Table 1.

Baseline characteristics and comorbidities by time period^* (n = 41,993)

Characteristic	1996 – 2000 (n = 24,278)	2001 – 2005 (n = 11,058)	2006 – 2009 (n = 6,123)
Age (years), median (IQR)	44 (39 – 50)	48 (41 – 55)	50 (42 – 57)
Male, %	98	98	97
Race/ethnicity, %
Black	49	47	49
White	39	38	35
Hispanic	8	6	7
Other	4	9	9
HIV-related variables
CD4+ cell count (cells/μL), median (IQR)	280 (124 – 470)	317 (124 – 524)	325 (139 – 546)
CD4+ cell count <200 cells/μL, %	37	35	32
HIV viral load >500 copies/mL, %	68	65	64
ART use, %	29	25	20
Smoking status, %
Never smoker	16	25	29
Former smoker	10	13	12
Current smoker	43	53	54
Missing	31	9	5
Alcohol-related diagnoses, %	17	15	14
Drug use disorders, %	20	16	16
COPD, %	3.7	5.0	6.0
Comorbid conditions, %
CHF	1.4	1.9	2.1
CAD/MI	13	19	23
Renal insufficiency	3.4	5.0	5.4
ESLD	1.5	1.5	1.6
HCV infection	37	32	24
Any malignancy	4.2	4.8	5.0
Diabetes mellitus	18	17	12
Prior pneumonia, %
CAP	6.4	6.0	6.0
TB	1.9	1.2	0.7
PCP	3.9	4.2	2.9
Vaccinations, %
Influenza	14	39	51
Pneumococcal	12	36	43

^*Chi-square tests or score tests for trends across time periods were statistically significant (p<0.05) for all variables except prior bacterial pneumonia and ESLD.

CAP = community-acquired pneumonia; TB = pulmonary tuberculosis; PCP = Pneumocystis jirovecii pneumonia; COPD = chronic obstructive pulmonary disease; CHF = congestive heart failure; CAD/MI = coronary artery disease/myocardial infarction; ESLD = end-stage liver disease