Increased risk of venous thromboembolism associated with polymyositis and dermatomyositis: a meta-analysis

Figures & data

Figure 1 Flow chart for eligible studies.

Abbreviations: DM, dermatomyositis; PM, polymyositis; VTE, venous thromboem-bolism.

Table 1 Characteristics of all studies

Study	Country	Study design	Case number	Control number	Case group	Control group	Adjustment	Study quality
Carruthers et al,^Citation20 2016	Canada	Retrospective cohort	PM, 443; DM, 335	8958	Diagnosed PM/DM from Population Data British Columbia between 1996 and 2010	General population with age, sex, and entry time matched	Birth year, sex, calendar year of follow-up, relevant risk factors	9
Chung et al,^Citation23 2014	Taiwan	Retrospective cohort	PM/DM, 2031	10155	Diagnosed PM/DM from the National Health Insurance Research Database between 2000 and 2010	National Health Insurance beneficiaries matched with age, sex, and year of diagnosis	Age, sex, atrial fibrillation, hypertension, diabetes, hyperlipidemia, CVA, heart failure, lower leg fracture or surgery, cancer, and pregnancy	9
Bleau et al,^Citation19 2014	Canada	Retrospective cohort	PM, 80; DM, 107	7917266	Pregnant women diagnosed PM/DM from the Health Care Cost and Utilization Project, Nationwide Inpatient Sample between 2003 and 2011	General pregnant women from the same database	Age	6
Zoller et al,^Citation18 2012	Sweden	Retrospective cohort	PM/DM, 2122	533416	Diagnosed PM/DM from Swedish national hospital admission database between 1964 and 2008	General population	Age, sex, period, hospital admission for chronic obstructive pulmonary disease, obesity, alcoholism, and alcohol-related liver disease, coronary heart disease, stroke, hypertension, sepsis, varicose veins, peripheral vascular disease, and congestive heart failure	7
Johannesdottir et al,^Citation22 2012	Denmark	Case–control	PM/DM, 47	147210	Diagnosed with DVT or PE from Danish national registry database between 1999 and 2009	General population with sex and age matched from the same database	Age, sex, classic risk factors, other comorbidities, and medication use	6
Ramagopalan et al,^Citation17 2011	United Kingdom	Prospective cohort study	PM/DM, 6002	Not available	Diagnosed PM/DM from the English National Hospital Episode Statistics between 1963 and 2008	Hospitalized patients with minor medical or surgical conditions from the same database	Sex, age in 5-year bands, time-period in single calendar years	7

Abbreviations: DM, dermatomyositis; DVT, deep venous thrombosis; PE, pulmonary embolism; PM, polymyositis.

Figure 2 Association between inflammatory myositis and risk of VTE, PE and DVT.

Note: Weights are from random effects analysis.
Abbreviations: CI, confidence interval; OR, odds ratio; DVT, deep venous thrombosis; PE, pulmonary embolism; VTE, venous thromboembolism.

Figure 3 Sensitivity analysis of association between inflammatory myositis and risk of VTE, PE and DVT.

Abbreviations: CI, confidence interval; DVT, deep venous thrombosis; PE, pulmonary embolism; VTE, venous thromboembolism.

Figure 4 Subgroup analyses by PM/DM of association between inflammatory myositis and risk of VTE, PE and DVT.

Abbreviations: CI, confidence interval; OR, odds ratio; DVT, deep venous thrombosis; PE, pulmonary embolism; VTE, venous thromboembolism.

Figure 5 Association between inflammatory myositis and VTE risk.

Note: Weights are from random effects analysis.
Abbreviations: CI, confidence interval; OR, odds ratio; VTE, venous thromboembolism.

Figure 6 Association between inflammatory myositis and DVT risk.

Note: Weights are from random effects analysis.
Abbreviations: CI, confidence interval; OR, odds ratio; DVT, deep venous thrombosis.

Figure 7 Association between inflammatory myositis and PE risk.

Note: Weights are from random effects analysis.
Abbreviations: CI, confidence interval; OR, odds ratio; PE, pulmonary embolism.

Figure 8 Publication bias risk.

Abbreviations: HR, hazard ratio; SE, standard error of the mean.

Table S1 Characteristics of all studies according to types of VTE and inflammatory myositis

