Table 1. Articles on VTE (or DVT/PE) following OSA diagnosis obtained from database search.

OSA: obstructive sleep apnea; VTE: venous thromboembolism; DVT: deep vein thrombosis; PE: pulmonary embolism; CPAP: continuous positive airway pressure; SBD: sleep breathing disorder; AHI: apnea-hypopnea index; PTE: pulmonary thromboembolism; OSAHS: obstructive sleep apnea-hypopnea syndrome; OSAS: obstructive sleep apnea syndrome; INR: international normalized ratio; PT: prothrombin time; PESI: pulmonary embolism severity index; HR: hazard ratio

	Author	Country	Design & Study Population	Findings	Conclusion
1	Le Mao et al., 2020 [80]	Germany	Prospective cohort study n=(4,153)	5.8% (n=241) of patients with PE had OSA. Patients with concomitant OSA and acute PE had a higher 30-day PE-specific mortality (P< 0.01).	Prophylactic therapeutic regimens must be developed as the presence of concomitant OSA and PE has adverse clinical outcomes.
2	Toledo-Pons et al., 2019 [71]	Spain	Prospective cohort study, n=(120)	OSA patients also had a higher pulmonary embolism severity index (PESI) compared to the AHI ≤ 15/hr cohort (P = 0.007).	PE patients with moderate to severe OSA have worse PE clinical severity. AHI is an independent risk factor for worse PESI outcomes.
3	Berhgaus et al., 2015 [76]	Germany	Prospective cohort study n=(106)	7.5% of patients were diagnosed as having high-risk pulmonary embolism (PE). Frequency of high-risk PE was significantly higher among patients with moderate to severe OSA (P = 0.005).	OSA is a common comorbidity in patients with PE and may contribute as a risk factor for the hemodynamic alterations observed in PE.
4	Jiang et al., 2015 [75]	China	Prospective cohort study n=(97)	Patients with OSAHS require higher doses of warfarin compared to their non-OSAHS counterparts (P < 0.001).	OSAHS patients appear to have a procoagulant state and require a more aggressive anticoagulant treatment regimen to prevent recurrence of PE.
5	Chou et al., 2012 [57]	Taiwan	Non-randomized, pair-matched cohort study, n=(10,185)	Patients with sleep apnea had a 3.113x increase in subsequent DVT (P < 0.002). The incidence of DVT was higher in patients with OSA that required CPAP treatment (P< 0.001).	Sleep apnea was identified as an independent risk factor for subsequent DVT, and patients with severe sleep apnea may be at a higher risk for DVT.
6	Alonso-Fernandez et al., 2013 [58]	USA	Case-control study, n=(209)	The AHI was significantly higher in patients with PE (P< 0.001). 33.6% (n=36) of patients had idiopathic PE.	OSA prevalence is higher in PE patients and there is an independent and significant association between OSA and PE.
7	Konnerth et al., 2018 [77]	Germany	Observational cohort study, n=(253)	Frequency of moderate to severe OSA was higher in high-risk PE patients (P = 0.006). PE patients with moderate to severe OSA had significantly higher D-dimer levels (P = 0.024) compared to patients without OSA.	Acute PE may present more severely when coupled with OSA due to pathophysiological mechanisms such as OSA-related hypoxemia and hypercoagulability.
8	Berhgaus et al., 2016 [79]	Germany	Prospective cohort study, n=(206)	Patients with moderate OSA had a 3.75-fold higher risk of acute PE compared to patients with mild OSA (P < 0.001.). Patients with moderate or severe OSA had significantly lower mean and nadir asleep saturation  (P < 0.01 and P < 0.001, respectively).	Likelihood of sleep-related acute PE manifestations is significantly associated with the severity of OSA. Intermittent hypoxia seen in OSA might have prothrombotic effects which lead to VTE.
