Table 2.
Comparative analysis of patients with normal and prolonged QTc interval
| Variables | QTc interval | p-value | |
|---|---|---|---|
| Normal (N = 382) a n (%) |
Prolonged (N = 23) b n (%) |
||
| Gender | |||
| Male | 229 (92.3) | 19 (7.7) | 0.03 |
| Female | 153 (97.5) | 4 (2.5) | |
| Age (years) | |||
| ≤ 20 | 75 (19.6) | 6 (26.1) | 0.45 |
| 21–30 | 105 (27.5) | 4 (17.4) | |
| 31–40 | 94 (24.6) | 4 (17.4) | |
| > 40 | 108 (28.3) | 9 (39.1) | |
| All prescribed drugs | |||
| 1 | 47 (12.3) | 1 (4.3) | 0.48 |
| 2–3 | 240 (62.8) | 15 (65.2) | |
| > 3 | 95 (24.9) | 7 (30.4) | |
| QT prolonging drugs | |||
| 1 | 216 (56.5) | 10 (43.5) | 0.22 |
| ≥ 2 | 166 (43.5) | 13 (56.5) | |
| QT drug-drug interactions | 109 (28.5) | 9 (39.9) | 0.27 |
| Diagnosis | |||
| Psychosis | 29 (7.6) | 2 (8.7) | 0.84 |
| Manic depressive psychosis | 33 (8.6) | 10 (13) | 0.47 |
| Obsessive compulsive disorder | 16 (4.2) | 2 (8.7) | 0.30 |
| Schizophrenia | 16 (4.2) | 1 (4.3) | 0.97 |
| Major depression | 200 (52.4) | 11 (47.8) | 0.67 |
| Hypomania | 13 (3.4) | 0 (0) | 0.36 |
| Panic disorder | 34 (8.9) | 0 (0) | 0.13 |
| Bipolar affective disorder | 11 (2.9) | 0 (0) | 0.40 |
| Substance abuse | 17 (4.9) | 0 (0) | 0.30 |
| Co-morbid illnesses | |||
| Hypertension | 40 (10.5) | 3 (13) | 0.67 |
| Diabetes mellitus | 17 (4.5) | 0 (0) | 0.80 |
| Epilepsy | 13 (3.4) | 0 (0) | 0.27 |
| QT prolonging drug classes (ATC Code) | |||
| Antipsychotic (N05A) | 140 (36.6) | 11 (47.8) | 0.28 |
| Proton pump inhibitors (A02BC) | 48 (12.6) | 1 (4.3) | 0.24 |
| Antidepressant (N06A) | 253 (66.2) | 14 (60.9) | 0.59 |
| Other drugs | 19 (5) | 2 (8.7) | 0.43 |
a Percentage calculated in total of 382 patients with normal QTc interval except gender; b Percentage calculated in total of 23 patients with prolonged QTc interval except gender