26 studies reviewed were insufficiently powered to detect even large effects. However it was acknowledged that it is very difficult to recruit even moderate sample sizes of people who stutter. It was concluded that one way to help improve this situation is collaboration of multiple research centres or, in the case of a randomised controlled trial, inclusion of multiple recruitment sites in one study. This strategy was adopted in the randomised controlled trial reported in this thesis. Two retrospective file audit studies of children treated with the Lidcombe Program were conducted in Australia and Britain. One purpose of these file audits was to obtain information relevant to the design and conduct of the randomised controlled trial. Data from the case reports on more than 300 children from the two sites were included in a meta-analysis. Results showed that a median of 11 weekly clinic sessions were required for children to attain the criteria for low levels of stuttering for completion of Stage 1 of the Lidcombe Program. Approximately 90% of children had achieved those criteria within 6 months of beginning treatment and almost all children had achieved them within 1 year. In addition two variables were found to be associated with longer treatment duration: more severe pre-treatment stuttering and shorter times from onset of stuttering to the start of treatment. The latter was apparent in the meta-analysis but not for the individual cohorts. As a result of these findings, pre-treatment stuttering severity was stratified along with other relevant variables in the randomised controlled trial and follow up for participants was a minimum of 9 months. A simulation study was conducted prior to analysis of data from the primary outcome measure of the randomised controlled trial: percentage of syllables stuttered (%SS). The distribution of %SS scores is positively skewed. Nonetheless, simulation showed t-test to be an appropriate analysis for this primary outcome measure. There were two treatment sites for the randomised controlled trial: the University of Canterbury (Christchurch, New Zealand) and the Stuttering Treatment and Research Trust (Auckland, New Zealand). A total of 54 preschool-age children were recruited: 29 to the Lidcombe Program and 25 to the control group. Half the proposed sample size was achieved due to slower than anticipated recruitment. This occurred because, as the trial progressed, treatment with the Lidcombe Program became common knowledge among parents in New Zealand and they became increasingly reluctant to agree to have their child randomised to the trial. Analysis with t-test showed a highly statistically significant difference (p = 0.003) at 9-months post-randomisation. The mean percentage of syllables stuttered (%SS) at 9-months post-randomisation was 1.5 (SD = 1.4) for the Lidcombe Program group compared to 3.9 (SD = 3.5) for the control group, resulting in a treatment effect of 2.3 %SS (95% confidence interval: 0.8-3.9). This treatment effect was more than double the minimum clinically worthwhile difference specified in the trial protocol. These results show that the Lidcombe Program is significantly more effective than natural recovery for reducing stuttering levels in preschool children. The Lidcombe Program is the first early stuttering treatment to be shown to be more effective than natural recovery in a randomised controlled trial.

Philosophy(PhD) / This thesis presents a randomised controlled trial of the Lidcombe Program of Early Stuttering Intervention. The Lidcombe Program was developed for the treatment of stuttering in preschool-age children. The effectiveness of the Lidcombe Program was compared to a control group in a parallel group randomised controlled trial with blinded outcome assessment. A number of supplementary studies were conducted in support of the trial; two literature reviews, two retrospective file audits and a statistical simulation study. A review of randomised studies of treatments for stuttering showed that there have been 27 such studies published in English language journals. Of these only one was devoted to a treatment for early stuttering and that was the Lidcombe Program. The randomised study showed that 3 months of this treatment was associated with a lower level of stuttering compared to a control group who received no treatment. However, with a sample size of 23, this study lacked power and the children did not receive a full course of treatment. Despite these limitations, this study provided evidence that a medium to large effect size could be anticipated in an adequately powered and properly conducted randomised controlled trial. The second review was of sample size and power in stuttering research studies that had been published in two speech pathology journals; the Journal of Speech, Language and Hearing Research (Vol 39, No. 1 to Vol 40, No, 4) and the Journal of Fluency Disorders (Vol 21, No. 1 to Vol 22, No, 3). Results suggested that the majority (73%) of the 26 studies reviewed were insufficiently powered to detect even large effects. However it was acknowledged that it is very difficult to recruit