9	Lin et al., 2013 [81]	Taiwan	Prospective matched-cohort study, n=(15,664)	Risk of developing VTE during the five-year follow-up period was 2.07 times greater in OSA patients than in pair-matched controls after adjusting for confounding variables such as gender, age, and obesity.	Patients with OSA have an increased risk of subsequent DVT in the first five years of their diagnosis, and early recognition and therapy would help in diminishing adverse outcomes.
10	Chung et al., 2015 [86]	Taiwan	Population-based study,  n=(139,113)	Incidence of VTE was higher in patients with sleep disorders compared to patients without sleep disorders (adjusted HR of 1.79, 95% CI, 1.49–2.16). Women with sleep disorders are at a higher risk of developing subsequent VTE compared to men (adjusted HR of 2.19, 95% CI, 1.74–2.74).	Patients with sleep disorders are at a higher risk of developing subsequent VTE and sleep-disorder management is important to reduce the incidence of VTE.
11	Alonso-Fernández et al., 2016 [83]	Spain	Prospective cohort study, n=(120)	OSA patients with a previous PE episode had a higher risk of PE recurrence compared to patients without OSA (P = 0.026).	OSA is an independent risk factor for recurrent PE. OSA patients with recurrent PE events should continue anticoagulation treatment as they present with a persistent hypercoagulable state.
12	Bahar et al., 2019 [70]	Turkey	Prospective cohort study, n=(239)	The rate of D-dimer positivity was found to be 17.6% higher in patients with OSAS compared to the control cohort (P = 0.034). The overall prevalence of DVT in OSAS patients was 2.2%.	OSAS is a significant risk factor for subsequent DVT, and patients with severe OSAS should be evaluated for DVT symptoms and possible prophylaxis.
13	Peng et al., 2014 [59]	Taiwan	Retrospective population-based cohort study, n=(38,621)	The risk of DVT was 3.50 fold higher (95% CI = 1.83–6.69) in OSA patients compared to the control cohort. The risk of PE was 3.97 fold higher (95% CI = 1.85–8.51) in OSA patients compared to the control group.	OSA remains an independent risk factor for subsequent DVT and PE after adjusting for age, sex, and other comorbidities.
14	Abd El-Azem, 2019 [69]	Kuwait	Prospective cohort study, n=(107)	A total of 72 patients were diagnosed with OSA and 25% (n=18) of them developed subsequent VTE; 67% (n=12) of the patients who developed VTE had severe OSA (AHI≥30/h).	The occurrence and recurrence of VTE are due to the underlying pathophysiological effects of OSA. The severity of OSA is associated with an increased risk of VTE.
15.	Ghiasi et al., 2015 [74]	Iran	Prospective cohort study, n=(137)	There was no association between OSA and 30-day mortality (P = 0.389) in PE patients. Complications of OSA such as hypertension increased the risk of 30-day mortality among patients with PE (P = 0.003).	Complications of OSA, rather than OSA itself, are associated with an increase in 30-day mortality among patients with PE.
16.	Seckin et al., 2020 [89]	USA	Retrospective cohort study, n=(25,038)	Frequency of acute PE in patients with OSA was 2.4% (P < 0.001). After confounding variables were adjusted, OSA remained an independent risk factor for PE occurrence (P= 0.017).	OSA is an independent risk factor for the occurrence of acute PE, however, OSA does not have a significant effect on hospital mortality among PE patients.
17.	Kezban et al., 2012 [60]	Turkey	Cross-sectional study, n=(30)	Prevalence of OSA in patients with PTE was higher (57%) than in the general population (1-5%). In patients diagnosed with PTE without any known VTE risk factors, OSA was the only significant risk factor  (P = 0.045).	PTE patients with OSA symptoms must be evaluated for OSA as there seems to be a significant relationship between OSA and PTE.
18.	Bosanquet et al., 2011 [82]	USA	Retrospective cohort study, n=(840)	Prevalence of OSA in patients with VTE was 15.5% (n=130). Concomitant occurrences of VTE and OSA were associated with obesity (P< 0.001).	There is a link between OSA and venous thrombotic disorders, and obesity is one of the confounding variables.
