Key Takeaway
Nearly two-thirds of 143 HRVB studies failed to report enough methodological detail to replicate the protocol, highlighting a major gap the authors address with standardized reporting guidelines.
Summary
This systematic review examined 143 studies on heart rate variability biofeedback (HRVB) published between 2000 and 2021, focusing specifically on methodological reporting and protocol standardization. The primary goal was to assess how well researchers describe their HRVB interventions and to develop guidelines for future studies.
The findings revealed a significant methodological gap in the field: almost two-thirds of included studies did not report sufficient information to replicate the HRVB protocol used. Key details frequently omitted included breathing rate targets, session duration, number of sessions, type of biofeedback display, and whether resonance frequency was individually determined. This lack of standardization makes it difficult to compare results across studies and identify which protocol parameters are most important for efficacy.
Based on their findings, the authors proposed comprehensive reporting guidelines for HRVB research. These guidelines cover essential protocol details including breathing parameters, biofeedback modality, session structure, training duration, and outcome measures. The guidelines aim to improve reproducibility and allow more meaningful meta-analyses of HRVB interventions going forward.
Methods
Systematic search of databases for HRVB studies published 2000-2021. Included 143 studies meeting criteria. Assessed each study for reporting of key methodological details: breathing protocol, biofeedback type, session parameters, training duration, and outcome measures. Developed reporting guidelines based on identified gaps.
Key Results
143 studies included in the review. Almost two-thirds of studies did not report enough methodological information to replicate the HRVB protocol. Commonly missing details included specific breathing rates, session structure, and biofeedback display type. Proposed standardized reporting guidelines covering all essential HRVB protocol parameters.
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Limitations
Review focused on reporting quality rather than efficacy outcomes, so it does not directly assess whether HRVB works. Limited to studies published 2000-2021, potentially missing earlier foundational work. Assessment of reporting adequacy required subjective judgment on what constitutes sufficient detail. Proposed guidelines have not yet been empirically validated for improving research quality.