Inter-centre comparison of data on surgery and speech outcomes at 5 years of age based on the Swedish quality registry for patients born with cleft palate with or without cleft lip

In Sweden, about one in 500 children are born with cleft lip with or without cleft palate (CL/P), which on average gives 175 births annually. These children receive treatment by a multidisciplinary team at one of six regional cleft lip and palate (CLP) centres, all connected to the Swedish quality registry for patients born with CL/P (CLP registry). The CLP registry was initiated to enable the continuous evaluation of treatment results at the Swedish CLP centres, with the objective to promote quality control, research and improvements in treatment, via the comparison of long-term results [1].

There are various procedures for primary cleft palate surgery [2]. The procedures differ regarding timing, staging and technique. Speech development benefits from early closure of the hard palate [3, 4], whereas maxillary growth may benefit from delayed closure of the palate [4, 5]. Today, two-stage palatal closure with delayed hard palate closure is used at four of six Swedish CLP centres, with the objective of promoting maxillary growth [5]. At the other two Swedish CLP centres, the palate is closed in one stage.

Surgical protocols for primary palatal surgery have a high degree of diversity and poor evidence base [6]. An aggravating circumstance for research in the area is that the population with cleft palate with or without cleft lip (CP ± L) is small and heterogeneous. Therefore, it may take a long time to collect data of larger groups of children. Timing, techniques for surgery and methods and materials for data collection may then change over time and violate the standardised evaluation of treatment outcome [7]. Multi-centre studies, such as the Scandcleft randomised trials [6] and the TOPS trial [8], allow for the recruitment of larger data sets during a period of time where these variables are kept constant.

However, in randomised controlled trials requiring the participating surgeons to master a new surgical technique, a learning curve could be expected, which may influence the results [9]. This raises ethical issues. Other challenges may include the recruitment of patients at CLP centres where the annual case load is low, and rules of research governance, which may increase the associated costs [9].

Four hundred and forty-eight children born with non-syndromic unilateral cleft lip and palate (UCLP) participated in the Scandcleft trials. In all trials, lip and soft palate closure at 3–4 months and hard palate closure at 12 months was the common method. In trial 1, this method was compared with lip and soft palate closure at 3–4 months and hard palate closure at 36 months, in trial 2 with lip closure at 3–4 months and hard and soft palate closure at 12 months and in trial 3 with lip and hard palate closure at 3–4 months and soft palate closure at 12 months. Speech and dentofacial development served as the primary outcomes. The only statistically verified finding in the Scandcleft trials was that delaying hard palate closure to 36 months of age is associated with poorer consonant proficiency at 5 years of age [10]. Shaw and Semb [9] concluded “that familiarity and operator skill outweigh the importance of protocol”. Thus, when comparing the treatment results of different protocols for primary palatal surgery, it is better if the surgeons adhere to surgical methods that they are already trained to use.

Nationwide studies/audits allow the inter-centre comparison of outcomes and can contribute to valuable scientific knowledge in the CLP area. This has been done for example in the United Kingdom [11] and New Zealand [12]. The Americleft project [13] covers several centres in the United States. Based on the Americleft project, one study on speech outcome after one versus two stage palatal surgery in children with cleft lip and complete cleft palate has been published [14]. National quality registries for patients born with CL/P facilitate continuous follow-up and evaluation of the results in CLP care. The CRANE database [15] in the United Kingdom (England, Wales, Northern Ireland) has published several studies, of which one focused on maxillary growth and speech in 5-year-olds with UCLP [16]. Although the speech assessment procedures in the Swedish CLP registry [1] are based on the same principles for speech analysis [17, 18] as those in the CRANE database [19], the speech outcome measures differ and are not comparable. The Norwegian CLP registry uses the same speech outcome measures [20] as the Swedish CLP registry [1] to a high degree. In the future, it may be possible to compare speech data between the Swedish and Norwegian CLP registries.

