Estimates of the dose–response effects of the NEMP on LG-OPV
| Intervention year (exposure time to NEMP implementation in years) | ||||||
|---|---|---|---|---|---|---|
| Method | coefficient | 2009 (1) | 2010 (2) | 2011 (3) | 2012 (4) | |
| Multilevel DID (M2) | Intercepts | β0 (SE) | 7.859 (0.170) | 7.889 (0.171) | 8.039 (0.171) | 8.208 (0.173) |
| U value (p) | 46.23 (<0.0001) | 46.13 (<0.0001) | 47.01 (<0.0001) | 47.45 (<0.0001) | ||
| Time × intervention (effect of the NEMP) | β3 (SE) | 0.036 (0.018) | 0.073 (0.018) | 0.064 (0.018) | 0.097 (0.019) | |
| U value (p) | 2.00 (0.044) | 4.06 (<0.0001) | 3.56 (0.0005) | 5.11 (<0.0001) | ||
| Multilevel RM (M4) | Intercepts | β0 (SE) | 9.610 (0.179) | |||
| U value (p) | 53.69 (<0.0001) | |||||
| Exposure times | β1 (SE) | 0.012 (0.002) | ||||
| U value (p) | 6.00 (<0.0001) | |||||
DID, difference-in-differences; NEMP, national essential medicine policy; RM, repeated measures.