Table 1.

Distribution of ICD-9 codes by patient characteristic in regression modelling

Characteristic	Case	Control
Number of ICD-9 Codes	31,066†	36,218‡
Age at Dental Service*
Average (years)	57	57
Range [min (years), max (years)]	[40,69]	[46,68]
Gender (%, No. of codes)*
Female	63% (19,495)	67% (24,132)
Male	37% (11,571)	33% (12,086)
Ethnicity (%, No. of codes)*
African–American	12% (3,835)	12% (4,325)
Hispanic	71% (22,005)	68% (24,720)
European Descent	4% (1253)	6% (2347)
Asian/Pacific Origin	2% (470)	10% (326)
Other	2% (720)	3% (966)
Unreported	9% (2783)	10% (3546)

^*For p < 0.001.

^†Extracted from 994 patients.

^‡Extracted from 1223 patients.