Several studies have assessed the reliability of speech data in the Swedish CLP registry [21‐23]. Brunnegård et al. [22] assessed the reliability of data on perceived velopharyngeal competence in the CLP registry, which was good to excellent. Furthermore, data on percentage consonants correct and percentage non-oral speech errors have been proven to be satisfying [22, 23]. Data from the Swedish CLP registry now allow for open comparison between CLP centres. The aim of the current study was to compare surgical treatment up to 5 years of age and speech outcomes at 5 years of age using data from the Swedish CLP registry.

Surgical procedures up to 5 years of age and speech outcomes at 5 years of age varied between the six Swedish CLP centres. At centre 4, where the palate was closed in more stages in several cases than at the other centres, the children underwent a higher number of cleft palate-related surgeries, with complete primary palate closure at a higher age; they also showed less favourable speech outcome on average. At centre 5 children were more likely to achieve ≥86% correct consonants, at centre 6 to have no non-oral speech errors, and at centre 3 to have competent or marginally incompetent velopharyngeal competence compared to the average results of the other centres.

The results indicate that it does not matter whether the last primary palatal surgery is performed before 13 months or between 13 and 25 months of age for the speech results. At centre 6 the palate in most cases was closed in one stage before 13 months of age, at centres 1, 2, and 3 most children had their last primary palatal surgery before 13 months or between 13 and 25 months of age, and at centre 5 a major part of the children were treated with one stage closure of the palate between 13 and 25 months of age. At these five centres, no deviating negative speech results were seen. However, at centre 4, where a major part of the children had their last primary palatal surgery after 25 months of age, the children were more likely to have a negative speech result at 5 years of age. This is in line with findings of the Scandcleft trials, where delaying hard palate closure to 36 months of age was associated with poorer consonant proficiency at 5 years of age [10].

According to the surgical protocols at all six Swedish CLP centres, the last primary palatal surgery should be performed at 24 months of age at the latest. Sometimes, surgery is delayed due to the child’s health condition, or organisational reasons, such as a lack of operating rooms, anaesthesiologists and surgical nurses. In centre 4, a delay was also related to more complications that required additional secondary surgical treatment associated with the new method of soft palate closure that was introduced in 2008. However, this method was also abandoned in 2014. Nevertheless, the results of the present and previous studies [10] are important when decisions are made to delay the primary palate surgery in children with cleft palate and when prioritising among patients awaiting surgery. Delaying palatal closure may require more healthcare resources in the long-term. In the present study, the centre with the highest proportion of children who underwent the last primary palatal surgery after 25 months of age, had a higher proportion of children who underwent secondary palatal surgery before the age of 5. As previously mentioned, this was due to a new modified method of palate repair with a high frequency of complications leading to poor velopharyngeal function. In addition, this centre also had a higher proportion of children who underwent speech-language therapy before 5 years of age.

As in previously published studies comparing speech outcome after one and two stage primary palatal surgery [10, 14, 32], the results of the present study indicated that whether the cleft in the palate is closed in one or two stages does not affect speech outcome. At two centres (5, 6) out of the five centres with no deviating negative speech results at 5 years of age, the palate was closed in one stage. At the other three (1, 2, 3) the palate was closed in two stages in 40.6 to 53.6% of the cases, and in one stage in the remaining cases. At centre 4, where the children were more likely to have negative speech results at 5 years of age, primary palatal surgery was performed in two stages in 61.5% of the cases and in three stages in 16.7% of the cases. Furthermore, as described above, at centre 4 the last primary palatal surgery was performed at a later age than at the other centres. It cannot be ruled out that both the later timing of the last primary palatal surgery and complications regarding the surgical technique, resulting in up to three stages of primary palatal closure, had a negative effect on speech.

