Table 5.
Subgroup analyses.
| Subgroup | Number of studies | Results of Heterogeneity |
Effect model | Meta-analysis |
||
|---|---|---|---|---|---|---|
| (I2, %) | P | OR (95% CI) | P | |||
| Age | ||||||
| Cohort studies | 2 | 95.0 | p < 0.0001 | Random | 2.84 [0.43, 18.62] | p = 0.28 |
| Case-control studies | 6 | 91.0 | p < 0.0001 | Random | 1.71 [1.11, 2.65] | p = 0.02 |
| Department of internal neurology | 5 | 90.0 | p < 0.0001 | Random | 1.62 [1.25, 2.11] | p = 0.0003 |
| Another department | 3 | 95.0 | p < 0.0001 | Random | 2.52 [0.36, 17.52] | p = 0.35 |
| Conscious disturbance | ||||||
| Cohort studies | 2 | 0 | p = 0.46 | Fixed | 5.17 [1.82, 14.69] | p = 0.002 |
| Case-control studies | 5 | 93.0 | p < 0.0001 | Random | 1.99 [1.25, 3.18] | p = 0.0004 |
| Department of internal neurology | 4 | 62.0 | p = 0.05 | Random | 2.04 [1.64, 2.52] | p < 0.00001 |
| Another department | 3 | 90.0 | p < 0.0001 | Random | 1.06 [1.04, 1.08] | p < 0.00001 |
| NOS≥7 | 5 | 50.0 | p = 0.09 | Fixed | 2.09 [1.74, 2.50] | p < 0.00001 |
| NOS<7 | 2 | 50.0 | p = 0.15 | Fixed | 1.06 [1.04, 1.08] | p < 0.00001 |
| Dysphagia | ||||||
| Cohort studies | 2 | 0 | p = 0.73 | Fixed | 1.75 [1.17, 2.62] | p = 0.006 |
| Case-control studies | 6 | 87.0 | p < 0.0001 | Random | 3.59 [3.08, 4.18] | p < 0.00001 |
| Department of internal neurology | 3 | 86.0 | p = 0.001 | Random | 3.13 [1.66, 5.90] | p = 0.0004 |
| Another department | 5 | 85.0 | p < 0.0001 | Random | 3.28 [1.59, 6.76] | p = 0.01 |
| NOS≥7 | 6 | 68.0 | p = 0.009 | Random | 2.53 [2.13, 2.99] | p < 0.00001 |
| NOS<7 | 2 | 0 | p = 0.56 | Fixed | 6.52 [4.96, 8.57] | p < 0.00001 |
| Diabetes | ||||||
| Department of internal neurology | 2 | 93.0 | p = 0.0002 | Random | 3.14 [1.25, 7.85] | p = 0.01 |
| Another department | 3 | 93.0 | p < 0.0001 | Random | 1.93 [0.77, 4.83] | p = 0.16 |
| COPD | ||||||
| Department of internal neurology | 3 | 84.0 | p = 0.002 | Random | 2.11 [1.50, 2.97] | p < 0.00001 |
| Another department | 3 | 92.0 | p < 0.0001 | Random | 3.52 [1.55, 8.01] | p = 0.003 |
| Smoking history | ||||||
| Department of internal neurology | 2 | 91.0 | p = 0.007 | Random | 2.07 [0.90, 4.72] | p = 0.08 |
| Another department | 2 | 97.0 | p < 0.0001 | Random | 1.65 [0.32, 8.56] | p = 0.55 |
| Invasive procedure | ||||||
| Department of internal neurology | 3 | 85.0 | p = 0.001 | Random | 2.82 [1.57, 5.06] | p = 0.0005 |
| Another department | 4 | 86.0 | p < 0.0001 | Random | 3.90 [2.27, 6.72] | p < 0.00001 |
| NOS≥7 | 5 | 85.0 | p < 0.0001 | Random | 2.89 [1.88, 4.45] | p < 0.00001 |
| NOS<7 | 2 | 79.0 | p = 0.003 | Random | 5.26 [2.23, 12.40] | p = 0.0001 |
| Hospital stays | ||||||
| Department of internal neurology | 3 | 80.0 | p = 0.007 | Random | 1.29 [1.11, 1.51] | p = 0.0009 |
| Another department | 3 | 87.0 | p = 0.0004 | Random | 1.66 [1.25, 2.21] | p = 0.0005 |