Table 1 Characteristics of patients with at least one encounter for heart failure between January 1, 2004 and December 31, 2005 stratified by their participation in the study derivation and validation sets.
From: Comparing methods for identifying patients with heart failure using electronic data sources
Variable | Total Population (n = 4,174) | Derivation sample (n = 300) | Validation sample (n = 100) | Unselected patients (n = 3,774) | P-value* |
|---|---|---|---|---|---|
Age (years) -- mean ± SD | 67 ± 14 | 67 ± 14 | 68 ± 14 | 67 ± 14 | 0.47 |
Male -- no.(%) | 2011 (48%) | 155 (52%) | 46 (46%) | 1810 (48%) | 0.42 |
White -- no. (%) | 2615 (63%) | 61% | 59% | 63% | 0.12 |
Hypertension -- no. (%) | 3384 (81%) | 244 (81%) | 77 (77%) | 3063 (81%) | 0.57 |
Diabetes -- no. (%) | 1409 (34%) | 104 (35%) | 31 (31%) | 1274 (34%) | 0.80 |
Chronic obstructive pulmonary disease - no. (%) | 600 (14%) | 46 (15%) | 12 (12%) | 542 (14%) | 0.71 |
Coronary Atherosclerosis - no. (%) | 829 (20%) | 42 (14%) | 15 (15%) | 772 (20%) | 0.012 |
≥1 BNP measurement during the study period - no. (%) | 2374 (57%) | 170 (57%) | 53 (53%) | 2151 (57%) | 0.73 |
Maximum BNP level - median (interquartile range) | 198 (88-494) | 192 (84-500) | 144 (90-379) | 201 (89-500) | 0.634 |