Table 3.
Effect of OPV on the Main Composite Outcome (Mortality, Hospital Admissions, and Consultations for Infections) in Strata Defined by the Potential Effect Modifiers
| Strata | Rate/100 PYRS (Events/PYRS) | HR (95% CI)a | P Value, Test of No Differenceb | |
|---|---|---|---|---|
| OPV | No OPV | |||
| Sex | ||||
| Male | 17.8 (55/309) | 25.3 (102/403) | 0.71 (.51–.98) | .02 |
| Female | 26.1 (114/436) | 22.7 (137/604) | 1.18 (.91–1.52) | |
| BCG Scar | ||||
| Yes | 15.8 (47/298) | 22.6 (101/447) | 0.70 (.49–.99) | .03 |
| No | 27.4 (121/441) | 25.0 (138/551) | 1.13 (.88–1.45) | |
| Smallpox Scar | ||||
| Yes | 22.8 (98/430) | 24.1 (141/586) | 1.00 (.77–1.31) | .64 |
| No | 22.4 (70/312) | 23.5 (97/413) | 0.91 (.67–1.24) | |
| Age | ||||
| Below median | 18.2 (70/384) | 21.3 (107/502) | 0.89 (.65–1.20) | .47 |
| Above median | 27.3 (99/362) | 26.2 (132/504) | 1.03 (.79–1.35) | |
| Visual Classification of Weight | ||||
| Below median | 24.6 (126/512) | 26.9 (178/663) | 0.91 (.72–1.15) | .42 |
| Above median | 18.0 (41/228) | 17.6 (59/335) | 1.10 (.74–1.63) | |
| Season of Enrollment | ||||
| Rainy | 26.8 (86/320) | 31.0 (147/474) | 0.85 (.65–1.12) | .13 |
| Dry | 19.5 (83/425) | 17.3 (92/532) | 1.16 (.86–1.58) | |
| Chronic Illness | ||||
| Yes | 26.1 (93/356) | 26.3 (135/514) | 1.03 (.79–1.36) | .65 |
| No | 19.6 (75/382) | 20.7 (99/478) | 0.94 (.69–1.28) | |
| Follow-up Time | ||||
| First 3 months | 24.7 (94/381) | 27.7 (143/516) | 0.90 (.70–1.17) | .42 |
| After 3 months | 20.6 (75/365) | 19.6 (96/491) | 1.06 (.78–1.44) | |
| Season of Follow-up | ||||
| Rainy season | 30.6 (94/307) | 29.5 (121/410) | 1.06 (.81–1.40) | .30 |
| Dry season | 17.1 (75/439) | 19.8 (118/596) | 0.86 (.64–1.16) | |
| COVID-19 Transmission | ||||
| Low transmission | 19.2 (72/376) | 21.3 (108/508) | 0.91 (.68–1.23) | .62 |
| High transmission | 26.2 (97/370) | 26.3 (131/498) | 1.01 (.77–1.32) | |
| Health Worker Strikes | ||||
| Few | 24.7 (134/542) | 26.8 (195/728) | 0.94 (.75–1.17) | .56 |
| Continuous | 17.2 (35/203) | 15.8 (44/278) | 1.09 (.69–1.70) | |
Abbreviations: BCG, Bacillus Calmette-Guérin; CI, confidence interval; COVID-19, coronavirus disease 2019; HR, hazard ratio; OPV, oral polio vaccine; PYRS, person-years.
a
Hazard ratio compared in Cox proportional hazards models with time since enrollment as underlying timescale. Adjusted for age and zone of residence.
b
Wald test of same effect across the strata.