Table 1.
Subgroup analyses of BMI and sudden cardiac death
| BMI | |||||
|---|---|---|---|---|---|
| n | RR (95% CI) | I2 (%) | P ah | P bh | |
| All studies | 14 | 1.16 (1.05–1.28) | 68.2 | < 0.0001 | |
| Sex | |||||
| Men | 3 | 1.11 (0.70–1.75) | 70.7 | 0.03 | 0.82/0.99c |
| Women | 3 | 1.16 (0.83–1.62) | 82.8 | 0.003 | |
| Men and women | 9 | 1.15 (1.04–1.27) | 59.2 | 0.01 | |
| Assessment of weight/height | |||||
| Measured | 10 | 1.19 (1.10–1.30) | 47.8 | 0.05 | 0.21 |
| Self-reported (validated) | 2 | 0.98 (0.41–2.33) | 92.8 | < 0.0001 | |
| Not available | 2 | 0.93 (0.74–1.17) | 0 | 0.88 | |
| Duration of follow-up | |||||
| < 5 years | 0 | 0.06 | |||
| 5–< 10 years | 5 | 0.99 (0.76–1.28) | 70.6 | 0.009 | |
| 10–< 15 years | 3 | 1.12 (1.02–1.23) | 0 | 0.49 | |
| 15–< 20 years | 2 | 1.32 (1.17–1.50) | 0 | 0.54 | |
| ≥ 20 years | 4 | 1.28 (1.08–1.51) | 67.8 | 0.03 | |
| Geographic location | |||||
| Europe | 8 | 1.21 (1.08–1.35) | 55.8 | 0.03 | 0.09 |
| America | 3 | 1.26 (1.05–1.50) | 77.7 | 0.01 | |
| Asia | 3 | 0.84 (0.66–1.07) | 26.3 | 0.26 | |
| Number of cases | |||||
| Cases < 100 | 2 | 0.89 (0.45–1.73) | 85.8 | 0.008 | 0.44 |
| Cases 100–< 200 | 6 | 1.18 (1.01–1.39) | 64.3 | 0.02 | |
| Cases ≥ 200 | 6 | 1.20 (1.05–1.36) | 69.4 | 0.006 | |
| Study quality | |||||
| 0–3 | 0 | 0.35 | |||
| 4–6 | 1 | 0.94 (0.72–1.23) | |||
| 7–9 | 13 | 1.18 (1.07–1.30) | 67.7 | < 0.0001 | |
| Adjustment for confounders | |||||
| Age | |||||
| Yes | 14 | 1.16 (1.05–1.28) | 68.2 | < 0.0001 | NC |
| No | 0 | ||||
| Smoking | |||||
| Yes | 12 | 1.14 (1.02–1.28) | 72.4 | < 0.0001 | 0.49 |
| No | 2 | 1.23 (1.08–1.40) | 0 | 0.32 | |
| Alcohol | |||||
| Yes | 4 | 1.11 (0.82–1.48) | 85.6 | < 0.0001 | 0.99 |
| No | 10 | 1.16 (1.07–1.27) | 45.7 | 0.06 | |
| Physical activity | |||||
| Yes | 6 | 1.09 (0.89–1.34) | 83.2 | < 0.0001 | 0.54 |
| No | 8 | 1.21 (1.10–1.33) | 36.7 | 0.14 | |
| Adjustment for potential intermediates | |||||
| Hypertension | |||||
| Yes | 4 | 1.03 (0.76–1.40) | 87.0 | < 0.0001 | 0.48 |
| No | 10 | 1.19 (1.09–1.31) | 49.3 | 0.04 | |
| Blood pressure | |||||
| Yes | 8 | 1.17 (1.05–1.32) | 58.1 | 0.02 | 0.89 |
| No | 6 | 1.13 (0.94–1.37) | 79.2 | < 0.0001 | |
| Cholesterol | |||||
| Yes | 6 | 1.27 (1.11–1.45) | 60.1 | 0.03 | 0.24 |
| No | 8 | 1.10 (0.97–1.24) | 62.0 | 0.01 | |
| Diabetes mellitus | |||||
| Yes | 13 | 1.11 (0.98–1.26) | 73.6 | < 0.0001 | 0.24 |
| No | 3 | 1.28 (1.15–1.42) | 0 | 0.37 | |
| Coronary heart disease | |||||
| Yes | 7 | 1.17 (1.05–1.30) | 62.4 | 0.01 | 0.90 |
| No | 7 | 1.13 (0.93–1.37) | 75.2 | < 0.0001 | |
n denotes the number of studies. The number of studies is not always equal to the total because the subgroup analyses were not applicable to some studies or information was not provided in the publication
aP for heterogeneity within each subgroup
bP for heterogeneity between subgroups
cP for heterogeneity between men and women (excluding men/women combined)