Table 3.
Higher versus lower QT-prolonging SSRIs and SCD risk, overall and stratified by multilevel serum-to-dialysate potassium gradient
| Cohort study | ||||
|---|---|---|---|---|
| Exposure | n | Events, n | Crude HR (95% CI) | Weighted HR (95% CI) |
| Overall | ||||
| Lower QT-prolonging-potential | 13 992 | 231 | 1.00 (ref.) | 1.00 (ref.) |
| Higher QT-prolonging-potential | 11 107 | 212 | 1.15 (0.96–1.38) | 1.03 (0.86–1.24) |
| K+ gradient ≥4 mEq/l | ||||
| Lower QT-prolonging-potential | 1293 | 15 | 1.00 (ref.) | 1.00 (ref.) |
| Higher QT-prolonging-potential | 951 | 26 | 2.37 (1.25–4.48) | 2.17 (1.16–4.03) |
| K+ gradient 3 to <4 mEq/l | ||||
| Lower QT-prolonging-potential | 4063 | 53 | 1.00 (ref.) | 1.00 (ref.) |
| Higher QT-prolonging-potential | 3134 | 56 | 1.38 (0.94–2.01) | 1.24 (0.85–1.81) |
| K+ gradient <3 mEq/l | ||||
| Lower QT-prolonging-potential | 8636 | 163 | 1.00 (ref.) | 1.00 (ref.) |
| Higher QT-prolonging-potential | 7022 | 130 | 0.97 (0.77–1.22) | 0.86 (0.68–1.09) |
| Nested case–control study | ||||
| Exposure | n | SCD cases, n |
Crude
OR (95% CI) |
Adjusted
OR (95% CI) |
| Overall | ||||
| Lower QT-prolonging-potential | 2748 | 231 | 1.00 (ref.) | 1.00 (ref.) |
| Higher QT-prolonging-potential | 2111 | 211 | 1.20 (0.99–1.47) | 1.15 (0.93–1.43) |
| K+ gradient ≥4 mEq/l | ||||
| Lower QT-prolonging-potential | 208 | 15 | 1.00 (ref.) | 1.00 (ref.) |
| Higher QT-prolonging-potential | 132 | 22 | 2.59 (1.28–5.21) | 2.81 (1.30–6.07) |
| K+ gradient 3 to <4 mEq/l | ||||
| Lower QT-prolonging-potential | 789 | 52 | 1.00 (ref.) | 1.00 (ref.) |
| Higher QT-prolonging-potential | 561 | 49 | 1.36 (0.91–2.05) | 1.13 (0.73–1.76) |
| K+ gradient <3 mEq/l | ||||
| Lower QT-prolonging-potential | 1751 | 164 | 1.00 (ref.) | 1.00 (ref.) |
| Higher QT-prolonging-potential | 1418 | 140 | 1.06 (0.83–1.43) | 1.06 (0.82–1.37) |
In the cohort study, Fine and Gray proportional subdistribution hazards models were used to estimate HRs and corresponding 95% CIs, and IPT weighting was used for confounding control. In the nested case–control study, conditional logistic regression models were used to estimate ORs and corresponding 95% CIs, and multivariable adjustment was used for confounding control.CI, confidence interval; HR, hazard ratio; K+ gradient, serum-to-dialysate potassium gradient; No., number; OR, odds ratio; ref., referent; SSRI: selective serotonin reuptake inhibitor.