Association of alternative polysomnographic features with patient outcomes in obstructive sleep apnea: a systematic review.

STUDY OBJECTIVES: Polysomnograms (PSGs) collect a plethora of physiologic signals across the night. However, few of these PSG data are incorporated into standard reports, and hence, ultimately, under-utilized in clinical decision making. Recently, there has been substantial interest regarding novel alternative PSG metrics that may help to predict obstructive sleep apnea (OSA)-related outcomes better than standard PSG metrics such as the apnea-hypopnea index. We systematically review the recent literature for studies that examined the use of alternative PSG metrics in the context of OSA and their association with health outcomes. METHODS: We systematically searched EMBASE, MEDLINE, and the Cochrane Database of Systematic Reviews for studies published between 2000 and 2022 for those that reported alternative metrics derived from PSG in adults and related them to OSA-related outcomes. RESULTS: Of the 186 initial studies identified by the original search, data from 31 studies were ultimately included in the final analysis. Numerous metrics were identified that were significantly related to a broad range of outcomes. We categorized the outcomes into 2 main subgroups: (1) cardiovascular/metabolic outcomes and mortality and (2) cognitive function- and vigilance-related outcomes. Four general categories of alternative metrics were identified based on signals analyzed: autonomic/hemodynamic metrics, electroencephalographic metrics, oximetric metrics, and respiratory event-related metrics. CONCLUSIONS: We have summarized the current landscape of literature for alternative PSG metrics relating to risk prediction in OSA. Although promising, further prospective observational studies are needed to verify findings from other cohorts, and to assess the clinical utility of these metrics. CITATION: Hajipour M, Baumann B, Azarbarzin A, et al. Association of alternative polysomnographic features with patient outcomes in obstructive sleep apnea: a systematic review. J Clin Sleep Med. 2023;19(2):225-242.

Sleep Deficiency: Epidemiology and Effects.

Adequate sleep is an important pillar of physical and mental health. Sleep deficiency, resulting from short sleep or suboptimal sleep quality, is highly prevalent in modern society. Occupation, social demands, psychiatric disorders, physical disorders, and sleep disorders are some of the contributing factors to sleep deficiency. Some populations are at increased risk of sleep deficiency based on ethnicity, age, marital status, sex, and hospitalization. Sleep deficiency influences cognition, alertness, mood, behavior, diabetes, cardiovascular health, renal function, immune system, and respiratory physiology. This review summarizes the epidemiology and effects of sleep deficiency.

Revisiting level II sleep studies in the era of COVID-19: a theoretical economic decision model in patients with suspected obstructive sleep apnea.

BACKGROUND: The recent pandemic has made it more challenging to assess patients with suspected obstructive sleep apnea (OSA) with in laboratory polysomnography (PSG) due to concerns of patient and staff safety. The purpose of this study was to assess how Level II sleep studies (LII, full PSG in the home) might be utilized in diagnostic algorithms of suspected OSA using a theoretical decision model. METHODS: We examined four diagnostic algorithms for suspected OSA: an initial PSG approach, an initial LII approach, an initial Level III approach (LIII, limited channel home sleep study) followed by PSG if needed, and an initial LIII approach followed by LII if needed. Costs per patient assessed was calculated as a function of pretest OSA probability and a variety of other variables (e.g. costs of tests, failure rate of LIII/LII, sensitivity/specificity of LIII). The situation in British Columbia was used as a case study. RESULTS: The variation in cost per test was calculated for each algorithm as a function of the above variables. For British Columbia, initial LII was the least costly across a broad range of pretest OSA probabilities (< 0.80) while initial LIII followed by LII as needed was least costly at very high pretest probability (> 0.8). In patients with a pretest OSA probability of 0.5, costs per patient for initial PSG, initial LII, initial LIII followed by PSG, and initial LIII followed by LII were: $588, $417, $607, and $481 respectively. CONCLUSIONS: Using a theoretical decision model, we developed a preliminary cost framework to assess the potential role of LII studies in OSA assessment. Across a broad range of patient pretest probabilities, initial LII studies may provide substantial cost advantages. LII studies might be especially useful during pandemics as they combine the extensive physiologic information characteristic of PSG with the ability to avoid in-laboratory stays. More empiric studies need to be done to test these different algorithms. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s41606-021-00063-5.

