Table 8. Results of univariate Cox proportional hazards regression analyses by quartile of polity, 1996–2014.
| Polity quartile | No. outbreaks* | Days to discovery hazard ratio (95% CI) | No. outbreaks* | Days to communication hazard ratio (95% CI) |
|---|---|---|---|---|
| Q1: Highest polity | 67 | 1.04 (0.99–1.10) | 67 | 1.01 (0.96–1.06) |
| Q2: High-intermediate | 84 | 1.04 (1.00–1.09) | 87 | 1.00 (0.96–1.05) |
| Q3: Low-intermediate | 67 | 1.06 (1.00–1.13)† | 67 | 1.05 (0.99–1.11) |
| Q4: Lowest polity | 87 | 1.08 (1.04–1.13)† | 88 | 1.03 (1.00–1.07) |
*Quartiles are uneven because polity score is ordinal, not continuous. †Statistically significant (α = 0.05).