even moderate sample sizes of people who stutter. It was concluded that one way to help improve this situation is collaboration of multiple research centres or, in the case of a randomised controlled trial, inclusion of multiple recruitment sites in one study. This strategy was adopted in the randomised controlled trial reported in this thesis. Two retrospective file audit studies of children treated with the Lidcombe Program were conducted in Australia and Britain. One purpose of these file audits was to obtain information relevant to the design and conduct of the randomised controlled trial. Data from the case reports on more than 300 children from the two sites were included in a meta-analysis. Results showed that a median of 11 weekly clinic sessions were required for children to attain the criteria for low levels of stuttering for completion of Stage 1 of the Lidcombe Program. Approximately 90% of children had achieved those criteria within 6 months of beginning treatment and almost all children had achieved them within 1 year. In addition two variables were found to be associated with longer treatment duration: more severe pre-treatment stuttering and shorter times from onset of stuttering to the start of treatment. The latter was apparent in the meta-analysis but not for the individual cohorts. As a result of these findings, pre-treatment stuttering severity was stratified along with other relevant variables in the randomised controlled trial and follow up for participants was a minimum of 9 months. A simulation study was conducted prior to analysis of data from the primary outcome measure of the randomised controlled trial: percentage of syllables stuttered (%SS). The distribution of %SS scores is positively skewed. Nonetheless, simulation showed t-test to be an appropriate analysis for this primary outcome measure. There were two treatment sites for the randomised controlled trial: the University of Canterbury (Christchurch, New Zealand) and the Stuttering Treatment and Research Trust (Auckland, New Zealand). A total of 54 preschool-age children were recruited: 29 to the Lidcombe Program and 25 to the control group. Half the proposed sample size was achieved due to slower than anticipated recruitment. This occurred because, as the trial progressed, treatment with the Lidcombe Program became common knowledge among parents in New Zealand and they became increasingly reluctant to agree to have their child randomised to the trial. Analysis with t-test showed a highly statistically significant difference (p = 0.003) at 9-months post-randomisation. The mean percentage of syllables stuttered (%SS) at 9-months post-randomisation was 1.5 (SD = 1.4) for the Lidcombe Program group compared to 3.9 (SD = 3.5) for the control group, resulting in a treatment effect of 2.3 %SS (95% confidence interval: 0.8-3.9). This treatment effect was more than double the minimum clinically worthwhile difference specified in the trial protocol. These results show that the Lidcombe Program is significantly more effective than natural recovery for reducing stuttering levels in preschool children. The Lidcombe Program is the first early stuttering treatment to be shown to be more effective than natural recovery in a randomised controlled trial.

The Lidcombe-program (LP) is an empirically developed treatment program for stuttering based on behavioral therapy that adopts operant conditioning as methodology. The program is designed for children up to the age of six, and it is mainly conducted in the home environment by a parent under the supervision of a speech-language pathologist (Onslow, 2003a). In countries around the world, studies of outcomes of the program have shown positive effects (Lincoln &Onslow, 1997). LP is conducted in Sweden, but no major long-term study has been performed.Criticism towards LP regards that the intervention would affect the relationship between thechild and the parent in negative ways (Woods, Shearsby, Onslow & Burnham, 2002).The present study is a follow up of children and parents who have undergone treatment withLP. The aim was to investigate how childrens’ fluency of speech changed after treatmentand to examine how parents' experiences of the program can be characterized. Ten parents were included in the study, and they all answered a questionnaire about the experiences of thetreatment. Fluency of speech was documented and assessed in eight children.The results of the present study showed that all of the participating childrens’ stuttering was significantly reduced after treatment. A strong significant correlation between the time the child spent in treatment and the percentage of stuttered syllables at baseline was observed. The majority of the parents had positive experiences of the treatment, and would recommend the program to other families. However, parents also found it difficult to execute the therapy, mainly as regards finding the time in the everyday life of the family. In addition, four of the participating parents disregarded the treatment manual and shared the responsibility of implementing the treatment with their spouse, but this did not appear to