Latent Tuberculosis Therapy Outcomes in Dialysis Patients: A Retrospective Cohort.

RATIONALE & OBJECTIVES: Maintenance dialysis patients are at an increased risk for active tuberculosis (TB). In 2012, British Columbia, Canada, began systematically screening maintenance dialysis patients for latent TB infection (LTBI) and treating people with evidence of LTBI when appropriate. We examined LTBI treatment outcomes and compared treatment outcomes before and after rollout of the systematic screening program. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: The study comprised 365 people in British Columbia, Canada, initiating at least 90 days of dialysis from January 1, 2001, to May 31, 2017, and starting LTBI therapy: 290 (79.5%) people in the recent cohort and 75 (20.5%) in the historical cohort. People starting LTBI therapy from January 1, 2012, onward were classified as the recent cohort, whereas people starting LTBI therapy before January 1, 2012, were classified as the historical cohort. EXPOSURE: Systematic LTBI screening and therapy. OUTCOMES: Proportion of people who experience grade 3 to 5 adverse events (AEs) or any grade rash and end-of-treatment outcomes. ANALYTICAL APPROACH: Outcomes were reported using descriptive statistics. 2-sample test of proportions using χ2 distribution was used to test for statistical significance between the recent and historical cohorts. RESULTS: 298 (81.6%) people successfully completed LTBI therapy. The proportion of people experiencing a grade 3 to 4 AE or any grade rash was 21.1%. Most AEs were related to gastrointestinal events, general malaise, or pruritus that resulted in regimen changes. 2 (0.5%) people were hospitalized for AEs related to LTBI therapy. No significant difference was found between the recent and historical cohorts in all outcomes of interest. No grade 5 AEs (deaths) were attributed to LTBI therapy. LIMITATIONS: Retrospective data and generalizability outside low-TB-burden settings. CONCLUSIONS: Our findings suggest that a high proportion of people receiving maintenance dialysis can complete LTBI therapy. The rate of grade 3 to 4 AEs was high and associated with frequent medication changes during therapy. LTBI therapy in maintenance dialysis may be safe but requires close monitoring.

Long-term all-cause mortality in people treated for tuberculosis: a systematic review and meta-analysis.

BACKGROUND: Accurate estimates of long-term mortality following tuberculosis treatment are scarce. This systematic review and meta-analysis aimed to estimate the post-treatment mortality among tuberculosis survivors, and examine differences in mortality risk by demographic and clinical characteristics. METHODS: We systematically searched Embase, MEDLINE, and the Cochrane Database of Systematic Reviews for cohort studies published in English between Jan 1, 1997, and May 31, 2018. We included research papers that used a cohort study design, included bacteriological or clinical confirmation of tuberculosis disease for all participants, and reported, or provided enough data to calculate, mortality estimates for people with tuberculosis and a valid control group representative of the general population. We excluded studies that reported duplicate data, had a study population of fewer than 50 people overall, had a follow-up period shorter than 12 months after treatment completion, or had a loss to follow-up of more than 30%. From eligible studies, we extracted standardised mortality ratios (SMRs), or calculated them when the data were sufficient, by dividing the sum of the observed deaths by the sum of the expected deaths. For studies that did not report SMR as their mortality estimate, either mortality hazard ratios or mortality rate ratios were extracted and pooled with SMRs. Random-effects meta-analysis was used to obtain pooled SMRs. Between-study heterogeneity was estimated with I2. This study was prospectively registered in PROSPERO (CRD42018092592). FINDINGS: Of the 7283 unique studies identified, data from ten studies, reporting on 40 781 individuals and 6922 deaths, were included. The pooled SMR for all-cause mortality among people with tuberculosis, compared with the control group, was 2·91 (95% CI 2·21-3·84; I2=99%, pheterogeneity<0·0001). When restricted to people with confirmed treatment completion or cure, the pooled SMR was 3·76 (95% CI 3·04-4·66; I2=95%). Effect estimates were similar when stratified by tuberculosis type, sex, age, and country income category. Causes of mortality were extracted for 4226 deaths that occurred post-treatment, with most deaths attributable to cardiovascular disease (20% [95% CI 15-26]; I2=92%). INTERPRETATION: People treated for tuberculosis have significantly increased mortality following treatment compared with the general population or matched controls. These findings support the need for further research to understand and address the biomedical and social factors that affect the long-term prognosis of this population. FUNDING: None.