Discussion
TD, depression, voice, anxiety
RECRUITMENT
We reported on treatment fidelity in a multi-national clinical trial, LongSTEP. Average TD composite scores indicate that music therapists adhered to central elements of the intervention protocol to a satisfactory degree and that MT was a uniform intervention during the NICU stay and follow-up post-discharge. TR scores were also satisfactory, with several items scoring very high, suggesting that parents received the essential elements of the intervention. Parents who received MT during both NICU and post-discharge had the highest TR composite score, but differences between receiving MT in one or both phases were smaller than expected. Due to cultural differences between the participating countries, variation in experience of therapists and raters, and the complex nature of the intervention, we were pleasantly surprised by these results. In line with a pragmatic approach [Treatment fidelity questionnaires had acceptable internal consistency and moderate interrater reliability (IRR). The moderate results on IRR could be due to the complex, flexible character of the intervention. Interpreting musical interaction and subtle infant behaviours from recordings with varying quality is challenging. We also believe that rater training could have been better. Whereas the music therapists received standardized training in the intervention and supervision, the external raters received written instructions for evaluation of the sessions and written individual support when they requested it. We recommend providing more systematic training of raters, including establishing adequate interrater reliability with the intervention trainer using sample videos before commencing rating of study data. We also recommend recruiting raters who have a similar level of familiarity with the intervention and population in question, since the level of experience likely influences assessments. We did not complete an analysis of test-rest reliability due to a lack of resources but recommend such analysis. Instructions for raters should also include a narrow time window for completing ratings and we suggest that ratings be completed shortly after sessions take place, so that potential problems with recordings or other factors are discovered early in the process.Overall TD scores were high but one item concerning parents’ voices serving as prominent musical voices during MT, which scored below the threshold for satisfactory adherence (≥4). This finding could be explained by the fact that singing to one’s baby is an intimate action that many parents can feel shy or insecure about with others present. At some sites, lack of space meant that several families shared rooms, which poses several challenges including the risk of contamination. Control group families were asked to avoid participating in any music-related intervention during the intervention period, but due to open-bay units and lack of space, intervention and control group families may at times have been in the same room. While MT was tailored individually, such that other families in the room would not have received MT per protocol, there is still a chance that they overheard tips and strategies and applied these independently. A cluster randomized design could have reduced this risk for contamination but was not chosen as it among other things would have required recruitment of more participants [It may be that expectations regarding active participation through the use of voice vary considerably among external raters, music therapists, and parents. Where external raters and music therapists might have expected that parents would sing often in most sessions, and hence rated this item low when singing occurred less often than expected, parents might have felt that any amount of singing was more than they would have done without MT and thus perceived their own vocal engagement as substantial. An item unique to the TR questionnaire addressed whether parents experienced their voices as being unique and important to their baby. This item had a very high (>5) score, which suggests that parents experienced their own voices as unique resources, despite the music therapist and external raters rating parents low on the use of voice in sessions.While the results from the main timepoint of the LongSTEP trial are not yet published, results from the preliminary timepoint of discharge report a non-significant effect of MT on mother-infant bonding, maternal depression, or parental anxiety [Our TF analysis has limitations. For TD evaluation, all raters knew when in the therapeutic process the session happened which might have affected raters’ expectations and the outcomes of the ratings. There were large differences between the therapists’ number of participants and sessions and hence large variation in the data from which the scores were calculated. It may be that the sample of participants for TD was not representative due to our strategy of excluding participants with missing video/audio. It is also possible that poor audio/video quality in some instances made certain behaviours correspondent with the intervention’s essential elements very difficult to observe. The TF questionnaires lacked an option for raters to report if the item was not possible to observe, and the degree to which raters reported poor data quality may have varied. In contrast to recordings strategically selected for TD assessment, parents who evaluated TR rated their overall experience with MT thinking back on the course of sessions over time, meaning they could base their evaluation on more sessions and probably a broader range of experiences.LongSTEP was designed as a pragmatic trial aiming to increase the applicability of study results to real-world settings and usual treatment. However, through developing and implementing strategies to enhance, monitor, and evaluate TF which included the development of intervention guidelines [