Study	Study design	Ethnicity	Inflammatory myositis	Type of VTE
Carruthers et al,^Citation1 2016	Retrospective cohort study	Caucasians	PM	VTE
Carruthers et al,^Citation1 2016	Retrospective cohort study	Caucasians	PM	PE
Carruthers et al,^Citation1 2016	Retrospective cohort study	Caucasians	PM	DVT
Carruthers et al,^Citation1 2016	Retrospective cohort study	Caucasians	DM	VTE
Carruthers et al,^Citation1 2016	Retrospective cohort study	Caucasians	DM	PE
Carruthers et al,^Citation1 2016	Retrospective cohort study	Caucasians	DM	DVT
Chung et al,^Citation2 2014	Retrospective cohort study	Xanthoderm	PM/DM	VTE
Bleau et al,^Citation3 2014	Prospective cohort study	Caucasians	DM	VTE
Bleau et al,^Citation3 2014	Prospective cohort study	Caucasians	DM	PE
Bleau et al,^Citation3 2014	Prospective cohort study	Caucasians	DM	DVT
Zoller et al,^Citation4 2012	Prospective cohort study	Caucasians	PM/DM	PE
Johannesdottir et al,^Citation5 2012	Case–control study	Caucasians	PM/DM	VTE
Johannesdottir et al,^Citation5 2012	Case–control study	Caucasians	PM/DM	DVT
Johannesdottir et al,^Citation5 2012	Case–control study	Caucasians	PM/DM	PE
Ramagopalan et al,^Citation6 2011	Prospective cohort study	Caucasians	PM/DM	VTE
Ramagopalan et al,^Citation6 2011	Prospective cohort study	Caucasians	PM/DM	VTE
Ramagopalan et al,^Citation6 2011	Prospective cohort study	Caucasians	PM/DM	VTE

Abbreviations: DM, dermatomyositis; DVT, deep venous thrombosis; PE, pulmonary embolism; PM, polymyositis; VTE, venous thromboembolism.

Table S2 Quality evaluation of studies included in this meta-analysis

Study	Study selectiona	Outcomeb	Comparabilityc	Totald
Carruthers et al,^Citation1 2016	4	2	3	9
Chung et al,^Citation2 2014	4	2	3	9
Bleau et al,^Citation3 2014	3	1	2	6
Zoller et al,^Citation4 2012	4	0	3	7
Johannesdottir et al,^Citation5 2012	4	1	1	6
Ramagopalan et al,^Citation6 2011	4	0	3	7

Notes:

a Maximum 4 stars awarded for cohort representativeness, selection of nonexposed cohort, exposure assessment, and demonstration outcome not present at baseline.

b Maximum 3 stars awarded for follow-up length, adequacy of follow-up, and outcome assessment.

c Maximum 2 stars awarded for controlling for main confounders.

d Studies receiving ≥6 points were considered high quality; a maximum of 9 points could be awarded.

CarruthersECChoiHKSayreECAvina-ZubietaJARisk of deep venous thrombosis and pulmonary embolism in individuals with polymyositis and dermatomyositis: a general population-based studyAnn Rheum Dis201675111011625193998

 PubMed Web of Science ®Google Scholar

ChungWSLinCLSungFCLuCCKaoCHIncreased risk of venous thromboembolism in patients with dermatomyositis/polymyositis: a nationwide cohort studyThromb Res2014134362262625034321

 PubMed Web of Science ®Google Scholar

BleauNPatenaudeVAbenhaimHARisk of venous thromboembolic events in pregnant patients with autoimmune diseases: A Population-Based StudyClin Appl Thromb Hemost201622328529125294635

 PubMed Web of Science ®Google Scholar

ZollerBLiXSundquistJSundquistKRisk of pulmonary embolism in patients with autoimmune disorders: a nationwide follow-up study from SwedenLancet2012379981224424922119579

 PubMed Web of Science ®Google Scholar

JohannesdottirSASchmidtMHorvath-PuhoESorensenHTAutoimmune skin and connective tissue diseases and risk of venous thromboembolism: a population-based case-control studyJ Thromb Haemost201210581582122353382

 PubMed Web of Science ®Google Scholar

RamagopalanSVWottonCJHandelAEYeatesDGoldacreMJRisk of venous thromboembolism in people admitted to hospital with selected immune-mediated diseases: record-linkage studyBMC Med20119121219637

 PubMed Web of Science ®Google Scholar

CarruthersECChoiHKSayreECAvina-ZubietaJARisk of deep venous thrombosis and pulmonary embolism in individuals with polymyositis and dermatomyositis: a general population-based studyAnn Rheum Dis201675111011625193998

 PubMed Web of Science ®Google Scholar

ChungWSLinCLSungFCLuCCKaoCHIncreased risk of venous thromboembolism in patients with dermatomyositis/polymyositis: a nationwide cohort studyThromb Res2014134362262625034321

 PubMed Web of Science ®Google Scholar

BleauNPatenaudeVAbenhaimHARisk of venous thromboembolic events in pregnant patients with autoimmune diseases: A Population-Based StudyClin Appl Thromb Hemost201622328529125294635

 PubMed Web of Science ®Google Scholar

ZollerBLiXSundquistJSundquistKRisk of pulmonary embolism in patients with autoimmune disorders: a nationwide follow-up study from SwedenLancet2012379981224424922119579

 PubMed Web of Science ®Google Scholar

JohannesdottirSASchmidtMHorvath-PuhoESorensenHTAutoimmune skin and connective tissue diseases and risk of venous thromboembolism: a population-based case-control studyJ Thromb Haemost201210581582122353382

 PubMed Web of Science ®Google Scholar

RamagopalanSVWottonCJHandelAEYeatesDGoldacreMJRisk of venous thromboembolism in people admitted to hospital with selected immune-mediated diseases: record-linkage studyBMC Med20119121219637

 PubMed Web of Science ®Google Scholar