influence the outcome of the treatment. / Lidcombe-programmet (LP) är ett empiriskt framtaget behandlingsprogram som grundar sig i beteendeterapi och som antar operant betingning som metod. Behandlingen är utformad för barn upp till sex års ålder och bedrivs huvudsakligen i hemmet av en förälder under handledningav logoped (Onslow, 2003a). I flera länder runt om i världen har uppföljningsstudier visat positiva effekter av programmet (Lincoln & Onslow, 1997). Behandlingsprogrammet bedrivs i Sverige, men ingen större långtidsuppföljning har utförts. Kritik som riktats mot LP avser att interventionsformen påverkar relationen mellan barn och förälder negativt (Woods et al., 2002).Föreliggande studie är en uppföljning av barn och föräldrar som genomgått stamningsbehandling enligt LP. Syftet var att undersöka hur barns talflyt förändrats efter avslutad behandling samt att undersöka hur föräldrars upplevelser av programmet kan karaktäriseras. I studien ingick tio föräldrar, vilka besvarade en enkät kring upplevelser av behandlingen, samt åtta barn vars talfly tdokumenterades och bedömdes.Resultatet visade att samtliga av de deltagande barnens stamning minskade signifikant efteravslutad behandling. Ett starkt signifikant samband mellan tiden barnet spenderade i behandling och andelen stammade stavelser i procent vid behandlingsstart kunde påvisas. Majoriteten av föräldrarna hade positiva upplevelser av behandlingen och samtliga skulle rekommendera behandlingsprogrammet till andra familjer. Dock upplevde föräldrarna vissa svårigheter kring implementeringen av behandlingen, främst avseende att finna tid i vardagen. Fyra av de deltagande föräldrarna frångick behandlingens manual och delade på ansvaret för utförandet medmake/maka eller motsvarande, men detta föreföll inte påverka utgången av behandlingen.

The aim of this paper is to study the long-term effects of stuttering treatment according to the Lidcombe Program in Sweden and to answer questions whether underlying factors may have affected the treatment results. Participants were seven children, one girl and six boys aged 7:10-14:2, who all completed Stage 1 of the program approximately 2-7 years ago.The children were video recorded during a conversation with one of the authors and while reading aloud. Before the recording, their parents estimated the level of stuttering according to a Severity Range (SR) Scale. The evaluations were used as reference for determining whether the recordings were representative for the children´s current speech fluency. Proportions of stuttered syllables (%SS) were calculated from the video recorded material and compared with the proportions of stuttered syllables (%SS) at the time when the first stage of the program was initiated.The results showed that the Lidcombe Program had a significant (z=-2.37, p=0.02) long term effect on stuttering treatment for the participants in this study. The effect size was calculated to 1.05, which indicates a large effect. No correlation between underlying factors and treatment results could be established at group level. However, the results showed differences among the participants and underlying factors as age at stuttering onset and age when treatment was introduced may have affected the treatment results.This is one of the very first long term follow-ups on Swedish preschool children that have been treated according to the Lidcombe Program and the authors hope to see further research. / Studien syftade till att undersöka långtidseffekten av Lidcombeprogrammet för svenska förskolebarn som stammar samt fastställa om bakgrundsfaktorer påverkar behandlingseffekt. I studien deltog sju svensktalande barn, en flicka och sex pojkar, i åldrarna 7:10–14:2, som alla avslutade det första steget i behandlingen för cirka 2-7 år sedan.Långtidsuppföljningen genomfördes i form av videoinspelningar av barnens tal under samtal med en av författarna samt under en högläsningssituation. Föräldrarna till varje barn fick inför inspelningarna skatta sitt barns stamning på en Severity Rating (SR) Scale. Utvärderingarna användes för att få information om huruvida inspelningarna var representativa för barnens tal idag. Utifrån samtliga inspelningar beräknades sedan den procentuella andelen stammade stavelser (%SS) och denna mätning jämfördes sedan med den procentuella andelen stammade stavelser (%SS) för tidpunkten när behandlingen enligt Lidcombeprogrammet introducerades.Resultatet i föreliggande studie visade att Lidcombeprogrammet har haft effekt på lång sikt för deltagarna i föreliggande studie och resultatet var statistiskt signifikant (z=-2.37, p=0.02). Effektstorleken för dessa beräkningar var 1.05, vilket motsvarar en stor effekt. Inget samband kunde påvisas mellan bakgrundsfaktorer och behandlingseffekt på gruppnivå men resultatet på individnivå påvisar skillnader mellan deltagarna avseende ålder vid stamningsdebut och ålder vid behandlingsstart, eventuellt kan detta ha påverkat behandlingsresultatet för enskilda deltagare.Det här är en av de första långtidsuppföljningarna av svenska förskolebarn som behandlats enligt Lidcombeprogrammet och författarna efterfrågar fler studier.