# Interpreting odds ratios

I have the following set of results for one of the factors (birth weight) with different levels and their corresponding Odds ratios for survival. I am using the first level (<1.25) as the reference level:

Birth weight (kg):

Levels      Number/level    Odds Ratio
<1.25       1615            1.00
1.25-1.46   1617            1.37
1.46-1.65   1462            1.25
1.65-1.87   1632            1.68
>1.87       1466            2.35


From this result, I am trying to estimate, by using the OR, the approximate number of newborns that would survive in each level.

Are there ways that this can be achieved using R?

In a separate calculation, the actual number of survival per level are shown below:

Levels      Number/level    Odds Ratio    Actual number survived
<1.25       1615            1.00         1088
1.25-1.46   1617            1.37         1346
1.46-1.65   1462            1.25         1238
1.65-1.87   1632            1.68         1447
>1.87       1466            2.35         1351


EDIT: The above is just one of the independent factors from my model.

mod <- glm(formula = surv ~ as.factor(var1) + as.factor(var2)+...as.factor(varn)+family = binomial(link = "logit"), data=mydf)

summary(mod)

glm(formula = surv ~ as.factor(season) + as.factor(bwt5) + as.factor(prectem5) +
as.factor(pcscore) + as.factor(pindx5) + as.factor(presp2) +
as.factor(ppscore) + as.factor(mtone2) + as.factor(fos) +
as.factor(psex) + as.factor(pscolor) + as.factor(pshiv) +
as.factor(backfat5) + as.factor(srect2) + as.factor(gest3) +
as.factor(int3) + as.factor(agit) + as.factor(tacc), family = binomial(link = "logit"),
data = lesna)

Deviance Residuals:
Min       1Q   Median       3Q      Max
-3.0562   0.3120   0.4478   0.5929   1.9412

Coefficients:
Estimate Std. Error z value Pr(>|z|)
(Intercept)           1.441842   0.290536   4.963 6.95e-07 ***
as.factor(season)2   -1.064053   0.107666  -9.883  < 2e-16 ***
as.factor(bwt5)2      0.314332   0.099776   3.150 0.001631 **
as.factor(bwt5)3      0.223824   0.110566   2.024 0.042935 *
as.factor(bwt5)4      0.524586   0.120182   4.365 1.27e-05 ***
as.factor(bwt5)5      0.854196   0.138993   6.146 7.97e-10 ***
as.factor(prectem5)2  0.745025   0.094238   7.906 2.66e-15 ***
as.factor(prectem5)3  0.856777   0.098326   8.714  < 2e-16 ***
as.factor(prectem5)4  0.997219   0.111529   8.941  < 2e-16 ***
as.factor(prectem5)5  0.930925   0.120052   7.754 8.88e-15 ***
as.factor(pcscore)2   0.384534   0.137564   2.795 0.005185 **
as.factor(pcscore)3   0.668390   0.154608   4.323 1.54e-05 ***
as.factor(pindx5)2    0.243485   0.101755   2.393 0.016718 *
as.factor(pindx5)3    0.262779   0.108809   2.415 0.015733 *
as.factor(pindx5)4    0.595672   0.118124   5.043 4.59e-07 ***
as.factor(pindx5)5    0.467277   0.120401   3.881 0.000104 ***
as.factor(presp2)2   -0.286214   0.126012  -2.271 0.023127 *
as.factor(ppscore)2  -0.246369   0.093568  -2.633 0.008462 **
as.factor(mtone2)2   -0.482397   0.118218  -4.081 4.49e-05 ***
as.factor(fos)2      -0.255652   0.075749  -3.375 0.000738 ***
as.factor(psex)2      0.182437   0.066964   2.724 0.006442 **
as.factor(pscolor)2  -0.694197   0.282069  -2.461 0.013852 *
as.factor(pshiv)2    -0.241515   0.080792  -2.989 0.002796 **
as.factor(backfat5)2 -0.309427   0.104176  -2.970 0.002976 **
as.factor(backfat5)3 -0.004152   0.108669  -0.038 0.969523
as.factor(backfat5)4  0.013233   0.103491   0.128 0.898257
as.factor(backfat5)5 -0.221935   0.104639  -2.121 0.033926 *
as.factor(srect2)2   -0.236981   0.104962  -2.258 0.023960 *
as.factor(gest3)2     0.207375   0.106065   1.955 0.050562 .
as.factor(gest3)3     0.904959   0.191307   4.730 2.24e-06 ***
as.factor(int3)2     -0.204870   0.127674  -1.605 0.108573
as.factor(int3)3     -1.271092   0.388924  -3.268 0.001082 **
as.factor(agit)2     -0.496856   0.157553  -3.154 0.001613 **
as.factor(agit)3     -0.360247   0.148520  -2.426 0.015284 *
as.factor(tacc)2     -0.282180   0.090556  -3.116 0.001833 **
as.factor(tacc)3     -0.429249   0.082520  -5.202 1.97e-07 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

(Dispersion parameter for binomial family taken to be 1)

Null deviance: 7096.2  on 7791  degrees of freedom
Residual deviance: 6143.0  on 7756  degrees of freedom
AIC: 6215

Number of Fisher Scoring iterations: 5