The objective of two-stage palatal surgery is to promote maxillary growth [5]. In the Scandcleft trials, no differences in the dental arch relationships of children were seen at 5, 8 and 10 years of age related to different surgical protocols [33]. The final outcomes of maxillary growth can only be evaluated when growth is completed, in adulthood. This will be investigated in future studies based on the Swedish CLP registry.

In the present study, children with BCLP were less likely to achieve ≥86% correct consonants and have no non-oral speech errors and children with SP more likely to achieve ≥86% correct consonants, compared to children with UCLP. This finding is in accordance with results in previous studies, where more extensive orofacial clefts have been associated with poorer speech [34, 35]. Children with SHP were less likely to have competent or marginally incompetent velopharyngeal function than children with UCLP. A tendency of poorer velopharyngeal function in 5-year-olds with SHP compared to peers with other cleft types was seen in an earlier study, although the subgroups were small, and no significant differences were seen between groups [35]. Furthermore, girls were more likely than boys to achieve ≥86% correct consonants. This could be explained by the fact that cleft palate involving the lip is more common in males and cleft palate only in females [36], with the risk of consonant errors being higher in cases with more extended clefts.

A quality registry with high coverage and reporting degree may be an effective means for continuous open comparisons and knowledge-based management of CLP care. At centre 4, a new modified surgical method was used for closure of the palate of children born from 2009 to 2014. By evaluating the results of surgery and speech and comparing the results with those of the other Swedish CLP centres, it was clarified that the modified surgical method resulted in poorer postoperative speech results. Due to the poor results with high complication rate resulting in later closure of the palate when using the modified Gothenburg method, the method was changed for children born in 2015 and after. The original method of primary palatal surgery has therefore been/is used in both centre 4 and centre 3 since then. Open comparisons of data from the Swedish CLP registry are carried out every year and the effect of reverting to the original method at centres 4 and 3 will be evaluated. This is an example of how quality registries for CLP care may be used.

Forty-two children were excluded from the study. They did not differ significantly from participants, and no resulting bias is likely to have affected our findings. Several factors may contribute to the variations in speech results at different CLP centres, such as differences in treatment methods, coding of diagnoses and surgery and speech assessment. Within the Swedish CLP registry network, continuous data validation and calibration of registry users are ongoing [1]. However, it cannot be excluded that differences in assessment and coding may have affected the results of this study, since it was based on retrospective data. Although the reliability of the registered speech data has generally been proven to be good [22, 23], there may be differences in how strict different speech-language pathologists are when assessing different speech variables. Therefore, if deviant results are discovered when evaluating retrospective data, it is important to go back and scrutinise the raw data. If the deviating results remain, one needs to try to remedy the causes of the deviating results, as done at centre 4.

The centralisation of cleft care has been proposed as an intervention for the improvement of cleft care [11]. In the United Kingdom, the number of CLP centres was reduced from 57 to 11, to improve the treatment outcomes. Surgeons at these 11 CLP centres operate on at least 35 cases annually. The outcomes have improved post-centralisation [11]. In the present study, no clear association between patient volume and speech outcome was observed. Centres with fewer patients than 30 per year (1, 5, 6) and centres with more than 35 patients per year (2, 3) showed broadly equivalent results. One explanation for this may be that it is not only the caseload of a CLP centre that affects the outcomes, but also other factors, such as how many surgeons are active at a centre and routines for training inexperienced surgeons. The number of chief operators varied between one and four at different centres in the present study. In addition, the availability of anaesthesiologists, surgical nurses and surgery theatres are important, as it affects whether the established surgery protocol can be followed. The results highlight the importance of a well-functioning organisation of CLP care.

The results indicated a risk of a negative speech result if the last primary palatal surgery was performed after 25 months of age. Whether the cleft in the palate was closed in one or two stages did not affect speech outcome. The Swedish CLP registry is useful for the open comparison of treatment results, to provide a basis for the improvement of treatment methods. If deviating negative results are seen consistently at a centre, one should act on this information by further investigation and analysis and making changes to the treatment protocol as needed.