The need for rigour in insomnia clinical trial research

The current issue of Sleep Medicine X contains an article by Pakdee et al. [1], which reports on a clinical trial of lorazepam, and two herbal/cannabinoid therapies for chronic insomnia. The experience of those with insomnia seeking diagnosis and treatment has been described in qualitative work by Henry et al. [2] as a “source of frustration” and “a prolonged process of seeking relief”. It is, therefore, incumbent on researchers to use sound methods, to ensure that those with insomnia do not experience additional frustration in trialling purportedly evidence-based therapies, where that evidence-base is of questionable validity.

Pakdee et al. [1] contains, in my opinion, several flaws in design and analysis, which were not broached by the authors in their article. Firstly, the authors recruited middle-aged patients with insomnia per DSM 5 criteria, with a view to treating that condition. However, the primary outcome measure, the Pittsburgh Sleep Quality Index, was developed to measure broad-ranging sleep disturbance [3], rather than insomnia, specifically. The authors also excluded younger patients due to concerns about circadian rhythm disorders, yet do not report any screening of Obstructive Sleep Apnoea, a common insomnia comorbidity and contributor to negative clinical outcomes [4]. With respect to statistical analyses, the authors report multiple between-groups one-way ANOVAs of the pre-post timepoints, however it is unclear why an analysis incorporating repeated measures was not performed, given the pre-post nature of the trial. Furthermore, the statistical reporting in the article does not report the F statistics for the ANOVAs, nor whether alpha-level corrections for multiple tests were performed. As we begin another exciting new year of sleep research, my hope is that this letter serves as a reminder to also be excited about good methodology, and the need for rigour in insomnia clinical research.

Declaration of competing interest

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Daniel Paul Sullivan reports a relationship with Australian Government Medical Research Future Fund that includes: funding grants. Daniel Paul Sullivan reports a relationship with Metro North Hospital and Health Service that includes: funding grants. Daniel Paul Sullivan reports a relationship with ResMed that includes: funding grants. Daniel Paul Sullivan reports a relationship with Pharmaceutical Society of Australia that includes: speaking and lecture fees and travel reimbursement. Daniel Paul Sullivan reports a relationship with Flinders University that includes: board membership. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.