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

Table 1

Well-known associations with Charcot foot, based on 388 patients with Charcot foot. Although not all associations presented here show a significant temporal relationship with Charcot foot, those that do preceded the diagnosis of Charcot foot.

Disease category	ICD-9 code	ICD-9 description	Number (%) with both disorders	Association odds ratio	Association 𝑃 value	Temporal 𝑃 value
Endocrine, nutritional and metabolic diseases, and immunity disorders	250.00*	Type 2 diabetes mellitus	243 (62.6)	55.4	<5 ×  10^−324	8.5×10^−37
	278.00	Obesity	52 (13.4)	11.7	2.4×10^−95	4.1×10^−4
Nervous system	356.9	Peripheral neuropathy	161 (41.5)	101.2	<5 ×  10^−324	3.9×10^−12
Blood and blood-forming organs	280.0	Anemia due to chronic blood loss	16 (4.1)	9.9	1.0×10^−26	0.80
	285.9	Anemia, not otherwise specified	98 (25.3)	14.9	3.3×10^−205	0.085
	285.29	Anemia of other chronic diseases	10 (2.6)	43.1	1.1×10^−79	1
	280.9	Iron deficiency anemia	32 (8.2)	14.5	1.5×10^−79	0.60
Skin and subcutaneous tissue	682.6	Cellulitis/abscess of leg	87 (22.4)	41.9	<5 ×  10^−324	4.4×10^−6
	682.7	Cellulitis/abscess of foot	98 (25.3)	133.8	<5 ×  10^−324	5.5×10^−6
Genitourinary system	593.9	Renal & ureteral disorder, not otherwise specified	119 (30.7)	20.9	<5 ×  10^−324	4.5×10^−4
	585	Chronic kidney disease	64 (16.5)	29.4	7.7×10^−314	2.4×10^−5
Musculoskeletal system and connective tissue	714.0	Rheumatoid arthritis	37 (9.5)	13.5	1.2×10^−83	1.3×10^−5
	733.00	Osteoporosis	44 (11.3)	12.1	4.4×10^−86	0.29
	733.90	Bone/cartilage disorder, not otherwise specified	233 (60.1)	26.0	<5 ×  10^−324	5.9×10^−12
Injury and poisoning	996.81	Complication of kidney transplant	44 (11.3)	43.3	<5 ×  10^−324	3.9 × 10^−4
External causes of injury and supplemental classification	V42.0	Kidney transplant	50 (12.9)	42.1	<5 ×  10^−324	9.0×10^−5

∗This table only lists ICD-9 code 250.00, not the other diabetes codes that also appeared in this cohort of patients.