Data Mining for Identifying Novel Associations and Temporal Relationships with Charcot Foot

Table 3

Well-known associations with Charcot foot, compared between those with (𝑛=282) and without (𝑛=106) diabetes, defined as any ICD-9 250.x code. The associations shown here are based on the ones shown in Table 1.

Disease category	ICD-9 code	ICD-9 description	Number (%) among those with diabetes	Number (%) among those without diabetes	𝑃 value for difference in proportions
Endocrine, nutritional and metabolic diseases, and immunity disorders	278.00	Obesity	46 (16.3)	6 (5.7)	10.0×10^−3
Nervous system	356.9	Peripheral neuropathy	143 (50.7)	18 (17.0)	3.80×10^−9
Blood and blood-forming organs	280.0	Anemia due to chronic blood loss	14 (5.0)	2 (1.9)	0.28
	285.9	Anemia, not otherwise specified	88 (31.2)	10 (9.4)	2.0×10^−5
	285.29	Anemia of other chronic diseases	8 (2.8)	2 (1.9)	0.87
	280.9	Iron deficiency anemia	29 (10.3)	3 (2.8)	0.030
Skin and subcutaneous tissue	682.6	Cellulitis/abscess of leg	80 (28.4)	7 (6.6)	8.8×10^−6
	682.7	Cellulitis/abscess of foot	94 (33.3)	4 (3.8)	5.2×10^−9
Genitourinary system	593.9	Renal & ureteral disorder, not otherwise specified	111 (39.4)	8 (7.5)	3.0×10^−9
	585	Chronic kidney disease	63 (22.3)	1 (0.9)	9.3×10^−7
Musculoskeletal system and connective tissue	714.0	Rheumatoid arthritis	28 (9.9)	9 (8.5)	0.81
	733.00	Osteoporosis	36 (12.8)	8 (7.5)	0.21
	733.90	Bone/cartilage disorder, not otherwise specified	175 (62.1)	58 (54.7)	0.23
Injury and poisoning	996.81	Complication of kidney transplant	43 (15.2)	1 (0.9)	1.6×10^−4
External causes of injury and supplemental classification	V42.0	Kidney transplant	49 (17.4)	1 (0.9)	3.6×10^−5