BY-COVID - WP5 - Baseline Use Case: COVID-19 vaccine effectiveness assessment

Matching cases to controls (1:1) and assessing covariate balance after matching

Covariate balance is the extent to which the distribution of covariates is similar across the intervention groups.

Standardized mean differences

The Standardized Mean Difference (SMD) represents a standardized difference in mean between contrasted intervention groups for each covariate.

Means intervention group Means control group Standardized mean difference
distance 0.925057100 0.823514045 1.310700718
age_cd 10.480069606 6.118489785 1.025914956
sex_cd 1.514035359 1.484918076 0.058257493
residence_area_cdES241 0.164072339 0.174890827 -0.029212219
residence_area_cdES242 0.098104038 0.094572887 0.011871200
residence_area_cdES243 0.737823623 0.730536286 0.016568982
institutionalized_blTRUE 0.007470582 0.005556812 0.022224954
foreign_blTRUE 0.127859671 0.222272462 -0.282729327
pregnancy_blTRUE 0.019706786 0.030389929 -0.076862258
essential_worker_blTRUE 0.005550689 0.006044669 -0.006648819
comorbidities_blTRUE 0.375748926 0.148284766 0.469660953
immunestatus_blTRUE 0.026308922 0.010590069 0.098210682
Means intervention group Means control group Standardized mean difference
distance 0.500000059 0.499999941 6.854922e-04
age_cd 11.615281975 11.615246515 9.918098e-06
sex_cd 1.521130553 1.521129239 2.628973e-06
residence_area_cdES241 0.164656641 0.164699980 -1.168584e-04
residence_area_cdES242 0.098138641 0.098011250 4.282034e-04
residence_area_cdES243 0.737204718 0.737288770 -1.909613e-04
institutionalized_blTRUE 0.008934470 0.008899010 3.768309e-04
foreign_blTRUE 0.107874232 0.107859785 4.656816e-05
pregnancy_blTRUE 0.015835930 0.015837244 -1.051993e-05
essential_worker_blTRUE 0.006582326 0.006553433 3.573019e-04
comorbidities_blTRUE 0.433833312 0.433835938 -5.299864e-06
immunestatus_blTRUE 0.030386127 0.030371681 8.416352e-05

Variance ratios

The variance ratio (VR) represents the ratio of the variance in the contracted intervention groups for each covariate. A VR close to 1, implies that variances are similar in the compared groups and as such indicates good covariate balance.

Var. Ratio
distance 0.5387455
age_cd 1.1165740
sex_cd 1.0001112
residence_area_cdES241 NA
residence_area_cdES242 NA
residence_area_cdES243 NA
institutionalized_blTRUE NA
foreign_blTRUE NA
pregnancy_blTRUE NA
essential_worker_blTRUE NA
comorbidities_blTRUE NA
immunestatus_blTRUE NA
Var. Ratio
distance 1.0053051
age_cd 0.9997302
sex_cd 0.9999998
residence_area_cdES241 NA
residence_area_cdES242 NA
residence_area_cdES243 NA
institutionalized_blTRUE NA
foreign_blTRUE NA
pregnancy_blTRUE NA
essential_worker_blTRUE NA
comorbidities_blTRUE NA
immunestatus_blTRUE NA

Propensity score distribution