Level 2 Polysomnography for the Diagnosis of Sleep Disorders: A Health Technology Assessment.

BACKGROUND

It is estimated that half of Canadians have insufficient sleep, which over time is associated with poor physical and mental health. Currently, the only publicly funded option for the diagnosis of sleep disorders in Ontario is an in-person overnight sleep study, performed in a hospital or independent health facility (known as a level 1 polysomnography). Level 2 polysomnography has been proposed as an alternative that can be conducted at home for the diagnosis of suspected sleep disorders, if considered to have sufficient diagnostic accuracy. We conducted a health technology assessment of level 2 polysomnography for the diagnosis of suspected sleep disorders in adults and children, which included an evaluation of the test performance, cost-effectiveness, and budget impact of publicly funding level 2 polysomnography, and the experiences, preferences, and values of people with suspected sleep disorders.

METHODS

We performed a systematic literature search of the clinical evidence to identify diagnostic accuracy, test failures and subjective measures of patient preferences. We assessed the risk of bias of each included study (using the Quality Assessment of Diagnostic Accuracy Studies [QUADAS-2] tool) and the quality of the body of evidence (according to Grading of Recommendations Assessment, Development, and Evaluation [GRADE] Working Group criteria). We performed a systematic literature search of economic evidence and conducted a primary economic evaluation and budget impact analysis to determine the cost-effectiveness and additional costs of publicly funding level 2 polysomnography for adults and children with suspected sleep disorders in Ontario. To contextualize the potential value of using level 2 polysomnography, we spoke with people with sleep disorders.

RESULTS

We included 10 studies that reported on diagnostic accuracy and found level 2 polysomnography had sensitivity ranging between 0.76-1.0 and specificity ranging between 0.40-1.0 (GRADE: Moderate to Very low) when compared with level 1 polysomnography. Studies reported test failure rates from 0% to 20%, with errors present in both level 1 and level 2 tests conducted (GRADE: Very low). As well, some of these studies reported patients were found to have mixed opinions about their experiences, with more people preferring their experience with level 2 testing at home and having better quality of sleep compared with when they underwent level 1 testing (GRADE not conducted).Our primary economic evaluation showed that for adults with suspected sleep disorders, the new diagnostic pathway with level 2 polysomnography was equally effective (outcome: confirmed diagnosis at the end of the pathway) as the current practice diagnostic pathway with level 1 polysomnography. With the assumption of a lower technical fee for level 2 polysomnography, the new diagnostic pathway with level 2 polysomnography was less costly than the current practice diagnostic pathway (a saving of $27 per person with a wide 95% credible interval [95% CrI, -$137 to $121]), indicating that the results are highly uncertain. For children, a new diagnostic pathway with level 2 polysomnography was associated with additional costs (mean, $9.70; 95% CrI, -$125 to $190), and similarly, this estimate was highly uncertain.We estimated that the budget impact of publicly funding level 2 polysomnography for adults is uncertain and could range from savings of $22 million to additional costs of $43 million. Publicly funding a diagnostic pathway with level 2 polysomnography for children could result in additional costs of about $0.005 million over the next 5 years.People with whom we spoke reported that their sleep disorder negatively impacted their day-to-day lives, mental health, social and family relationships, and work. Participants who had experience with in-clinic (level 1) polysomnography described negative experiences they had at the clinic. Most people said they would prefer at-home (level 2) polysomnography over in-clinic (level 1) polysomnography, citing comfort and convenience as the main reasons; however, some people who have physical limitations preferred level 1 (in-clinic) polysomnography because they needed assistance to set up the equipment.

CONCLUSIONS

Level 2 polysomnography may have good test performance for adults and children, with adequate diagnostic accuracy, compared with level 1 polysomnography. The economic analyses showed that level 2 polysomnography for adults with suspected sleep disorders could be potentially cost saving but there is high uncertainty in the cost-effectiveness results. Given very limited information, the cost-effectiveness of this technology is also highly uncertain for children and young adults with suspected sleep disorders. The budget impact of publicly funding level 2 polysomnography for adults could range from savings of $22 million to additional costs of $43 million. Publicly funding level 2 polysomnography in children would require additional costs of about $0.005 million over the next 5 years. A clearer understanding of uptake of the technology, test costs, and the implementation pathway for adopting the technology is needed to improve the certainty of the cost-effectiveness and budget impact estimates. People with sleep disorders highlighted how important getting a diagnosis had been in order to be able to seek proper treatment for their sleep disorder and improve their lives. For many people with suspected sleep disorders, undergoing a sleep study at home would be a more comfortable and convenient option than undergoing a sleep study in clinic.