Assessment of the Accuracy of Using ICD-10 Codes to Identify Systemic Sclerosis

Figures & data

Table 1 Validation of International Classification of Diseases, Tenth Revision (ICD-10) Codes Used to Identify Systemic Sclerosis Cases in the Toulouse University Hospital in-Patient Database (2010–2017)^a

Systemic Sclerosis-Related ICD-10 Code	Description	No.^b	Confirmed^c	PPV, %
M34.0	Progressive systemic sclerosis	35	33	94
M34.1	CR(E)ST syndrome	56	53	95
M34.8	Other forms of systemic sclerosis	60	53	88
-M34.8 + J99.1	-Systemic sclerosis with lung involvement	26	26	100
-M34.8 + G73.7	-Systemic sclerosis with myopathy	4	3	75
M34.9	Systemic sclerosis, unspecified	65	60	92
Total		216	200	93

Notes: ^aAll Systemic Sclerosis cases came from codes in this table. ^bIdentified through electronic search. ^cConfirmed through medical record review.

Abbreviations: PPV, positive predictive value; CR(E)ST syndrome, combination of calcinosis, Raynaud phenomenon, (o)esophageal dysfunction, sclerodactyly, telangiectasia.

Table 2 Reasons for Excluding Patients Identified by Systemic Sclerosis-Specific International Classification of Diseases, Tenth Revision (ICD-10) Codes in the French Hospital Database (2010–2017)^a

Reason	No.	Associated Systemic Sclerosis ICD-10 Codes^b
Localized Scleroderma	3	M34.0, M34.8, M34.9
Primitive Sjogren’s syndrome	3	M34.8, M34.9^b
Undifferentiated Connective Tissue Diseases	3	M34.9^b
Scleredema Adultorum	2	M34.8, M34.9
Raynaud Disease	1	M34.8
Systemic Lupus Erythematosus	1	M34.1
Dermatomyositis	1	M34.8
Multiple Sclerosis	1	M34.8
HCV-related cryoglobulinemia vasculitis	1	M34.8
Total excluded	16

Notes: ^aThere were 216 patients with a systemic sclerosis-specific code. ^bCodes contributing more than 1 case.

Abbreviation: HCV, hepatitis C virus.