19.	Hong et al., 2017 [18]	Korea	Retrospective cohort study, n=(146)	Patients with severe OSA had a shorter PT compared to the control group (median difference, 0.59; 95% CI, 0.14 to 1.03).	Patients with moderate to severe OSA have higher blood coagulability markers compared to the general population, suggesting that the severity of OSA is associated with an increased procoagulant state.
20.	Geissenberger et al., 2020 [72]	Germany	Prospective cohort study, n=(101)	All patients enrolled were diagnosed with acute PE (n=101).  Patients with moderate to severe OSA had a higher PE severity score (P < 0.001).	OSA is associated with disease severity and survival in patients with acute PE.
21.	Xie et al., 2019 [88]	China	Retrospective cohort study, n=(1,939)	Patients with overlap syndrome (coexistence of obstructive sleep apnea and chronic obstructive pulmonary disease) had significantly higher odds of PE (P < 0.001).	OS is more closely associated with the prevalence of PE than OSA alone.
22.	Epstein et al., 2010 [61]	USA	Prospective cohort study, n=(270)	Patients diagnosed with PE had a higher prevalence of snoring (P = 0.001) and an increased risk of having OSA (P < 0.001) compared to patients without PE.	Findings support that OSA may be an independent risk factor for the development of PE.
23.	Arzt et al., 2012 [87]	Germany	Prospective cohort study, n=(164)	SBDs were found to be more prevalent in patients with DVT and/or PE (P = 0.046). This association was significant in females (P = 0.042), but not in males (P = 0.391).	SBDs are more prevalent in females with DVT and/or PE than in pair-matched controls and are independently associated with thromboembolic events.
24.	Zhang et al., 2012 [84]	China	Retrospective cohort study, n=(58)	PTE patients diagnosed with OSAHS had a higher BMI (P < 0.001), lower age of onset of disease (P < 0.01), and a higher smoking index (P < 0.05).	PTE patients with OSAHS were associated with more severe disease outcomes and should be offered anticoagulant medications and CPAP therapy.
25.	Xu et al., 2020 [73]	China	Meta-analysis, n=(1,570)	PE patients with OSA were more likely to have recurrent PE compared to patients without OSA (RR = 3.87, 95% CI, 1.65-9.07).	Patients with moderate to severe OSA have a significantly increased risk for high-risk PE and recurrent PE and may need more aggressive treatment.
26	Mraovic et al., 2010 [68]	USA	Retrospective, case-control study n=(7,282)	There was no significant association between OSA prevalence in PE patients (6.5% vs 5.4%; P = 0.593).	No significant relationship between the prevalence of OSA in patients with PE undergoing arthroplasty.
27	Sapala et al., 2003 [62]	USA	Retrospective, observational study n=(5,554)	OSA was considered a significant risk factor for the development of postoperative VTE. There was a high prevalence of OSA in patients with PE (33%).	OSA is associated with postoperative VTE.
28	Kosovali et al., 2013 [63]	Turkey	Case-control study n=(73)	The AHI was significantly higher in patients with PE  (P =0.010). Severe OSA was found in 21.4% of the PE group but in no controls ( P =0.015).	OSA is highly prevalent and more severe in subjects with PE compared with control subjects.
29	D’Apuzzo et al., 2012 [64]	USA	Case-control study n=(258,455 patients including 16,608 OSA patients)	OSA patients were twice as likely to develop PE when compared to controls(odds ratio, 2.02; 95% CI, 1.3-2.9; P < 0.001). OSA remained an independent risk factor for PE after adjustment for confounding variables (OR, 2.02; 95 % CI, 1.3–2.9).	OSA is an independent risk factor for postoperative PE development.
30	Louis et al., 2014 [65]	USA	Retrospective, cross-sectional study n=(55,781,965)	OSA was significantly associated with pregnancy-related morbidities such as PE (OR, 4.5; 95% CI, 2.3-8.9).	OSA is an independent risk factor for pregnancy-related morbidities including PE.