Table 2. Hazard Ratios (HR) for Nonaffective Psychosis by Number and Distance of Moves in Each Age Period.
| Exposures | Cases, No. (%) | HR (95% CI) | ||||
|---|---|---|---|---|---|---|
| Crude | Adjustment 1a | Adjustment 2b | Adjustment 3c | Adjustment 4d | ||
| Age 0-6, ye | ||||||
| 1 move | 1416 (31.2) | 1.29 (1.21-1.38) | 1.13 (1.04-1.21) | NA | NA | NA |
| 2 moves | 696 (15.3) | 1.81 (1.66-1.97) | 1.47 (1.32-1.62) | NA | NA | NA |
| 3 moves | 241 (5.4) | 1.92 (1.68-2.20) | 1.46 (1.25-1.70) | NA | NA | NA |
| ≥4 moves | 114 (2.5) | 2.51 (2.08-3.03) | 1.83 (1.48-2.26) | NA | NA | NA |
| Distance (square root)f | NA | 1.37 (1.31-1.43) | 1.13 (1.06-1.19) | NA | NA | NA |
| Age 7-15, ye | ||||||
| 1 move | 1062 (23.4) | 1.44 (1.34-1.55) | 1.24 (1.15-1.34) | 1.22 (1.13-1.32) | NA | NA |
| 2 moves | 580 (12.8) | 1.94 (1.77-2.13) | 1.58 (1.43-1.75) | 1.51 (1.36-1.68) | NA | NA |
| 3 moves | 288 (6.4) | 2.41 (2.13-2.72) | 1.86 (1.62-2.13) | 1.74 (1.52-2.01) | NA | NA |
| ≥4 moves | 218 (4.8) | 2.99 (2.60-3.44) | 2.14 (1.82-2.53) | 1.95 (1.65-2.31) | NA | NA |
| Distance (square root)f | NA | 1.52 (1.46-1.59) | 1.16 (1.09-1.23) | 1.11 (1.05-1.19) | NA | NA |
| Age 16-19, ye | ||||||
| 1 move | 1125 (24.8) | 1.45 (1.35-1.55) | 1.47 (1.36-1.59) | 1.35 (1.25-1.47) | 1.28 (1.18-1.39) | NA |
| 2 moves | 497 (11.0) | 2.47 (2.25-2.72) | 2.45 (2.20-2.74) | 2.08 (1.85-2.33) | 1.79 (1.60-2.01) | NA |
| 3 moves | 117 (2.6) | 2.61 (2.17-3.14) | 2.55 (2.09-3.11) | 2.00 (1.63-2.45) | 1.57 (1.28-1.92) | NA |
| ≥4 moves | 23 (0.5) | 3.96 (2.62-5.97) | 3.87 (2.54-5.90) | 2.88 (1.89-4.40) | 1.99 (1.30-3.05) | NA |
| Distance (square root)f | NA | 1.32 (1.26-1.40) | 0.98 (0.92-1.06) | 0.95 (0.88-1.02) | 0.99 (0.98-1.03) | NA |
| Age ≥20, ye,g | ||||||
| 1 move | 787 (28.2) | 0.82 (0.74-0.89) | 1.11 (1.01-1.22) | 1.04 (0.94-1.14) | 1.05 (0.96-1.16) | 1.04 (0.94-1.14) |
| 2 moves | 491 (17.6) | 0.69 (0.62-0.78) | 1.18 (1.04-1.33) | 1.05 (0.93-1.19) | 1.07 (0.95-1.21) | 1.05 (0.93-1.18) |
| 3 moves | 254 (9.1) | 0.70 (0.61-0.81) | 1.46 (1.25-1.71) | 1.25 (1.07-1.47) | 1.27 (1.08-1.49) | 1.23 (1.05-1.44) |
| ≥4 moves | 194 (6.9) | 0.88 (0.75-1.05) | 2.35 (1.95-2.84) | 1.91 (1.58-2.31) | 1.91 (1.58-2.30) | 1.82 (1.51-2.20) |
| Distance (square root)f | NA | 0.60 (0.57-0.63) | 0.58 (0.54-0.61) | 0.56 (0.53-0.60) | 0.60 (0.56-0.63) | 0.67 (0.63-0.71) |
Abbreviation: NA, not applicable.
Adjustment 1: age, quadratic age, sex, foreign background, parental history of severe mental illness, parental death before age 16 years, disposable income quintile, mother’s age at participant birth, population density at birth (log transformed people per square kilometer), and distance moved in age period.
Adjustment 2: adjustment 1 + number of and distance moved at previous ages.
Adjustment 3: adjustment 2 + educational attainment at age 15 to 16 years.
Adjustment 4: adjustment 3 + university attendance.
Reference group for number of moves: 0 moves.
A nonlinear distance function (square root transformation) was provided to better fit to the data than a linear term; assessed via Akaike Information Criterion (Figure 2; eTable 3 in the Supplement).
After age 20 years, model was restricted to cohort not censored before this point (n = 998 967).