Dermatomyositis and polymyositis in total hip arthroplasty

Table 1 Demographic factors for patients included in this study

	No. of IIM patients	No. of control patients	P value
Total number of patients	545	545
Female patients	74.90%	74.90%	1.000
Age (yr)
≤ 64	24.4%	23.6%
65-69	25.0%	24.1%
70-74	19.1%	19.7%	0.993
75-79	17.1%	18.1%
80-84	11.4%	11.2%
≥ 85	3.1%	3.4%
Region
Midwest	23.1%	26.8%
Northeast	18.5%	21.5%	0.1851
South	41.3%	36.9%
West	17.1%	14.9%

Reported percentages reflect the proportion of total patients in each of the two sample populations (e.g., patients with idiopathic inflammatory myopathies or controls). IIM: Idiopathic inflammatory myopathies.

Table 2 Additional comorbidities for patients included in this study

Comorbidity	Proportion of IIM patients without comorbidity	Proportion of control patients without comorbidity	P value
AIDS	0.59%	1.74%	0.479
Congestive heart failure	29.66%	30.68%	1.000
Depression	37.3%	40.52%	0.402
Diabetes mellitus1	44.35%	58.61%	0.000
SUD–Drugs	6.31%	7.96%	0.910
SUD–Alcohol	2.35%	4.2%	0.716
Hypertension	89.43%	92.19%	0.112
Hypothyroidism	42.44%	38.21%	0.059
Liver disease	12.92%	12.45%	0.355
Lymphoma	3.38%	4.63%	1.000
Metastatic cancer	5.14%	6.8%	0.901
Neurological disease	13.07%	13.6%	0.742
Pulmonary disease1	45.96%	55.86%	0.001
PVD1	30.1%	30.54%	0.008

¹Denotes significance, P < 0.05. Reported percentages reflect the proportion of total patients in each of the two sample populations (e.g., patients with idiopathic inflammatory myopathies or controls) with the listed comorbidity. AIDS: Acquired immunodeficiency syndrome; SUD: Substance use disorder; PVD: Peripheral vascular disease; IIM: Idiopathic inflammatory myopathies.

Table 3 Results of multivariate regression analysis to evaluate the relative risk of complications in patients with idiopathic inflammatory myopathies compared with controls following total hip arthroplasty

Complication		OR (95%CI)	P value
Acute kidney injury	0.034	1.035 (0.817-1.311)	0.778
Cardiac arrest	0.315	1.370 (0.712-2.636)	0.346
Deep vein thrombosis	0.423	1.526 (0.524-4.443)	0.438
Nerve injury	-0.966	0.381 (0.039-3.687)	0.405
Pneumonia1	0.376	1.456 (1.170-1.812)	0.001
Pulmonary embolism1	0.378	1.460 (1.026-2.077)	0.035
Urinary tract infection	0.123	1.131 (0.931-1.374)	0.215
Wound disruption	-0.249	0.780 (0.485-1.253)	0.304
Hematoma1	-0.542	0.582 (0.406-0.833)	0.003
Transfusion	0.060	1.062 (0.861-1.310)	0.573
Capsulitis	0.355	1.426 (0.952-2.137)	0.085
Infection	-0.342	0.71 (0.442-1.139)	0.156

¹Denotes significance, P < 0.05. CI: Confidence interval; OR: Odds ratio.