Table 2. Description of Main Results of Meta-analysis for Association of ASD or ADHD With Risk of Mortalitya.
| Outcomes of interest | No. | RR (95% CI) | P value for effect estimate | I2 (95% CI) | 95% Prediction interval | P value for heterogeneity | Confidence | |||
|---|---|---|---|---|---|---|---|---|---|---|
| Studies | Participants with ASD or ADHD | Death cases | Pooled | Largest study | ||||||
| Primary outcome, all-cause mortality | ||||||||||
| All-cause mortality, ASD | ||||||||||
| Both | 12 | 154 238 | 2017 | 2.37 (1.97-2.85) | 2.06 (1.64-2.58) | <.001 | 89 (82-93) | 1.25-4.48 | <.001 | Moderate (probable) |
| Male | 8 | 75 085 | 1071 | 2.09 (1.50-2.92) | 1.25 (1.08-1.45) | <.001 | 94 (90-96) | 0.68-6.40 | <.001 | Low (suggestive) |
| Female | 8 | 25 338 | 562 | 4.87 (3.07-7.73) | 2.75 (2.09-3.64) | <.001 | 91 (85-95) | 1.09-21.78 | <.001 | Low (suggestive) |
| All-cause mortality, ADHD | ||||||||||
| Both | 8 | 396 488 | 1302 | 2.13 (1.13-4.02) | 1.07 (1.00-1.17) | .02 | 98 (97-99) | 0.28-16.42 | <.001 | Low (suggestive) |
| Male | 5 | 291 201 | 982 | 2.43 (1.01-5.83) | 1.04 (0.94-1.14) | .046 | 99 (98-99) | 0.10-58.40 | <.001 | Low (suggestive) |
| Female | 4 | 103 839 | 302 | 2.84 (1.02-7.89) | 1.24 (1.04-1.48) | .045 | 97 (96-99) | 0.03-277.30 | <.001 | Low (suggestive) |
| Secondary outcomes, cause-specific mortality | ||||||||||
| Natural causes, ASD | ||||||||||
| Both | 4 | 65 421 | 613 | 3.80 (2.06-7.01) | 2.59 (2.36-2.85) | <.001 | 96 (92-98) | 0.22-66.96 | <.001 | Low (suggestive) |
| Male | 2 | 22 430 | 256 | 2.95 (2.35-3.69) | 2.85 (2.50-3.24) | <.001 | 10 (NA) | NA | .29 | Low (suggestive) |
| Female | 2 | 9387 | 220 | 6.57 (0.60-71.91) | 2.44 (2.12-2.80) | .123 | 79 (NA) | NA | .03 | Low (not conclusive) |
| Natural causes, ADHD | ||||||||||
| Both | 4 | 394 833 | 516 | 1.62 (0.89-2.96) | 0.91 (0.80-1.15) | .1 | 88 (72-95) | 0.11-23.10 | <.001 | Low (not conclusive) |
| Male | 3 | 290 908 | 348 | 1.22 (0.74-2.01) | 0.83 (0.72-1.15) | .43 | 80 (36-94) | 0.00-451.06 | .007 | Low (not conclusive) |
| Female | 3 | 103 803 | 138 | 2.02 (0.91-4.48) | 1.03 (0.82-1.30) | .09 | 91 (77-97) | 0.00-39.6x103 | <.001 | Low (not conclusive) |
| Unnatural causes, ASD | ||||||||||
| Both | 6 | 117 345 | 318 | 2.50 (1.49-4.18) | 3.75 (2.85-4.92) | .001 | 95 (92-97) | 0.38-16.35 | <.001 | Low (suggestive) |
| Male | 4 | 61 031 | 182 | 1.94 (0.83-4.49) | 3.48 (2.57-4.74) | .12 | 96 (94-98) | 0.03-112.04 | <.001 | Low (not conclusive) |
| Female | 4 | 22 712 | 58 | 3.61 (1.71-7.60) | 2.63 (1.46-4.76) | .001 | 79 (45-92) | 0.15-88.22 | .002 | Low (suggestive) |
| Unnatural causes, ADHD | ||||||||||
| Both | 10 | 432 900 | 847 | 2.81 (1.73-4.55) | 1.51 (1.51-1.72) | <.001 | 92 (88-95) | 0.61-12.91 | <.001 | Low (suggestive) |
| Male | 5 | 316 851 | NA | 2.49 (1.36-4.56) | 1.45 (1.25-1.67) | .003 | 97 (96-98) | 0.23-26.59 | <.001 | Low (suggestive) |
| Female | 5 | 114 816 | NA | 2.98 (1.46-6.10) | 1.82 (1.32-2.51) | .003 | 92 (85-96) | 0.20-44.17 | <.001 | Low (suggestive) |
| Neoplasms, ASD both | 2 | 40 233 | 109 | 2.05 (1.46-2.87) | 1.80 (1.46-2.23) | <.001 | 53 (NA) | NA | .14 | Low (suggestive) |
| Nervous system, ASD both | 4 | 61 066 | 102 | 10.79 (5.42-21.10) | 7.49 (5.78-9.72) | <.001 | 85 (64-94) | 0.52-219.57 | <.001 | Low (suggestive) |
| Respiratory system, ASD both | 2 | 40 233 | 62 | 3.87 (1.80-8.32) | 2.68 (1.99-3.62) | .001 | 86 (NA) | NA | .007 | Low (suggestive) |
| Digestive system, ASD both | 2 | 40 233 | 40 | 4.59 (2.29-9.19) | 3.31 (2.25-4.87) | <.001 | 76 (NA) | NA | .0 | Low (suggestive) |
| Congenital malformations, ASD both | 2 | 40 233 | 37 | 11.74 (4.49-30.74) | 19.10 (11.94-30.55) | <.001 | 87 (NA) | NA | .005 | Low (suggestive) |
Abbreviations: ADHD, attention-deficit/hyperactivity disorder; ASD, autism spectrum disorder; NA, not available; RR, risk ratio.
a
Outcomes with at least 2 studies for meta-analysis. Predictive intervals were inestimable with less than 3 studies.