Table 1. Baseline characteristics of patients: all, and stratified in subgroups based on QTc duration before haloperidol.
| All patients (N = 97) | Normal (N = 57) | Borderline (N = 17) | Abnormal (N = 23) | |
| Male, n (%)* | 62 (63.9) | 29 (50.9) | 12 (70.6) | 21 (91.3) |
| Age, years, mean (SD) | 67.7 (14.3) | 68.2 (14.5) | 66.1 (15.8) | 67.4 (13.5) |
| Dose of haloperidol, mean (SD) | 2.6 (2.2) | 2.5 (2.3) | 2.3 (1.9) | 3.1 (2.1) |
| QTc duration, ms, mean (SD)* | 433.6 (43.2) | 408.8 (24.6) | 444.4 (11.3) | 487.0 (43.0) |
| Heart rate, beats per minute, mean (SD) | 86.8 (25.6) | 85.0 (23.9) | 98.0 (31.0) | 83.1 (24.0) |
| QRS width, ms, mean (SD) | 93.2 (15.1) | 91.3 (14.9) | 91.8 (16.2) | 99.0 (13.7) |
| Serum sodium level, mmol/l, mean (SD) | 139.8 (3.6) | 139.5 (3.8) | 140.5 (3.9) | 140.0 (2.9) |
| Serum potassium level, mmol/l, mean (SD) | 4.1 (0.5) | 4.1 (0.4) | 4.3 (0.5) | 3.9 (0.6) |
| Diabetes, n (%) | 20 (20.6) | 12 (21.1) | 4 (23.5) | 4 (17.4) |
| Hypertension, n (%) | 41 (42.3) | 22 (38.6) | 9 (53.9) | 10 (43.5) |
| Heart failure, n (%) | 11 (11.3) | 5 (8.8) | 3 (17.6) | 3 (13.0) |
| Ischemic heart disease, n (%) | 54 (55.7) | 31 (54.4) | 9 (52.9) | 14 (60.9) |
| Surgery before haloperidol use, n (%) | 36 (37.1) | 22 (38.6) | 7 (41.2) | 7 (30.4) |
| Signs of inflammation, n (%) | 70 (72.2) | 40 (70.2) | 12 (78.3) | 18 (78.3) |
| Use of QT interval prolonging drugs, n (%) | 6 (6.2) | 3 (5.3) | 0 (0) | 3 (13.3) |
Normal QTc duration: male <430 ms, female <450 ms,; borderline QTc duration: male 431–450 ms, female 451–470 ms;
abnormal QTc duration: male >450 ms, female >470 ms.
*Significant differences between subgroups (p<0.05).