Table 2.

Risk of incident CKD in hydroxychloroquine users compared with nonusers

ExposureEvents, n/NIncident Ratea (95% CI)cHR (95% CI)P ValueaHRb,c (95% CI)P Value
Cohorts
 Hydroxychloroquine nonusers121/140713.8 (11.3–16.2)1.001.00
 Hydroxychloroquine users48/121210.3 (7.4–13.2)0.67 (0.48 to 0.94)0.020.64 (0.45 to 0.90)0.01
Cumulative defined daily dosed
 Hydroxychloroquine121/140713.8 (11.3–16.2)1.001.00
 Hydroxychloroquine users
  ≤3522/52112.1 (7.1–17.2)0.79 (0.50 to 1.24)0.300.77 (0.48 to 1.21)0.25
  36–7020/47010.6 (6.0–15.3)0.70 (0.44 to 1.12)0.140.66 (0.40 to 1.07)0.09
  >706/2216.1 (1.2–11.0)0.40 (0.18 to 0.90)0.030.37 (0.16 to 0.84)0.02
P value for trend0.010.004
Prescribed daily dose
 Hydroxychloroquine nonusers121/140713.8 (11.3–16.2)1.001.00
 Hydroxychloroquine users, mg
  ≤20017/44111.0 (5.8–16.2)0.71 (0.43 to 1.18)0.190.69 (0.42 to 1.16)0.16
  201–40024/52311.1 (6.7–15.5)0.73 (0.47 to 1.13)0.160.69 (0.44 to 1.08)0.11
  >4007/2487.3 (1.9–12.6)0.47 (0.22 to 1.00)0.050.45 (0.21 to 0.96)0.04
P value for trend0.020.01
  • cHR, crude hazard ratio; 95% CI, 95% confidence interval; aHR, adjusted hazard ratio; —, not applicable.

  • a Per 1000 person-years.

  • b Adjusted for propensity scores.

  • c All-cause death was considered a competing risk.

  • d Within 90 days after rheumatoid arthritis diagnosis.