Table 2. Different Reference Groups for the Association Between Infection Treated With Anti-infective Agents and the Risk of Any Treated Mental Disorder Among Persons Born Between 1995 and 2012 in Denmark.
| Variable | Hospitalization for Any Mental Disorder | Prescription for Any Psychotropic Medication | ||
|---|---|---|---|---|
| Cases, No. (%) | HRR (95% CI)a | Cases, No. (%) | HRR (95% CI)a | |
| Total | 42 462 | NA | 56 847 | NA |
| Reference Group 1 With 0 Anti-infective Agents | ||||
| No. of anti-infective agents | ||||
| 0 [Reference] | 702 (1.7) | 1 [Reference] | 4701 (8.3) | 1 [Reference] |
| 1 | 2783 (6.6) | 1.06 (0.97-1.16) | 4063 (7.1) | 1.19 (1.14-1.24)b |
| 2 | 2938 (6.9) | 1.14 (1.05-1.24)b | 6729 (11.8) | 1.13 (1.07-1.17)b |
| 3 | 2777 (6.5) | 1.22 (1.12-1.32)b | 5463 (9.6) | 1.20 (1.16-1.25)b |
| 4 | 2513 (5.9) | 1.30 (1.20-1.41)b | 4518 (7.9) | 1.22 (1.16-1.27)b |
| 5-9 | 12 210 (28.8) | 1.45 (1.35-1.57)b | 14 814 (26.1) | 1.28 (1.24-1.33)b |
| 10-19 | 13 272 (31.3) | 1.71 (1.59-1.84)b | 12 104 (21.3) | 1.49 (1.44-1.55)b |
| ≥20 | 5267 (12.4) | 2.04 (1.88-2.21)b | 4455 (7.8) | 1.73 (1.65-1.81)b |
| Reference Group 2 With 0-1 Anti-infective Agents | ||||
| No. of anti-infective agents | ||||
| 0-1 [Reference] | 3485 (8.2) | 1 [Reference] | 8764 (15.4) | 1 [Reference] |
| 2 | 2938 (6.9) | 1.28 (1.17-1.40)b | 6729 (11.8) | 1.04 (1.01-1.07) |
| 3 | 2777 (6.5) | 1.30 (1.18-1.43)b | 5463 (9.6) | 1.11 (1.07-1.15)b |
| 4 | 2513 (5.9) | 1.22 (1.11-1.34)b | 4518 (7.9) | 1.12 (1.08-1.16)b |
| 5-9 | 12 210 (28.8) | 1.36 (1.30-1.43)b | 14 814 (26.1) | 1.18 (1.15-1.21)b |
| 10-19 | 13 272 (31.3) | 1.61 (1.54-1.68)b | 12 104 (21.3) | 1.37 (1.33-1.41)b |
| ≥20 | 5267 (12.4) | 1.97 (1.88-2.08)b | 4455 (7.8) | 1.59 (1.52-1.65)b |
| Reference Group 3 With 0-2 Anti-infective Agents | ||||
| No. of anti-infective agents | ||||
| 0-2 [Reference] | 6423 (15.1) | 1 [Reference] | 15 493 (27.3) | 1 [Reference] |
| 3 | 2777 (6.5) | 1.07 (1.02-1.12)b | 5463 (9.6) | 1.09 (1.05-1.12)b |
| 4 | 2513 (5.9) | 1.00 (0.95-1.04) | 4518 (7.9) | 1.10 (1.06-1.14)b |
| 5-9 | 12 210 (28.8) | 1.12 (1.09-1.16)b | 14 814 (26.1) | 1.16 (1.13-1.18)b |
| 10-19 | 13 272 (31.3) | 1.33 (1.29-1.37)b | 12 104 (21.3) | 1.34 (1.31-1.38)b |
| ≥20 | 5267 (12.4) | 1.53 (1.48-1.59)b | 4455 (7.8) | 1.56 (1.50-1.62)b |
| Reference Group 4 With 0-3 Anti-infective Agents | ||||
| No. of anti-infective agents | ||||
| 0-3 [Reference] | 9200 (21.7) | 1 [Reference] | 20 956 (36.9) | 1 [Reference] |
| 4 | 2513 (5.9) | 0.98 (0.93-1.02) | 4518 (7.9) | 1.07 (1.04-1.11)b |
| 5-9 | 12 210 (28.8) | 1.10 (1.07-1.13)b | 14 814 (26.1) | 1.13 (1.10-1.16)b |
| 10-19 | 13 272 (31.3) | 1.30 (1.26-1.34)b | 12 104 (21.3) | 1.31 (1.28-1.34)b |
| ≥20 | 5267 (12.4) | 1.50 (1.45-1.56)b | 4455 (7.8) | 1.52 (1.46-1.57)b |
Abbreviations: HRR, hazard rate ratio; NA, not applicable.
a
The analyses were adjusted for age, sex, Charlson Comorbidity Index, highest parental educational level, any parental mental disorder since 1969, calendar period, and hospitalization for infection. The significance level was set at .05 divided by 14, which equals .0036, for reference group 1 with 0 anti-infective agents; as .05 divided by 12, which equals .0042, for reference group 2 with 0 to 1 anti-infective agents; as .05 divided by 10, which equals .0050, for reference group 3 with 0 to 2 anti-infective agents; and as .05 divided by 8, which equals .0063, for reference group 3 with 0 to 3 anti-infective agents.
b
Statistically significant.