Table 4.
Multivariable regression models on the association with epidemic growth of COVID-19.
| Variable | Ratio unit | Model 1 |
Model 2 |
Model 3 |
|||
|---|---|---|---|---|---|---|---|
| Adjusted RRR (95% CI) | p value | Adjusted RRR (95% CI) | p value | Adjusted RRR (95% CI) | p value | ||
| Male inhabitant | 1% | 1.05 (0.92–1.20) | 0.473 | 1.02 (0.95–1.10) | 0.587 | 1.03 (0.95–1.10) | 0.485 |
| Inhabitants aged ≥65 years | 1% | 1.00 (0.95–1.06) | 0.949 | 0.98 (0.93–1.02) | 0.350 | 0.98 (0.94–1.02) | 0.403 |
| Urban density | 1000 inhabitants/km2 | 0.95 (0.91–1.00) | 0.038* | 0.93 (0.90–0.97) | <0.001** | 0.93 (0.90–0.97) | <0.001** |
| Taxable income | 1,000,000 JPY/inhabitant | 0.85 (0.52–1.38) | 0.512 | 0.90 (0.64–1.28) | 0.556 | 0.94 (0.66–1.33) | 0.719 |
| Health expenditure | 1000 JPY/inhabitant | 1.00 (0.99–1.01) | 0.686 | 1.00 (1.00–1.01) | 0.756 | 1.00 (1.00–1.01) | 0.681 |
| Life expectancy at birth | 1 year | 1.10 (0.87–1.40) | 0.426 | 1.02 (0.83–1.26) | 0.850 | 1.00 (0.81–1.24) | 0.989 |
| Mean temperature | 1 °C | 1.05 (1.01–1.08) | 0.013* | 1.04 (1.01–1.08) | 0.018* | 1.03 (1.00–1.07) | 0.048* |
| Sunshine hours | 1 h | 1.02 (1.00–1.04) | 0.039* | – | – | – | – |
| NO2 | 1 ppb | – | – | 1.01 (0.99–1.02) | 0.468 | – | – |
| SPM | 1 μg/m3 | – | – | – | – | 1.02 (0.99–1.04) | 0.144 |
Values are expressed as ratios of rate ratios (95% CIs) and 2-sided p values. Significant at * p < 0.05, ** p < 0.01. Abbreviations: JPY, Japanese Yen; CI, confidence interval; RRR, ratio of rate ratio; NO2, nitrogen dioxide; SPM, suspended particulate matter.