Sleep study documentation: is less more, or is more better?

In this issue of Journal of Clinical Sleep Medicine the study by Herberts and Morgenthaler¹ evaluates the consistency of documentation of certain quality criteria in interpretations of sleep studies and clinical notes in patients with obstructive sleep apnea (OSA). The researchers formulated a list of quality criteria and OSA phenotypes that they suggest should be reflected in study interpretations. They then retrospectively reviewed the documentation of sleep studies to determine how often these factors were incorporated in interpretation reports or clinical notes. The study found that sleep apnea phenotypes, such as positional OSA (POSA) or OSA without obesity, were frequently undocumented. Additionally, predetermined quality criteria were not mentioned in a high proportion of interpretations or clinical notes.

The lack of consistency in documentation of quality criteria and clinically important OSA phenotypes is a cause for concern because it may affect patient outcomes. For example, inadequate total recording time during polysomnography or total sleep time on home sleep apnea testing may lead to less reliable, or inaccurate, diagnosis and treatment. Similarly, failure to document positionality of OSA and absence of supine rapid eye movement sleep during positive airway pressure titration may affect treatment decisions and outcomes.

The lack of standardization in documentation and interpretation of sleep studies may be due to several factors, including differences in training and expertise among sleep provider, lack of consensus on quality criteria and disease phenotypes, and lack of standardization in reporting formats. The authors suggest that better organization of test results, automated calculation, and more graphical display of important quality indicators and/or phenotype classification might improve recognition and reporting.

However, the study has some limitations that need to be considered. First, the study sample size is relatively small, and the study represents a single institution, which limits the generalizability of the findings. The study also did not examine the reasons behind the inadequate documentation of sleep study quality criteria and phenotypes. Additionally, the study did not evaluate the impact of inadequate documentation on patient outcomes, such as management choices, treatment adherence and clinical outcomes.

The authors also discuss POSA, which they define as a supine apnea-hypopnea index (AHI) of 10 or more events/h plus a lateral AHI less than 10 events/h. While the point about POSA is accurate, the definition used in this study is simplistic and may be misleading. To illustrate this point, consider the following sleep study results from 4 hypothetical patients:

1. AHI 11 supine and AHI 9 nonsupine

2. AHI 9 supine and AHI 1 nonsupine

3. AHI 50 supine and AHI 5 nonsupine, with sleep in nonsupine position for 6.5 hours or more out of 7 hours of sleep.

4. AHI 50 supine and AHI 5 nonsupine, with sleep in supine position for 6.5 hours or more out of 7 hours of sleep.

The definition used by the authors, as well as several other POSA definitions, may not be able to accurately guide the appropriate therapy for patients in such cases. For instance, patient 1, who meets the definition of POSA, may not benefit from positional therapy, whereas patient 2, who does not meet the definition, may still benefit from it. Patients 3 and 4 have the same supine and nonsupine AHI, but the former will be more likely to be able to adhere to avoiding supine sleep assuming the study was done in natural sleep positions. Thus, caution must be exercised when interpreting the results of studies using POSA definitions, and clinical acumen should be applied to tailor interpretations as well as therapy for individual patients. Nevertheless, it is important to acknowledge the potential impact of supine sleep on the severity of sleep apnea, albeit with appropriate caveats.

Within the Discussion section, the authors briefly touch upon the concept of endotypes in the context of OSA, a notion that has recently garnered attention as a promising avenue for personalized treatment. Endotypes refer to subsets of patients with OSA who exhibit specific physiological characteristics, such as variations in upper airway structure and collapsibility, arousal threshold, and ventilatory control.² Identification of these subgroups holds potential to illuminate the underlying mechanisms of each patient’s OSA and may ultimately enhance clinical decision-making. It is important to acknowledge, however, that the current evidence is not adequate to support the diagnosis of endotypes based on sleep studies in clinical practice or offer a role in management. Although initial investigations have examined endotypes in polysomnograms, validation of endotypes in portable sleep studies is still pending.³ As such, it is imperative to exercise caution when considering documenting the possible endotypes in the sleep studies or their clinical implications in OSA management.

The implementation of any guidelines supporting the recording of data with equivocal clinical significance can pose a formidable challenge to health care staff and providers, exacerbating the already burdensome documentation requirements. Extensive literature exists on the impact of documentation burden on health care providers,⁴ and further discussion on this issue is beyond the scope of this paper.

In addition, there exists a risk that the treating providers may misconstrue the meaning of ambiguous terminology, leading to inappropriate therapeutic interventions. This is particularly concerning in the context of sleep medicine, where many providers are not sleep specialists and have limited knowledge of the field. Furthermore, patients may have queries regarding their sleep study findings and may struggle to interpret equivocal terminology, creating confusion and further delays in treatment.

Thus, it is imperative that the clinical implications of these variables be validated before their inclusion in sleep study interpretations. Clinicians must exercise clinical judgment when interpreting sleep study data to make appropriate conclusions for individual patients.

Despite these challenges, this study has significant implications for clinical practice. It underscores the gaps in sleep study quality criteria documentation and argues for standardization in the documentation and interpretation of sleep studies for OSA. Standardization may be achieved through the development of balanced reporting guidelines and quality parameters. Sleep centers may also need to improve their documentation practices to enhance recognition and reporting of important clinical findings. As the authors propose, the use of graphics and tools to facilitate pattern recognition in sleep studies can aid in the identification and reporting of clinical findings.

Future research is required to understand the reasons behind inadequate documentation and to evaluate the effects of insufficient documentation on patient outcomes. Furthermore, future work should aim to elucidate the significance of recognizing sleep apnea phenotypes and endotypes and whether this recognition can help clinicians make more personalized treatment decisions.

DISCLOSURE STATEMENT

This was not an industry-supported study. The author reports no conflicts of interest.