Letter in Response to the Article: Network Meta-analysis of the Efficacy of Different Music Therapy Interventions for Delirium in Adult Intensive Care Unit Patients

Abstract

How to cite this article: Kwakernaak LTS, Klimek M. Letter in Response to the Article: Network Meta-analysis of the Efficacy of Different Music Therapy Interventions for Delirium in Adult Intensive Care Unit Patients. Indian J Crit Care Med 2026;30(5):446–447.

The Editor,

We read with interest the recent analysis by Hao et al. regarding the efficacy of various music interventions on delirium in critically ill adults and recognize their contributions to the growing evidence base on this topic.¹ While the subject is clinically relevant and the attempt to compare different interventions is commendable, several concerns limit this analysis and warrant careful consideration.

First, the assumption of transitivity between included studies is not met. The included studies differ substantially in patient populations, baseline delirium risk, and sedation practices. These factors are all plausible effect modifiers, even if inherent to the intensive care unit (ICU) setting. More importantly, there is no transitivity within the intervention characteristics. Music type, delivery mode, dose/frequency, and the presence of co-interventions vary substantially. The inclusion of both prerecorded music interventions and music therapy (MT), despite the clear distinction between these modalities, further complicates comparability. These issues of heterogeneity are compounded by persistent challenges in specifying music interventions. As noted in our meta-analysis on prerecorded music, structured reporting frameworks, for instance the adapted TiDier checklist as proposed by Dirven et al., could enhance transparency.^2,3 Although the various interventions are clearly presented at a general level, study-level specification is lacking. This limits reproducibility and weakens the validity of indirect comparisons, making the transitivity assumption a fundamental limitation.

Second, the assertion of evaluating “commonly used ICU music interventions” against usual care (UC) and positioning this analysis as an advance over previous reviews is not correct. For instance, five-element music [traditional Chinese medicine (TCM)] is used almost exclusively in China, and 85% (n = 12) of the included studies originate from Chinese hospitals, making it inappropriate to generalize this as internationally common.⁴ Likewise, “UC” is insufficiently specified and should be contextualized as the standard within Chinese hospitals rather than a universal comparator. Furthermore, the network structure is essentially star-shaped, with UC as the sole comparator and no direct head-to-head comparisons. As a result, all comparative estimates rely on indirect evidence, and inconsistency cannot be meaningfully assessed. This is particularly problematic in a field where interventions are heterogeneous, culturally embedded, and context-sensitive. Although multimodal delirium interventions are recommended, the absence of trials isolating and directly comparing individual components, such as music, renders any comparative conclusion between intervention types inherently fragile.

Third, there is an overinterpretation of surface under the cumulative ranking curve (SUCRA)-rankings. The apparent superiority of combined music interventions and TCM is derived from sparse data and wide uncertainty. Confidence is limited by the inclusion of mostly small studies, which are at risk of bias and are affected by incomplete data, lack of blinding, and small study effects. Practical constraints of ICU research add to these limitations.

In conclusion, while music may be beneficial against delirium, current evidence does not support reliable differentiation between interventions. Substantial heterogeneity and reliance on indirect comparisons limit validity. Implementing music against delirium remains a promising, patient-centered adjunct, and we appreciate the authors' efforts in synthesizing new evidence. However, comparative claims await head-to-head evidence, which will help clarify the best approaches.

Yours sincerely,

Lucas TS Kwakernaak and Markus Klimek

Artificial Intelligence (AI) Statement

No generative AI tools were used in the writing of this response letter. All of the enclosed content of this response letter was drafted and revised solely by the authors. Where AI-assisted tools (e.g., grammar checks, reference managers) were employed, they were solely utilized for language editing and formatting. The authors take full responsibility for the content of this work.

Orcid

Lucas TS Kwakernaak https://orcid.org/0009-0000-4321-6539

Markus Klimek https://orcid.org/0000-0002-0122-9929