Table 2.

Clinical Characteristics by Age

	Age-Stratifieda
	Total		18–64 y		≥65 y
Clinical and Disease Characteristics	na = 408 360		na = 199 190		na = 52 757
	No.	%	No.	%	No.	%
Pre-index (365-d) baseline comorbidities
Charlson comorbidity index, mean (SD)	0.61	1.28	0.58	1.18	2.01	2.07
Charlson comorbidity index
0	281 757	69.0	135 981	68.3	14 373	27.2
1	73 606	18.0	37 954	19.1	12 035	22.8
2	24 462	6.0	13 959	7.0	9581	18.2
3+	28 535	7.0	11 296	5.7	16 768	31.8
Individual CCI comorbidities
Chronic pulmonary disease	69 067	16.90	29 063	14.5	16 635	31.50
Cardiovascular disease	42 808	10.5
Myocardial infarction	4149	1.0	1673	0.8	2468	4.7
Congestive heart failure	12 120	3.0	3822	1.9	8153	15.5
Peripheral vascular disease	12 775	3.1	3853	1.9	8834	16.7
Cerebrovascular disease	13 764	3.4	4530	2.3	8904	16.9
Diabetic disease	38 044	9.30
Diabetes	29 276	7.2	18 675	9.4	10 181	19.3
Diabetes with chronic complications	8768	2.1	4205	2.1	4549	8.6
Dementia	2762	7.0	126	0.1	2618	5.0
Cancer	14 898	3.6	6986	3.5	6968	3.5
Renal disease	8976	2.2	3172	1.6	5685	10.8
Chronic kidney disease	8880	2.2	3132	1.6	5631	10.7
End-stage renal disease	1019	0.2	513	0.3	493	0.9
Mild liver disease	7629	1.9	5774	2.9	1684	3.2
Metastatic cancer	2461	0.6	1347	0.7	1079	2.0
Hemiplegia or paraplegia	1835	0.4	657	0.3	550	1.0
Peptic ulcer disease	1813	0.4	1068	0.5	693	1.3
AIDS	600	0.1	573	0.3	22	0.0
Moderate or severe liver disease	429	0.1	279	0.1	132	0.3
Other comorbidities
Asthma	42 787	10.5	17 249	8.7	5362	10.2
Arrhythmias	22 906	5.6	8687	4.4	13 476	25.5

Data are presented as No. and % unless otherwise specified. All comparisons were statistically significant at P < .0001.

Abbreviations: CCI, Charlson comorbidity index; NEC, not elsewhere classified.

^aAll clinical and disease characteristic analyses excluded patients with index drug (ceftriaxone and ciprofloxacin), due to low counts.